Health and environmental impact of mercury in the Philippines using nuclear techniques

Mercury and its compounds are toxic to man and his environment. The toxicity of mercury is dependent on the species i.e. elemental, inorganic and organic forms. The general population may be exposed through occupational and environmental sources. In the Philippines, two major sources of mercury contamination were studied namely small-scale gold mining activities utilizing mercury and pollution brought about by mine tailings in a former mercury mines. Small-scale mining in this report is defined as artisanal operations, labor intensive, low level mechanization using crude methods of mining, extraction and refining procedures. Women and children usually participate in these activities. In another island in the Philippines, a mercury mine was operational from 1955 to 1976 producing about 140,000 kg of mercury yearly. Approximately 2,000,000 tons of mine-waste calcines (retorted ore) were produced during mining and roughly 1,000,000 tons of these calcines were dumped into nearby Honda Bay to construct a jetty to facilitate mine operations where about 2,000 people reside in the nearby three barangays. At present the effects of total mercury exposure combined with Me-Hg consumption remain an important issue especially those of low-dose and continuous uptake. However, information on the effects of low and prolonged exposure of total and methylmercury to offspring throughout their prenatal and postnatal periods have been limited. This study will compare possible health risks of lower level at chronic exposure to total and methylmercury in communities situated near a former mercury mine and a control group with minimal or limited exposure. (author)