Toxic heavy metals: impact on the environment and human health, and treatment with conducting organic polymers, a review.

Water pollution by heavy metals has many human origins, such as the burning of fossil fuels, exhaust gases of vehicles, mining, agriculture, and incineration of solid and liquid wastes. Heavy metals also occur naturally, due to volcanoes, thermal springs activity, erosion, infiltration, etc. This water contamination is a threat for living beings because most heavy metals are toxic to humans and to aquatic life.

Establishment of an EC database of pesticides using a Vibrio fischeri bioluminescence method.

An EC database was established to assess the acute toxicity of 16 PESTANAL pesticide standards and of seven pesticide commercial formulations using a Vibrio fischeri bioluminescence method. Half maximal effective concentration (EC ) is defined as the concentration of pollutant (in this case, pesticide) destroying 50% of the bacteria population and causing 50% bioluminescence inhibition, after a specified exposure time. Linear curves of bioluminescence inhibition versus pesticide concentration and EC values were obtained for exposure times (t) of 5 or 15 min for these pesticides.