INTRODUCTION A water sample@ taken from the room in which the test animals were housed throughout the study@ was extracted with methylene chloride and concentrated to 1.0 nl in hexane. An aliquot of the final extract was injected into a gas chronatograph to measure concentrations of Dieldrin@ Heptachlor@ Lindane@ Malathion@ pp'DDT@ and PCB's. Concentrations of arsenic@ cadmium@ lead and selenium in the water sample that was acidified were measured by atomizing the metals in a graphite furnace followed by atomic absorption analysis. Mercury in the sample was reduced to a vapor and driven into a quartz cell at ambient temperatures where the absorption is measured on an atomic absorption spectrophotometer.