THE HEALTH SIGNIFICANCE OF PAH IN DRINKING WATER
Report No FR0425
W F YOUNG
Understanding the health significance of polycyclic aromatic hydrocarbons (PAHs) commonly found in some drinking water supplies, will better enable the water industry to prioritise improvement programmes in relation to potential health-related problems. Understanding their significance to health will also aid in the derivation of a scientifically justifiable basis for regulating PAH in drinking water.
To review the occurrence and toxicity of the six regulated PAHs and any others likely to be present in water and prioritise these according to their toxicological risk.
Trace concentrations of PAH are commonly detected in some drinking waters due to the historical use of internal coal-tar pitch linings in cast iron distribution pipes. Some supplies can exceed the UK PAH standard of 200 ng l-1 which is specified for the sum of six named PAHs. However, this value as well as the six 'representative ' PAHs are not based on toxicological considerations. Affected water suppliers, therefore, need to be aware of the health effects of PAHs in order to understand the significance, if any, when the standard for total PAH is exceeded.
Based on the available evidence, it would appear that the concentrations of PAH which are commonly detected in drinking water are unlikely to be of significant risk to human health.
This report is presented as an extended summary with a discussion of the legislation, occurrence and health concerns of PAH commonly found in drinking water, with emphasis on the implications for the water industry. More detailed technical information to support these findings is given in the appendices.
Copies of the Report are available from FWR, price £25.00 less 20% to FWR Members