Arsenic is a common environmental pollutant and associated with adverse health outcomes in humans including cancer. Less well known, but equally important, is evidence that arsenic is immunotoxic. This pollutant readily crosses the placenta and there is mounting evidence that the developing immune system is more sensitive to chemical insult than the immune system of adults. Yet few studies have examined the effect of early life exposure to either arsenic on children's immune functioning. We propose, therefore, to extend the follow-up of a birth cohort recruited in Bangladesh whose early life exposure to arsenic. We will utilize archived biospecimens to determine prenatal and early postnatal exposure to arsenic and collect additional blood samples that will be used to measure vaccine antibody levels in the children who are now 5 years of age. This will allow us to accomplish the following aims: 1) Determine the relationship between prenatal arsenic exposure and infectious diseases morbidity, 2) Determine the relationship between prenatal arsenic exposure and development of humoral immunity against human pathogens, and 3) Explore the association between prenatal arsenic and changes in immune profiles in peripheral leukocytes in paired cord-infant blood samples. Completion of the proposed research is expected to provide new insights into the immunomodulatory effects of environmental exposure during critical windows of development in children. This information addresses an important gap in our knowledge regarding the developmental toxicity of arsenic exposure at environmentally- relevant concentrations in susceptible populations. The outcomes from this research will be clinically relevant and help to inform public health interventions that can reduce the burden of disease in children.
This systematic study will examine prenatal and early life exposure to arsenic, a common environmental pollutant, and its relationship to clinically relevant outcomes including infectious disease morbidity and antibody response to routine childhood vaccinations in children up to age 5 years. The findings from this study will provide a stronger basis for prevention of immune system dysfunctions related to environmental chemicals in children and inform human health risk assessments on arsenic.