Glacial episodes have been linked to Ordovician-Silurian extinction events, but cooling itself may not be solely responsible for these extinctions. Teratological (malformed) assemblages of fossil plankton that correlate precisely with the extinction events can help identify alternate drivers of extinction. Here we show that metal poisoning may have caused these aberrant morphologies during a la...

Using two biological characteristics of the land snail (subspecies Helix aspersa aspersa and Helix aspersa maxima), i.e., soil eating and crawling on wet surfaces, methods were developed to assess the bioavailability of heavy metals (Cd, Cr, Pb, and Zn) from soil and aqueous leachates of soil. Measurement of heavy-metal concentrations in soil, leachates, and soft tissues of snails showed that c...

Industrial activities and high traffic density are the most important heavy metal pollution sources in urban areas. Roadside dust created by atmospheric deposition can be one of the best indicators for heavy metal contamination levels. The present study reports the spatial distribution patterns and degree of heavy metal pollution (Cd, Cr, Ni, Pb, Zn, and As) in 50 roadside dust samples from urb...

this study at first level focused on definitions and descriptions of  some landfills and landfills sites all around the world and  survey on how important they are for regional governments and responsible in duty  as a very important responsibility for locals and their health. at the second level we had a look on heavy metals concentration which are by many definitions as follows: lead, nickel,...

For the past three decades it has been known that considerable numbers of South African children have blood lead levels that exceed international guidelines. The health effects associated with even very low blood lead levels are beyond doubt, and include reductions in IQ scores, an inability to concentrate and learning difficulties. There is also an emerging body of evidence that links lead exp...

Metal phosphides in general and aluminium phosphide in particular are potent insecticides and rodenticides. These are commercially used for protection of crops during storage, as well as during transportation. However, these are highly toxic substances. Their detrimental effects may range from nausea and headache to renal failure and death. It is, therefore, pertinent to ensure their circumspec...

background: the most important factors and problems threatening the anzali wetland are the contaminant load and sediments entering the wetland, as well as lack of an integrated management plan for this wetland. the main objectives of the current research were to explore whether there are significant differences in concentrations of zn, cd, and pb in surface sediments among different sites (base...

background: a pot experiment was conducted to determine the toxic effects of some heavy metals on the plant growth and seed yield of maize (zea mays l.). materials and metheds: heavy metals mn, pb, cd, cr and co individually and in combinations were added as chloride salts in solutions to the pots before sowing. the test plants for were harvested after 80 days of germination and evaluated for n...