Health related studies of organic compounds in relation to re-use in the United Kingdom.

Approximately one third of the water supplies in the United Kingdom are derived from lowland rivers receiving industrial and domestic effluent and in some cases the level of indirect re-use may be high. Research, funded by the Department of the Environment, is being undertaken to identify any potentially hazardous organic compounds that may be present in such supplies and to determine whether there is evidence of any effects on the health of the relevant populations. Analysis of drinking water from various types of source has shown that a wide variety of organic compounds is present in drinking water derived from groundwater and polluted lowland rivers but with few exceptions concentrations are much higher in the latter case. The mutagenicity screening of water samples as a means of directing analytical effort at the substances of greatest potential health significance is being investigated. In a study of cancer mortality in 29 London boroughs an association between high levels of re-use and cancers of the gastrointestinal and urinary tracts disappeared when socioeconomic characteristics and borough size were taken into account. A national study is now being undertaken.