Dissolved Heavy Metals in Water
Mercury, silver, cadmium, chromium, copper, lead, nickel and zinc are heavy metals present in fresh waters.
They are toxic to man and aquatic organisms in varying degrees and concentrations. They can be serious pollutants because these stable compounds can have persistent toxic effects for many years following their deposit.
The heavy metal compounds of chromium, cadmium, mercury and lead have minute biological function in animal life but can act synergistically with other substances to increase toxicity.
Some toxic effects are cumulative and are harmful to the degree that the dosage and resultant concentrations approach lethal thresholds.
Non-Metals in Water