Estimating the quantities of persistent chemicals entering coastal waters of England and Wales from land-based sources

Total load estimates of the inputs of Cd, Hg, Cu, Pb, Zn, lindane, total nitrogen, and orthophosphate into coastal waters of England and Wales are made annually. Some 320 inputs are currently routinely sampled and analysed. Results for the period 1990]1996 indicate that reductions have occurred in the inputs of all metals, and that such changes generally reflect actions taken to reduce industrial discharges, and thus the balance of point and diffuse sources. The pattern is however less clear for the other chemicals studied, where inputs are dominated by agricultural activities and changes in river flows.