Copper and gold smelting began in Trail, BC, in 1896. Today the community is home to the largest lead-zinc smelter operation in the world, and Teck Cominco Metals Ltd. is the region’s largest employer (Figure 1). Beginning in 1975, childhood lead poisoning, lead contamination, and other undesirable effects of smelting activities, including the appearance of the plants and the noise and odour they generate, became a cause of concern for the community.
The high rates of childhood lead poisoning from the smelter first became apparent when Neri and his colleagues (1978) reported average blood lead levels of 22 mg/dL among children who were 12 to 36 months of age.1 In a more comprehensive study, conducted in 1989, Clyde Hertzman and his colleagues reported a geometric mean blood lead level of 13.1 mg/dl among children aged 24 to 72 months; almost 40% of children had blood lead levels above 15 ug/dL.2 In recognition of the high lead levels, the Trail Community Lead Task Force was established in 1990 to create a comprehensive childhood lead exposure prevention program. The members of the task force, which included industry, government, and community representatives, took several actions to address contamination: they studied exposure pathways, conducted comprehensive education and case-management programs, and monitored blood lead levels in children each year.
In 1997, the opening of a new state-of-the-art smelter led to a reduction in airborne lead concentrations. Between 1994 and 1999, environmental monitoring data showed that levels of lead in indoor settled dust had declined by 50% (Figure 2). At the same time, children’s blood lead levels in Trail had declined (Figure 3).34
The most recent results from the community blood lead monitoring found that the average blood lead level among children aged 6 to 36 months was 5.4 mg/dL,5 a significant reduction from the 1989 levels (Figure 4). Still, approximately 3% of children under the age of 3 in Trail were found to have a blood lead level of 15 μg/dL or greater, well above Canada’s current action guideline of 10 mg/dL, and considerably higher than the levels of other children in Canada.5 Thus, despite some success in reducing exposure, children in Trail are still at risk of lead poisoning.
- 1. Neri LC, Johansen HL, Schmitt N, et al. Blood lead levels in children in two British Columbia communities. In: Hemphill DD (ed). Trace substances in environmental health—XII, Proceedings of the University of Missouri’s 12th Annual Conference on Trace Substances in Environmental Health, 6-8 June 1978, Columbia, MO. Columbia: University of Missouri; 1978. p. 403-409.
- 2. Hertzman C, Ward H, Ames N, et al. Childhood lead exposure in Trail revisited. Can J Public Health. 1991;82:385-391.
- 3. Hilts SR, Bock SE, Oke TL, et al. Effects of interventions on children’s blood lead levels. Environ Health Perspect. 1998;106:79-83. www.ncbi.nlm.nih.gov/pmc/articles/PMC1533008/.
- 4. Hilts SR. Effect of smelter emission reductions on children's blood lead levels. Sci Total Environ. 2003;303:51-58. http://dx.doi.org/10.1016/S0048-9697(02)00357-1.
- 5. a. b. Trail Health and Environment Committee. Fall 2012 Blood Lead Results. 2012. www.thep.ca/pages/reports