The transfer of heavy metals through trophic levels and their toxicity effects on organisms including humans

This research has investigated a number of topics pertaining to the effects of metalliferous mining. The combination of these has shown that past mining activities and their resultant waste have led to the accumulation of metals through trophic levels. During visits to Blanchdown Wood, Devon, UK and Snailbeach, Shropshire, UK, samples were collected to examine the effects of the spoil tips on the surrounding ecosystem. Samples of vegetation, soil and animal materials were extracted and analysed by inductively coupled plasma-optical emission spectrometry for the presence of heavy metals and were found to contain varying concentrations of lead, copper, arsenic, tin, tungsten and zinc. Laboratory investigations followed to determine the toxicity effects of lead, copper, and tungsten on Pandorina morum. This demonstrated that although single elements have effects on population growth, a combination of the three cations had pronounced and cumulative effects. It was found that the algae reduced the concentration of lead in the nutrient media, but it was not possible to determine whether lead was accumulated by the algae or adhered to the surface of the cells. In either case it is hypothesized that lead could then be transferred to the succeeding trophic levels. Further samples examined included archaeological finds, such as Anglo-Saxon human skeletons from a non-mining area. The concentrations of lead in these samples indicated that the population had been exposed to lead, and this is further explored. Since the population resided in a non-mining area, it is suggested that the contaminant was ingested via trophic level inputs; thus, providing further evidence certain metals are available to be transferred through the trophic levels to be stored in the human skeleton