Perfluoroalkyl Substances (PFASs) by Any Other Name ...
There is continuing concern that many chemicals found commonly in municipal sewage sludges are released to the environment by their disposal in forests and on farms and rangelands. Most of the known toxic chemicals in nearly any municipal sewage sludge are not tested, monitored or evaluated, simply because the relevant codes, regulations and laws were not written based on the potential for risk, threat or harm to human and environmental health. The consequences that may be realized from exposure to the unknown chemicals in land-disposed sewage sludge present an even greater mystery. Current sewage sludge disposal practices contaminate and pollute our soils, foods and waters. The summary points from a key article are presented below to demonstrate that all County, State and Federal agencies in the US are fully informed and aware of the dangers and likely harm by these disposal practices. This article merits your careful review. rch
National inventory of perfluoroalkyl substances in archived US biosolids from the 2001 EPA National Sewage Sludge Survey. Arjun K. Venkatesan and Rolf U. Halden, J Hazard Mater. 2013 May 15; 0: 413–418. PMCID: PMC3776589NIHMSID: NIHMS464002.
http://www.ncbi.nlm.nih.gov/pubmed/23562984
Abstract
Using liquid chromatography tandem mass spectrometry, we determined the first nationwide inventories of 13 perfluoroalkyl substances (PFASs) in US biosolids via analysis of samples collected by the US Environmental Protection Agency in the 2001 National Sewage Sludge Survey. Perfluorooctane sulfonate [PFOS; 403 ± 127 ng/g dry weight (dw)] was the most abundant PFAS detected in biosolids representing 32 US states and the District of Columbia, followed by perfluorooctanoate [PFOA; 34 ± 22 ng/g dw] and perfluorodecanoate [PFDA; 26 ± 20 ng/g dw]. Mean concentrations in US biosolids of the remaining ten PFASs ranged between 2 and 21 ng/g dw. Interestingly, concentrations of PFOS determined in biosolids collected prior to the phase-out period (2002) were similar to levels reported in the literature for recent years. The mean load of ΣPFASs in US biosolids was estimated at 2749–3450 kg/year, of which about 1375–2070 kg is applied on agricultural land and 467–587 kg goes to landfills as an alternative disposal route. This study informs the risk assessment of PFASs by furnishing national inventories of PFASs occurrence and environmental release via biosolids application on land.
Introduction
Perfluoroalkyl substances (PFASs) are anthropogenic chemicals that have been widely used in commercial products since the 1950s. Due to their unique properties of repelling both water and oil, PFASs are extensively used in the manufacture of surfactants, lubricants, polishes, textile coatings, and fire-retarding foams. As a result PFASs are released into the environment at significant quantities and have been detected in surface water, fish, birds, mammals and humans worldwide. Although the production of two major PFASs, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), has been phased out in several major US companies, continued environmental contamination of PFASs results from the use of precursors, such as fluorotelomer alcohols and polyfluoroalkyl phosphates. PFASs are emerging contaminants of increasing interest to the scientific community, due to their widespread occurrence in the environment and evidence of potential or known adverse human health effects. PFASs have been shown to persist in the environment, to bioaccumulate in animals and to occur at significant levels even in remote regions like the Arctic. PFOS is the predominant PFAS detected in all wildlife species worldwide. One study reported bioaccumulation of PFOS in polar bears at concentrations even greater than polychlorinated biphenyls (PCBs). Results from animal studies have associated PFOS and PFOA with developmental and reproductive toxicity, as well as cancer. In humans, both PFOS and PFOA are shown to cross the placenta readily, and epidemiological studies on fetal exposure have associated high levels of PFOS with reduced growth metrics of newborns. Additionally, both PFASs have been associated with elevated total cholesterol levels in humans.
PFASs are considered to be highly resistant to biodegradation due to their extremely strong carbon–fluorine bonds. They are not efficiently removed in municipal wastewater treatment plants (WWTPs), and the presence of PFASs in wastewater effluents and biosolids is of increasing concern. Concentrations of PFOS and PFOA have been reported of up to 990 and 241 ng/g of biosolids, respectively. Studies have also shown that several PFASs increase in concentration during the WWTP process train, suggesting the presence of precursor compounds that degrade and release persistent perfluorinated carboxylic acids and sulfonates (PFCAs and PFSAs). Land application of biosolids contaminated with PFASs was shown to contaminate soil, groundwater, and surface waters. Soil concentrations of PFOS as high as 483 ng/g were reported at a land reclamation site in Illinois after 32 years of consecutive applications of biosolids at the rate of 69 Mg biosolids ha−1 yr−1. In Decatur, AL, about 22% of samples collected from surface and well water near fields with a history of PFASs contaminated biosolids application exceeded the health advisory level of the US Environmental Protection Agency (US EPA) of 400 ng/L for PFOA. Multiple studies have shown that PFASs of shorter chain length tend to become mobilized from soil readily to contribute to contamination of surface water and groundwater. The widespread occurrence of PFASs at significant concentrations in the environment necessitates a better understanding of environmental occurrence and transport processes in order to inform both human health risk assessments and regulatory requirements for these recalcitrant, mobile chemicals.
The US EPA performed several National Sewage Sludge Surveys (NSSS) to evaluate the need for regulating trace contaminants. The present study was performed to extend this effort to other emerging contaminants that were excluded from past US EPA studies. In a research collaboration, unused samples from EPA's 2001 survey were acquired and are being archived in the Biodesign Institute at Arizona State University as part of the US National Biosolids Repository maintained there. The approach of analyzing archived composite biosolids had been validated previously in studies of pharmaceuticals and personal care products (PPCPs) and alkylphenol surfactants performed to evaluate their nationwide occurrence in biosolids. The present work employed a similar methodology to analyze for PFASs to enable risk assessment and to determine baseline concentrations and national inventory for these chemicals in treated municipal sludge fit for land application.
End Notes:
PFASs persist in the environment
PFASs bioaccumulate in animals
PFASs occur at significant levels even in the Arctic
PFOS is the predominant PFAS detected in all wildlife species worldwide
PFOS bioaccumulates in polar bears at concentrations greater than polychlorinated biphenyls (PCBs)
PFOS and PFOA are associated with developmental and reproductive toxicity, as well as cancer
Both PFOS and PFOA are shown to cross the placenta readily in Humans
Epidemiological studies on fetal exposure show high levels of PFOS and reduced growth of newborns
PFOS are not efficiently removed in municipal wastewater treatment plants
The presence of PFASs in wastewater effluents and biosolids is of increasing concern
Concentrations of PFOS and PFOA have been reported up to 990 and 241 ng/g of biosolids
Several PFASs increase in concentration during the WWTP process
PFAS precursors degrade and release persistent perfluorinated carboxylic acids and sulfonates
Land disposal of biosolids contaminated with PFASs contaminates soil, groundwater and surface waters
Rough-skinned Newt (Taricha granulosa), a tetrodotoxin producer rescued from the forest sludge dumping grounds and placed in a clean forest, lethargic, but alive. Diet consists of invertebrates, but includes salamander and frog eggs and larvae, and even tiny fish. Newt larvae feed on protozoans. As they grow larger, they feed on small aquatic invertebrates. Makes you wonder if this tetrodotoxin producer can tolerate a toxic diet of invertebrates, which reside in toxic sewage sludge leachate ponds.
A sludged forest of western Washington. Few life forms survive, so how can we?
A sludged farm of central Washington. Who eats what grows in this?
Fungal sludge survivor. Adapted to a toxic life-style.
Another sludge survivor. Just a few of a hundred species grow in this toxic waste.
Yet another fungal sludge survivor, though few in number, growing in a splash of sewage sludge in a hole in a rock.
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