[Trihalomethane levels in drinking water in the province of Granada [Spain]]

Drinking water chlorination generates potentially harmful by-products, such as trihalomethanes. Trihalomethane levels are high in some parts of Spain. The aim of the present study was to investigate trihalomethane concentrations in drinking water from distinct water supplies in the province of Granada, within the framework of the Childhood and Environment (INMA) study.

Eighty-two tap water samples were collected in two campaigns during the winter and summer of 2006. An optimized procedure based on gas chromatography and mass spectrometry was used to determine concentrations of chloroform, bromodichloromethane, dibromochloromethane, and bromoform in the samples.

Total trihalomethane concentrations ranged from 0.14 to 18.75 microg/l in winter samples and from 0.01 to 31.87 microg/l in summer samples. The most abundant compound was chloroform. Mean trihalomethane concentrations were 10.13 in surface waters and 1.41 microg/l in ground waters.

The trihalomethane levels found were considerably below the maximum permitted level of 100 microg/l in the European Union. The values obtained varied widely according to the type of water source: the highest concentrations were found in urban and sub-urban areas, where the water is largely of surface origin. The presence of trihalomethanes was lower than that reported in other Spanish regions.