Paper No. 8
Presentation Time: 10:15 AM
THE INCLUSION OF ARSENIC, LEAD AND MERCURY AS BIOPHILE ELEMENTS
Arsenic, lead, and mercury have great affinity to concentrate in the biosphere. Under certain conditions they will reach relatively high concentrations in coal and humans. Log plots of man versus ocean show associations of As, Hg, and Pb with biophile elements. The ratios of human/ocean for As, Hg, and Pb are 43.5, 1,720, and 56,600, respectively. The ratios of average coal to crust for As, Hg, Pb are 11.4, 2.5, and 1.1, respectively. Arsenic and mercury are biophile elements because they form methyl compounds with carbon and can build up in the food chain. Lead, because it has the same charge and a similar ionic radius to calcium, builds up in the human body when ingested. This is especially true in young children (below 6 years old) that require high levels of calcium to grow. Toxic levels of Ar, Pb, and Hg can result in death to all ages. Less than toxic levels can cause birth defects and brain damage (Hg), cancer and skin warts (As), and brain damage and lower IQ (Pb). Our research indicates that classification of these traditional chalcophile elements as biophile elements is indispensable to future proper understanding and utilization of arsenic, lead, and mercury in the modern industrial, developing, and impoverished world. In Georgia with its warm humid climate (~50 inches rain/year) lead, arsenic, and mercury are significant concerns. Where fish consumption guidelines occur for Georgia lakes mercury is listed as the cause of contamination 71% of the time. For streams and rivers that have fish consumption guidelines mercury is the cause 83% of the time. Pressure treated wood is laced with arsenic with one landscape timber containing about one ounce of arsenic. Fieldwork in rural west Georgia finds life-time guaranteed arsenic-treated landscape timbers less than ten years old that are occupied by fire ants and termites. Monitoring of arsenic-treated landscape timbers was done from 1992 to 2004. New timbers show progressive changes that include fading of color, intense summer drying, development of open cavities on the surface in contact with the ground, progressive development of cavities throughout the timber, and invasion of the timbers by fire ants and termites. Complete disassociation of older timbers occurs. At one ounce arsenic per timber extensively landscaped yards may contain 70 ounces arsenic per acre.