One-year follow-up of perfluorinated compounds in plasma of German residents from Arnsberg formerly exposed to PFOA-contaminated drinking water.

In Arnsberg, Sauerland area Germany, 40000 residents were exposed to PFOA-contaminated drinking water (500-640ng PFOA/l; May 2006). In July 2006, the PFOA-concentrations in drinking water were lowered significantly by activated charcoal filtering in the waterworks, mostly below the limit of detection (10ng/l). A first human biomonitoring study performed in autumn 2006 revealed that PFOA-concentrations in blood plasma of residents living in Arnsberg were 4.5-8.3 times higher than in the reference groups. One year after the first survey, all participants (2006: 164 mothers, 90 children, 101 men) were invited to take part in a follow-up study. It was the aim of the study to determine the decline of the PFOA-concentrations in blood plasma. 288 persons (81%) were included in the statistical analysis. The (geometric) mean PFOA-concentrations in blood plasma of Arnsberg's residents decreased from 22.1 to 17.4 microg/l in children, from 23.4 to 18.8 microg/l in mothers and from 25.3 to 23.4 microg/l in men within one year. The average (geometric mean) changes in each individual's PFOA-concentrations were approximately 10 (men), 17 (mothers) and 20 (children) percent/year. The observed decline in PFOA-concentrations indicates a slow elimination in humans. This finding in groups of the general population is in agreement with data on long elimination half-lives observed in occupationally exposed workers.