Wednesday, 29 August 2018

Ten Toxic Truths by Prof. Marc Cohen


March 3, 2015, by Professor Marc Cohen

It is widely recognised that the greatest underlying cause of death among humans today is lifestyle-related chronic disease. The world is in the grip of an epidemic of obesity, diabetes, cardiovascular disease, cancer, dementia and more, fuelled by a high intake of sugar, fat, salt, alcohol and tobacco, and a lack of physical activity. In addition to this voluntary consumption, the entire human population is exposed to a toxic cocktail of industrial chemicals. The impact of industrial chemicals on human health was recently highlighted by the World Health Organisation, which forecasts a “tidal wave of cancer” (International Agency for Research On Cancer 2014). Meanwhile, public health researchers suggest we are experiencing a “silent pandemic of neuro-developmental disorders” and a “chemical brain drain” brought about by the exposure of an entire generation to industrial chemicals (Grandjean 2014). There are many actions we can take to avoid voluntary and involuntary health risks and, rather than becoming despondent, we need to become more aware and vigilant. Since the 16th century when Paracelsus stated “the dose makes the poison”, this idea has formed the basis for the regulation of toxic chemicals, including the use of pesticides and pharmaceuticals. We now know that this truth is incomplete. It is not only the dose, but also the type of chemical, the timing of exposure, the combination of chemicals and individual risk factors that combine to produce toxic effects. These factors give rise to what I call the “10 toxic truths”.


Everyone is affected

Since the advent of the Industrial Revolution, industrial chemicals have permeated the globe and it is clear that the world will never return to the conditions that existed prior to this period. Many toxic chemicals are carried throughout the world dispersed as atmospheric aerosols, while billions of tons of chemicals and plastics have entered the oceans, resulting in plastic microparticles being reported in nearly every litre of ocean water. Toxic chemicals have now entered every habitat and ecosystem on earth, from the most arid deserts to the deepest seas, and virtually all living creatures now contain pollutants at or near harmful levels. Toxic chemical exposure has become an inevitable part of modern life and everyone is affected. Toxic chemicals are pervasive in our food, soil, air, water and indoor environments as well as in all human tissue, including umbilical cord blood and breast milk. Only a few countries such as the US, Canada and Germany have programs that aim to monitor toxic chemicals in their general population. The National Health and Nutrition Examination Survey (NHANES) conducted by the US Centers for Disease Control and Prevention includes the world’s most comprehensive assessment of human chemical exposures. The most recent NHANES report examined only 212 chemicals and found chemicals such as polybrominated diphenyl ethers (PBDEs), used as fire retardants, and bisphenol A (BPA), a component of epoxy resins and polycarbonates, in the vast majority of participants (Centers for Disease Control and Prevention 2009).


The full extent is unknown

While we are all chronically exposed to a toxic cocktail of industrial pollutants, the full impact of industrial chemicals on human health remains unknown. There are more than 80,000 industrial chemicals that are commercially produced with more than 3000 produced in high volume and many tens of thousands more being inadvertently produced from industrial processes. Yet while the number of industrial chemicals increases every year, in most cases it is not possible to determine a chemical’s ‘safe level’, or ‘toxicity threshold’. And even when levels are measured, it is often difficult to interpret their clinical significance. The measurement of the body’s toxic load is still an emerging science (Sexton 2004, Committee on Human Biomonitoring for Environmental Toxicants, 2006). There are very few laboratories that currently have the facilities to perform comprehensive measures of toxic chemicals and, as yet, there are no general assessment measures that doctors can request to assess the ‘toxic load’ or ‘body burden’ of their patients. Thus, even though the signs and symptoms of overdose or overt toxicity are known for some compounds, the relationship between toxic load, individual susceptibility, clinical symptoms and chronic disease is incredibly complex and far from understood.


Tiny doses can have big effects

In the past it was thought that dose-response curves were linear, displaying a direct relationship between dose and toxicity. It is now known that dose-response curves can be non-linear or ‘non-monotonic’. This occurs when chemicals disturb the body’s regulatory processes rather than just impacting on target organs or tissues. By disrupting the endocrine system, the potential to reap metabolic havoc is greatly increased and extremely small exposures – orders of magnitude below recognised safety levels – can have dramatic effects. The hazards of endocrine disrupting chemicals and their potential for irreversible, latent effects was first brought into the public spotlight by Theo Colborn and Pete Myers in the mid-1990s with their book Our Stolen Future. In it they highlighted the science that shows that many chemicals, which are still being used, can impair reproduction, behaviour, intellectual capacity and the ability to resist disease in current and future generations. The book also suggested that: “World-wide exposure to endocrine disruption has thrust everyone into a large-scale, unplanned, unintended experiment with health, the outcome of which may not be known for generations.” While at the time of its release Our Stolen Future was seen by many as alarmist, a 2013 joint report from the World Health Organisation and United Nations Environment Program on the ‘State-of-the-Science of Endocrine Disruptors’ confirms many of the book’s findings and suggests that exposure to industrial chemicals with endocrine-disrupting actions are contributing to the global increase in obesity, cancer, psychiatric diseases, birth deformities, ADHD and neuro-developmental problems in children, with current findings being “the tip of the iceberg”.


Biomagnification occurs up the food chain

Many toxic chemicals are fat soluble and last for decades in the environment where they undergo biomagnification (tissue concentrations increase) as they pass up the food chain. The toxicity of DDT and other persistent organic pollutants (POPs) (see ‘The rise of pesticides’ box on page 47) was first brought to the public’s attention in 1962 by Rachel Carson in her book Silent Spring. In May 2004, the Stockholm Convention on POPs came into effect, banning the use of nine of the most dangerous pesticides along with dioxins, furan and polychlorinated biphenyls (PCBs). These so-called legacy chemicals were all known to persist in the environment; undergo long-range environmental transport; be toxic to humans; and biomagnify up the food chain. Even though the use of most POP pesticides is banned in agriculture, these chemicals now permeate the global environment and lodge in the fatty tissue of animals where they biomagnify millions of times as they travel up the food chain. Being a precious biological resource, fat is seldom excreted, except for special situations such as breastfeeding where valuable fat (along with fat-soluble pollutants) is transferred to infants who sit at the very top of the food chain. POPs are also absorbed by micro-plastics in the oceans and are found in high concentrations in marine mammals, with some beached whales being classified as toxic waste.


Chemical cocktails are synergistic 

While exposure to individual toxic chemicals can be harmful, exposure to chemical mixtures is even more harmful. It has been shown that chemical cocktails can produce ‘something from nothing’ with toxic mixture effects arising even when the level of each contaminant in the mixture is below its specific ‘NOAEL’ (no observable adverse effect limit). Such mixture effects are not accounted for when determining chemical safety, which is assessed one chemical at a time, if at all. A 2009 ‘State of the Art Report on Mixture Toxicity’ commissioned by the European Union found that “there is consensus in the field of mixture toxicology that the customary chemical-by-chemical approach to risk assessment might be too simplistic. It is in danger of underestimating the risk of chemicals to human health and to the environment.” While mixture toxicity is currently not accounted for in chemical risk assessments, it is actively used in pesticide formulations to increase their potency. In order to kill pests, pesticides contain active ingredients with their own inherent toxicity, yet when pesticides are packaged and used, they are prepared as formulations. Pesticide formulations include the addition of often unnamed and unlabelled adjuvants that are designed to make the active ingredient more potent by acting as surfactants and cell penetrants. While these so-called ‘inert’ adjuvant chemicals are excluded from safety testing, recent research suggests they are far from inert and that they make formulations hundreds of times more toxic than the active ingredient alone (Mesnage 2014).


Bioaccumulation occurs over the lifespan

Over a human’s lifespan, exposure rates to fat-soluble chemicals often exceed the excretion rate leading to their accumulation in fatty tissue. Exposure begins in the womb with fat-soluble chemicals in umbilical cord blood crossing the placenta and lodging in foetal fat, which is mainly in the developing brain. A Canadian report has begun to document the extent to which children are born “pre-polluted” (Group 2005, WWF 2005, Canada 2013). Throughout a person’s lifespan, combinations of persistent chemicals accumulate in fatty tissue such as the brain, breast, prostate and bone marrow, which are often the tissues that develop cancers in later years. In addition to persistent fat-soluble chemicals, there are many other water-soluble endocrine-disrupting chemicals such as BPA and organophosphate (OP) pesticides that are ingested continually throughout a person’s lifespan, making them pseudo-persistent.


Windows of development are critical

The toxic effects of chemical exposure during critical periods, such as early childhood, can be irreversible. This became tragically evident in the 1970s with the birth of thousands of children without limbs and other birth defects after being exposed in utero to thalidomide. More recently, in-utero exposure to OP pesticides has been shown to impair children’s intellectual development in later life (see Ref 1).


Effects are trans-generational

Parental exposure to industrial chemicals can affect offspring and future generations. Many chemicals interfere with biochemical and endocrine pathways; induce genetic and developmental abnormalities; and produce trans-generational epigenetic effects that may lead to abnormalities in the third or fourth generation post-exposure. This can influence all aspects of an individual’s life history. This has recently been demonstrated experimentally with a single exposure to a commonly used fungicide being shown to alter the physiology, behaviour, metabolic activity and brain development in offspring three generations later, changing how they perceive and respond to a stress (see Ref 2).


Risk is unequal, unjust and greater for the young

The health risks of chemical exposures differ according to individual risk factors that include health status, physiology and genetics as well as demographic and social differences. Children are most vulnerable due to their higher dietary exposure, contact with the ground, hand-to-mouth behaviour, higher metabolic activity, immature organ systems, longer latency period for developing disease and sensitive development windows so that exposures lead to lifelong consequences (Landrigan 2005). The US-based Pesticide Action Network recently published a review of the scientific literature titled ‘Generation in Jeopardy: How pesticides are undermining our children’s health and intelligence’, which reports on the many studies that demonstrate that pesticide exposure compromises children’s cognitive function and leads to later chronic disease (Schafer 2013).


Exposure is unequal and unjust, and accidents happen

Everyone is exposed to industrial pollutants, yet exposure risk is not equal. Exposures vary with age, income, education, occupation, location, lifestyle, public policy and proximity to industrial activity and accidents. People living in poverty and lower socio-economic conditions often have the greatest exposure, which then compounds the effects of wealth inequality (Wright 2009). This makes environmental justice an important issue. Industrial accidents raise further justice issues as catastrophic accidents have inadvertently exposed vast populations of humans and wildlife to industrial pollutants. These accidents have occurred at every stage of the chemical-production cycle including mining (BP oil spill); transport (Exxon Valdez); manufacture (Bhopal); use (Fukushima and Chernobyl); and disposal (Love Canal). What’s more, often accidents are associated with minimal, delayed and inadequate compensation and remediation measures. Here are the detailed references for this article including ‘Ref 1’ and ‘Ref 2’ for Toxic Truths 7 & 8 respectively.


·         Ref 1: Bouchard, M., Chevrier, J., Harley, KG., Kogut, K., Vedar, M., Calderon, N., Trujillo, C., Johnson, C., Bradman, A., Barr, DB., Eskenazi, B. (2011). "Prenatal exposure to organophosphate pesticides and IQ in 7-year-old children." Environ Health Perspect 119(8).

·         Ref 2: Crews D, G. R., Scarpino SV, Manikkam M, Savenkova MI, Skinner MK. (2012). "Epigenetic transgenerational inheritance of altered stress responses." Proc Natl Acad Sci 109(23): 9143-9148 

·         Baillie-Hamilton (2002). "Chemical toxins: a hypothesis to explain the global obesity epidemic." J Altern Complement Med. 2002 Apr;8(2):185-92.

·         Bouchard, M., Chevrier, J., Harley, KG., Kogut, K., Vedar, M., Calderon, N., Trujillo, C., Johnson, C., Bradman, A., Barr, DB., Eskenazi, B. (2011). "Prenatal exposure to organophosphate pesticides and IQ in 7-year-old children." Environ Health Perspect 119(8).

·         Canada, E. D. (2013). Pre-polluted: A report on toxic substances in the umbilical cord blood of Canadian newborns. Toronto.

·         Carson, R. (1962). Silent Spring. New York, Houghton Mifflin.

·         Centers for Disease Control and Prevention (2009). Fourth National Report on Human Exposure to Environmental Chemicals, US Department of Health and Human Services Committee on Human Biomonitoring for Environmental Toxicants. (2006). Human Biomonitoring for Environmental Chemicals National Research Council

·         Crews D, G. R., Scarpino SV, Manikkam M, Savenkova MI, Skinner MK. (2012). "Epigenetic transgenerational inheritance of altered stress responses." Proc Natl Acad Sci 109(23): 9143-9148

·         Curl, C., Fenske, FA., Elgethun, K. (2003). "Organophosphorus Pesticide Exposure of Urban and Suburban Preschool Children with Organic and Conventional Diets." Environmental Health Perspectives 111(3): 377-382.

·         Grandjean, P., Landrigan, P.J. (2014). "Neurobehavioural effects of developmental toxicity." The Lancet 13(3): 330-338.

·         Group, E. W. (2005). Body Burden: The Pollution in Newborns. Washington, DC.

·         International Agency for Research On Cancer (2014). World Cancer Report 2014. B. W. Stewart, Wild, C.P.,. Geneva, World Health Organisation.

·         Krüger, M., Schledorn, P., Schrödl, W., Hoppe, H.W., Lutz, W., Shehata, A.A., (2014). "Detection of Glyphosate Residues in Animals and Humans." Journal of Environmental & Analytical Toxicology 4(2).

·         Landrigan, P., Garg, A. (2005). Children are not little adults. Children’s health and the environment: A global perspective - A resource manual for the health sector. J. Pronzczuk de Garbino. Geneva, World Health Organization.

·         Lu, C. and K. Toepel, Irish, R., Fenske, RA., Barr, DB., Bravo, R. (2006). "Organic diets significantly lower children’s dietary exposure to organophosphorus pesticides." Environ Health Perspect 114: 260–263.

·         Mesnage, R., Defarge, N., Spiroux de Vendômois, J., & Séralini, G.-E. (2014). "Major pesticides are more toxic to human cells than their declared active principles. ." BioMed Research International: 1-15.

·         Oates, L., Cohen, M., Braun, L., Schembri, A., Taskova, R., (2014). "Reduction in Urinary Organophosphate Pesticide Metabolites in Adults after a Week-Long Organic Diet." Environmental Research 132: 105-111

·         Schafer, K., Marquez, EC. et al. (2013). Generation in Jeopardy: How pesticides are undermining our children’s health and intelligence. Oakland CA, Pesticide Action Network.

·         Sexton, K., Needham, LL., Pirkle, JL. (2004). "Human Biomonitoring of Environmental Chemicals." American Scientist 92: 38-45.

·         van der Sluijs, J. P., Simon-Delso, N., Goulson, D., Maxim, L., Bonmatin, J.M., Belzunces, L.P. (2013). "Neonicotinoids, bee disorders and the sustainability of pollinator services." Current Opinion in Environmental Sustainability 5(3-4): 293–305.

·         Vogt, R., D. Bennett, D. Cassady, J. Frost, B. Ritz and I. Hertz-Picciotto (2012). "Cancer and non-cancer health effects from food contaminant exposures for children and adults in California: a risk assessment." Environmental Health 11(1): 83.

·         WHO/UNEP (2013). State of the science of endocrine disrupting chemicals - 2012: An assessment of the state of the science of endocrine disruptors prepared by a group of experts for the United Nations Environment Programme (UNEP) and WHO. Geneva, World health Organisation & United Nations Environment Program.

·         Wright, R. J. (2009). "Moving towards making social toxins mainstream in children's environmental health." Curr Opin Pediatr 21(2): 222-229.

·         WWF, G. (2005). A present for life: hazardous chemicals in umbilical cord blood. Amsterdam.

·         Zeng, G., Chen, M., Zeng, Z. (2013). "Risks of Neonicotinoid Pesticides." Science 340: 1403.

The 10 Toxic Truths - In short form

1) Everyone is affected

Toxic chemicals are pervasive and are distributed through long-range environmental transport so that all living things contain pollutants at or near harmful levels. Toxic chemicals are found in all human tissues and in food, soil, air, water and indoor environments.

2) The full extent is unknown 

Toxic chemicals are often invisible and have latent effects. Over 80,000 chemicals are produced commercially and industrial processes inadvertently create many more. Most chemicals are not tested for toxicity - and very few are routinely tested for in human tissue. 

3) Tiny doses can have big effects

Dose responses can be non-linear with extremely small doses of endocrine disrupting chemicals (EDCs) contributing to the global increase in obesity, birth deformities, cancers, psychiatric diseases and neurodevelopmental problems with current findings being “the tip of the iceberg”.

4) Bio-magnification occurs up the food chain

Persistent organic pollutants (POPs) last for decades in the environment, accumulate in fatty tissue and magnify up the food-chain. Bio-magnification leads to much higher concentrations in predatory species and human infants who sit at the top of the food-chain.

5) Windows of development are critical

The toxic effects of exposure during critical periods can be irreversible, yet remain hidden until later in life. Early exposure can impair intellectual development and metabolism and foster the development of metabolic syndrome, cancer and other chronic diseases.

6) Effects are trans-generational

Parental exposure to industrial chemicals affects offspring and future generations. Industrial chemicals can induce genetic and developmental abnormalities and transgenerational epigenetic effects that can lead to abnormalities in the third and fourth generation post-exposure.

7) Chemical cocktails are synergistic

Exposure to chemical mixtures is more harmful than individual chemicals. Mixture effects can produce ‘something from nothing’, with toxicity arising even when individual chemical concentrations have no effect, yet chemicals are tested for safety individually, if at all.

8) Bioaccumulation occurs over the lifespan

Exposure rates of fat-soluble chemicals often exceed the excretion rate leading to accumulation over the lifespan in fatty tissue such as the brain, breast, prostate and bone marrow. This accumulated body burden crosses the placenta and targets the fetal brain.

9) Risk is unequal, unjust and greater for the young

Risks vary with physiology, genetics, demographics and income. Children are most vulnerable due to higher dietary exposure, contact with the ground, hand-to-mouth behavior, higher metabolic activity, immature organ systems and a longer latency period for developing disease.

10) Exposure is unequal and unjust and accidents happen

Exposure is not equal and varies with age, income, education, occupation, location, lifestyle, public policy and proximity to industrial accidents. Accidents that inadvertently expose vast populations to toxic chemicals happen at every stage of the industrial chemical lifecycle.

Professor Cohen's Ten Toxic Truths article appeared in the March/April 2015 issue of Organic Gardener magazine. 

Monday, 9 April 2018

Do you buy "compost" from your city? You need to read this !

Andrew Drouin has been looking into this practice near where he lives in the Okanagan, but this is done ALL OVER North America, and people simply DO NOT KNOW what they are getting when they innocently buy what they believe is "compost" 

During a recent ride along the KVR, through the area between Sunglo Dr. and West Bench Hill Rd., I was struck by an incredibly strong stench in the air. I tried to discern the particular aroma, wondering “manure?”, “sewage treatment plant?”... when it hit me; a local home-owner had accepted and widely spread the free material that the City of Penticton / RDOS mislabels as “compost” and supplies cheap-to-free at the landfill.
The product that the aforementioned parties refer to as “compost” is actually not compost in the classic sense at all. Rather, it’s a mildly toxic blend of lime, sand, chipped wood and the tens of thousands of products that our society purchases, then pees, poos, dumps, pours, flushes or otherwise disposes of down the drain.
These dried solids, originating from the Penticton Wastewater Treatment Plant, are then labeled “compost” and made available to the public and commercial landscaping operations in the region.
Now, before someone from the RDOS / City of Penticton staff rushes off a counter-letter to the paper, scorning and hoping to ‘correct’ me on this missive; please don’t.
I ask that instead, you please take some time on your own, as a citizen, not as a public employee - to learn what this “faux-compost” product is comprised of.
A great place to start is with the modern wonder-tool: Google. The first phrase that you want to search for is “What are Contaminants of Emerging Concern?” (CEC’s), so that you understand the (current) science on the subject. Scan through the results of your search and read any government or university peer-reviewed study that catches your interest.
Note that there is a distinct difference between what government’s media-communications homepages present vs. what their published peer-reviewed science presents…
What you will find from countless sources is what UNESCO defines as: "Contaminants of Emerging Concern, include alkylphenols, flame retardants, hormones, personal care products, pharmaceuticals, micro-fibers from plastics, steroids, lubricants and pesticides”. In total, the Canadian marketplace hosts some seventy thousand different chemicals - a large portion of which end up down one drain or another.
How is this possible? Can these statements possibly be accurate? Over and above the proverbial trainloads of peer-reviewed scientific publications available online, an interesting and easily accomplished thought-experiment goes like this: close your eyes and imagine walking through your local big-box grocery, hardware or general merchandise retail outlet.
See all of those liquid cleaning products, personal care products - including makeup, shampoos, cream-rinses, deodorants, perfumes, powdered cleansers etc.? They all end up down the drain or adsorbed to material and added to our (unlined) landfill post-use.

Now, mentally wander down the aisles of any of the dozen or so pharmacies in the city, keeping the volumes flushed by hospital and long-term care facilities in mind. Those walls of retail pharmaceuticals are re-stocked daily, and all of it ends up down the drain, as the human body only metabolizes a small percent of the active ingredient in pharmaceuticals. In the case of antibiotics, it can be as low as ten percent.
Google the phrase “Drugs can pass through human body almost intact: New concerns for antibiotic resistance, pollution identified” for the full article by Amy Pruden, National Science Foundation recipient and assistant professor of civil and environmental engineering at Virginia Tech.
The balance of all of these Contaminants of Emerging Concern end up down the drain, through the wastewater treatment plant, and into the industrial product that local and regional governments refer to as “compost” or “biosolids”.
Outside of small-scale laboratory experiments, with very limited numbers of CEC’s, mankind does not possess a technology that will clear CEC’s from the human waste stream. That’s because those aforementioned “thousands of chemicals” are comingled, and modern science simply doesn’t possess a tool or technology that will both separate and ameliorate them.
Try this: mix any three of four (non-toxic) liquid products in your home in a jar and shake the container. Now consider; how would you separate them? That, my fellow citizens, is the conundrum of our societies’ wastewater treatment plants, but on a much larger scale, and involving tens of thousands of chemicals…

If you were to schedule a visit to the Penticton Advanced Wastewater Treatment Plant and inquire about the workings of our excellent facility, you will learn that that there are no specific mechanisms built into the plant to deal with CEC’s.
In fact, no waste water treatment plant in North America is currently able to remove most CEC’s from wastewater treatment plant outfall - be it liquid or solid. And this is a critical problem for our society and our environment going forward.
Our wastewater treatment plants are great at reducing nasty bits such as bacteria, protozoa, viruses and a few heavy-metals, but ineffective at dealing with Contaminants of Emerging Concern - because they were never designed to address this issue.
In most cases, “the solution”, is to separate the liquid and solid components of the wastewater treatment plant stream, filter out the large bits, dry the remaining solids, mix them with various fillers, such as the sand, lime and chipped wood - and give or sell this product to the public.
The (CEC-bearing) liquid is pumped into the river channel and sprayed on parks and school-grounds as “reclaimed water”...

The problem with this tactic is that the solid product - mislabeled as “compost”, still contains traces of tens of thousands of Contaminants of Emerging Concern. All the drying and distributing process really solves are the municipal storage issues (chiefly, volume) associated with wastewater treatment plant dried outfall.
How is this absurdity possible? Several factors are at play. The first is that our society has an addiction to drugs and ‘wonder-chemicals’. If we didn’t, there simply wouldn’t be tens of thousands of pharmaceuticals and chemicals on the market.
The second factor is that North American governments are operating on fudged data. If you’d like to read up on the fiasco that is the 25-year old “EPA Part 503 Biosolids Rule” (which all North American governments base their handling of wastewater treatment plant outfall on) then I recommend Googling the phrase “Dr. David Lewis was a senior-level research microbiologist for the US Environment Protection Agency's Office of Research & Development during the 1990s” for an interesting story of whistleblowers and fudged EPA science.
In a nutshell - properly dealing with Contaminants of Emerging Concern is expensive, and very few government bodies wish to implement of a true solution to the dried solids issue: a mature technology known as Gasification. I’ve spoken with multiple levels of government, on several occasions, and the universal response to Gasification is that “the return on investment is not there”.
In reply, I suggest that government factors in the medical implications of distributing tens of thousands of comingled Contaminants of Emerging Concern into the environment, and tell us, their employers, if the Return on Investment is valid.
In the meantime, we are in a bizarre situation where the media-mouths of the EPA and Environment Canada (and thus, all local governments) state that “Contaminants of Emerging Concern are not a problem, but that the topic merits further research” - while simultaneously, much of the actual, peer-reviewed science that they are producing (and we pay for) unequivocally states that CEC’s are indeed a concern - as a countless number of their own published papers will attest.
In closing; please do some research on this topic on your own and form your own opinions. In the meantime, I personally urge you to not accept any of the RDOS / City of Penticton “compost” for gardening or landscaping use. A quick ‘Google’ of the phrase “Plant Uptake of Contaminants of Emerging Concern” and “bioaccumulation of Contaminants of Emerging Concern in Soil” will demonstrate why applying city “compost” to your property is, in my studied opinion, a sketchy option.

“Friends don’t let friends use industrial compost”

- Household Chemicals and Drugs Found in Biosolids from Wastewater Treatment Plants -
- A Sample of 8676 articles published on this topic (!):

Saturday, 24 March 2018


Here is an in-depth study done on the weaknesses inherent in the EPA's assurances of safety. Please note that the Canadian standards are modeled on the US standards, and the critical assessment made here is equally valid in Canada, and indeed anywhere that sewage waste is disposed of on land. 



Sewage sludge is a complex mixture of inorganic and organic materials and pathogens generated by the treatment of domestic sewage. Section 40 of the Code of Federal Regulations Part 503 regulates the land application of sewage sludge based on pathogen content and sets standards for nine inorganic chemicals. It is believed that the Part 503 standards are protective of human health and the environment and that sewage sludge applied to land poses little risk. A critical inspection of the pertinent literature, however, reveals that the standards were based on outdated methods, outdated data, inaccurate data, and flawed assumptions, leading to underestimation of risk. The standards are not sufficiently protective, and even if changes were made, sewage sludge is so complex that it is very unlikely it could be monitored to ensure the protection of human health and the environment. For these reasons, the practice of land application of sewage sludge must be discontinued.

Sewage sludge is defined by the U.S. Environmental Protection Agency (EPA) as the “solid, semi-solid, or liquid residue generated during the treatment of domestic sewage in a treatment works” [1]. Sewage from homes, industries, medical facilities, agriculture, street runoff, and businesses is collected at wastewater treatment facilities where it undergoes treatment processes to remove contaminants. Sewage sludge is the byproduct generated by the processes that remove contaminants from the wastewater so that the treated wastewater can be discharged back into waterways. Sludge is generated mainly during primary treatment, where solids settle out, and also during secondary treatment, where microorganisms are added to degrade the biological content of the sewage and the solids settle out. Further treatment can also generate sludge [1]. Many of the contaminants that were in the wastewater concentrate in the sludge, resulting in a mixture with an unknown composition of inorganic and organic materials and human pathogens [1]. Sludge itself can be treated by a variety of processes including aerobic digestion, anaerobic digestion, composting, heat drying, air drying, lime stabilization, and chemical fixation. Sewage sludge that has undergone treatment and meets federal and state standards for land application is called biosolids by EPA. Treated sludge can be applied to land—such as agricultural land, forests, parks and gardens, and home gardens and lawns. Sludge that is untreated or not treated enough to meet land application standards can be disposed of in landfills or incinerated [1-3].

The EPA and other agencies have widely promoted the use of sewage sludge for land application as a safe, beneficial, and economical way to recycle the massive amounts of sludge generated. They claim it is a fertilizer that contains beneficial plant nutrients and has other soil-conditioning properties [2, 3]. Approximately 5.6 million tons of dry sewage sludge are used or disposed of annually in the United States, of which 60 percent is used for land application or public distribution [1]. There are federal standards governing the use and disposal of all sewage sludge in Section 40 of the Code of Federal Regulations Part 503. The land application of sewage sludge has been a hotly debated topic since its inception. The EPA maintains that the standards for land application of sewage sludge are protective of human health and the environment [3]. Numerous reviews of the risk assessment used to establish the standards, however, have found serious flaws with the way EPA conducted the risk assessment. These reports critically assessed the methods used in the risk assessment, the data used, and current scientific data on sewage sludge to determine if the standards were adequate. The review presented here examined these papers and other current literature to determine if there was significant evidence to support the concern over the land application of sewage sludge and found that the literature clearly demonstrates that the current policies and regulations do not adequately protect human health and the environment. Based on the available data, the application of sewage sludge to land must be stopped because the current standards are based on inaccurate and outdated science. If the practice of land application is not stopped, the consequences to humans and the environment twill be severe and long-lasting.


Human excreta have been applied as fertilizer for hundreds of years, and this practice was generally safe because the excreta did not contain industrial waste. As populations grew, the old methods used to remove waste became inadequate and resulted in numerous disease outbreaks. Sewers were invented to deal with the problem by removing the wastewater from the city and town centers. Domestic and industrial sewage was dumped into waterways until they became so polluted that a new method was needed to deal with waste. Wastewater treatment became the new technique to deal with the problem and with wastewater treatment came sewage sludge. The passage of the Clean Water Act in 1972 more than doubled the amount of sludge generated as the treatment processes that create it became mandatory and all water had to be treated. The use of sludge for land application became widespread with the 1988 Ocean Dumping Ban, which eliminated dumping of sludge in the ocean and forced EPA to invest in land application. In 1990 the term “biosolids” was coined for sewage sludge that was treated and acceptable for land application in order to increase its appeal. Biosolids were classified as a fertilizer, and EPA pushed this use [4, 5]. In 1993 the Part 503 standards established pollution limits, operational standards, and management practices to “protect public health and the environment from any reasonably anticipated adverse effects from chemical pollutants and pathogenic organisms” in sewage sludge [1].

Minimum standards regarding ceiling concentration (mg/kg), pollutant concentration (mg/kg), cumulative pollutant loading rate limits (kg/ha), and annual pollutant loading rate (kg/ha/yr) for contaminants in sludge were established that had to be met for the sludge to be approved for land application. Originally 10 inorganic chemicals were regulated: arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc. Chromium was dropped in 1995 and molybdenum has only a ceiling concentration [1]. Since sewage sludge can contain bacteria, viruses, protozoa, parasites, and other microorganisms, Part 503 mandates that sewage sludge undergo specific treatment processes to reduce pathogens before it can be applied to land. Based on the treatment processes and the amount of pathogens still present, treated sludge can be classified as Class A or B biosolids. Class A biosolids are treated to reduce pathogens to below detectable levels and can be used without any application restrictions. Class B biosolids are also treated to reduce pathogens, but pathogens remain at measurable levels, so there are restrictions regarding the application of Class B biosolids and the use of the land receiving the biosolids to minimize human contact until natural processes can further reduce pathogen content [3]. Using available data on chemicals and data from the 1988 National Sewage Sludge Survey (NSSS), EPA conducted an extensive risk assessment to establish the Part 503 standards. To support the safety of land application of sludge, proponents often quote a 1996 National Research Council (NRC) report that reviewed the use of wastewater and biosolids for agricultural purposes: the use of biosolids “presents negligible risks to the consumer, to crop production, and to the environment . . . existing regulation and guidelinesgoverning the use of reclaimed wastewater and sludge in crop production are adequate to protect human health and the environment” [1].

What proponents fail to mention is that the report also highlighted limitations and inconsistencies in the risk assessment approach and NSSS data used by EPA and made recommendations for further research [1, 6]. In fact, EPA did not follow through on any of the recommendations and made no changes to the standards. A 2002 National Research Council (NRC) report re-evaluated the standards and again focused on the inconsistencies and problems identified earlier, as well as on EPA’s failure to make any adjustments [1]. The 2002 report found “no substantial reassessment has been done to determine whether the chemical or pathogen standards promulgated in 1993 are supported by current scientific data and risk-assessment methods” [1]. It is because of the inconsistencies, flawed methods, and outdated data used to create the Part 503 standards documented in the NRC reports and other reviews that strongly support the end to the land application of sewage sludge. There are fundamental errors in the science on which the standards are based because of inaccurate and outdated data, outdated methods, and questionable assumptions. Part 503 cannot be counted on to be truly protective of human health and the environment.

Inaccurate Data

A major problem with Part 503 is the way in which EPA determined which chemicals to regulate. Two rounds of hazard assessment and chemical selection were conducted. Round 1 identified an initial set of pollutants using hazard screening and risk assessment. Using information from studies from 1984, 200 potential chemicals of concern were initially identified, of which 50 were chosen for evaluation. These were further screened by data on toxicity, occurrence, fate, and pathway-specific hazards, and 22 chemicals were selected for potential regulation. Based on available data, a hazard index was calculated for each chemical via each of the 14 exposure pathways decided on by EPA to determine if a full risk assessment was needed for the chemical via the most limiting exposure pathway. Background exposure was eliminated from the assessment, and if the hazard index was greater than 1.0, a full risk assessment was done for the specific pathway [1]. Not including background levels is questionable because there are chemicals, like metals, for which background exposure in soil is high due to geologic properties of the area, so an additional source of exposure to the chemical could potentially elevate one’s risk. Including all relevant sources of exposure would have been a better way to generate the hazard index to ensure all possible sources of exposure were assessed and included [1]. In 1988, the NSSS was conducted; it collected information on 400 pollutants from 180 sewage plants throughout the country. The EPA used this information to further screen out chemicals not at concentrations deemed to pose a risk. Chemicals were eliminated if they were banned from use, had restricted use, were no longer manufactured in the United States, had a detection frequency of less than 5 percent in the NSSS, and/or the concentrations reported in the NSSS were so low that the estimated annual amount applied to cropland would fall below the standard annual pollution loading rate [1]. For example, even if the chemical was detected in more than 5 percent of the samples, it was not considered for further evaluation if it was no longer being manufactured. The result of this first round of selection was regulation of 10 inorganic contaminants, and because of the criteria, all organic chemicals under consideration for regulation were eliminated. These criteria do not adequately address the adverse health effects of organic chemicals. Ignoring them does not make them or their toxic effects go away. As an example of the impact of these criteria, the selection process eliminated polychlorinated biphenyls (PCBs) because they were no longer used or manufactured, even though they were detected in more than 5 percent of samples and the concentrations would have resulted in an annual pollutant loading rate over allowable risk-based levels [1]. PCBs have not been manufactured in the United States since the 1970s but they continue to contaminate the environment and are found in sludge. Slow to degrade, they are persistent organic pollutants found all over the world and are classified as “probably carcinogenic.” PCBs can bioaccumulate in animal fat, making ingestion of animal meat and milk of animals that grazed on sludgecovered land a significant concern [7]. Thus, PCB contamination is still a problem even though they have not been manufactured in almost 30 years. It is a matter of great concern that out of 200 chemicals fromone study and 400 found in the NSSS, only 10 were deemed problematic, and all were metals. This is a very limited number of contaminants, and the fact that no organic chemicals were chosen raises serious questions about the validity of the methods EPA used. A second round of evaluations was done using the 411 pollutants analyzed in the NSSS. This time chemicals were eliminated if they were not detected (254) or were detected in less than 10 percent of samples (69). Chemicals for which there was insufficient data to adequately complete the risk assessment (15) were also dropped from consideration. Of the 31 chemicals left, only dioxins, furans, and coplanar PCBs were evaluated in a risk assessment [1].

In 2003, EPA decided not to regulate these chemicals, believing they posed little risk. Yet dioxins are highly toxic and known to cause cancer and neurologic and immunologic problems. Since approximately 90 percent of dioxins in wastewater are likely to end up in sludge—and according to David Carpenter, director of the Institute for Health and the Environment at the State University of New York at Albany, “sewage sludge is the second greatest source” of exposure to dioxins for the general U.S. population—it is unclear how EPA arrived at this decision[7,8]. The criteria that were used to eliminate chemicals in the second round of evaluations potentially missed many chemicals of concern. The 2002 NRC report found “no adequate justification for EPA’s decision to eliminate from regulation all chemicals detected at less than 5% frequency in the NSSS” [1]. The NSSS reported data on a national level, which may not be representative of sludge in different locations. The contents of sludge are likely to be site-specific, reflecting the homes and industries in the area that are discharging to local wastewater plants. Thus, for a particular type of industry that releases large amounts of certain chemicals, nationwide concentrations and frequencies appear low, but high concentrations in sludge from a specific site would be of a concern for the people receiving the sewage sludge from that treatment plant. Thus eliminating a chemical because it was detected at a low frequency in a national survey could be putting an area that does have high concentrations at risk [7].

Furthermore, eliminating a chemical because there is not enough data to do a risk assessment is irresponsible and not good science. Lack of data is a serious limitation, but “ignorance is not a solution to uncertainty” [7]. The EPA disregarded the chemicals on which there was not a lot of information as though this indicated there was not a problem with these chemicals. Lack of data is not equal to lack of risk. It means there are data gaps that need to be addressed by additional research. There might not have been enough information at the time, but these chemicals should not have been disregarded completely. The EPA also relied on concentration data in the NSSS in the selection of chemicals to potentially regulate. The accuracy and reliability of the NSSS data have been called into question by two NRC reports [1]. Accurate concentration data is essential in assessing whether a chemical poses a risk. Errors in measurements can lead to over- or underestimation of concentrations, which in turn affect the risk estimates. The methods used by the NSSS were flawed and led to chemicals of concern being eliminated erroneously. Analytical problems and high detection limits prevented accurate measurements of chemicals. Some of the detection limits exceeded several hundred parts per million [1]. Many chemicals in the NSSS had levels of detection that were greater than EPA soil screening levels (SSLs) [1]. SSLs are soil concentrations used to determine if a risk assessment is required at a Superfund site, and they are risk-based conservative assumptions.

The 2002 NRC report re-assessed eight organic chemicals and found that five of them had limits of detection higher than their respective SSLs [1, 9]. Thus the NSSS results were “not sensitive enough to detect pollutant concentrations that, if present in soil at a Superfund site, would have triggered a risk assessment” [9]. Hexachlorobenzene, a persistent organic pollutant considered a probable human carcinogen, is an example of a chemical that was eliminated because it was not detected in any of the samples. However, the limits of detection ranged from 5 to 100 mg/kg, while the SSL is 0.1 to 2 mg/kg, depending on the route of exposure [9]. Analysis of recent data on chemicals in sludge showed that the majority of reported hexachlorobenzene levels exceeded the lowest SSL [9]. Thus, the NSSS failed to achieve low enough detection levels to adequately determine if the concentrations present required further action. The NSSS concentrations were used to calculate the hazard indexes to determine if a full risk assessment for a specific chemical via the most limiting exposure pathway should be done. Even if the hazard index for a chemical was greater than 1, if the chemical was detected infrequently, it was eliminated [1]. Given that the detection limits were so high, it is unclear how many of these chemicals were incorrectly identified as having low frequencies and/or concentrations. If more sensitive detection limits had been used, many more chemicals of concern would have been selected to be evaluated further and possibly regulated.

The NSSS data lack credibility, given that the limits of detection were so high that chemicals were missed but would have warranted assessment under different conditions. Every analytical method has a limit of detection, but the goal is to have consistent and low detection limits. One wants to be able to detect the lowest concentration present with the greatest accuracy possible. The fact that NSSS had unreliable data undermines all the standards in Part 503 [1, 7, 9]. How can these standards adequately protect human health and the environment given that chemicals were erroneously eliminated and never assessed because of poor science?

Outdated Exposure Assessment Methods and Flawed Assumptions

After choosing the chemicals to be included in the risk assessment, human exposure to sewage sludge by various exposure routes was assessed to calculate risks. For 14 exposure pathways, the risk associated with each pathway for each contaminant was assessed separately; risks from multiple pathways or from exposure to multiple chemicals were not examined. Current practice is to perform a risk assessment after aggregating all the pathways to which a single individual is likely to be exposed to in order to have the most complete exposure assessment. Part 503 assessed exposure assuming one would be exposed via only one pathway, which is not realistic. This method severely underestimates risks because it is highly unlikely one will be exposed to a chemical in the soil via only one route. It is much more likely that a child playing in the soil will have incidental ingestion of the soil, ingestion of plants that grew in the soil, ingestion of animals that grazed on grass that grew in the soil, and dermal contact with the soil, all contributing to the child’s exposure to the chemicals. Exposure to a single pathway might not pose a significant risk but once all the pathways are combined, there could be a very different outcome [1, 7].

The EPA also used limited exposure pathways, assessing inhalation only for sludge applicators, not residents. The EPA also assessed only chronic exposure, but there is a risk of short-term exposure to volatile compounds. Volatile organic compounds were eliminated because EPA believed release occurred during the wastewater processing that produced the sludge. However, when sludge is applied, it can release volatile organic compounds (VOCs) such as sulfur- or nitrogen-containing compounds, acids, aldehydes, and ketones [1, 7]. There was also inadequate assessment of pathogen risk. Movement of pathogens to groundwater was not addressed completely, nor was exposure to pathogens in dust and
aerosols after land application of sludge. Exposure to radioactive chemicals was not addressed at all [7]. In generating risk calculations, EPA had to make many assumptions. A number of “untenable assumptions” were made and probably led to underestimation of risk [7]. A very limited risk assessment for groundwater contamination was conducted in Part 503, and contamination of waterways was not adequately assessed.

The EPA assumed metals cannot leach into groundwater, but recent data has shown that metals exhibit facilitated transport, by which they attach to organic chemicals and travel to groundwater; metals can also move through flow paths created by worm holes or root channels [7, 10]. Also, the rate of contaminant movement in soil that was calculated was much slower than what actually occurs. The rate was not based on actual field data but on data from a single paper based on test tube motility tests from a single soil type [10]. Contamination of surface and groundwater is an area of great concern. Runoff or leachates from land that received biosolids is a significant source of exposure, and it is likely that important water resources could become contaminated, exposing people to the chemicals in drinking water that originated in sludge [10]. Not considering this exposure severely underestimates risk. When determining cancer risk resulting from sludge application, EPA decided to use the less restrictive value of 1 in 10,000 as an acceptable level of cancer risk compared to what is used in most other regulations to determine cancer risk and influence regulations, including the drinking water standards, of between 1 in 10,000 and 1 in 1,000,000 [7]. When questioned on why this value was used, the EPA acknowledged it was a less restrictive number and was chosen as a policy decision because the agency considered the overall risk from sewage sludge was “especially low” and the more restrictive value would have an economic impact, and it was “difficult to justify such an expense for little or no actual difference in risk” [11].

For soil ingestion, only ingestion as a child was calculated even though incidental ingestion can occur throughout adulthood, especially for home gardeners [1]. Dietary intake of sewage sludge is a critical pathway, and EPA based its recommendations on dietary intakes from the late 1970s. American diets are very different now with regard to vegetable and fruit consumption, meat intake, and water consumption. Comparing the dietary assumptions EPA used with the current food pyramid guidelines shows that the current dietary recommendations specify 16 times the amount of fruits and vegetables that was assumed in developing the Part 503 standards. This is significant: for example, for cadmium, changing only the dietary assumptions, the standard drops from 39 ppm to 15 ppm [1, 7]. The EPA also assumed that the degradation products of organic chemicals were less toxic than the original chemical, but this is not always the case. Surfactants are a group of chemicals found in sludge, and the degradation products of the surfactant alkyl phenol ethoxylate are significantly more toxic than the original compound. The anaerobic digestion process at treatment plants actually promotes this transformation, resulting in a much more toxic compound in the sludge [10]. Uptake by plants and animals is critical to assessing exposure to and risk from sewage sludge, and EPA used very low plant uptake coefficients and low ingestion rates for grazing animals. Many of the soil uptake coefficients are based on plants grown in greenhouses, but these conditions have been shown not to reflect how metals behave in biosolids [1, 7].

The EPA assumed its uptake coefficients would be applicable to all plants under all soil conditions, but uptake differs greatly across plants and soil conditions, so the numbers used were not highly protective [7]. The EPA also assumed that metals would be bound to the sludge, limiting the uptake by plants, but they did not assess if this was reversible due to soil changes or if continual application of sludge changed these parameters [1]. When doing a standard risk assessment, one accounts for the assumptions made and the uncertainties still present by incorporating safety or uncertainty factors. This was not done by EPA for the Part 503 standards [7]. Taken together, the incomplete exposure assessments and flawed assumptions probably lead to an underestimation of exposure to sewage sludge, indicating that the standards are not adequately protective.


There are also problems with the chemicals for which there are standards. Arsenic is regulated in Part 503 as a noncarcinogen. However, arsenic is an established cause of skin cancer via ingestion of drinking water, and there is evidence that it also causes lung and urinary bladder cancer. There are no data to suggest that arsenic ingested in soil behaves differently from arsenic ingested in drinking water [1]. With cadmium, ingestion is a significant route of exposure. The EPA looked at ingestion of soil only for a child even though the reference dose is based on ingestion over a lifetime. Exposure as a child and as an adult should have been assessed. Furthermore, cadmium is well taken up by plants so exposure via multiple pathways of ingestion should have been analyzed to better assess risk. Recent studies also suggest that cadmium is an endocrine disruptor, an endpoint not assessed in Part 503 [1, 10]. The mercury assumed to be in the sludge was considered to be similar in toxicity to the inorganic form mercuric chloride. However, mercury can appear in many forms and the speciation is critical to its fate and transport. The organic form methylmercury has been found in sludge. This is of great concern because it can bioaccumulate in fish. Inhalation exposure to nickel is the most toxic pathway, but this was not thoroughly assessed. Molybdenum has no standard, just a ceiling concentration, but it is well known that molybdenum is toxic to ruminant animals, which are exposed by ingesting legumes, grasses, soybeans, and other crops [1, 10].


Another significant problem with Part 503 repeatedly discussed in the literature is that thousands of new chemicals have been produced, used, and released since 1990, and there are new pathogens of concern that have not been considered since the initial standards went into place. The Toxics Release Inventory tracks releases of over 600 toxic chemicals, of which only nine are currently being regulated in sludge; thus very few of these 600 chemicals have been assessed. Brominated flame retardants, antibacterials, pharmaceuticals, fragrance chemicals, surfactants, personal care products, and organotins are just a few of the new chemicals of growing concern. Kinney et al. (2006) analyzed organic wastewater contaminants in nine different sewage sludge products [12]. The most commonly detected chemicals were pharmaceuticals, detergent metabolites, steroids, fragrances, polycyclic aromatic hydrocarbons (PAHs), fire retardants, plasticizers, and disinfectants. Nonylphenol and octylphenol detergent metabolites, known or suspected endocrine disruptors, were detected in greater concentrations than most of the other chemicals measured. Polar compounds were also found at concentrations higher than previously thought possible. Harrison et al. (2006) examined peer-reviewed literature and official government reports to assess the presence and concentrations of organic chemicals in sewage sludge [9]. Data were found for 516 chemicals. There were SSLs for 15 percent of the chemicals, and for 86 percent of these, the reported maximum concentration exceeded the SSL. In 2006–2007, EPA conducted a new analysis of 145 chemicals in sewage sludge, including anions, metals, polycyclic aromatic hydrocarbons, semi-volatiles, flame retardants, pharmaceuticals, and steroids/ hormones [13]. Twenty-seven metals were found in virtually every sample; four VOCs were in 72 samples; three pharmaceuticals were in all samples, and nine were in at least 80 samples; three steroids were in all samples, and six were in at least 80 samples; and all flame retardants except one were in every sample. The EPA states that it plans to evaluate the pollutants identified in the survey, first focusing on the nine they had previously determined to be of concern, but if EPA conducts the risk assessment in the same manner as was done for Part 503, the results will again have little credibility.


Occupational exposure to Class B biosolids is considered a concern by the U.S. Centers for Disease Controland Prevention (CDC) and the NationalInstitute for Occupational Safety and Health (NIOSH) due to the pathogens still present in biosolids. Health effects after occupational exposure have been reported in numerous studies [1, 14]. There is little data regarding health effects in the general population exposed to sewage sludge. Two recent studies assessing healtheffectsfromexposuretoaerosolsaftersewagesludgeapplicationtonearby lands suggest increased risk for certain respiratory, gastrointestinal, and other diseases as well as irritation of the eyes, throat, and lungs and prevalence of Staphylococcus aureus infections [10]. The highly publicized case of Andy McElmurray and his dairy farm ruined by the application of sewage sludge further highlights the fact that there are health concerns associated with the application of sewage sludge. One of the chemicals found in Andy McElmurray’s sludge was thallium, a metal not regulated under Part 503 [15]. The bacterium Listeria monocytogenes has been detected frequently in treated sewage sludge, and crop contamination has been observed when sludge containing this pathogen has been applied [1]. Even these few cases raise significant doubt regarding how protective the standards in Part 503 really are.


The recent studies on the composition of chemicals in biosolids show the fundamental problem with sewage sludge: it is a complex, always-changing mixture. Even if major changes were made to the standards, there are too many unknowns regarding the amounts, behaviors, and toxicity of thousands of chemicals that are found in sewage sludge to regularly ensure the protection of human health. Sewage sludge is too complex to properly monitor and regulate. In a 2006 study examining reported organic compounds in sludge, of the 516 organic chemicals that had available data, 83 percent of the chemicals were not on the priority pollutant list and 80 percent were not on the target compound list of chemicals that must be detected and quantified in analyses of soil from Superfund sites, leading the authors to conclude that even if monitoring were expanded to include chemicals on these lists, it “will not capture the vast majority of chemicals that may be present” [9]. It is significant that this study found data on only 516 chemicals even though thousands are in use. There are too many variables and too many unknowns to properly regulate the land application of sewage sludge in a way that adequately protects human health and the environment.

The EPA assumes “that models approximating the reality of a ranch in west Texas are also appropriate for a vegetable farm in New York” [7]. This could not be further from the truth. The components of the wastewater, type of treatment process, application rates, climate, and soil characteristics vary greatly from location to location, and these are just a few of the numerous factors that impact the fate, transport, bioavailability, and toxicity of the chemicals in sewage sludge. People are not exposed to just one chemical. It is difficult enough to assess risk for one chemical, and adding multiple chemicals makes the assessment infinitely more difficult. Evaluating risk posed by individual chemicals requires multiple assumptions; adding in mixtures means more assumptions have to be made and this can lead to unacceptably high levels of uncertainty [1, 5, 7]. The 2002 NRC report concluded that it was “not possible to conduct a risk assessment for biosolids at this time (or perhaps ever) that will lead to risk
management strategies that will provide adequate health protection without some form of ongoing monitoring and surveillance,” because sewage sludge is a complex mixture that can change unexpectedly over time and place [1].

It is impractical and financially impossible to continually monitor sewage sludge for every type of chemical that could be in it. For many of the chemicals, much is unknown: how they interact with other chemicals, the form that is found in sludge, how bioavailable they are, and how toxic. How can sewage sludge be properly regulated if there is not complete information on all the chemicals present in it and the variables that govern their fate in the environment? Ignoring the unknowns is not the answer. Inadequate enforcement of rules and practice adds to the problem. The EPA itself says the Part 503 regulations are “self-implementing” [7]. Periodic reporting is required, but no permits are needed for land application and no recordkeeping regarding application rates is required. After application of Class B biosolids, there are waiting periods from 30 days to one year. However, the rules for enforcement are vague, and there is no testing required after the time limit to ensure that natural processes have reduced the pathogens to safe levels [7]. A recent example exhibits the consequences of inadequate enforcement. In a county in Alabama, the blood of 200 residents is being tested for the presence of perfluorinated chemicals in drinking water. The chemicals were released from nearby industries and concentrated in sewage sludge, which was distributed as free fertilizer for 12 years.

The EPA knew the chemicals were in the sludge but did not know the sludge was being applied to agricultural land until finding out by accident in 2008 [16]. The federal Clean Water Act defines sewage sludge as a pollutant, and it needs to be treated as one. It is not a fertilizer with soil-conditioning properties. Sludge is a complex mixture that contains organic, inorganic, and biological pollutants from wastewater coming from a variety of sources [5, 6]. Basically, anything flushed down the drain or toilet can make its way into sludge. The point of a wastewater treatment plant is to make the effluent as clean as possible. In doing so, the sludge becomes more toxic as it concentrates the pollutants that were in the liquid sewage [5]. Although EPA believes the standards in Part 503 are keeping the public safe, the “data gaps and non-protective policy choices result in regulations that are not adequately protective of human health and the environment” [7]. There are other methods to manage sludge that are more environmentally friendly and safer that need to be investigated [6]. Until the Part 503 standards are reevaluated using more current and reliable data and methods, the practice of land application must be discontinued because that is the only way to protect human health and the environment. The data strongly support that applying sewage sludge to land is not safe, and if things continue as they are, the long-term consequences to human health and the environment have yet to be felt.


1. National Research Council, Biosolids Applied to Land: Advancing Standards and Practices (Washington DC: The National Academies Press, 2002), http://www.nap. edu/openbook.php?record_id=1042&page=R1. 2. New York State, Department of Environmental Conservation, The Basics of Biosolids, 1999, (accessed December 14 , 2009). 3. U.S. Environmental Protection Agency, Office of Water, Biosolids Technology Fact Sheet: Land Application of Biosolids (EPA 832-F-00-064), 2000, owm/mtb/land_application.pdf (accessed December 14, 2009). 4. Sludge News, “Sludge News,” (accessed December 14, 2009). 5. Sierra Club, Zero Waste: Land Application of Sewage Sludge, February 2008,…/conservation/LandApplicationSew… (accessed December 14, 2009). 6. Caroline Snyder, “Testimony of Caroline Snyder, Ph.D.,” Citizens for Sludge-Free Land, testimony before the U.S. Senate Environment and Public Works Committee, September 11, 2008, (accessed December 14, 2009). 7. E. Z. Harrison, M. B. McBride, and D. R. Bouldin, “Land Application of Sewage Sludges: An Appraisal of the U.S. Regulations,” International Journal of Environment and Pollution 11(1) (1999): 1-36. 8. The Washington Post Company, “Farm Dioxins Won’t be Monitored, Fertilizer Posed Little Risk in Studies, EPA Says,” October 23, 2003, news_item.asp?new_id=1607 (accessed December 14, 2009). 9. E. Z. Harrison et al., “Organic chemicals in sewage sludge,” Science of the Total Environment 367 (2006): 481-497. 10. Ellen Z. Harrison and Murray McBride, Case for Caution Revisited: Health and Environmental Impacts of Application of Sewage Sludges to Agricultural Land, March 2009, (accessed December 14, 2009). 11. U.S. Environmental Protection Agency, Office of Wastewater Management, “Questions and Answers on the Part 503 Risk Assessment,” Chapter 6 in A Guide to the Biosolids Risk Assessment for the EPA Part 503 Rule (EPA/832-B-93-005), September 1995, (accessed December 14, 2009). 12. C. A. Kinney et al., “Survey of Organic Wastewater Contaminants in Biosolids Destined for Land Application,” Environmental Science & Technology 40 (2006): 7207-7215. 13. U.S. Environmental Protection Agency, Office of Water, Targeted National Sewage Sludge Survey Overview Report (EPA-822-R-08-014), January 2009, (accessed December 14, 2009). 14. U.S. Department of Health and Human Services, National Institute for Occupational Safety and Health, Guidance for Controlling Potential Risk to Workers Exposed to Class B Biosolids (publication no. 2002-149), July 2002, http:// (accessed December 14, 2009).
15. John Heilprin and Kevin S. Vineys, “Court Finally Recognizes Spreading Sewage Sludge on Farmland is a Very Bad Idea,” Organic Consumers Association, March 7, 2008, (accessed December 14, 2009). 16. Eric Fleischauer, “Feds to Test 200 for DU Toxic Waste,”, December 2, 2009. (accessed December 14, 2009).