Category Archives: Organic Contaminants

PFOA/PFOS emerges as an election issue

In an election year political statements raising ‘hot button’ environmental issues like PFOA and PFOS are to be expected (e.g. click here). Ms. Dingell’s characterization of PFOA and PFOS are not based on science or even a proper understanding of environmental law.

The article below presents the only publicly available, independent peer-reviewed published paper examining the full implications of regulating of PFOA and PFOS in drinking water.

F.W. Pontius. Regulation of Perfluorooctanoic Acid (PFOA) and
Perfluorooctane Sulfonic Acid (PFOS) in Drinking
Water: A Comprehensive Review. Water 2019, 11, 2003; doi:10.3390/w11102003

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are receiving global attention due to their persistence in the environment through wastewater effluent discharges and past improper industrial waste disposal. They are resistant to biological degradation and if present in wastewater are discharged into the environment. The US Environmental Protection Agency (USEPA) issued drinking water Health Advisories for PFOA and PFOS at 70 ng/L each and for the sum of the two. The need for an enforceable primary drinking water regulation under the Safe Drinking Water Act (SDWA) is currently being assessed. The USEPA faces stringent legal constraints and technical barriers to develop a primary drinking water regulation for PFOA and PFOS. This review synthesizes current knowledge providing a publicly available, comprehensive point of reference for researchers, water utilities, industry, and regulatory agencies to better understand and address cross-cutting issues associated with regulation of PFOA and PFOS  contamination of drinking water.

Organophosphorus flame retardants in drinking water, Nanjing, China

Liu X, Xiong L, Li D, Chen C, Cao Q. Monitoring and exposure assessment of organophosphorus flame retardants in source and drinking water, Nanjing, China. Environ Monit Assess. 2019 Jan 31;191(2):119. doi: 10.1007/s10661-019-7239-0.

This study developed a new method to determine the residues of 13 organophosphorus flame retardants (OPFRs) in drinking water by gas chromatography-tandem mass spectrometry (GC-MS/MS) technique and investigated the chemical distribution in water samples from municipal plants along the Yangtze River in Nanjing. The linear calibration correlation coefficients R2 for all 13 OPFRs were at least 0.998 0. Three levels of spiked test were performed. Most of the recoveries were in the range of 80~120%, and the relative standard deviations (RSDs) for the 13 OPFRs were 2.1~17% (n = 6). Five OPFRs were 100% positively detected in the samples, and 3 OPFRs were positively detected in some samples. The concentrations of detected OPFR in the water ranged from 0.7 to 5780.0 ng L-1. The average concentrations of OPFRs in wet season were higher than those in dry season, and the contaminants mainly originated from the source water in the Yangtze River. The exposure assessments of individual and total OPFRs were investigated. The estimated daily intakes of total OPFRs via ingestion of drinking water reached up to 64.8 and 45.2 ng/kg bw/day in dry and wet season, respectively. This study demonstrates a profile of OPFR distribution in Nanjing municipal water and provides information on human exposure assessment via drinking water in the Nanjing District, China.

PFAS in US source and treated drinking waters

Boone JS, Vigo C, Boone T, Byrne C, Ferrario J, Benson R, Donohue J, Simmons JE, Kolpin DW, Furlong ET, Glassmeyer ST. Per- and polyfluoroalkyl substances in source and treated drinking waters of the United States. The Science of the total environment. 2018 Oct 18;653:359-369. doi: 10.1016/j.scitotenv.2018.10.245.

Contaminants of emerging concern (CECs), including per- and polyfluoroalkyl substances (PFAS), are of interest to regulators, water treatment utilities, the general public and scientists. This study measured 17 PFAS in source and treated water from 25 drinking water treatment plants (DWTPs) as part of a broader study of CECs in drinking water across the United States. PFAS were quantitatively detected in all 50 samples, with summed concentrations of the 17 PFAS ranging from <1 ng/L to 1102 ng/L. The median total PFAS concentration was 21.4 ng/L in the source water and 19.5 ng/L in the treated drinking water. Comparing the total PFAS concentration in source and treated water at each location, only five locations demonstrated statistically significant differences (i.e. P < 0.05) between the source and treated water. When the perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) concentrations in the treated drinking water are compared to the existing US Environmental Protection Agency’s PFOA and PFOS drinking water health advisory of 70 ng/L for each chemical or their sum one DWTP exceeded the threshold. Six of the 25 DWTPs were along two large rivers. The DWTPs within each of the river systems had specific PFAS profiles, with the three DWTPs from one river being dominated by PFOA, while three DWTPs on the second river were dominated by perfluorobutyric acid (PFBA).

A comparison of management strategies for trace organic chemicals in water

Bieber S, Snyder SA, Dagnino S, Rauch-Williams T, Drewes JE. Management strategies for trace organic chemicals in water – A review of international approaches. Chemosphere. 2017 Dec 16;195:410-426. doi: 10.1016/j.chemosphere.2017.12.100.

To ensure an appropriate management of potential health risks and uncertainties from the release of trace organic chemicals (TOrCs) into the aqueous environment, many countries have evaluated and implemented strategies to manage TOrCs. The aim of this study was to evaluate existing management strategies for TOrCs in different countries to derive and compare underlying core principles and paradigms and to develop suggestions for more holistic management strategies to protect the environment and drinking water supplies from the discharge of undesired TOrCs. The strategies in different industrial countries were summarized and subsequently compared with regards to three particular questions: 1) Do the approaches different countries have implemented manage all or only specific portions of the universe of chemicals; 2) What implementation and compliance strategies are used to manage aquatic and human health risk and what are their pros and cons; and 3) How are site-specific watershed differences being addressed? While management strategies of the different countries target similar TOrCs, the programs differ in several important aspects, including underlying principles, the balance between aquatic or human health protection, implementation methods, and financing mechanisms used to fund regulatory programs.

Occurrence of Illicit Drugs in Water and Wastewater

Meena K.Yadav, Michael D. Short, Rupak Aryal, Cobus Gerber, Benvan den Akker, Christopher P. Saint. Occurrence of illicit drugs in water and wastewater and their removal during wastewater treatment. Water Research Vol. 124, Nov. 2017, p713-727. 

This review critically evaluates the types and concentrations of key illicit drugs (cocaine, amphetamines, cannabinoids, opioids and their metabolites) found in wastewater, surface water and drinking water sources worldwide and what is known on the effectiveness of wastewater treatment in removing such compounds. It is also important to amass information on the trends in specific drug use as well as the sources of such compounds that enter the environment and we review current international knowledge on this. There are regional differences in the types and quantities of illicit drug consumption and this is reflected in the quantities detected in water. Generally, the levels of illicit drugs in wastewater effluents are lower than in raw influent, indicating that the majority of compounds can be at least partially removed by conventional treatment processes such as activated sludge or trickling filters. However, the literature also indicates that it is too simplistic to assume non-detection equates to drug removal and/or mitigation of associated risks, as there is evidence that some compounds may avoid detection via inadequate sampling and/or analysis protocols, or through conversion to transformation products. Partitioning of drugs from the water to the solids fraction (sludge/biosolids) may also simply shift the potential risk burden to a different environmental compartment and the review found no information on drug stability and persistence in biosolids. Generally speaking, activated sludge-type processes appear to offer better removal efficacy across a range of substances, but the lack of detail in many studies makes it difficult to comment on the most effective process configurations and operations. There is also a paucity of information on the removal effectiveness of alternative treatment processes. Research is also required on natural removal processes in both water and sediments that may over time facilitate further removal of these compounds in receiving environments.

Development of Drinking Water Guidelines for Perfluoroalkly acids

Post GB, Gleason JA, Cooper KR. Key scientific issues in developing drinking water guidelines for perfluoroalkyl acids: Contaminants of emerging concern. PLoS Biol. 2017 Dec 20;15(12):e2002855. doi: 10.1371/journal.pbio.2002855.

Perfluoroalkyl acids (PFAAs), a group of synthetic organic chemicals with industrial and commercial uses, are of current concern because of increasing awareness of their presence in drinking water and their potential to cause adverse health effects. PFAAs are distinctive among persistent, bioaccumulative, and toxic (PBT) contaminants because they are water soluble and do not break down in the environment. This commentary discusses scientific and risk assessment issues that impact the development of drinking water guidelines for PFAAs, including choice of toxicological endpoints, uncertainty factors, and exposure assumptions used as their basis. In experimental animals, PFAAs cause toxicity to the liver, the immune, endocrine, and male reproductive systems, and the developing fetus and neonate. Low-dose effects include persistent delays in mammary gland development (perfluorooctanoic acid; PFOA) and suppression of immune response (perfluorooctane sulfonate; PFOS). In humans, even general population level exposures to some PFAAs are associated with health effects such as increased serum lipids and liver enzymes, decreased vaccine response, and decreased birth weight. Ongoing exposures to even relatively low drinking water concentrations of long-chain PFAAs substantially increase human body burdens, which remain elevated for many years after exposure ends. Notably, infants are a sensitive subpopulation for PFAA’s developmental effects and receive higher exposures than adults from the same drinking water source. This information, as well as emerging data from future studies, should be considered in the development of health-protective and scientifically sound guidelines for PFAAs in drinking water.

Persistent Organic Pollutants in the River Niger

Unyimadu JP, Osibanjo O, Babayemi JO. Selected persistent organic pollutants (POPs) in water of River Niger: occurrence and distribution. Environ Monit Assess. 2017 Dec 6;190(1):6. doi: 10.1007/s10661-017-6378-4.

This study assessed the levels and distribution of selected persistent organic pollutants (POPs) in water of River Niger. The selected POPs of interest were organochlorine pesticides (OCPs). Fifteen representative sites along River Niger: three each from Gurara River (tributary) in Niger State, Lokoja (confluence) in Kogi State, Onitsha in Anambra State, Brass and Nicolas Rivers (tributaries) in Bayelsa State were selected for sampling quarterly over a 24-month period. A total of 240 surface and bottom water samples were collected using Van Dorn water sampler in the eight quarters of 2008-2009. At the Delta locations where tidal effects take place, high- and low-tide water samples were taken as compared to surface and bottom at the River Niger locations. For sample extraction, EPA method 3510c was employed with slight modifications. Certified reference standards from Accustandards USA was used for the instrument calibration and quantification of OCPs. The extracted samples were subjected to gas chromatography (GC/ECD) for identification/quantification. And Shimadzu GCMS QP2010 was used for confirmation. Chlordane, endosulfan, endrin and DDT metabolites were very prominent in the water samples, compared to HCH, dieldrin, and isomers which occurred at lower concentrations. The sequence in the concentration of the organochlorine pesticides were ∑chlordane > ∑DDT > ∑endosulfan > ∑endrine > ∑dieldrin > ∑HCH. The highest concentration of ∑OCPs in water samples of River Niger, 1138.0 ± 246.7 ng/L, with range 560.8-1629 ng/L was detected at Onitsha location, while the lowest concentration, 292.6 ± 74.9, with range 181-443.0 ng/L was detected at Nicolas River. Levels of OCPs in a larger percentage of the samples exceeded guidelines and therefore hold potential harmful effects on benthic fauna, fish, and man. Abstraction of water from the River for drinking water treatment should be discouraged. Because of the potential danger, this presents, continuous monitoring of the water body and if possible remediation, determination of the sources of the POPs is therefore very necessary.