T Lundh1, A Axmon2, S Skerfving3, K Broberg4. 1. Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE-22185 Lund, Sweden. Electronic address: Thomas.Lundh@med.lu.se. 2. Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE-22185 Lund, Sweden. Electronic address: Anna.Axmon@med.lu.se. 3. Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE-22185 Lund, Sweden. Electronic address: Staffan.Skerfving@med.lu.se. 4. Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE-22185 Lund, Sweden; Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Nobels väg 13, SE-171 77 Stockholm, Sweden. Electronic address: Karin.Broberg@ki.se.
Abstract
PURPOSE: Knowledge about changes in exposure to toxic metals over time remains very sparse, in particular for children, the most vulnerable group. Here, we assessed whether a reduction in environmental pollution with cadmium (Cd) and mercury (Hg) caused a change in exposure over time. In total, 1257 children (age 4-9) in two towns in Sweden were sampled once in 1986-2013. Blood concentrations of Cd (b-Cd; n=1120) and Hg (b-Hg; n=560) were determined. RESULTS: The median b-Cd was 0.10 (geometric mean 0.10; range 0.010-0.61) μg/L and b-Hg was 0.91 (geometric mean 0.83; range 0.021-8.2) μg/L. Children living close to a smelter had higher b-Cd and b-Hg than those in urban and rural areas. There was no sex difference in b-Cd or b-Hg, and b-Cd and b-Hg showed no significant accumulation by age. b-Cd decreased only slightly (0.7% per year, p<0.001) over the study period. In contrast, b-Hg did show a clear decrease over the study period (3% per year, p<0.001). CONCLUSIONS: The exposure to Cd was very low but still might increase the risk of disease later in life. Moreover, b-Cd only showed a minor decrease, indicating that Cd pollution should be further restricted. b-Hg was relatively low and decreasing, probably because of reduced use of dental amalgam and lower Hg intake from fish. The b-Cd and b-Hg levels decreased much less than the levels of lead in the blood as previously found in the same children.
PURPOSE: Knowledge about changes in exposure to toxic metals over time remains very sparse, in particular for children, the most vulnerable group. Here, we assessed whether a reduction in environmental pollution with cadmium (Cd) and mercury (Hg) caused a change in exposure over time. In total, 1257 children (age 4-9) in two towns in Sweden were sampled once in 1986-2013. Blood concentrations of Cd (b-Cd; n=1120) and Hg (b-Hg; n=560) were determined. RESULTS: The median b-Cd was 0.10 (geometric mean 0.10; range 0.010-0.61) μg/L and b-Hg was 0.91 (geometric mean 0.83; range 0.021-8.2) μg/L. Children living close to a smelter had higher b-Cd and b-Hg than those in urban and rural areas. There was no sex difference in b-Cd or b-Hg, and b-Cd and b-Hg showed no significant accumulation by age. b-Cd decreased only slightly (0.7% per year, p<0.001) over the study period. In contrast, b-Hg did show a clear decrease over the study period (3% per year, p<0.001). CONCLUSIONS: The exposure to Cd was very low but still might increase the risk of disease later in life. Moreover, b-Cd only showed a minor decrease, indicating that Cd pollution should be further restricted. b-Hg was relatively low and decreasing, probably because of reduced use of dental amalgam and lower Hg intake from fish. The b-Cd and b-Hg levels decreased much less than the levels of lead in the blood as previously found in the same children.