During the past decade, considerable concern has been expressed by environmental scientists over the increasing levels of a range of toxic elements in the environment. Among the most potentially hazardous are the so-called ‘heavy metals’, a term applied to cover a range of transition elements, including copper, zinc and nickel and other elements such as cadmium, mercury and lead. Acutely toxic ...

This is the second part of a study that evaluates the influence of nonpoint sources on the sediment quality of five adjacent streams within the metropolitan Kansas City area, central United States. Physical, chemical, and toxicity data (Hyalella azteca 28-day whole-sediment toxicity test) for 29 samples collected in 2003 were used for this evaluation, and the potential causes for the toxic effe...

Various metals, in trace amounts, are essential for proper biological functioning. However, there are many heavy metals that are toxic and exposure to their high intake may result in serious adverse effects on health. Cadmium (Cd) is one of the most toxic pollutants in environment. Accumulation of Cd in blood affects the kidney and liver. The toxicity of cadmium is much affected by deficiency o...

Mixtures of metals are often present in surface waters, leading to toxicity that is difficult to predict. To provide data for development of multimetal toxicity models, Daphnia magna neonates were exposed to individual metals (Cd, Cu, Ni, Zn) and to binary combinations of those metals in standard 48-h lethality tests conducted in US Environmental Protection Agency moderately hard reconstituted ...

Pollution of the environment with toxic metals is widespread and often involves large volumes of wastewater. Remediation strategies must be designed to support high throughput while keeping costs to a minimum. Biosorption is presented as an alternative to traditional physicochemical means for removing toxic metals from wastewater. We have investigated the metal binding qualities of two biomass ...

Juvenile hybrid tilapia (Oreochromis sp.) was tested with different concentration of heavy metals under varying exposure time to examine acute toxicity effect on their survival rate and bioaccumulation in fish tissues. Copper (Cu), cadmium (Cd) and zinc (Zn) was used at rates 0.0, 0.50, 1.0, 3.0 and 5.0 mg L-1. The medial lethal concentration of Cu, Cd and Zn (96h LC50) was determined to be 0.4...

ticular concern are “heavy metals,” which occur naturally in the earth’s crust and are defined in physiochemical terms as metals with a density at least 5 times as great as water. This definition translates into an approximate heavy-metal minimum density of 5, and—in addition to cadmium, lead, and mercury—the metals zinc, copper, iron, cobalt, nickel, tin, manganese, and molybdenum also qualify...