Perfluurinated Chemicals in Drinking and Environmental Waters

摘要

Perfluorinated chemicals (PFCs) have been used for many years as surfactants in a variety of industrial and consumer products with the main ones being perfluorooctane sulphonate (PFOS) and perfluorooctanoic acid (PFOA). However, owing to their persistent, bioaccumulative and toxic (PBT) characteristics, PFOS has been phased out by its principal producer and the use of PFOA has been severely reduced. In their place, a number of newer PFCs are being introduced and, while they appear to have a shorter persistence in humans and the environment, their toxicity is at present uncertain and further studies are required. Recent monitoring studies suggest that these other newer PFCs and previously unmonitored breakdown products, are detected in environmental waters, in some cases at levels similar to those of PFOS and PFOA. Some new data are described which indicate that PFOS, PFOA and other PFCs can be removed by granular activated carbon absorption, such as that seen in advanced drinking water treatment, under appropriate controlled conditions, although these conditions vary with different PFCs. The data suggest that the toxicology of PFCs is complex with PFOS and PFOA having different effects at varying concentrations in different species. Cancer, developmental delays, endocrine disruption, immunotoxicity and neonatal mortality are all potential toxic endpoints. Contamination and occupational exposure have led to a number of ongoing epidemiological studies in populations exposed to high levels of PFOS or PFOA, as well as on those with background exposure. Many of these studies are examining reproductive and developmental endpoints. The work is ongoing but at present, the results are inconsistent with only small effects, if any, being observed in populations exposed to high levels of PFOA. Monitoring suggests that, although PFOS and PFOA are persistent, controls on their manufacture and use since 2000 have led to a decrease in their presence in the human population and the environment.