Maternal arsenic exposure and birth outcomes: a comprehensive review of the epidemiologic literature focused on drinking water.
Inorganic arsenic (iAs) is a human toxicant to which populations may be exposed through consumption of geogenically contaminated groundwater. A growing body of experimental literature corroborates the reproductive toxicity of iAs; however, the results of human studies are inconsistent. Therefore, we conducted a comprehensive review of epidemiologic studies focused on drinking water iAs exposure and birth outcomes to assess the evidence for causality and to make recommendations for future study. We reviewed 18 English language papers assessing birth weight, gestational age, and birth size. Thirteen of the studies were conducted among populations with frequent exposure to high-level groundwater iAs contamination (>10 μg/L) and five studies were conducted in areas without recognized contamination. Most studies comprised small samples and used cross-sectional designs, often with ecologic exposure assessment strategies, although several large prospective investigations and studies with individual-level measurements were also reported. We conclude that: (1) the epidemiologic evidence for an increased risk of low birth weight (<2500 g) is insufficient, although there exists limited evidence for birth weight decreases; (2) the evidence for increased preterm delivery is insufficient; and, (3) there exists minimal evidence for decreased birth size. In further investigation of birth weight and size, we recommend incorporation of individual susceptibility measures using appropriate biomarkers, with collection timed to windows of vulnerability and speciated arsenic analysis, as well as consideration of populations exposed primarily to drinking water iAs contamination <10 μg/L. Given the large potential public health impact, additional, high quality epidemiologic studies are necessary to more definitively assess the risk.
Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, NY USA; Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, NY USA. Electronic address: mbloom@albany.edu.
Michael S
MS
Bloom
Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, NY USA.
Simona
S
Surdu
Environmental Health Center, Cluj-Napoca, Romania.
Iulia A
IA
Neamtiu
Environmental Health Center, Cluj-Napoca, Romania; University of Medicine and Pharmacy "Iuliu Hatieganu", Cluj-Napoca, Romania.
Eugen S
ES
Gurzau
D001151:Arsenic / Q000633:toxicity*; D001724:Birth Weight; D060766:Drinking Water / Q000737:chemistry*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D018570:Risk Assessment; D014874:Water Pollutants, Chemical
D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001151:Arsenic
Arsenic (As); Birth size; Birth weight; Drinking water; Epidemiology; Gestation