Are biosolids safe?

25 08 2015

In a recent email from the Green Science Policy Institute, Arlene Blum mentioned that she was just back from Fluoros 2015, which aims to examine the “state of the science” on fluorinated organic compounds in the environment. Her take away was that many of these fluorinated compounds (like those found in fire retardants)  are found in vegetables such as lettuce, tomatoes and strawberries. The assumption is that these man-made chemicals are found in our vegetables because biosolids were used as fertilizer and reclaimed water was used for irrigation.

How does this happen?

First we have to know what a biosolid is: Bascially, biosolids are made from treated sewage sludge, under another (less prejudicial) name. According to the U.S. Environmental Protection Agency, biosolids are “nutrient-rich organic materials”, which contain useful amounts of plant nutrients such as nitrogen, phosphorus and micronutrients. Because it is made from treated sewage, it’s considered safe for use as fertilizer or land reclamation, and about 50% of all biosolids produced in the U.S. are being used as fertilizer, though only about 1% of cropland has biosolids applied.  But the use is growing because the cost to farmers is far less than for chemical fertilizers – by a factor of 4![1]   They can also be composted and sold for use on lawns and home gardens.

Sounds like a dream, right? Using  sewage sludge as fertilizer is a sweet way to get rid of the mountain of sludge produced in the U.S. each year.   Sludge management is an integral part of any municipal waste management system. The most common disposal method is incineration (which has its own problems) and landfills, storage in huge sludge ponds, dried in the sun or dumped in the oceans. But ocean dumping, which created vast dead moon-scapes on the ocean floor, was halted by the Ocean Dumping ban of 1987. Thus the policy of disposing of sludge by spreading it on agricultural land (a policy given the name “land application”) was born.     biosolidsGOC

The problem with biosolids is that most municipal treatment facilities are not able to remove the many chemicals found in sewage. The four main categories of potential pollutants – nutrients, pathogens, toxic organics, and heavy metals – behave differently and cannot all be managed by any single kind of treatment. The goal of “safe management” of such a complex toxic mixture cannot be met at a reasonable cost.

The EPA itself conducted the national Sewage Sludge Survey (NSSS) in 1988 to get information on pollutants found in treated biosolids. They found dozens of hazardous substances, including heavy metals, organics, PBDE’s, pharmaceuticals, steroids and hormones[2] in ALL the sludge samples the EPA took around the USA.

Rolf Halden is a professor at Arizona State University, member of the adjunct faculty at Johns Hopkins and an expert on the environmental impacts of industrial chemicals. His lab recently used treated sewage sludge to identify and prioritize persistent bioaccumulative chemicals.[3] The study found that chemicals contributed between 0.04% – 0.15% of the total dry mass of biosolids produced in the USA annually, which is equivalent to 2,866 – 8,708 tons of chemicals. The top individual chemicals found included:

  • Brominated fire retardants
    • DecaBDE
    • pentaBDE
    • 1,2-bis(2,4,6 tribromophenoxy
    • ethane
  • Surfactants
    • Nonylphenol (NP) and their ethoxylates (NPEOs) – both used in textile processing
  • Antimicrobials
    • Triclosan and triclocarban
  • Antibiotics
    • Azithromycin
    • Ciprofloxacin
    • ofloxacin

The Centers for Disease Control and Prevention (CDC) did a comprehensive exposure assessment of environmental chemicals found the U. S. population. They found about 139 organic chemicals in human blood, serum, urine and tissue samples. About 70% of the chemicals found in biosolids are also found in humans.

New studies have shown that:

  • Sewage sludge is mutagenic (it causes inheritable genetic changes in organisms), but no one seems sure what this means for human or animal health. Regulations for the use of sewage sludge ignore this information.
  • Two-thirds of sewage sludge contains asbestos. Because sludge is often applied to the land dry, asbestos may be a real health danger to farmers, neighbors and their children. Again, regulations don’t mention asbestos.
  • Governments issue numeric standards for metals. However, the movement of metals from soils into groundwater, surface water, plants and wildlife – and of the hundreds of other toxins in sludge – are poorly understood.
  • Soil acidity seems to be the key factor in promoting or retarding the movement of toxic metals into groundwater, wildlife and crops. The National Research Council (NRC) of the National Academy of Sciences gives sewage sludge treatment of soils a clean bill of health in the short term, “as long as…acidic soils are agronomically managed.” However the NRC acknowledges that toxic heavy metals and persistent organic pollutants can build up in treated soils.
  • There is good reason to believe that livestock grazing on plants treated with sewage sludge will ingest the pollutants – either through the grazed plants, or by eating sewage sludge along with the plants. Sheep eating cabbage grown on sludge developed lesions of the liver and thyroid gland. Pigs grown on corn treated with sludge had elevated levels of cadmium in their tissues. An AP story published in 2008 documented that milk sold throughout the U.S contained high levels of thallium (the primary toxin in rat poison), which had been present in the sewage sludge spread on crops fed to dairy cows.[4]
  • Small mammals have been shown to accumulate heavy metals after sewage sludge was applied to forestlands.
  • Insects in the soil absorb toxins, which then accumulate in birds.
  • It has been shown that sewage sludge applied to soils can increase the dioxin intake of humans eating beef (or cow’s milk) produced from those soils.
  • Traces of prescription drugs and household chemicals were found deep in the soil as a result of a couple of decades of use of biosolids as fertilizer.[5]

A study done in Sweden found that scientists have found antibiotic resistant “super bugs” in sewage sludge; they’re sounding the alarm about the danger of antibiotic resistant genes passing into the human food chain. Of the samples collected, 79% tested positive for the drug-resistnat vancomycin-resistant enterococci (VRE)

Astonishingly, in a November, 1990 edition of the United States Federal Register, the Environmental Protection Agency (EPA) had this to say of sewage sludge: “Typically, these constituents may include volatiles, organic solids, nutrients, disease-causing pathogenic organisms (bacteria, viruses, etc.), heavy metals and inorganic ions, and toxic organic chemicals from industrial wastes, household chemicals and pesticides.”

Not all contaminants are created equal:  some chemicals are stored in the human body, and others pass through it.  Some break down in our digestive system, and others don’t.  Each person is different, with a different body size, stage of development and metabolism.   The same chemical may wreak devastating effects if a pregnant woman eats it but may go unnoticed if eaten by a man.  And remember, chemicals are synergistic, and very little is known about interactions between low levels of large numbers of chemicals.  As an example, take the chemical triclosan, one of the antimicrobials that Rolf Halden’s lab found in highest quantities in treated sludge. Triclosan has been used for several decades in antibacterial products like soaps, deodorants and cosmetics.  It is also nearly universally found in sewage sludge.  A recently published study found that soybeans planted in soil containing triclosan took the triclosan up into their beans.

Triclosan is a suspected endocrine disruptor and recent CDC reports show more than a 40 percent increase in triclosan levels in the urine of Americans over a recent two-year period.  The amount in our bodies can’t be blamed entirely on sewage sludge; humans can absorb triclosan through their skin and those who use triclosan-containing toothpastes put the chemical directly into their mouths.   But at what point does exposure to triclosan become more than an individual body can bear?

According to the EPA, about half of all sewage sludge is applied to land, but it is only applied to about one percent of the nation’s farmland.  The likely result is that, if dangers do lurk in the sludge applied to land, we rarely find out about them.

Most people’s chances of eating enough tainted food from farms that apply sewage sludge as fertilizer to cause an acute reaction are pretty slim.  The chance that anyone who got sick would be able to correctly trace his or her illness back to the farm and to sewage sludge is even smaller.  However, a lack of easily traceable acute illnesses does not prove that sewage sludge is safe.  Health harm due to exposure to low levels of toxins over a long period of time is no more acceptable than acute problems, even if they are less obvious.

As a consumer, the only sure way to avoid food grown in sewage sludge is to buy organic food (or grow your own).  If you are a gardener and you wish to avoid sewage sludge fertilizers or composts, avoid any product that says it contains “biosolids.”  Last, if you wish to keep sewage sludge from being spread on farm fields near where you live, you can take action locally to make it illegal in your city or county.

[1] “Davison, Janet, “Earth Day: Is sewage sludge safe for farm fields?”, CBC news Canada, April 22, 2014.

[2] EPA , “Targeted National Sewage Sludge Survey Statistical Analysis Report”, revised April, 2009

[3] Halden, Rolf et al; “Wastewater treatment plants as chemical observatories to forecase ecological and human health risks of manmade chemicals”, Scientific Reports, January 2014

[4] Hellprin, John and Vineys, Kevin: “Sewage-based fertilizer safety doubted”, USA Today; 3.6.2008

[5] Bienkowski, Brian, “Farm sludge contaminates soil with drugs, other chemicals”, Environmental Health News, May 2014.


Toxic lies

14 07 2015

Julie Gunlock wrote a blog post entitled “The ‘toxic’ lies behind Jessica Alba’s booming baby business” (to read the post, click  here ) We’re not necessarily fond of Jessica Alba nor her Honest Company, but the statements made by Julie Gunlock need to be addressed. She contends that the Honest Company’s main commodity is fear and the “false promise that their products are safer than others.”

I will not comment on her admonitions about how The Honest Company’s products are full of chemicals (as this should be obvious), or that Alba had recognized that “many people  –  particularly women (sic) – have been convinced that common chemicals are a bogeyman that lurks, waiting to harm them” – since everything is made of chemicals, some bad for us, some that are not.  We aren’t part of the “man made is absolutely bad, natural is absolutely good” camp.

What I will address is her claim that chemicals used in products are “there for a reason” and they’re completely safe because “chemicals are regulated under nearly a dozen federal agencies and regulations.”   She states:   “ chemicals in products … are used in trace amounts, often improve the safety of those products and have undergone hundreds of safety tests.”

As she herself says, nothing could be further from the truth.

First, let’s address her contention that “chemicals in products…are used in trace amounts.”

 The idea that chemicals won’t harm us because the amounts used are so tiny is not new; it’s been used by industry for many years. However, new research is being done which is profoundly changing our old belief systems. For example, we used to think that a little dose of a poison would do a little bit of harm, and a big dose would do a lot of harm (i.e., “the dose makes the poison”) – because water, as Julie Gunlock herself reminds us, can kill you just as surely as arsenic, given sufficient quantity.   The new paradigm shows that exposure to even tiny amounts of chemicals (in the parts-per-trillion range) can have significant impacts on our health – in fact some chemicals impact the body profoundly in the parts per trillion range, but do little harm at much greater dosages. The old belief system did not address how chemicals can change the subtle organization of the brain. Now, according to Dr. Laura Vandenberg of the Tufts University Center for Regenerative and Developmental Biology[1] “we found chemicals that are working at that really low level, which can take a brain that’s in a girl animal and make it look like a brain from a boy animal, so, really subtle changes that have really important effects.”

In making a risk assessment of any chemical, we now also know that timing and order of exposure is critical – exposures can happen all at once, or one after the other, and that can make a world of difference.   And we also know another thing: mixtures of chemicals can make each other more toxic. For example: a dose of mercury that would kill 1 out of 100 rats, when combined with a dose of lead that would kill 1 out of 1000 rats – kills every rat exposed.

And finally, the new science called “epigenetics” is finding that pollutants and chemicals might be altering the 20,000-25,000 genes we’re born with—not by mutating or killing them, but by sending subtle signals that silence them or switch them on or off at the wrong times.  This can set the stage for diseases, which can be passed down for generations. So exposure to chemicals can alter genetic expression, not only in your children, but in your children’s children – and their children too.  Researchers at Washington State University found that when pregnant rats were exposed to permethrin, DEET or any of a number of industrial chemicals, the mother rats’ great granddaughters had higher risk of early puberty and malfunctioning ovaries — even though those subsequent generations had not been exposed to the chemical.[2]  Another recent study has shown that men who started smoking before puberty caused their sons to have significantly higher rates of obesity. And obesity is just the tip of the iceberg—many researchers believe that epigenetics holds the key to understanding cancer, Alzheimer’s, schizophrenia, autism, and diabetes. Other studies are being published which corroborate these findings.[3]

So that’s the thing: we’re exposed to chemicals all day, every day – heavy metals and carcinogenic particles in air pollution; industrial solvents, household detergents, Prozac (and a host of other pharmaceuticals) and radioactive wastes in drinking water; pesticides in flea collars; artificial growth hormones in beef, arsenic in chicken; synthetic hormones in bottles, teething rings and medical devices; formaldehyde in cribs and nail polish, and even rocket fuel in lettuce. Pacifiers are now manufactured with nanoparticles from silver, to be sold as ‘antibacterial.’ These exposures all add up – and the body can flush out some of these chemicals, while it cannot excrete others.  Chlorinated pesticides, such as DDT, for example, can remain in the body for 50 years.   Scientists call the chemicals in our body our “body burden”.  Everyone alive carries within their body at least 700 contaminants.[4]

This cumulative exposure could mean that at some point your body reaches a tipping point and, like falling dominoes, the stage is set for something disastrous happening to your health.

The generations born from 1970 on are the first to be raised in a truly toxified world. Probably one in three of the children you know suffers from a chronic illness – based on the finding of many studies on children’s health issues.[5]   It could be cancer, or birth defects – perhaps asthma, or a problem that affects the child’s mind and behavior, such as a learning disorder, ADHD or autism or even a peanut allergy. We do know, for example:

  • Childhood cancer, once a medical rarity, is the second leading cause of death (following accidents) in children aged 5 to 14 years.[6]
  • According to the American Academy of Allergy Asthma & Immunology, for the period 2008-2010, asthma prevalence was higher among children than adults – and asthma rates for both continue to grow. [7]
  • Autism rates without a doubt have increased at least 200 percent.
  • Miscarriages and premature births are also on the rise,
  • while the ratio of male to female babies dwindles and
  • teenage girls face endometriosis.

Dr. Warren Porter delivered a talk at the 25th National Pesticide Forum in 2007, in which he explained that a lawn chemical used across the country, 2,4-D, mecoprop and dicambra was tested to see if it would change or alter the capacity of mice to keep fetuses in utero. The test found that the lowest dosage of this chemical had the greatest effect – a common endocrine response.[8]

Illness does not necessarily show up in childhood. Environmental exposures, from conception to early life, can set a person’s  cellular code for life and can cause disease at any time, through old age. And the new science of epigenetics is showing us that these exposures can impact not only us, but our children, grandchildren and great-grandchildren.

I think that pretty much demolishes the argument that chemicals in “trace amounts” don’t do us any harm.

Second, what about her contention that “chemicals are regulated under nearly a dozen federal agencies and regulations … which have undergone hundreds of safety tests.”

 The chief legal authority for regulating chemicals in the United States is the 1976 Toxic Substances Control Act (TSCA).[9]

It is widely agreed that the TSCA is not doing the job of protecting us, and that the United States is in need of profound change in this area. Currently, legislation entitled the 2013 Chemical Safety Improvement Act, introduced by a bipartisan group of 26 senators, is designed to improve the outdated TSCA but it is still in committee.  The chemicals market values function, price and performance over safety, which poses a barrier to the scientific and commercial success of green chemistry in the United States and could ultimately hinder the U.S. chemical industry’s competitiveness in the global marketplace as green technologies accelerate under the European Union’s requirements.

We assume the TSCA is testing and regulating chemicals used in the industry[10]. It is not:

  • Of the more than 60,000 chemicals  in use prior to 1976, most were “grandfathered in”; only 263 were tested for safety and only 5 were restricted.  Today over 80,000 chemicals are routinely used in industry, and the number which have been tested for safety has not materially changed since 1976.  So we cannot know the risks of exposing ourselves to certain chemicals.  The default position is that no information about a chemical = no action.
  • The chemical spill which occurred in West Virginia in 2014 was of “crude MCHM”, or 4-methylcyclohexanemethanol, one of the chemicals that was grandfathered into the Toxic Substances Control Act of 1976.   That means that nobody knows for sure what that chemical can do to us.
    • Carcinogenic effects? No information available.
    • Mutagenic effects? No information available.
    • Developmental toxicity? No information available.

Lack of information is the reason the local and federal authorities were so unsure of how to advise the local population about their drinking  water supplies.  (And by the way, in January, 2014,  a federal lawsuit was filed in Charleston, WV, which claims that the manufacturer of MCHM hid “highly toxic and carcinogenic properties” of components of MCHM, hexane and methanol, both of which have been tested and found to cause diseases such as cancer.)

We assume that the TSCA requires manufacturers to demonstrate that their chemicals are safe before they go into use. It does not:

  • The EPA requires a “Premanufacture Notification” of a new chemical, and no data of any kind is required[11].   The EPA receives between 40-50 each week and 8 out of 10 are approved, with or without test data, with no restrictions on their proposed use. As 3M puts it on their PMN forms posted on EPA’s web site, “You are not required to submit the listed test data if you do not have it.”
  • The TSCA says the government has to prove actual harm caused by the chemical in question before any controls can be put in place.  The catch-22 is that chemical companies don’t have to develop toxicity data or submit it to the EPA for an existing product unless the agency finds out that it will pose a risk to humans or the environment – which is difficult to do if there is no data in the first place.  Lack of evidence of harm is taken as evidence of no harm.

We assume that manufacturers must list all ingredients in a product, so if we have an allergy or reaction to certain chemicals we can check to see if the product is free of those chemicals. It does not:

  • The TSCA allows chemical manufacturers to keep ingredients in some products secret.   Nearly 20% of the 80,000 chemicals in use today are considered “trade secrets”.  This makes it impossible for consumers to find out what’s actually in a product.  And there is no time limit on the period in which a chemical can be considered a trade secret.

These limitations all help to perpetuate the chemical industry’s failure to innovate toward safer chemical and product design.  It’s one of the reasons the USA is one of the few nations in the world in which asbestos is not banned.

Finally, and because I just couldn’t resist: her example of using what she concedes are “toxic fragrances” to cover up that “other toxic stink – the one coming out of your baby” speaks for itself.

In conclusion, I don’t think that we’re being alarmist in trying to find better alternatives for products we use every day.  Nor are the promises of companies like Alba’s false.


[1] Living on Earth, March 16, 2012,

[2] Sorensen, Eric, “Toxicants cause ovarian disease across generations”, Washington State University,



[5] Theofanidis, D, MSc., “Chronic Illness in Childhood: Psychosocial and Nursing Support for the Family”, Health Science Journal,

[6] Ward, Elizabeth, et al; Childhood and adolescent cancer statistics, 2014, CA: Cancer Journal for Clinicians, Vol 64, issue 2, pp. 83-103, March/April 2014


[8] Porter, Warren, PhD; “Facing Scientific Realities: Debunking the “Dose Makes the Poison” Myth”, National Pesticide Forum, Chicago, 2007;

[9] The “regulations” mentioned, all of which fall under the TSCA, might include:

  • the Environmental Protection Agency’s Chemical Action Plans for certain chemicals – to date, 10 chemicals have Chemical Action Plans in place. These plans attempt to outline the risks each chemical may present and identify the specific steps the agency is taking to address the concerns.
  • Confidential Business Information (CBI) – designed to protect intellectual property and confidential business information.
  • Chemical Data Reporting (CDR) Rule: use and exposure information to help the EPA screen and prioritize chemicals for additional review.
  • Chemical Prioritization: Which allows the EPA to identify which chemicals in commerce warrant additional review.
  • Risk Assessment: Under TSCA, EPA assesses chemicals using conservative assumptions about the possible hazards a chemical may pose.


[11] Ibid.

What kind of filling for your sofa cushions?

12 05 2015


One thing that most people care about is how the cushions feel to them – do you like to sink down into the cushions or you like a denser, more supportive cushion? Either way, the cushions are important.

Before plastics, our grandparents filled cushions with feathers, horsehair, wool or cotton batting – even straw (one of the earliest stuffing materials). This stuff often shifted, meaning that you’d have to plump up the feathers, horsehair or batting to make the sofa look, and feel, good.  But with the advent of plastics, our lives changed.  Polyurethane foam was introduced as a cushion component in furniture in 1957 –  only a bit more than 55 years ago – and quickly replaced latex, excelsior, cotton batting, horsehair and wool because it was CHEAP and it behaved!  Imagine – polyfoam cushions at $2 vs. natural latex at $7 or $8.  Price made all the difference.  Today, Eisenberg Upholstery’s website says that “easily 25% of all furniture repairs I see deal with bad foam or padding. The point is: start with good foam and you won’t be sorry.”

Polyurethane foam for cushions are generally measured by two values:

  1. The density or weight per cubic foot. The higher the number, the more it weighs.   Foam that has a density of 1.8, for example, contains 1.8 lbs. of foam per cubic foot and foam that has a density of 2.5 would have 2.5 lbs of foam per cubic foot.  Density for sofa cushions ranges between 1.6 and 5 or even 6.
  2. The second measurement tells you the firmness of the foam  (called the IFD  – the Indentation Force Deflection). The IFD is the feel of the cushion, and tells you how much weight it takes to compress the foam by one third. The lower IFD will sit softer. The higher IFD will sit firmer.  IFD numbers range between 15 to 35.

What many people don’t realize is that the density and firmness numbers go hand in hand – you can’t look at one without the other.  They are expressed as density/firmness, for example: 15/30 or 29/52.  The first, 15/30 means that 1.5 pounds of foam per cubic foot will take 30 pounds of weight to compress the foam 33%.  The second example means that 2.9 pounds per cubic foot of foam will take 52 pounds of weight to compress the block 33%.

After choosing which foam to use, it is then wrapped with something to soften the edges – for example,  Dacron or polyester batting, cotton or wool batting or down/feathers.

Lowest quality sofas will not even wrap the (low quality) foam; higher quality sofas have cushions that are made from very high quality foam and wrapped in wool or down.  But as you will see, the foam is itself very problematic.

You will now commonly find in the market polyurethane foam, synthetic or natural latex rubber and the new, highly touted soy based foam.  We’ll look at these individually:

The most popular type of cushion filler today is polyurethane foam. Also known as “Polyfoam”, it has been the standard fill in most furniture since its wide scale introduction in the 1960’s because of its low cost (really cheap!).  A staggering 2.1 billion pounds of flexible polyurethane foam is produced every year in the US alone.[1]

Polyurethane foam is a by-product of the same process used to make petroleum from crude oil. It involves two main ingredients: polyols and diisocyanates:

  • A polyol is a substance created through a chemical reaction using methyloxirane (also called propylene oxide).
  • Toluene diisocyanate (TDI) is the most common isocyanate employed in polyurethane manufacturing, and is considered the ‘workhorse’ of flexible foam production.
  • Both methyloxirane and TDI have been formally identified as carcinogens by the State of California
  • Both are on the List of  Toxic Substances under the Canadian Environmental Protection Act.
  • Propylene oxide and TDI are also among 216 chemicals that have been proven to cause mammary tumors.  However, none of these chemicals have ever been regulated for their potential to induce breast cancer.

The US Environmental Protection Agency (EPA) considers polyurethane foam fabrication facilities potential major sources of several hazardous air pollutants including methylene chloride, toluene diisocyanate (TDI), and hydrogen cyanide.   There have been many cases of occupational exposure in factories (resulting in isocyanate-induced asthma, respiratory disease and death), but exposure isn’t limited to factories: The State of North Carolina forced the closure of a polyurethane manufacturing plant after local residents tested positive for TDI exposure and isocyanate exposure has been found at such places as public schools.

The United States Occupational Safety and Health Administration (OSHA) has yet to establish exposure limits on carcinogenicity for polyurethane foam. This does not mean, as Len Laycock explains in his series “Killing You Softly”, “that consumers are not exposed to hazardous air pollutants when using materials that contain polyurethane. Once upon a time, household dust was just a nuisance. Today, however, house dust represents a time capsule of all the chemicals that enter people’s homes. This includes particles created from the break down of polyurethane foam. From sofas and chairs, to shoes and carpet underlay, sources of polyurethane dust are plentiful. Organotin compounds are one of the chemical groups found in household dust that have been linked to polyurethane foam. Highly poisonous, even in small amounts, these compounds can disrupt hormonal and reproductive systems, and are toxic to the immune system. Early life exposure has been shown to disrupt brain development.”

“Since most people spend a majority of their time indoors, there is ample opportunity for frequent and prolonged exposure to the dust and its load of contaminants. And if the dust doesn’t get you, research also indicates that toluene, a known neurotoxin, off gases from polyurethane foam products.”

I found this on the Sovn blog:

“the average queen-sized polyurethane foam mattress covered in polyester fabric loses HALF its weight over ten years of use. Where does the weight go? Polyurethane oxidizes, and it creates “fluff” (dust) which is released into the air and eventually settles in and around your home and yes, you breathe in this dust. Some of the chemicals in use in these types of mattresses include formaldehyde, styrene, toluene di-isocyanate (TDI), antimony…the list goes on and on.”

Polyurethane foams are advertised as being recyclable, and most manufacturing scraps (i.e., post industrial) are virtually all recycled – yet the products from this waste have limited applications (such as carpet backing).  Post consumer, the product is difficult to recycle, and the sheer volume of scrap foam that is generated (mainly due to old cushions) is greater than the rate at which it can be recycled – so it  mostly ends up at the landfill.  This recycling claim only perpetuates the continued use of hazardous and carcinogenic chemicals.

Polyfoam has some hidden costs (other than the chemical “witch’s brew” described above):  besides its relatively innocuous tendency to break down rapidly, resulting in lumpy cushions, and its poor porosity (giving it a tendency to trap moisture which results in mold), it is also extremely flammable, and therein lies another rub!

Polyurethane foam is so flammable that it’s often referred to by fire marshals as “solid gasoline.” When untreated foam is ignited, it burns extremely fast. Ignited polyurethane foam sofas can reach temperatures over 1400 degrees Fahrenheit within minutes. Making it even more deadly are the toxic gasses produced by burning polyurethane foam –  such as hydrogen cyanide. The gas was also implicated in the 2003 Rhode Island nightclub fire that killed 100 people, including Great White guitarist Ty Longley, and injured more than 200 others. Tellingly, a witness to that fire, television news cameraman Brian Butler, told interviewers that “It had to be two minutes, tops, before the whole place was black smoke.”   Just one breath of superheated toxic gas can incapacitate a person, preventing escape from a burning structure.

Therefore, flame-retardant chemicals are added to its production when it is used in mattresses and upholstered furniture.   This application of chemicals does not alleviate all concerns associated with its flammability, since polyurethane foam releases a number of toxic substances at different temperature stages. For example, at temperatures of about 800 degrees, polyurethane foam begins to rapidly decompose, releasing gases and compounds such as hydrogen cyanide, carbon monoxide, acetronitrile, acrylonitrile, pyridine, ethylene, ethane, propane, butadine, propinitrile, acetaldehyde, methylacrylonitrile, benzene, pyrrole, toluene, methyl pyridine, methyl cyanobenzene, naphthalene, quinoline, indene, and carbon dioxide.

According to the federal government’s National Institute of Standards and Technology, polyurethane foam in furniture is responsible for 30 percent of U.S. deaths from fires each year.

In conclusion, the benefits of polyfoam (low cost) is far outweighed by the disadvantages:  being made from a non-renewable resource (oil),  and the toxicity of main chemical components as well as the toxicity of the flame retardants added to the foam – not to mention the fact that even the best foams begin to break down after around 10 – 12 years of “normal use”.[2] The fact that California has amended the old law that required fire retardants in polyurethane foam doesn’t affect the fact that in a fire, the toxic gasses released by the foam (such as hydrogen cyanide) would incapacitate the occupants of a house in just a few minutes.

The newest entry in the green sweepstakes is what’s called a bio-based foam made from soybeans. This “soy foam” is highly touted as “A leap forward in foam technology, conserving increasingly scarce oil resources while substituting more sustainable options,” as one product brochure describes it. Companies and media releases claim that using soy in polyurethane foam production results in fewer greenhouse gas emissions, requires less energy, and could significantly reduce reliance on petroleum. Many companies are jumping on the bandwagon, advertising their green program of using foam cushions with “20% bio based foam” (everybody knows we have to start somewhere and that’s a start, right?).  As Len Laycock,  CEO of Upholstery Arts (which was the first furniture company in the world to introduce Cradle to Cradle product cycle and achieve the Rainforest Alliance Forest Stewardship Council Certification),  says  – who wouldn’t sleep sounder with such promising news?   (I have leaned heavily on Mr. Laycock’s articles on poly and soy foam, “Killing You Softly”, for this post.)

As with so many over hyped ‘green’ claims, it’s the things they don’t say that matter most.  While these claims contain grains of truth, they are a far cry from the whole truth. So called ‘soy foam’ is hardly the dreamy green product that manufacturers and suppliers want people to believe. To begin, let’s look at why they claim soy foam is green:

  • it’s made from soybeans, a renewable  resource
  • it reduces our dependence on fossil  fuels  by  both reducing the amount of fossil fuel needed for the feedstock  and  by reducing the energy requirements needed to produce the foam.

Are these viable claims?

It’s made from soybeans, a renewable resource:  This claim is undeniably true.   But what they don’t tell you is that this product, marketed as soy or bio-based,  contains very little soy. In fact, it is more accurate to call it ‘polyurethane based foam with a touch of soy added for marketing purposes’. For example, a product marketed as “20% soy based” may sound impressive, but what this typically means is that only 20 % of the polyol portion of the foam is derived from soy. Given that polyurethane foam is made by combining two main ingredients—a polyol and an isocyanate—in approximately equal parts, “20% soy based” translates to a mere 10% of the foam’s total volume. In this example the product remains 90% polyurethane foam and by any reasonable measure cannot legitimately be described as ‘based’ on soy. If you go to Starbucks and buy a 20 oz coffee and add 2-3 soy milk/creamers to it, does it become “soy-based” coffee?

It reduces our dependence on fossil fuels: According to Cargill, a multi-national producer of agricultural and industrial products, including BiOH polyol (the “soy” portion of “soy foam”), the soy based portion of so called ‘soy foam’ ranges from  5% up to a theoretical 40% of polyurethane foam formulations. This means that while suppliers may claim that ‘bio foams’ are based on renewable materials such as soy, in reality a whopping 90 to 95%, and sometimes more of the product consists of the same old petro-chemical based brew of toxic chemicals. This is no ‘leap forward in foam technology’. It is true that the energy needed to produce soy-based foam is, according to Cargill, who manufactures the soy polyol,  less that that needed to produce the polyurethane foam.  But the way they report the difference is certainly difficult to decipher:  soy based polyols use 23% less energy to produce than petroleum based polyols, according to Cargill’s LCA.   But the formula for the foam uses only 20% soy based  polyols, so by my crude calculations (20% of 50%…) the energy savings of 20% soy based foam would require only 4.6%  less energy than that used to make the petroleum based foam.  But hey, that’s still a savings and every little bit helps get us closer to a self sustaining economy and is friendlier to the planet.

But the real problem with advertising soy based foam as a new, miracle green product is that the foam, whether soy based or not, remains a “greenhouse gas spewing pretroleum product and a witches brew of carcinogenic and neurotoxic chemicals”, according to Len Laycock.

My concern with the use of soy is not its carbon footprint but rather the introduction of a whole new universe of concerns such as pesticide use, genetically modifed crops, appropriation of food stocks and deforestation.  Most soy crops are now GMO:  according to the USDA, over 91% of all soy crops in the US are now GMO; in 2007, 58.6% of all soybeans worldwide were GMO.  If you don’t think that’s a big deal, please read our posts on these issues (9.23.09 and 9.29.09).  The debate still rages today.  Greenpeace did an expose (“Eating Up The Amazon”) on what they consider to be a driving force behind Amazon rainforest destruction – Cargill’s race to establish soy plantations in Brazil.

In “Killing You Softly“, another sinister side of  soy based foam marketing is brought to light:

“Pretending to offer a ‘soy based’ foam allows these corporations to cloak themselves in a green blanket and masquerade as environmentally responsible corporations when in practice they are not. By highlighting small petroleum savings, they conveniently distract the public from the fact that this product’s manufacture and use continues to threaten human health and poses serious disposal problems. Aside from replacing a small portion of petroleum polyols, the production of polyurethane based foams with soy added continues to rely heavily on ‘the workhorse of the polyurethane foam industry’, cancer causing toluene diisocyanate (TDI). So it remains ‘business as usual ‘ for polyurethane manufacturers.”

Despite what polyurethane foam and furniture companies imply , soy foam is not biodegradable either. Buried in the footnotes on their website, Cargill quietly acknowledges that, “foams made with BiOH polyols are not more biodegradable than traditional petroleum-based cushioning”. Those ever so carefully phrased words are an admission that all polyurethane foams, with or without soy added, simply cannot biodegrade. And so they will languish in our garbage dumps, leach into our water, and find their way into the soft tissue of young children, contaminating and compromising life long after their intended use.

The current marketing of polyurethane foam and furniture made with ‘soy foam’ is merely a page out the tobacco industry’s current ‘greenwashing’ play book. Like a subliminal message, the polyurethane foam and furniture industries are using the soothing words and images of the environmental movement to distract people from the known negative health and environmental impacts of polyurethane foam manufacture, use and disposal.

Cigarettes that are organic (pesticide-free), completely biodegradable, and manufactured using renewable tobacco, still cause cancer and countless deaths. Polyurethane foam made with small amounts of soy derived materials still exposes human beings to toxic, carcinogenic materials, still relies on oil production, and still poisons life.

So what’s a poor consumer to do?  We think there is a viable, albeit expensive, product choice: natural latex (rubber). The word “latex” can be confusing for consumers, because it has been used to describe both natural and synthetic products interchangeably, without adequate explanation. This product can be 100% natural (natural latex) or 100% man-made (derived from petrochemicals) – or it can be a combination of the two – the so called “natural latex”. Also, remember latex is rubber and rubber is latex.

  • Natural latex – The raw material for  natural latex comes from a renewable resource – it is obtained from the sap of the Hevea Brasiliensis (rubber) tree, and was once widely used for cushioning.  Rubber trees are cultivated, mainly in South East Asia,  through a new planting and replanting program by large scale plantation and small farmers to ensure a continuous sustainable supply of natural  latex.  Natural latex is both recyclable and biodegradeable, and is mold, mildew and dust mite resistant.  It is not highly  flammable and does not require fire retardant chemicals to pass the Cal 117 test.  It has little or no off-gassing associated with it.    Because natural rubber has high energy production costs (although a  smaller footprint than either polyurethane or soy-based foams [3]),  and is restricted to a limited supply, it is more costly than petroleum based foam.
  • Synthetic latex – The terminology is very confusing, because synthetic latex is often referred to simply as  “latex” or even “100% natural latex”.  It is also known as styrene-butadiene rubber  (SBR).   The chemical styrene is  toxic to the lungs, liver, and brain; the EPA finds nervous system effects such as depression, loss of concentration and a potential for cancer(4).  Synthetic additives are added to achieve stabilization.    Often however, synthetic latex  can be made of combinations of polyurethane and natural latex, or a  combination of 70% natural latex and 30% SBR.  Most stores sell one of these versions under the term “natural latex” – so caveat emptor!    Being  petroleum based, the source of supply for the production of  synthetic latex is certainly non-sustainable and diminishing as well.

Natural latex is breathable, biodegradeable,  healthier (i.e., totally nontoxic, and mold & mildew proof) and lasts longer than polyfoam – some reports say up to 20 times longer.


[1] DFE 2008 Office Chair Foam;


[3] Op cit.,

(4) Technical Fact Sheet on: Styrene; Environmental Protection Agency;



Subtle effects of climate change

18 02 2015

I’m becoming anxious about climate change, and in particular what that means to my life. We humans are still in denial about climate change, and even though I’ve been told that climate change could  destroy ecosystems and economies within a generation – I like to look at the little changes that overpopulation and climate change bring about. Because the textile industry is a major contributor to the emissions which bring about these changes, I thought the topic was apt!

I was visiting a friend in Virginia recently. She and her friends were complaining about hiking conditions and how it’s so important to check for ticks after a hike because Lyme disease is so prevalent – complete with lots of stories of friends who had contracted the disease.

Less than four decades ago, scientists identified a spiral-shaped bacteria transmitted by the bite of a tiny hard-bodied tick as the cause of an arthritis outbreak among children in southern Connecticut. Since then, Lyme disease has emerged from obscurity to become the leading vector-borne (i.e., transmitted by mosquitos, ticks and/or fleas) disease in the United States. The 27,203 confirmed new cases reported to federal health authorities in 2013 marked nearly a 25 percent jump over the previous year,[1] and the total number of cases of Lyme disease has doubled since 1991. The CDC estimates that the number of infections is likely 10 times higher than reported, nearly 300,000 new cases per year based on lab test data.  Yale University researchers say that 10 percent of the population of southern New England has evidence of a previous Lyme disease infection. Why is this happening?

annual-cases-lyme-disease-us copy

While the disease is reported coast-to-coast, it is highly concentrated on the Eastern Seaboard, with a range expanding north into Canada and south through Virginia. Tick habitat and populations are influenced by many factors, but one of them is climate. This spring the U.S. Environmental Protection Agency added Lyme disease to its list of climate change indicators.

Scientists from Yale University have determined that climate impacts the severity of Lyme disease by influencing the feeding patterns of deer ticks that carry and transmit it.[2]  Deer ticks live for two years and have three stages of life – larval, nymphal and adult. They obtain one blood meal during each stage in order to survive. If the source of the first meal (a mouse, bird or other small animal) is infected with the bacterium that causes Lyme disease, the tick also becomes infected and passes it on to its next meal source – be it wildlife or human – in its second life stage as a nymph.

The researchers found that this cycle is heavily influenced by climate, which has the following effects on Lyme disease: An acceleration of the tick’s developmental cycle, a prolonged developmental cycle, increased egg production, increased population density, and a broader range of risk areas. Once the larvae have molted into the nymphal stage, the winter forces them to remain dormant until spring. An adult tick no longer needs to hibernate during the winter, so these ticks may become active on warm winter days, yielding a larger nymph population the following year. With an earlier winter thawing, nymphal-staged ticks will become active sooner. The warmer winters will also allow for a higher survival rate of the white-footed mouse, a popular host for the ticks, meaning an increased tick population in the spring and summer.

In the Midwest, where there are greater extremes of temperature, there is a shorter window of opportunity for tick feeding, and therefore a shorter gap between nymphal and larval feedings. Because of this, report the scientists, Midwestern wildlife and ticks are infected with less persistent strains, which correlates with fewer cases of Lyme disease reported in the Midwest.

The clear implication of this research, say the researchers, is that, as the planet warms, the Upper Midwest could find itself in the same situation as the Northeast: longer gaps between nymphal and larval feeding, and therefore, stronger, more persistent strains of Lyme disease.

Deer have been the main suspect in being the carrier of Lyme disease, but research shows that the new suspect is the white-footed mouse. Both deer and white-footed mouse populations have exploded recently – largely due to forest fragmentation. Forest fragments generally have fewer species than larger forest tracts, including the predators of deer and white-footed mice, which have allowed both of these populations to explode. “Our results suggest that efforts to reduce the risk of Lyme disease should be directed toward decreasing fragmentation of deciduous forests of the northeastern United States, particularly in areas with a high incidence of Lyme disease,” says Felicia Keesing of Bard College in Annandale, New York. “The creation of forest fragments smaller than five acres should especially be avoided.”


[1] Lavelle, Marianne, “Has Climate Change Made Lyme Disease worse?”, Scientific American, September 22, 2014

[2] Gatewood et al, “Climaate and Tick Seasonality are Predictors of Borrelia burgdorferl Genotype Distribution”, Applied and Environmental Microbiology, 2009; 75 (8): 2476 DOI: 10.1128/AEM.02633-08

Another concern for vigilant parents

19 11 2014

We live in an environment that is full of chemicals – some which are bad for us and yet are completely natural.   We don’t subscribe to the notion that man-made is absolutely bad and natural is absolutely good – botulism is completely natural and can kill you just as dead. But sometimes we adopt products for our use in ways that can hurt us, because we don’t pay attention to the chemicals that are contained in that product nor of how we use the product. Recently, the crushed up tires that are appearing in playgrounds and as the playfield surface of schools around the country have become an object of concern, so let’s take a look at those.

Discarded rubber tires are the bane of waste management – according to the EPA, we generate 290 million scrap tires each year.[1] Obviously finding a market for these slow-to-decompose materials is desirable, and many innovative uses have been developed, including using ground up tires on playground and sports field surfaces. According to the Synthetic Turf Council, this “crumb rubber has been installed in approximately 11,000 U.S. fields, tracks and playgrounds in the United States.[2] And the California Office of Environmental Health says that recycled rubber tires have become one of the top choice materials for surfacing children’s playgrounds.[3]

Crumb rubber is a black, pellet-like substance the size of a cracker crumb. Run your hand through the field, and you’ll pick up black dust, similar to the consistency of pencil graphite. It’s easy to spread, and can easily get into your mouth, shoes, clothing and nostrils. Routes of exposure, especially in the case of infants, can include dermal absorption, inhalation, and even ingestion directly from the material.

Here’s a story about crumb rubber from NBC news:

Various studies have identified the chemicals found in tires, which are made of 40-60% rubber polymers, carbon black (20-35%), silicas, process and extender oils (up to 28%), vulcanization chemicals and chemical anti-degradents, and plasticizers and softeners. It is well known that rubber tire debris contains toxic compounds such as highly aromatic oils and other reactive additives.[1]

The EPA has identified a number of compounds which may be found in tires, though they’re quick to point out that not all are contained in every tire:[2]

  • heavy metals ( cadmium, chromium, iron, lead, magnesium, manganese, molybdenum, selenium, sulfur, and zinc, which can be as much as 2% of tire mass) – most of which have documented health consequences including damage to the central nervous system.
  • Plasticizers (such as phthalates)- phthalates act as estrogens once absorbed by the body. They are considered endocrine disrupting chemicals (EDC’s); conditions associated with EDC’s include infertility; breast, prostate and ovarian cancers; asthma; and allergies.[3]
  • Styrene butadiene – associated with risk of leukemia[4]; known to be genotoxic[5]
  • Benzene – known to be a human carcinogen; also impacts the nervous and immune systems[6]
  • Chloroethane, which causes cancer in mice, is also a neurotoxin[7]
  • Halogenated flame retardants – need we reiterate how these impact human health?
  • Methyl ethyl ketone and methyl isobutyl ketone – there is no evidence of carcinogenicy or mutagenicy but studies show impairment of central nervous system; both are on the Hazardous Substances List by OSHA.[8]
  • Naphthalene – a group C carcinogen (possible human carcinogen); also causes neurological damage.[9]

Another concern is the smell that wafts up from the playing field – like old tires – coupled with the fact that the fields often are 10 – 15 degrees warmer than the ambient temperature, and many of the compounds evaporate at temperatures as low as 77 degrees F. Compounds found to be present in the air in a study done by the Connecticut Agricultural Experiment Station include: [10]

  • Benzothiazole: A skin and eye irritation, harmful if swallowed. There is no available data on cancer, mutagenic toxicity, teratogenic toxicity, or developmental toxicity.
  • Butylated hydroxyanisole: A recognized carcinogen, suspected endocrine toxicant, gastrointestinal toxicant, immunotoxicant, neurotoxicant, skin and sense-organ toxicant. There is no available data on cancer, mutagenic toxicity, teratogenic toxicity, or developmental toxicity.
  • n-hexadecane: A severe irritant based on human and animal studies. There is no available data on cancer, mutagenic toxicity, teratogenic toxicity, or developmental toxicity.
  • 4-(t-octyl) phenol: Corrosive and destructive to mucous membranes. There is no available data on cancer, mutagenic toxicity, teratogenic toxicity, or developmental toxicity.
  • Polycyclic aromatic hydrocarbons (PAHs): heavy occupational exposure leads to risk of lung, skin or bladder cancers; genotoxic, leading to malignancies and heritable genetic damage in humans. [11] In 2010, the EPA concluded that in the case of PAHs, “breathing PAHs and skin contact seem to be associated with cancer in humans.”[12] The total concentration of PAHs in crumb rubber exceedes the Norwegian Pollution Control Authority’s normative values for most sensitive land use.[13]

A 2012 study analyzing rubber mulch taken from children’s playgrounds in Spain found harmful chemicals present in all, frequently at high levels.[14] Twenty-one samples were collected from 9 playgrounds in urban locations and screened for various pollutants. The results showed that all samples contained at least one hazardous chemical, with most containing multiple PAHs found at high concentrations. The authors concluded that the use of rubber recycled tires on playgrounds “should be restricted or even prohibited in some cases.”[15]

Many, if not most, of the compounds present in tire crumbs and shreds have been incompletely tested for human health effects, so there is no data available to evaluate the chemicals (as evidenced by the four compounds above).

Artificial turf and rubber crumb manufacturers point to the fact that no research has linked cancer to artificial turf – yet most studies add the caveat that more research should be conducted.

According to Dr. Joel Forman, associate professor of pediatrics and preventive medicine at New York’s Mt. Sinai Hospital, in all these studies, data gaps make it difficult to draw firm conclusions. As he says, “None of [the studies] are long term, they rarely involve very young children and they only look for concentrations of chemicals and compare it to some sort of standard for what’s considered acceptable,” said Dr. Forman. “That doesn’t really take into account subclinical effects, long-term effects, the developing brain and developing kids.” Forman said that it is known that some of the compounds found in tires, “even in chronic lower exposures” can be associated with subtle neurodevelopmental issues in children.

“If you never study anything,” said Dr. Forman, “you can always say, ‘Well there’s no evidence that shows you have a problem,’ but that’s because you haven’t looked. To look is hard.”

Another notable critic of the stuff is Dr. Phillip Landrigan of the Mount Sinai School of Medicine, who submitted a letter to the New York City Planning Department last year expressing concerns over the carcinogens in tire crumbs.

He wrote that the principal chemical components of crumb rubber are Styrene and Butadiene — Styrene is neurotoxic, and Butadiene is a proven human carcinogen that has been shown to cause leukemia and lymphoma.

“There is a potential for all of these toxins to be inhaled, absorbed through the skin and even swallowed by children who play on synthetic turf fields,” Dr. Landrigan wrote. “Only a few studies have been done to evaluate this type of exposure risk.”

So if it walks like a duck, quacks like a duck and looks like a duck…

And as if to add insult to injury, wood chips were found to do a better job of protecting children from head trauma![16]

Remember that children are much more likely to be harmed by exposure to chemicals in their environment than adults because they’re smaller (therefore exposure is greater) and their bodies are still developing. So what’s a concerned parent to do?

  • First – ignore the tire crumb playgrounds and find a good old wood chip or grass site.
  • Teach your children the importance of frequent hand washing as many chemicals enter bodies via the mouth.
  • And persuade local officials to use wood chips rather than recycled rubber.


[1] Llompart, Maria et al, “Hazardous organic chemicals in rubber recycled tire playgrounds and pavers”, Chemosphere, Vol. 90, issue 2, January 2013, pages 423-431



[4] Santos-Burgoa, Carlos; “Lymphohematopoietic Cancer in Styrene-Butadiene Polymerization Workers”, American Journal of Epidemiology, Volume 136, issue 7, pp. 843-854.

[5] Norppa, H and Sorsa, M; “Genetic toxicity of 1,3-butadiene and styrene”, IARC Scientific Publications, 1993 (127): 185-193.


[7] US Department of Health and Human Services, Agency for Toxic Substances and Disease Registry, “Toxicological Profile for Chloroethane”, December 1998

[8]; and


[10]Mattina, MaryJane et al; “Examination of Crumb Rubber Produced From Recycled Tires”, The Connecticut Agricultural Experiment Station, 2007,


[12] US Environmental Protection Agency (EPA). Polycyclic Aromatic Hydrocarbons (PAHs)-Fact Sheet. January 2008.

[13] Llompart M, Sanchez-Prado L, Lamas JP, Garcia-Jares C, et al. “Hazardous organic chemicals in rubber recycled tire playgrounds and pavers”. Chemosphere. 2012; Article In Press.


[15] Ibid.

[16] State of California-Office of Environmental Health Hazard Assessment (OEHHA), Contractor’s Report to the Board. Evaluation of Health Effects of Recycled Waste Tires in Playground and Track PrRememoducts. January 2007.




[3] State of California-Office of Environmental Health Hazard Assessment (OEHHA), Contractor’s Report to the Board. Evaluation of Health Effects of Recycled Waste Tires in Playground and Track Products. January 2007.




31 07 2014

I just read the article by Mark Winston in the New York Times (July 15, 2014) in which he talks about the “thousand little cuts” suffered by honeybees which has led to the catastrophic decline of these insects. (The article is reproduced at the end of this blog.) I had been thinking about synergy and this seems to fit right in.

Synergy means the interaction of two (or more) things that produce an overall effect that’s greater than – or different from – the sum of the individual effects. In other words, we cannot predict the whole simply by looking at the parts.   Even so, we are challenged to understand and predict the impacts that contaminants have on communities – when understanding the effect of a single contaminant on a single organism is daunting. There are almost unlimited variables that impact any situation.

The EPA tests chemicals for adverse health effects, which they assume will occur individually. But in the real world, we’re exposed to a medley of chemicals every day – from car exhaust, to cosmetics, clothing, pesticide sprays for agriculture or mosquitos, even smog. The fact that these exposures can react with each other, and in effect, make each other more toxic, is a newly emerging science. In 1996, the EPA was required for the first time to consider cumulative pesticide exposure under the Food Quality Protection Act (FQPA). The FQPA recognizes that real-world pesticide exposure doesn’t occur as a single discrete exposure to a single pesticide, but rather as a combination of several pesticides at once. For example, USDA data shows that apples sold in the United States contained 22 different pesticide residues, and peaches contained 40.[1]

I just discovered the term “co-carcinogen”, which means the additive or synergistic effect of two or more agents which leads to cancer. These “co-carcinogens” may not themselves be a carcinogen. For example, a study by the University of Minnesota published a paper about the cancer-promoting effects of capsaicin – found in foods that contain hot chili peppers. It’s complicated – if you’re interested, please click here.

Here’s an interesting story:

In the summer of 1985, 30 year-old Thomas Latimer was leading a good life in the suburbs of Dallas, TX. He was a vigorous, athletic man with a promising engineering career. On one particular Saturday afternoon, Mr. Latimer spent the day mowing the lawn, picking up the clippings and edging the walkways. After about an hour, he began to feel dizziness, nausea, tightness in his chest and a pounding headache. Ten days later, he felt even worse and went to see his doctor.

Over the next six years, Mr. Latimer found himself unable to exercise. He suffered from brain seizures. He visited 20 different doctors and underwent numerous tests to determine the source of his medical problems. His symptoms were consistent with organophosphate poisoning, most likely from the insecticide diazinon that had been applied to his lawn. But because his symptoms were so severe and the amount of pesticide he was exposed to was so low, the doctors continued to look for a complicating factor. After further research, a toxicologist, three neurologists and two neuro-ophthalmologists all concluded independently that the popular ulcer drug Tagamet that Mr. Latimer was taking had suppressed his liver, making him more susceptible to pesticide poisoning.

Alfredo A Sudan, a professor of neurology and ophthalmology at the University of Southern California, who conducted extensive tests evaluating an eye disorder that Mr. Latimer developed, estimates that taking a medication like Tagamet “can make a person 100 to 1,000 times more sensitive to organophosphate poisoning.”[2]

In 2001, researchers at Duke University’s Department of Pharmacology and Cancer Biology published a series of papers looking at the synergistic effects of DEET (the active ingredient in most insect repellants) and permethrin (a pesticides commonly used in community mosquite programs, as well as many household bug killers.) The purpose of the studies was to determine a possible link between pesticides and other chemicals used during the Persian Gulf War and the “Gulf War Syndrome” – a neurological disease. When DEET, permethrin and pyridostigmine bromide (a drug taken by soldiers to counteract toxic gas warfare chemicals) were administered alone – even at doses three times the level soldiers received – no effects were observed. But when the three chemicals were used in combination, test animals suffered neurological symptoms similar to the Gulf War veterans.[3]

Neurology experts give three possible reasons for the synergistic effects seen in the above experiments. First, the stress endured by animals when exposed to a combination of chemicals undermines the protective role of the blood brain barrier, allowing the level of toxics to cross into the brain to be 100 times higher. Second, tissue that has been exposed becomes more sensitive and receptive to other toxic substances. Third, certain chemicals bind to enzymes that detoxify the body, making the enzymes unavailable to protect the body from other intruding chemicals. Dr. Goran Jamal, a neurologist at the West London Regional Neuro-Science Center of the Imperial College of Medicine, makes the following comparison, “It’s like releasing 200 criminals in London and taking away the police officers that are usually on duty. There is bound to be some damage.”[4]

The organization Beyond Pesticides suggests a variety of tests: testing for interactions between pesticides commonly used in agriculture, between pesticides used in agriculture and food contaminants, for pesticides commonly found in drinking water, for pesticides and pharmaceuticals, and for pesticides that are likely to drift. However, this testing is probably unrealistic so the best approach might be to limit exposure – by limiting exposure you also limit synergistic health effects.

Here is Mark Winston’s article, “Our Bees, Ourselves”:

New York Times, Katie Scott

New York Times, Katie Scott

AROUND the world, honeybee colonies are dying in huge numbers: About one-third of hives collapse each year, a pattern going back a decade. For bees and the plants they pollinate — as well as for beekeepers, farmers, honey lovers and everyone else who appreciates this marvelous social insect — this is a catastrophe.

But in the midst of crisis can come learning. Honeybee collapse has much to teach us about how humans can avoid a similar fate, brought on by the increasingly severe environmental perturbations that challenge modern society.

Honeybee collapse has been particularly vexing because there is no one cause, but rather a thousand little cuts. The main elements include the compounding impact of pesticides applied to fields, as well as pesticides applied directly into hives to control mites; fungal, bacterial and viral pests and diseases; nutritional deficiencies caused by vast acreages of single-crop fields that lack diverse flowering plants; and, in the United States, commercial beekeeping itself, which disrupts colonies by moving most bees around the country multiple times each year to pollinate crops.

The real issue, though, is not the volume of problems, but the interactions among them. Here we find a core lesson from the bees that we ignore at our peril: the concept of synergy, where one plus one equals three, or four, or more. A typical honeybee colony contains residue from more than 120 pesticides. Alone, each represents a benign dose. But together they form a toxic soup of chemicals whose interplay can substantially reduce the effectiveness of bees’ immune systems, making them more susceptible to diseases.

These findings provide the most sophisticated data set available for any species about synergies among pesticides, and between pesticides and disease. The only human equivalent is research into pharmaceutical interactions, with many prescription drugs showing harmful or fatal side effects when used together, particularly in patients who already are disease-compromised. Pesticides have medical impacts as potent as pharmaceuticals do, yet we know virtually nothing about their synergistic impacts on our health, or their interplay with human diseases.

Observing the tumultuous demise of honeybees should alert us that our own well-being might be similarly threatened. The honeybee is a remarkably resilient species that has thrived for 40 million years, and the widespread collapse of so many colonies presents a clear message: We must demand that our regulatory authorities require studies on how exposure to low dosages of combined chemicals may affect human health before approving compounds.

Bees also provide some clues to how we may build a more collaborative relationship with the services that ecosystems can provide. Beyond honeybees, there are thousands of wild bee species that could offer some of the pollination service needed for agriculture. Yet feral bees — that is, bees not kept by beekeepers — also are threatened by factors similar to those afflicting honeybees: heavy pesticide use, destruction of nesting sites by overly intensive agriculture and a lack of diverse nectar and pollen sources thanks to highly effective weed killers, which decimate the unmanaged plants that bees depend on for nutrition.

Recently, my laboratory at Simon Fraser University conducted a study on farms that produce canola oil that illustrated the profound value of wild bees. We discovered that crop yields, and thus profits, are maximized if considerable acreages of cropland are left uncultivated to support wild pollinators.

means a healthier, more diverse bee population, which will then move to the planted fields next door in larger and more active numbers. Indeed, farmers who planted their entire field would earn about $27,000 in profit per farm, whereas those who left a third unplanted for bees to nest and forage in would earn $65,000 on a farm of similar size.

Such logic goes against conventional wisdom that fields and bees alike can be uniformly micromanaged. The current challenges faced by managed honeybees and wild bees remind us that we can manage too much. Excessive cultivation, chemical use and habitat destruction eventually destroy the very organisms that could be our partners.

And this insight goes beyond mere agricultural economics. There is a lesson in the decline of bees about how to respond to the most fundamental challenges facing contemporary human societies. We can best meet our own needs if we maintain a balance with nature — a balance that is as important to our health and prosperity as it is to the bees.[5]






[2] Allen, Frank Edward. 1991. One Man’s Suffering Spurs Doctors to Probe Pesticide-Drug Link. The Wall Street Journal. October 14.

[3] Abou-Donia, M.B., et. al. 1996. Neurotoxicity resulting from coexposure to pyridostigmine bromide, DEET, and permethrin: Implications of Gulf War chemical exposures. J. Toxicol. Environ. Health 48:35-56.


[5] Winston, Mark, “Our Bees, Ourselves”, New York Times, July 15, 2014, pg. A25


What will nanotechnology mean to you?

2 04 2014

A hot topic in the media right now is the toxicity of chemical flame retardants that are in our furniture and are migrating out into our environment.  Tests have shown that Americans carry much higher levels of these chemicals in their bodies than anyone else in the world, with children in California containing some of the highest levels ever tested.   According to Ronald Hites of Indiana University, these concentrations have been “exponentially increasing, with a doubling time of 4 to 5 years.”[1]  These toxic chemicals are present in nearly every home – packed into couches, chairs and many baby products including (but not limited to) mattresses, nursing pillows, carriers and changing table pads (scary!).  Recent studies have found that most couches in America have over 1 pound of the toxic chemical Chlorinated Tris inside them[2], even though it was banned in children’s pajamas over cancer concerns over a generation ago.[3]

Why the concern?  Fire retardant chemicals, called PBDE’s (polybrominated diphenyl ethers) have been linked to cancer, reproductive problems and impaired fetal brain development, as well as decreased fertility.  And even though they’ve been banned in the U.S. and European Union, they persist in the environment and accumulate in your body – and they’re still being used today.

So its probably no surprise that there is a mad scramble on to produce a fire retardant that does not impact our health or the environment.   The current front runners, touted as being “exceptionally” effective yet safer and more environmentally friendly than the current fire retardants, use nanotechnology – specifically “nanocoatings” and “nanocomposites”[4] .  These composites and coatings are based on what are called “multiwalled carbon nanotubes” or MWCNTs.

Based on a final report published by the U.S. EPA in September 2013 about the assessment of the risks of using these  MWCNTs, the EPA found that there will be releases of these MWCNTs into the environment throughout the life cycle of textiles – to our air and water during production,  in the form of abraded particles of the textiles falling into the dust in our homes, and in the disposal of furniture in municipal landfills or incineration facilities.[5]

While it is reasonable to propose that substituting nanomaterials for polybrominated diphenyl ether (PBDEs)  or chlorinated triss  and calling it “sustainable”, the fact is that no quantitative study has ever been done to support this assertion . [6]

Please don’t misunderstand me – I am all for finding safer alternatives to the current crop of chemical fire retardants (assuming I buy into the argument that we actually need them).  However, I don’t want us to jump from the frying pan into the fire by rushing to use a technology which is still controversial.  But the race is on:  the US patent office published some 4000 patents under “977 – nanotechnology” in 2012, a new record.

patents nanotech

Here’s an interesting video which helps to explain how nano works – and why we will need extensive study to absorb the many implications of this emerging science.

Consider these science fiction type scenarios of how nano can be used to profoundly change our lives:

  • “nanomedicine” offers the promise of diagnosis and treatment of a disease – before you even have the symptoms.  Or it promises to rebuild neurons for people with Alzheimers or Parkinson’s disease – and stem cells for whatever ails you!   Bone regeneration.  [7]
  • Surfaces can be modified to be scratchproof, unwettable, clean or sterile, depending on the application.[8]
  • Quantum computing.
  • Solar cells capturing the sun’s visible spectrum – as well as infrared photons –  doubling the solar energy available to us.  How about zero net carbon emissions.
  • Nanoscale bits of metals can detoxify hazardous wastes.
  • Clothing that recharges your cell phone as you stroll, or an implant that measures blood pressure powered by your own heartbeat.

And yet.  The unknowns are great, and as Eric Drexler has said, the story involves a tangle of science and fiction linked with money, press coverage, Washington politics and sheer confusion.  Scientists and governments agree that the application of nanotechnology to commerce poses important potential risks to human health and the environment, and those risks are unknown. Examples of high level respected reports that express this concern include:

  • Swiss Federation (Precautionary Matrix 2008)[9]
  • Commission on Environmental Pollution (UK 2008)[10];
  • German Governmental Science Commission (“SRU”)[11];
  • Public testimony sought by USA National Institute for Occupational Safety and Health (NIOSH, Feb 2011)[12] ;
  • OECD working group (since 2007)[13];
  • World Trade Organization (WTO)[14]
  • as well as several industrial groups and various non-governmental organizations.

Nanotechnology is already transforming many products – water treatment, pesticides, food packaging and cosmetics to name a few – so the cat is already out of the bag.  Consider this small example of the nano particle  argument:  When ingested the nanoparticles pass into the blood and lymph system, circulate throughout the body and reach potentially sensitive sites such as the spleen, brain, liver and heart.[15]   The ability of nanoparticles to cross the blood brain barrier makes them extremely useful as a way to deliver drugs directly to the brain.  On the other hand, these nanoparticles may be toxic to the brain.  We simply don’t know enough about the size and surface charge of nanoparticles to draw conclusions.[16]  In textiles, silver nano particles are used as antibacterial/antifungal agents to prevent odors.

But there are almost no publications on the effects of engineered nanoparticles on animals and plants in the environment.

So it’s still not clear what nanoscience will grow up to be – if it doesn’t kill us, it might just save us.

[2] Stapleton HM, et al. Detection of organophosphate flame retardants in furniture foam and U.S. house dust. Environ Sci Technol 43(19):7490–7495. (2009);

[3] Callahan, P and Hawthorne, M; “Chemicals in the Crib”, Chicago Tribune, December 28, 2012,

[5] Comprehensive Environmental Assessment Applied to Multiwalled Carbon Nanotube Flame-Retardant Coatings in Upholstery Textiles: A Case Study Presenting Priority Research Gaps for Future Risk Assessments (Final Report), Environmental Protection Agency,

[6] Gilman,  Jeffrey W., “Sustainable Flame Retardant Nanocomposites”; National Institute of Standards and Technology

[7] Hunziker, Patrick,  “Nanomedicine: The Use of Nano-Scale Science for the Benefit of the Patient” European Foundation for Clinical Nanomedicine (CLINAM) Basel, Switzerland 2010.

[9] Swiss National Science Foundation, Opportunities and Risks of Nanomaterials Implementation Plan of the National Research Programme NRP 64 Berne, 6 October 2009; see also Swiss Precautionary Matrix, and documents explaining and justifying its use, available in English from the Federal Office of Public Health.

[10] Chairman: Sir John Lawton CBE, FRS Royal Commission on Environmental Pollution, Twenty-seventh report: Novel Materials in the Environment: The case of nanotechnology. Presented to Parliament by Command of Her Majesty November 2008.

[11] SRU, German Advisory Council on Environment, Special Report “Precautionary strategies for managing nanomaterials” Sept 2011. The German Advisory Council on the Environment (SRU) is empowered by the German government to make “recommendations for a responsible and precautionary development of this new technology”.

[12] See: Legal basis and justification: Niosh recommendations preventing risk from carbon nanotubes and nanofibers ”post-hearing comments Niosh current intelligence bulletin: occupational exposure to carbon nanotubes and nanofibers Docket NO. NIOSH-161 Revised 18 February 2011; Testimony on behalf of ISRA (International Safety Resources Association) Before NIOSH, USA. Comments prepared by Ilise L Feitshans JD and ScM, Geneva, Switzerland. Testimony presented by Jay Feitshans, Science Policy Analyst; ISRA Draft Document for Public Review and Comment NIOSH Current Intelligence Bulletin: Occupational Exposure to Carbon Nanotubes and Nanofibers, Docket Number NIOSH-161-A.

[13] The OECD Working Party for Manufactured Nanomaterials (WPMN) “OECD Emission Assessment for Identification of Sources of release of Airborne Manufactured Nanomaterials in the Workplace: Compilation of Existing Guidance”, ENV/JM/MONO (2009)16, “OECD Preliminary Analysis of Exposure Measurement and Exposure Mitigation in Occupational Settings: Manufactured Nanomaterials” OECD ENV/JM/MONO(2009)6, 2009.
“OECD Comparison of Guidance on selection of skin protective equipment and respirators for use in the workplace: manufactured nanomaterials”, OECD ENV/JM/MONO(2009) 17, 2009.

[14] WHO Guidelines on “Protecting Workers from Potential Risks of Manufactured Nanomaterials” (WHO/NANOH), (Background paper) 2011

[15] Dixon, D., “Toxic nanoparticles might be entering human food supply, MU study finds”, August 22, 2013,

[16] Scientific Committee on Emerging and Newly Identified health Risks (SCENIHR), The European Commission, 2006


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