Diet and toenail arsenic concentrations in a New Hampshire population with arsenic-containing water.

Kathryn L Cottingham,M Scot Zens,Margaret R Karagas,J Steven Morris,Roxanne Karimi,Tracy Punshon,Joann F Gruber,Vicki Sayarath,Carol L Folt

doi:10.1186/1475-2891-12-149

Abstract

BackgroundLimited data exist on the contribution of dietary sources of arsenic to an individual’s total exposure, particularly in populations with exposure via drinking water. Here, the association between diet and toenail arsenic concentrations (a long-term biomarker of exposure) was evaluated for individuals with measured household tap water arsenic. Foods known to be high in arsenic, including rice and seafood, were of particular interest.MethodsAssociations between toenail arsenic and consumption of 120 individual diet items were quantified using general linear models that also accounted for household tap water arsenic and potentially confounding factors (e.g., age, caloric intake, sex, smoking) (n = 852). As part of the analysis, we assessed whether associations between log-transformed toenail arsenic and each diet item differed between subjects with household drinking water arsenic concentrations <1 μg/L versus ≥1 μg/L.ResultsAs expected, toenail arsenic concentrations increased with household water arsenic concentrations. Among the foods known to be high in arsenic, no clear relationship between toenail arsenic and rice consumption was detected, but there was a positive association with consumption of dark meat fish, a category that includes tuna steaks, mackerel, salmon, sardines, bluefish, and swordfish. Positive associations between toenail arsenic and consumption of white wine, beer, and Brussels sprouts were also observed; these and most other associations were not modified by exposure via water. However, consumption of two foods cooked in water, beans/lentils and cooked oatmeal, was more strongly related to toenail arsenic among those with arsenic-containing drinking water (≥1 μg/L).ConclusionsThis study suggests that diet can be an important contributor to total arsenic exposure in U.S. populations regardless of arsenic concentrations in drinking water. Thus, dietary exposure to arsenic in the US warrants consideration as a potential health risk.

Highlights

Limited data exist on the contribution of dietary sources of arsenic to an individual’s total exposure, in populations with exposure via drinking water
In interpreting the results of our general linear models, we focused on the foods known to be high in arsenic and those foods that were statistically significant after correction for multiple testing (Q-values ≤0.1), based on the models that included potential confounders
We found that increased consumption of a number of individual diet items, including some but not all of the items expected to be high in arsenic concentrations, was associated with increasing toenail arsenic concentrations in this U.S population

Summary

Introduction

Limited data exist on the contribution of dietary sources of arsenic to an individual’s total exposure, in populations with exposure via drinking water. Human exposure to the more toxic, inorganic forms of arsenic is thought to occur primarily through drinking the form of arsenic differs among these different types of food: the arsenic in seafood is primarily in putatively less toxic, organic forms such as arsenobetaine, arsenolipids, and arsenosugars [9,14], while the arsenic in most other items includes both inorganic and organic forms of arsenic that have been associated with toxicity [2]. Xue et al [12] estimated that the general U.S population may be at greater risk of exposure to arsenic via food than drinking water, supporting similar conclusions by previous researchers [7,15,16,17]. Infants, children, the elderly, and those with compromised immune function could be vulnerable to the health effects of dietary arsenic exposure [1,12,18]

Methods

Results

Discussion

Conclusion