Water Quality and Health - Antimony

Exposure

Canadians can be exposed to antimony via water, air, food and urban dust. The concentrations of antimony detected in Canadian surface water range from 0.001 to 9.1 mg/L. ¹¹ Concentrations are typically less than 10 µg/L and are often closer to 1 µg/L.¹²In a recent survey of water supplies in Newfoundland,¹³samples were taken from both homes and raw water sources (surface water and groundwater); antimony was found at concentrations below 5 µg/L, regardless of the source or type of water. The levels of antimony in community drinking water supplies in New Brunswick were generally less than 5 µg/L; however, in one well water sample, antimony was reported at 17 µg/L. ¹⁴In a survey of municipal water supplies of 88 cities in the United States, the levels of antimony found in tap water were on average less than 0.2 µg/L.¹⁵In an analysis of 3834 drinking water samples collected from randomly selected households in 35 geographic areas of the United States, antimony was found in 16.5% of the samples, at concentrations ranging from 0.6 to 4.0 µg/L, with a mean value of 1.87 µg/L.¹⁶The average intake of antimony from drinking water has been estimated to be less than 8 µg/d. ¹⁷

Antimony concentrations are higher in urban air than in non-urban air, presumably due to fossil fuel combustion, automobile emissions and incineration in urban areas. The mean, median and maximum concentrations of antimony in aerosols at three sites in Quebec, Ontario and Nova Scotia were 0.04-0.10, 0.11-0.23 and 0.37-2.17 ng/m³, respectively.¹⁸Twenty-four-hour samples collected at 10 locations in Washington, DC, yielded average antimony concentrations ranging from 1.1 to 3.0 ng/m³.¹⁹

Concentrations of antimony in meat, freshwater fish, poultry, cereals, fruit and vegetables appear to range from about 1 to 10 ng/g wet weight; significantly higher levels have been measured in marine organisms.⁷The daily intake of antimony from food has not been estimated for Canadians. A study was conducted in 1967 to measure the concentrations of antimony in the diets of children (aged 9 to 12) in 28 U.S. cities. Concentrations of antimony (measured by atomic absorption spectrophotometry) ranged from 0.209 to 0.500 mg/kg of food (weighted average 0.361 mg/kg), resulting in daily dietary intakes between 0.25 and 1.28 mg.²⁰These values are thought to be too high because of the analytical method used.²¹ Iyengar et al.²²estimated the intake of antimony from food for 25- to 30-year-old males in the United States by analysing 201 foods (by instrumental neutron activation analysis) from the U.S. Food and Drug Administration's Total Diet Study. Antimony was found at a mean concentration of 0.0093 ± 0.0014 µg/g dry weight (mixed-diet composite); assuming an adult male consumes approximately 3075 g wet weight or 498 g dry weight (16.2% of wet weight), the authors suggested a total antimony intake of approximately 4.6 µg/d from food.

The information on levels of antimony in Canadian drinking water, air and food was insufficient to allow the determination of national intakes by these three routes of exposure. U.S. exposure levels and intakes are probably a reasonable approximation of Canadian exposure levels and intakes because of the similar environment and food habits in North America. Assuming a contribution of 4.6 µg from food (as calculated above),²⁰0.04 µg from air (calculated using the maximum measured Canadian concentration of 2.17 ng/m³and a daily air intake of 20 m³)¹⁸and 2.8 µg from water (calculated from the mean value of 1.87 µg/L and an average daily water consumption of 1.5 L),¹⁶an adult would receive 7.44 µg of antimony per day; approximately 38% of this total intake would come from drinking water.