Temporal variation of heavy metal contamination in fish of the river lot in southern France.

The present study aims at assessing the current situation of the heavy metal contaminated River Lot (SW France). Several fish species were captured in October 1987 and 2007 at three sampling sites. The concentration of copper, zinc, cadmium and lead were quantified in fish muscle and liver as well as in environmental samples (water, sediment, moss). The decrease in heavy metal concentrations in fish tissue between 1987 and 2007 reflects the decrease of heavy metal concentrations in the environment. Concentrations found in 2007 are comparable to those published by a study conducted in the 1990s. The situation of the River Lot has improved over the last 2 decades, although there is still margin for amelioration according to US EPA criterion to protect freshwater aquatic life. The average concentrations of cadmium in fish muscle in 2007 were above the maximum safe for human consumption defined by the European Commission.