Perfluorinated compounds are a large class of chemicals (several hundred molecules) manufactured since the 1950s, that are used in many industrial applications and everyday consumer products. Highly persistent and resistant to degradation, these compounds are found in all environmental compartments and in the food chain. Among these substances, PFOA and PFOS have been closely examined as they are the final degradation products of the most widely used perfluorinated compounds.
At present, the toxicity of some of these compounds is raising questions, with some of them being suspected of having endocrine disruption effects.
Water is an important vector in the dissemination of these substances. Recently, some American States, the US EPA and Germany proposed regulatory values in drinking water for certain perfluorinated compounds.
In this context and in particular following the discovery of heavily polluted sites in the United States and Germany, the French Ministry of Health sought to obtain a national snapshot of the presence of perfluorinated compounds in water resources and in drinking water. It commissioned ANSES and its Nancy Laboratory for Hydrology to perform this study.
A campaign conducted in two phases
The analysis campaign was conducted in two phases, on raw and treated water.
- a first round of tests, conducted in summer 2009, aimed to characterise the presence of these substances at the national level. A sampling plan was therefore developed mainly to obtain a homogeneous national coverage by taking into account at least two samples from each French département, including those in the overseas territories, and to use sampling points whose cumulative flows accounted for at least 20% of national production;
- the second round of tests (June 2010) aimed to confirm the results of the first round and to study possible temporal fluctuations.
In total, 331 raw water samples and 110 treated water samples were analysed using a method developed by the Laboratory for Hydrology. Ten perfluorinated compounds were screened for simultaneously: PFOS, PFHxS, PFBS, PFDA, PFNA, PFOA, PFHpA, PFHxA, PFPeA and PFBA.
Regarding environmental contamination, industrial discharges related to perfluorinated compound manufacturing processes were among the main sources. Further investigations were therefore conducted at two industrial sites producing perfluorinated compounds, to measure the presence of these substances at the industrial facilities themselves, as well as in downstream water resources in order to measure the impact of the discharges.
Results in keeping with existing data
Of the approximately 450 samples analysed, only 25% had sufficient levels of perfluorinated compounds to enable measurement, as the concentrations in the remaining samples were too low.
The three perfluorinated compounds found most commonly in raw water were PFOS, PFHxS and PFOA.
The three perfluorinated compounds found most commonly in treated water were PFOS, PFHxA and PFHxS.
With regard to the regulatory values proposed in the US and Germany for PFOA and PFOS (300 ng/L for PFOA+PFOS in Germany), the maximum values found in treated water during this study were 4-30 times lower, depending on the comparison basis used. In the vicinity of the industrial sites manufacturing perfluorinated compounds, values approaching the thresholds set in Germany were measured, but they did not exceed these thresholds for treated wastewater.
With some exceptions, few significant temporal fluctuations were observed during the two campaigns. The few cases where large fluctuations were observed mainly concerned surface water resources.
An initial investigation with high added value
As a result of this first major study on the presence of perfluorinated compounds in water, ANSES is able to issue a number of recommendations with which to establish a monitoring scheme for perfluorates in water:
- the Agency considers it advisable not to limit any health monitoring of the water to the analysis of PFOA and PFOS alone, but to include the compounds whose presence appeared high in this study (PFHxA and PFHxS). Within this framework, the Agency will be initiating risk assessment work on these different compounds to provide the authorities with a useful scientific and health basis for establishing possible regulatory thresholds;
- particular attention should be paid to surface water resources affected by industrial sites, mainly in order to better understand the magnitude of temporal variations in concentrations of perfluorinated compounds, to more thoroughly ascertain the quality of water distributed for human consumption in connection with these resources, and to seek a reduction in discharges at the source. Investigating all these aspects could lead to a better assessment of the exposure level, the populations affected and the exposure history;
- in terms of research, the fate of perfluorinated compounds and their precursors in drinking water systems should be further studied, particularly in order to better identify which systems are currently most effective. This work is related to European discussions on the next revision of the Water Framework Directive and the Drinking Water Directive, which could include new parameters to be monitored;
- finally, knowledge of management methods for solid waste in use in France, where these substances have now been used for some time, should allow targeting of other potentially exposed water resources and avoidance of cases similar to those found in Germany and the USA.
What is ANSES doing with regard to perfluorinated compounds?
ANSES is addressing the issue of perfluorinated compounds from various complementary angles:
Acquisition of data on the presence of perfluorinated compounds in water and food
The study conducted by ANSES's Nancy Laboratory for Hydrology has provided us with an initial status report on the presence of perfluorinated chemicals in water resources and in water intended for human consumption. As part of its partnership with ONEMA (the French National Agency for Water and Aquatic Environments), the Agency will be participating in studies on contamination of water resources and its impact on ecosystems.
In parallel, within the framework of the second total diet study (TDS2) whose results will be published in late June, 16 perfluorinated compounds were screened for in the analysed foods.
In 2009, the Agency issued an opinion on residues of PFOA in non-stick coatings for cookware.
As part of its substantial response to a recent solicited request on endocrine disruptors, the Agency will be assessing the risks of PFOA and PFOS. This work will focus on around thirty substances identified as of concern for their reprotoxicity and/or endocrine disruption effects. For each substance the hazards will be described, uses identified, mainly through implementation of a sector study, and exposure of the general population will be evaluated, in order ultimately to assess the risks through the use of products and/or items intended for the general public (the scope will exclude food, drugs, cosmetics and plant protection products). Another objective of this work will be to identify possible substitutes, particularly for substances for which a health risk has been highlighted, or substances which, because of the hazards they pose to health or the environment, are the subject of restriction processes under REACh.
This work will span several years and will give rise to a series of risk assessment reports, each one specific to a given substance. The first report will be published in 2011 and will focus specifically on bisphenol A, then from 2012, reports dealing with other substances will be released.
ANSES is involved in the Contreperf project selected and funded by the French National Research Agency (ANR) for the period 2011-2013. Its aim is to improve knowledge of the impact of perfluorinated compounds on health through four work themes:
- assaying of perfluorinated chemicals in food matrices (fish and breast milk);
- study of mother-child transfer through the assaying of blood samples from the mother and umbilical cord;
- study of the metabolism and toxicological impact, particularly hormonal disturbances;
- external exposure and relationship with blood concentrations in women of childbearing age.