Thursday, 12 March 2020

Biosolids - Critical Issues to Consider - a talk by Professor Murray McBride

Biosolids - Critical Issues to Consider Biosolids Information Webinar - November 2019 - Sponsored by New England Farmers Union, Ohio Farmers Union and Pennsylvania Farm

The webinar can be listened to here - https://pafarmersunion.org/biosolids-webinars

There is lots of great information in this webinar. There is good background information provided by Darree Sicher (from approx. minute 2:30 to 14:30)

Biosolids - Critical Issues to Consider



The Cornell Professor, Dr. Murray McBride, takes over from 14:30 to 35:00 - outlining the concerns he has around land disposal of biosolids.

Below is a transcription of the talk he gives during the webinar - 


"Let's look a little more carefully at the nutrient levels in these sludges, they are very highly variable and unbalanced, by that I mean unbalanced in terms of what crops need ... organic matter can vary between 40 - 70% - which is kind of interesting as you wonder what the rest of the material is ... so there is other material in there clearly ...the nitrogen to phosphorous ratio in this material, for most sludges, is not well matched to the crop needs ... there is a build up of phosphorous in these soils ... You also don't have enough potassium relative to the other nutrients ... so it is not an ideal fertilizer at all”

Now to the main concerns - 

"In my view the negative concerns outweigh the positives. The build up of contaminants, and this includes pathogenic organisms, metals, and synthetic organic chemicals (of which there are thousands) means that you potentially contaminate food crops, dairy products, and meat. You also have reduced forage quality on pastures, and forage crops where uptake of metals like molybdenum, and uptake of elements like sulfur, can lead to livestock health problems”

“There is also groundwater contamination, which is rarely monitored, even on long-term application sites ... In the long term you may end up building up enough heavy metals, particularly zinc and copper, that you could reach levels that impact crop growth. This is an issue for soil health. We also have the odor and bioaerosol problems -  I've encountered this numerous times, the effects on human health, of people living adjacent to land application sites”

“Finally, I stress again the tremendous variability and unpredictability of the composition of sludges”

Regarding regulations - 

"Only nine of the metals are regulated, and None of the toxic organic chemicals are under any regulation ... present day sludges do contain metals that are toxic that aren't regulated ...the metals stay put in the soils, and do build up over time ... some of these elements are taken up by forages and by food crops”

"Anaerobic digestion, in the WWTP, reduces the viral numbers, but there will still be between 100 - 10,000 viable viruses per kg in the "treated" sludge.  Viruses have lower infective doses than bacteria, so as little as 1 to 100 can give you a disease"

“Synthetic organic chemicals are not regulated, and there are thousands of them coming on every year. Some of these chemicals, like the fire retardants, are very persistent and long-lived in soils - they build up with time, because every time you apply sludge, you simply add to what is already there. Unfortunately few of these have been studied for human or animal toxicity so we really don't know how bad an effect they may have. Few of these chemicals have been studied for crop uptake, some have shown uptake, while others have not”



What is the concern about synthetic organic pollutants accumulating in farm soils? 

"Many of these chemicals are taken up by crops, research has shown that ... many of them are bioaccumulative in livestock - these are the ones that are fat soluble, things like the brominated fire retardants for example ... they accumulate in cows in the milk fat, or in the meat fat so there is a concentration build up from the soil into livestock, into humans, up the food chain” 

“Many of these organic chemicals are persistent in the soil. Many have known or suspected human or ecological toxicity, some are carcinogenic, others are endocrine disrupting”

 “Most are "invisible" - by that I mean, we do not test for them - so proponents of sludge application say "what's the problem?" They don't see a test for these chemicals, so the assumption is there is no problem there. - but -  a lack of evidence does not represent evidence of a lack of effect - so we simply cannot conclude anything from not having information” 

“There are new unevaluated contaminants showing up all the time ... as a scientist I see that the scientific understanding of the behavior and toxicity of these many chemicals is lagging far, far behind the actual application of these on farms - which seems like a backwards way of doing things"


Potential impacts of Endocrine Disrupting Chemicals on ecosystems and humans

"The proponents of land application have claimed that these synthetic chemicals have far too low a concentration in sludges or in soil to have harmful effects. This argument is based on the old toxicological argument, or paradigm, that the "dose makes the poison" (which makes sense for SOME chemicals) but the endocrine disrupting chemicals EDC's don't obey this rule because they have hormone-like behavior in animals and humans, and they operate a low parts per billion into parts per trillion level. Some of the most serious EDC's found in all sludge samples have been the PFOS and PFOA"  - about which there are great knowledge gaps. 

"How much PFOA or PFOS in soils would be sufficient to contaminate groundwater above the guidelines? How much PFOA or PFOS in soils would be sufficient to contaminate milk, dairy products or meat? There is NO research at this time that can answer these questions" 



Wednesday, 12 February 2020

Open Letter by Biochemist Dr. Thomas Maler - On the "Biosolids" Issue



Open Letter - on the topic of relaxing the ban on sewage sludge/biosolids spreading on the land






After much research and consultation, the CRD is about to reverse a previous decision made sometime around 2011 that protects our environment, watershed and the health of rural residents.  The earlier decision banned the application of toxic biosolids on land. What has changed since that earlier vote is that more is known about the toxicity levels contained in sludge/biosolids, and that other communities are using far superior methods that cost a fraction of what we're going to pay and they completely save the environment from toxins.

The value of biosolids as a fertilizer for trees is more than offset by the highly toxic nature of biosolids, which contain up to 85,000 different virtually indestructible chemicals, superbugs (multi-drug resistant bacteria) which breed in all sewage treatment plants, micro-plastics and micro-fibres which absorb many toxins on their surface.  The plants grown on sludge contaminated lands take up these chemicals which then end up in our food and the effluent from those lands contaminates our streams, rivers and oceans, including the fish we eat. 

A recent 2019 study shows that POPs (persistent organic pollutants) in the root level of sewage treated soils indicate extremely high stability and low degradability of a large variety of these chemicals.


A January 2020 study from France indicates that chemical pollution has reached unprecedented levels with every child being born “precontaminated” with hundreds of chemicals many of which can interfere with brain development. These epigenetic interactions are now being increasingly researched and documented. The chemicals get into our environment and into our bodies via industrial and urban waste water treatment plants and via the use of sewage sludge on the land as fertilizer. 


A recent paper described a group of 4700 man made chemicals called PFAS. They are used in a wide variety of consumer products and industrial applications and they have been implicated in developmental defects in unborn child. Reuse of sewage sludge as fertilizer has led to PFAS pollution of soil and water in Austria, Germany, Switzerland and the US. 
“The new European Commission is finally recognizing the need to strive for a non-toxic environment.” 



Many countries in Europe, including Switzerland, Sweden and Germany are turning away from this polluting strategy and banning the use of biosolids on the land. So why are we choosing such an environmentally damaging strategy when there are much better and safer ways to turn sewage sludge into energy. 

Furthermore, why are we choosing much more expensive process that only turns half of the energy in sludge into methane and the other leftover half is being shipped to kilns in Richmond. The CRD has environmentally damaging plan to spray the sludge on the land for 6 weeks of the year when the cement kilns are shut down. The New York/New Jersey metropolitan area(s) have a lowest cost plan to dispose of their sludge/biosolids in a gasifier being built by Aries Clean Energy at Aries Linden Roselle Sewerage Authority in Linden NJ. The cost for the Aries Linden facility will be US$50 million and it will serve population of 13.5 million people. This plant will operate only on sewage sludge with no need to build hugely expensive anaerobic digesters and will be in full operation in Q4 of 2020 . 


In contrast the cost for the  CRD system will be Can$ 330 million and the system will only turn 50% of the amount of sludge into energy ie. methane and will serve population of 368,000 people. In contrast the NJ gasifier will cost only a fraction (6%) of  what the CRD will pay, while serving a population 37 times larger. 

I understand that the CRD had two beneficial use proposals to build gasifiers to turn biosolids into electricity, but those proposals were not chosen. In fact, a lot of taxpayers money could have been saved by not building anaerobic digesters and simply gasifying sewage sludge directly. That approach would also provide a permanent solution so it would not have to be shipped anywhere. The sludge could be stored until the gasifier is built and that would satisfy the ministers requirement for beneficial use.


A more detailed review of this topic can be found here:




Thomas Maler, Ph.D

Monday, 10 February 2020

Open Letter to Minister George Heyman and the CRD's Board of Directors



Open Letter to Minister George Heyman and the CRD's Board of Directors


Minister George Heyman, in a recent letter, outlines that Victoria's biosolids strategy must include, in the long-term  "a range of beneficial uses including, but not limited to forestry (for example fertilizer / soil conditioner), reclamation (for example mines), landfill closure and agriculture." In the short-term, Heyman states that Victoria's strategy may include "applying biosolids to the land." He says that the present policy in place for the region "unnecessarily limits the options available for beneficial use."  (He is reacting to CRD's very wise ban against land disposal of biosolids - voted and passed several years back). Heyman goes on to state that, "it is the ministry's position that the land application of biosolids ... will benefit the environment and potentially reduce costs to the taxpayer."

This position is at odds with recent science. Biosolids is a pollutant-rich material, and spreading it on soils, whether on forests, farms, or flower gardens, means making those pollutants available to the terrestrial environment.

This past week alone three articles were published which dramatically encapsulates these concerns.  The Telegraph ( https://bit.ly/2usTXx6 ) published an article - "Microplastics making their way to British farms in human sewage fertilizer" - in which they warn, "microplastics could harm soil ecosystems or crops either directly or through hormone-disrupting substances, and contain chemicals that could be released slowly as they break down over hundreds of years" Interestingly, the Canadian Government published its "Draft science assessment of plastic pollution 2020" this past week, where it states that - "It is estimated that 99% of microplastics are removed from the influent but are retained in sewage sludge ... Microplastics can therefore enter terrestrial environments through the application and use of sewage sludge as fertilizers for agriculture or landscaping purposes"  (  https://bit.ly/39pgeLn ). 

Another Important new scientific study just came out on a related topic - "Pharmaceutical and Personal Care Products: From Wastewater Treatment into Agro-Food Systems"
( https://bit.ly/39jRJ1Q ) In this, the scientists demonstrate that "Use of biosolids in agriculture leads to soil contamination with PPCPs and their metabolites, providing a route for accumulation in food produce, which poses potential risks to environmental and human health" and that  "The extensive use of biosolids in agriculture introduces PPCPs and other contaminants of emerging concern to arable soil and has the potential to contaminate food produce, constituting a route for human exposure"  It is worth pointing out that the OMRR guidelines that Heyman and his government rely on to "assure safety" do not test for microplastics or pharmaceuticals - or other  CECs (contaminants of emerging concern) for that matter - sadly, out of the tens of thousands of pollutants known to be in biosolids, they test for barely a dozen!

A third major article was published this week by Greenpeace - "Secret Environment Agency report finds sewage sludge (biosolids) destined for English fields contaminated with microplastics, weedkiller, and "persistent organic pollutants" ( https://bit.ly/31zzuD6 ). The article notes that - "Investigators commissioned by the agency found sewage waste destined for English crops contaminated with dangerous "persistent organic pollutants" like dioxins, furans, and polycyclic aromatic hydrocarbons at "levels that may present a risk to human health". They also reported evidence that these sludges, which are routinely spread as fertilizer on hundreds of farms, were widely contaminated with microplastics that could ultimately leave soil "unsuitable for agriculture".

There have been many more damning studies published in just the past year. Here are just three more that might serve as an overview of this problematic practice - 

1. Root uptake of toxins - https://pubs.acs.org/doi/abs/10.1021/acs.est.8b07222?journalCode=esthag
2. Germination and growth issues after biosolids application - https://www.sciencedirect.com/science/article/pii/S0045653519306095
3. Grazing animals affected by biosolids pollutants - https://www.sciencedirect.com/science/article/pii/S0160412018317318

Minister Heyman assures us that government guidelines will protect the public. Many do not agree. The David Suzuki Foundation on the topic of "biosolids"  has made the following statement - "The David Suzuki Foundation does not support the dumping of sewage sludge, treated or otherwise ... sewage sludge can contain a brew of nutrients laced with PCBs [polychlorinated biphenyls - in low levels]; dioxins and furans (again, generally in low levels); chlorinated pesticides [such as DDT Aldrin, endrin, chlordane, indane, mirex, etc..); polybrominated diphenylethers (PBDE's - Flame retardant chemicals); hormone mimicking compounds like Phthalates and nonylphenols and their ethoxylates: carcinogenic polycyclic aromatic hydrocarbons [PAHs]; heavy metals ( in particular arsenic, cadmium, copper, lead, mercury, selenium, and zinc); bacteria, viruses, parasitic worms, and fungi; industrial solvents; asbestos; and petroleum products ... All of these chemicals can, and do contaminate the soil and can contaminate the crops grown in those soils.  There is also the associated problem of these contaminants running off treated fields and into local water courses when it rains." 

So too, The Sierra Club  has stated that it "opposes the land application of municipal sewage sludges as a fertilizer and/or soil amendment because the current policies and regulations governing this practice are not adequately protective of human health."

These views are also shared by enlightened European governments, and their Environmental agencies. For instance - 

Switzerland has completely banned the use of biosolids on agricultural soils because of "the risk of irreversible damage to the soil, the danger to public health and possible negative effects on the quality of the food farmers produce" https://bit.ly/2Fc6ObP

The Swedish Government - "since biosolids contain environmental and health hazardous substances, drug residues and microplastics, our task force will propose a ban on spreading sewage sludge on farmland" https://bit.ly/2PRKdFk

Norwegian Scientific Committee for Food and Environment - "biosolids application may be causing persistent, pernicious and almost totally ignored contamination of agricultural land" 

The German Environment Agency - "With the precautionary principle and in light of the pollutants found in biosolids, we deem the agricultural use of biosolids to be a serious public health & environmental hazard & advocate that this practice be phased out" https://bit.ly/2SXfLIQ

(It should be noted that in the EU, UK and Scandinavia, the allowable pollution levels are generally more strict than those listed in the OMRR guidelines that Heyman relies upon to "assure safety").


Those in favour of "land application" see merely organic matter along with some plant nutrients like nitrogen and phosphorus, and presumably, because it contains some human fecal matter, they see it as a form of manure. This limited view utterly ignores the actual make-up of this waste material. It is after all, the "stuff" taken out of the wastewater within these treatment facilities, in order to CLEAN the water - purify it of its pollutants as much as possible, before the water is released back into the environment. This "stuff" therefore represents the collected and concentrated toxic waste eliminated from the liquid stream. It is a mirror of modern urban life - a goulash comprised of myriad pollutants - the remains of everything we flush away - cleaners, pharmaceuticals, dyes, solvents, microplastics and microfibers, fire retardants - you name it.  As Prof. Murray McBride, of Cornell University, says, it is "a material containing unknown concentrations of thousands of chemicals with undetermined toxicities."

The sludge pushers will say that sewage sludge and "biosolids" are very different things. Not true. The minimal "processing" done to the sludge - be it adding lime, or woodchips, and composting it - anaerobic or aerobic digestion, pelletizing it, or liquefying it - all of these are superficial treatments. The problematic constituents within this matrix of pollutants remains primarily the same. As numerous studies, including those of the US Geological Survey, have shown - thousands of chemicals remain in these so-called "biosolids" ... for instance - 

Microplastics? - Still present - ( https://bit.ly/2Sngwd2 "43% of microplastics that go down the drain eventually end up applied to agricultural land as biosolids." ) Nanomaterials? -Still present - (Uptake of Nanomaterials see - https://rsc.li/2WfDdCA ). Endocrine disruptors like flame retardants? - Still present - (The U.S. Geological Survey scientists confirmed that rainfall mobilized chemicals (including detergents, fire retardants, plasticizers, and antibacterials) from municipal biosolids-amended agricultural fields, directly to runoff. Most (14 of 17) of the chemicals examined were present in edge-of-the-field runoff and not depleted in concentration after three 100-year rainfall events For more on this see - https://on.doi.gov/2Eisa4M ). Prions? - Still present - ( "if prions were to enter municipal wastewater treatment systems, most of the agent would partition to activated sludge solids, survive mesophilic anaerobic digestion, and be present in treated biosolids.'' see - https://bit.ly/2GznGZJ ) In fact some problems like superbugs - antimicrobials, may even get worse through these processes (Antibiotic residues and antibiotic-resistant bacteria - https://bit.ly/2KM7xj5 - "spreading of sewage sludge leads to a significant increase of ARG in the soil" )

This practice of land disposal is NOT "green" or "sustainable" or "recycling" or indeed "beneficial" -  it is merely a cheap way of shifting our cities' pollutants.  As Dr. Sierra Rayne has noted - "The science doesn't support the disposal of sewage sludge across the landscape. The supposed benefits are more than offset by the risks to human and environmental health. An unimaginably large number of chemical and biological contaminants exist in these materials, and they persist in the product up to, and after, land disposal. Scientific investigations have identified only a tiny fraction of the total contaminant load. Governments are playing Russian roulette with sewage sludge. Over time, there is a high probability this game will be lost at the public's expense." (http://bit.ly/1sb2qOP)

It is so disappointing to hear Minister Heyman aping the language of the sludge disposal industry when he uses phrases like "beneficial use" ! Perhaps he could explain exactly what is "beneficial" about loading our soils with microplastics, endocrine disrupters, antibacterial resistant bacteria and myriad other pollutants? Beneficial for whom? ...certainly for the sludge industry, and governments that merely search out cheap short-term strategies! It is decidedly NOT "beneficial" for the public - and not for future generations who will depend on healthy soils for years to come.

For the reasons set forth above, I believe that in the public's best interest, the ban on land disposal of biosolids within the CRD should remain in effect.



To dive more deeply into the issues 

To see what experts from leading institutions have to say about "biosolids" - go here - https://bit.ly/38d5H5t To see other new scientific studies on "biosolids" - go here - https://bit.ly/2Hb55kU To see more information around the faulty "risk assessment" practices (used by this government and the sludge industry) for "biosolids" - go here -  https://bit.ly/2H9zsbM To see what alternatives there are to land disposal of "biosolids" - go here - https://bit.ly/2H8MtSQ

Wednesday, 5 February 2020

What the Experts have to Say - Quotable Quotes on this Reckless Practice


"Biosolids" … the reality … without the PR spin … 




Prof. Murray McBride, Cornell University -  "Is it reasonable to conclude that there is little or no risk of land-applying a material (biosolids) containing unknown concentrations of thousands of chemicals with undetermined toxicities?" ... "Once contaminated, stopping the application of pollutants such as metals and many organic chemicals that are in sewage biosolids will not correct the problem. The contamination will remain for decades or centuries"


Prof. Jordan Peccia- Yale University - " biosolids contain heavy metals, hazardous organic chemicals, microbial pathogens, and antibiotic resistant bacteria ... polybrominated flame retardants, pharmaceuticals like Prozac and Tagamet, human hormones such as estrogen, antibiotics, narcotics"



Lidia Epp  (manager of  the Molecular Core Lab in the Biology Department of College of William and Mary in Williamsburg) "It is evident that the long term exposure to a host of the environmental pollutants is the foundation of many chronic conditions that are now at the epidemic levels. Rather than focusing narrowly on determination of specific sets of toxins present in biosolids from different sources – the research needs to shift to the epidemiological studies assessing the overall impact of complex mix of pollutants present in sludge."

Dr Andrew Singer (Microbiologist, Oxford) - "That sludge has e-coli in it,  plus antibiotics, plus biocides, plus metals - all of that breeds something called an antibiotic resistant bacteria. So as you are maybe rambling through a field that's been amended with this sludge, either last week or a year later, there is an elevated risk that you will - or your pet will - acquire this antibiotic resistant bacteria, carry it home with you, the dog licks you in the face, you have it. This is how it is transmitted. It is a rare event, but unfortunately rare events matter on a global scale, so you only need these rare events to happen once for it then to become important for the world.  So you’re effectively disseminating [in the environment] the very thing we should be trying to eliminate.”
Controlling the spread of antibiotic resistance was “one of the highest global priorities in the world,” he added. “There is virtually no higher priority than this, other than maybe climate change, and it is a seemingly routine occurrence that we are spreading this onto our land.”



Prof. Claudia Gunsch,  Duke University "As industry invents new materials and chemicals for modern products, many find their way to our skin and bloodstream and, subsequently, into our sinks and toilet bowls. More than 500 different organic chemicals have been identified in the biosolids used as fertilizer across the United States."

Dr. Sierra Rayne (microbiologist) - "The science doesn't support the disposal of sewage sludge across the landscape. The supposed benefits are more than offset by the risks to human and environmental health. As scientists, we have been watching the issue with increasing concern. An unimaginably large number of chemical and biological contaminants exist in these materials, and they persist in the product up to, and after, land disposal. Scientific investigations have identified only a tiny fraction of the total contaminant load. We cannot even say with any degree of confidence what the true range of contaminant risk is from the sludge ... Governments are playing Russian roulette with sewage sludge. Over time, there is a high probability this game will be lost at the public's expense."



Professor Alistair Boxall (University of York) , said sewage sludge contains "a real mixture of things ... It will contain microplastics, it will contain persistent organic pollutants, it will contain metals, it'll contain pharmaceuticals. We have no idea of how those work in combination to affect our health and also affect ecosystem health."

Brian Bienkowski (Scientific American - May 12, 2014) - "Sewage sludge used as fertilizer on farms can leave traces of prescription drugs and household chemicals deep in the soil, according to a new study by federal scientists. The findings suggest that the widespread use of biosolids could contaminate groundwater near farms with a variety of chemicals, including anti-depressants such as Prozac and hormone-disrupting compounds in antibacterial soaps ...The researchers looked for 57 “emerging” contaminants that are increasingly showing up in the environment. Ten were detected in the soil at depths between 7 and 50 inches 18 months after the treated sludge was applied. None was in the field’s soil beforehand... Other studies have found hormones, detergents, fragrances, drugs, disinfectants, and plasticizers in treated sludge used as fertilizer. But this is the first study to show how they can persist and move in soil."



Dr. Richard Honour (microbiologist) - ""Few in any governments appreciate that nearly all chronic diseases are caused by long-term exposure to low levels of environmental contaminants and pollutants. We should be trying to minimize this exposure, not amplifying it. It is time to end land disposal of Toxic Sewer sludge, and look at cleaner, greener alternatives - gasification / pyrolysis."


Laura Orlando (Boston University civil engineer)  believes a ban on land application is in order. “Everything we have that’s being manufactured in our society ends up in our sewer and it’s going to be in the sludge, so I think we should take land application out of the equation while we figure out what to do with it,” she said.


 Dr. Thomas Maler (biochemistry) -"it seems obvious that application of sewage sludge/biosolids on the land is not the answer to dispose of these toxins and pathogens. Disposal of the sludge mixed with municipal solids waste or with wood chips in a gasifier is the only safe way to go because it completely destroys the toxic chemicals and pathogens. Not putting this toxic soup on the land is the only way of protecting our environment and that’s the primary reason for treating our sewage in the first place" 

Dr. Caroline Snyder  (emeritus professor, Rochester Institute of Technology) -  "Land application is not "recycling"; it is simply transferring a complex mixture of toxic chemicals and pathogens from our large industrialized urban centers to arable farms; nor is the practice "strictly regulated." Current biosolids management is highly energy intensive using fossil fuel for processing and transportation, thus - actually adding greenhouse gas emissions (on top of all the pollution produced by hauling these materials all over). Finally, it is ludicrous to claim that using the nation's arable soils as a repository of persistent toxic chemicals, many of which bioaccumulate in the food chain, "enhances soil health".”

Norwegian Scientific Committee for Food and Environment - "biosolids application may be causing persistent, pernicious and almost totally ignored contamination of agricultural land" 

Switzerland has completely banned the use of biosolids on agricultural soils because of "the risk of irreversible damage to the soil, the danger to public health and possible negative effects on the quality of the food farmers produce" https://bit.ly/2Fc6ObP

The Swedish Government- "since biosolids contain environmental and health hazardous substances, drug residues and microplastics, our task force will propose a ban on spreading sewage sludge on farmland" https://bit.ly/2PRKdFk

The German Environment Agency - "With the precautionary principle and in light of the pollutants found in biosolids, we deem the agricultural use of biosolids to be a serious public health & environmental hazard & advocate that this practice be phased out" https://bit.ly/2SXfLIQ

Thursday, 24 October 2019

Sewage Sludge and Soil Worm Populations ... NOT a Good Combination !!

Sewage Sludge (biosolids) and Soil WORM Populations - not a good combination! 
Time to stop using our agricultural soils as a sink for our cities' toxic sewage waste! 




1. https://bigthink.com/surprising-science/microplastics-soil
Highlights -
  • New research from Anglia Ruskin University states that microplastics in soil are causing earthworms to lose weight.
  • Soil affected by microplastics produces less crop yield due to less productive earthworms and lower pH levels.
  • If this trend continues, our entire agricultural system could be compromised.


2. https://www.newsweek.com/microplastics-growth-worms-weight-study-1458887


3. https://pubs.acs.org/doi/full/10.1021/acs.est.9b01339  " The findings reported here imply that the pervasive microplastic contamination in soil may have consequences for plant performance and thus for agroecosystems and terrestrial biodiversity."

4. https://www.independent.co.uk/environment/microplastics-worm-growth-ecosystems-pollution-study-a9100866.html


5.  "Sewage sludge microplastics could pollute soil for thousands of years" https://bit.ly/2Sngwd2 "43% of microplastics that go down the drain eventually end up applied to agricultural land as biosolids."


6.   http://agris.fao.org/agris-search/search.do?recordID=US201900108222
 Highlights - 
"We investigated dissipation, earthworm and plant accumulation of organic contaminants in soil amended with three types of sewage sludge"
"This indicates that a chemical's short half-life in soil is no guarantee that it poses a minimal environmental risk, as even short term exposure may cause bioaccumulation and risks for chronic or even transgenerational effects."
"sewage sludge can present a potential risk for soil ecosystems and food webs, as a wide range of pollutants, organic and inorganic, enter water treatment facilities and end up in sewage sludge"
" there are no criteria taking into account the content of organic pollutants in sewage sludge"
"Organic pollutants may originate from detergents or other domestic chemicals, personal hygiene products, pharmaceuticals and a wide range of other products or wastes finding their way into the sewage system. Many of these organic pollutants are not degraded during waste water treatment processes, and reach soils where they may potentially cause harm to soil organisms … many of these chemicals are known or suspected endocrine disruptors
and may cause more chronic effects"
"The risk of adverse effects stems not only from their toxicity, but also from persistence and long-term exposure. High internal concentrations, as observed when organic pollutants bioaccumulate in organisms, can contribute to the environmental risk they may pose"
"The transfer of galaxolide and triclosan to earthworms was significant … . Although nonylphenol monoethoxylate rapidly dissipated in soil, it was still detected in earthworms three months after sludge application, suggesting that a chemical's short half-life in soil could still pose environmental risks." 







Friday, 9 August 2019

Sewage Sludge Management in Germany - A look at the recently published (2015) Overview

A few years ago (2015), Germany published a fascinating and frightening look at the sewage sludge situation. It is a wonderful guide to the present-day production, treatment and possible uses of this sludge.  Below I will present some of the more interesting and sobering findings in this German study. 



The entire document can be accessed here in English Translation -
Sewage Sludge Management in Germany



"Sewage sludge can be regarded as a multisubstance mixture. Because of the inhomogeneity and tremendous differences in the concentrations of its components, it is difficult to determine or define a standard composition for sewage sludge, which is mainly composed of organic substances. Sewage sludge (i. e. stabilized primary, secondary or tertiary sludge that occurs in a mixture at the end of the treatment process) contains plant nutrients such as nitrogen and phosphorous, as well as harmful substances such as pathogens, endocrine disrupters and heavy metals"




"Sewage sludge fertilizer is a pollution sink for harmful sewage components from households, businesses and diffuse sources, concerning whose environmental impact too little is known. The extent of the possible soil, plant, groundwater, and surface-water pollution resulting from these sources is difficult to determine, even in cases where relatively small amounts of sewage sludge are used ...  new breakdown products of pharmaceutical drugs are discovered in sewage sludge all the time. These breakdown products are incorporated into sewage sludge via human excretion and in other ways. It is simply not humanly possible for scientists to develop specific detection processes for and assess the environmental impact of all of these substances, whose combined impact is particularly difficult to characterize and assess. Scientists can merely estimate the theoretical hazards posed by these substances; and unfortunately, by the time the relevant hard facts become available, the pollutants in question will already have found their way into the biosphere."




"Owing to its extreme inhomogeneity, the quality of sewage sludge is difficult to characterize. Sewage sludge fertilizer contains the following elements, all of which are potential ecosystem pollutants: various organic substances that exert hormonal effects; various infectious agents; heavy metals; residues of pharmaceutical drugs."

"Sewage sludge fertilizer is also a pollution sink for harmful sewage components from households, businesses and diffuse sources, concerning whose environmental relevance too little is known. Notwithstanding tighter controls and stricter limit values for certain sewage sludge pollutants, uncontrolled pollutants such as hydrocarbons inevitably find their way into the soil. Incorporation of certain pollutants into the food chain cannot always be avoided, despite the fact that, for example, plants normally do not absorb organic pollutants. Nonetheless, new breakdown products of pharmaceutical drugs are discovered in sewage sludge all the time, and they are incorporated into sewage sludge via human excretion carried by the wastewater that is treated by sewage treatment plants." 

"In keeping with the precautionary principle and in light of the pollutants and pathogens found in sewage sludge, the UBA deems the agricultural use of sewage sludge to be a serious public health and environmental hazard and advocates that this practice be phased out."