title: Disparities in Children's Blood Lead and Mercury Levels According to Community and Individual Socioeconomic Positions.
abstract: We aimed to examine the associations between blood lead and mercury levels and individual and community level socioeconomic positions (SEPs) in school-aged children. A longitudinal cohort study was performed in 33 elementary schools in 10 cities in Korea. Among a total of 6094 children included at baseline, the final study population, 2281 children followed-up biennially, were analyzed. The geometric mean (GM) levels of blood lead were 1.73 μg/dL (range 0.02-9.26) and 1.56 μg/dL (range 0.02-6.83) for male and female children, respectively. The blood lead levels were significantly higher in males, children living in rural areas, and those with lower individual SEP. The GM levels of blood mercury were 2.07 μg/L (range 0.09-12.67) and 2.06 μg/L (range 0.03-11.74) for males and females, respectively. Increased blood mercury levels were significantly associated with urban areas, higher individual SEP, and more deprived communities. The risk of high blood lead level was significantly higher for the lower individual SEP (odds ratio (OR) 2.18, 95% confidence interval (CI) 1.36-3.50 in the lowest educational attainment of the father), with a significant dose-response relationship observed after adjusting for the community SEP. The association between high blood lead levels and lower individual SEP was much stronger in the more deprived communities (OR 2.88, 95% CI 1.27-6.53) than in the less deprived communities (OR 1.40, 95% CI 0.76-2.59), and showed a significant decreasing trend during the follow-up only in the less deprived communities. The risk of high blood mercury levels was higher in higher individual SEP (OR 0.64, 95% CI 0.40-1.03 in the lowest educational attainment of the father), with a significant dose-response relationship noted. Significant decreasing trends were observed during the follow-up both in the less and more deprived communities. From a public health point-of-view, community level intervention with different approaches for different metals is warranted to protect children from environmental exposure.
authors.affiliation: Department of Occupational and Environmental Medicine, Kyung Hee University Hospital, 23 Kyungheedae-Ro, Dongdaemun-Gu, Seoul 130-872, Korea. drforest@hanmail.net.
authors.forename: Sinye
authors.initials: S
authors.lastname: Lim
authors.affiliation: Department of Preventive Medicine, Dankook University College of Medicine, 119 Dandae-Ro, Dongnam-Gu, Cheonan, Chungnam 330-714, Korea. minaha@dku.edu.
authors.forename: Mina
authors.initials: M
authors.lastname: Ha
authors.affiliation: Department of Social Medicine, Inha University School of Medicine, 366 Seohae-Daero, Jung-Gu, Incheon 400-712, Korea. cyberdoc@inha.ac.kr.
authors.forename: Seung-Sik
authors.initials: SS
authors.lastname: Hwang
authors.affiliation: Department of Preventive Medicine, Kangwon National University School of Medicine, 1, Gangwondaehak-Gil, Chuncheon, Gangwon 200-701, Korea. sonmia@empal.com.
authors.forename: Mia
authors.initials: M
authors.lastname: Son
authors.affiliation: Department of Preventive Medicine, Dankook University College of Medicine, 119 Dandae-Ro, Dongnam-Gu, Cheonan, Chungnam 330-714, Korea. hojang@dku.edu.
authors.forename: Ho-Jang
authors.initials: HJ
authors.lastname: Kwon
mesh_terms: D002648:Child; D015331:Cohort Studies; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D006801:Humans; D007854:Lead / Q000097:blood*; D008297:Male; D008628:Mercury / Q000097:blood*; D056910:Republic of Korea; D012111:Residence Characteristics; D012959:Socioeconomic Factors
chemical_list: D007854:Lead; D008628:Mercury
keywords: blood lead; blood mercury; children; community intervention; socioeconomic position