Antimony in drinking-water
Background document for development of WHO Guidelines for Drinking-water Quality
Environmental levels and human exposure
Atmospheric antimony concentrations of about 0.2 ng/m3 were reported for the Alps at Jungfraujoch, Switzerland (Dams & de Jonge, 1976). In more densely populated areas of Europe, levels between 0.6 and 32 ng/m3 were determined in the 1980s (Hurtig, 1990). Concentrations of antimony in air are considered to be lower today because industrial emissions have been significantly reduced by the introduction of dust filters. At present, abrasion of antimony (and other metals) from brakes, tires and street surfaces as well as emission of aerosolic antimony in vehicle exhaust are the main sources of antimony in urban fine dust (Stechmann, 1993). In Göttingen, a medium-sized city in Germany, approximately 176 kg of antimony are emitted annually from the above sources (Plessow et al., 1997).
Exposure of the typical urban population to antimony from air is estimated to be between 60 and 460 ng/day per person (Slooff, 1992).
Antimony does not bioaccumulate, so exposure to naturally occurring antimony through food is very low. Antimony is present in food, including vegetables grown on antimony-contaminated soils, mostly in the low µg/kg wet weight range or less.
Concentrations of antimony in groundwater and surface water normally range from 0.1 to 0.2 µg/litre (Bowen, 1979). Marine antimony concentrations are approximately 0.15 µg/litre (Andreae et al., 1981). Antimony is not likely to occur at significantly higher concentrations in natural waters, except in those areas affected by acid mine drainage.
Domestic wastewater is practically free of antimony, in contrast to wastewater from glass or metal processing enterprises (Enders & Jekel, 1994).
Antimony at one time was considered as a possible replacement for lead in solders, but there is no evidence of any significant contribution to drinking-water concentrations from this source. The concentrations in drinking-water appear to be less than 5 µg/litre (US EPA, 1984; Longtin, 1985).
4 Estimated total exposure and relative contribution of drinking-water
Daily oral uptake of antimony ranges from 10 to 70 µg and therefore appears to be significantly higher than uptake via inhalation. Total exposure from environmental sources (air, soil) and food/drinking-water is very low compared with exposure in the workplace (Gebel, 1999a).