Arsenic exposure determinants on toddlers in Arica, Chile Open Access

Hitschfeld Bushell, Maureen (2016)

Permanent URL: https://etd.library.emory.edu/concern/etds/rj430530f?locale=en
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Abstract

Inorganic arsenic and arsenic compounds are considered class 1 chronic non-threshold carcinogenic to humans. Long-term oral exposure to arsenic is associated with several multi-systemic health conditions. Furthermore, in utero and early-life exposures to arsenic have been linked to increased risks for several types of cancer and other diseases during adulthood. Understanding sources of early exposure is crucial to prevent detrimental health effects. Our goal was to determine whether breast milk protects toddlers from arsenic exposure and whether formula, rice consumption, drinking tap water or other dietary and environmental factors contribute to arsenic exposure in toddlers in Arica, Chile. For this secondary analysis study, we used data from a subgroup of 192 subjects from a recently completed cohort study to examine the relationship between determinants in the last 48 hours followed by urinary arsenic speciated concentration. Multivariate models were developed for each arsenic specie: arsenobetaine (AsB), arsenite (AsIII), arsenate (AsV), dimethylarsinic (DMA), monomethylarsonic (MMA) and total arsenic (excluding AsB). Our study suggests that drinking 6 or more breast milk portions protects toddlers from arsenic exposure in this population. Further, our study confirms formula, rice consumption and drinking tap water as potential source of arsenic exposure in this population and hints to other dietary and environmental modulators.

Table of Contents

Introduction..................................................................................................................... 1

Methods............................................................................................................................. 7

Study sample............................................................................................................................................................................. 7

Study procedures and data collection....................................................................................................................... 8

Analytical methods................................................................................................................................................................ 8

Ethical considerations.......................................................................................................................................................... 9

Statistical analysis.................................................................................................................................................................. 9

Results............................................................................................................................. 12

Study participants' characteristics........................................................................................................................... 12

Log-transformed arsenic species concentrations correlation............................................................... 13

Toddler urinary arsenic metabolites concentration according to significant characteristics. 13

Toddlers urinary arsenic metabolites concentration modelling.......................................................... 15

Mothers urinary arsenic metabolites concentration modelling........................................................... 17

Discussion...................................................................................................................... 19

Toddlers' and mothers' analyses key results.................................................................................................. 19

Strenghts and limitations............................................................................................................................................... 25

References...................................................................................................................... 28

Tables.............................................................................................................................. 35

Appendix A..................................................................................................................... 47

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