Effects of prenatal exposure and co-exposure to metallic or metalloid elements on early infant neurodevelopmental outcomes in areas with small-scale gold mining activities in Northern Tanzania

Environment International

Jennifer Hatfield¹  Francois P. Bernier²  Mange Manyama³  Elias C. Nyanza⁴  Jonathan W. Martin⁵  Deborah Dewey⁶ 

[1] Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Room 294, Heritage Medical Research Building, 3330 Hospital Drive, NW Calgary, AB T2N 4N1, Canada;Department of Environmental, Occupational Health and GIS, School of Public Health, Catholic University of Health and Allied Sciences, P.O. Box 1464, Bugando, Mwanza, Tanzania;Department of Medical Genetics, Cumming School of Medicine, 3330 Hospital Drive NW University of Calgary, Canada;Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada;Department of Paediatrics, University of Calgary, Alberta Children’s Hospital, 28 Oki Drive NW, Calgary, AB T3B 6A8, Canada;Science for Life Laboratory, Department of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden;

关键词: Lead, Mercury;    Arsenic;    Cadmium;    Co-exposure;    Artisanal and small-scale gold mining;    Neurodevelopmental impairment;   

DOI  :  

来源: DOAJ

【 摘 要 】

Background: Artisanal and small-scale gold mining (ASGM) is associated with release of neurotoxic metallic or metalloid chemical elements including lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As). Objective: To examine associations between prenatal exposure and co-exposure to total lead (T-Pb), total mercury (T-Hg), total cadmium (T-Cd) and total arsenic (T-As) and infant neurodevelopment at 6 to 12 months of age in areas with ASGM activities in Tanzania. Methods: Women in their second trimester of pregnancy who resided in ASGM areas were enrolled from 2015 to 2017 (n = 883). At 6 to 12 months of age, children were assessed with the Malawi Developmental Assessment Tool (MDAT) (n = 439). We measured T-Pb, T-Hg, and T-Cd in maternal dried blood spots and T-As in maternal urines. Poisson regression was used to examine associations between prenatal concentrations of these elements and neurodevelopmental outcomes. Results: Prenatal T-Hg concentration was associated with global neurodevelopment status (aPR 1.03, CI:1.01–1.04; p < 0.001) and language impairment (aPR 1.05, CI:1.03–1.07; p < 0.001) on the MDAT. When prenatal T-Hg and T-As values were at or above the human biomonitoring reference values (≥95%) of the German Environmental Survey for Human Biomonitoring, that is 0.80 µg/L and 15 µg/L, respectively, the prevalence ratio of global neurodevelopmental impairment was two times higher (aPR 2.1, CI:1.0–4.3; p = 0.034). There was a 40% increase in the prevalence ratio of global neurodevelopmental impairment (aPR 1.4, CI:0.90–2.10, p = 0.027), when prenatal T-Hg was at or above the reference value of 0.80 µg/L and T-Pb was at or above the reference value of 35 µg/L. When prenatal T-Hg was at or above the reference value of 0.80 µg/L and T-As was at or above the reference value of 15 µg/L, the prevalence ratio of global neurodevelopmental impairment was two times higher (aPR 2.1, CI:1.0–4.3; p < 0.034). Discussion: Infants born to women in areas with ASGM activities are at significant risk for neurodevelopmental impairment and this is associated with exposure to higher concentrations of Hg prenatally. Co-exposure to high concentrations of Hg and Pb, or Hg and As appeared to have negative potentiated effects on infants’ neurodevelopment.

【 授权许可】

Unknown