Low-moderate arsenic exposure and respiratory in American Indian communities in the Strong Heart Study

Martha Powers,Christopher Heaney,Lyle G Best,Tiffany R Sanchez,Robert H Brown,Christine M George,Ana Navas-Acien,Walter Goessler,Fawn Yeh,Maria Grau-Perez,Kevin A Francesconi,Jason G Umans

doi:10.1186/s12940-019-0539-6

Abstract

BackgroundArsenic exposure through drinking water is an established lung carcinogen. Evidence on non-malignant lung outcomes is less conclusive and suggests arsenic is associated with lower lung function. Studies examining low-moderate arsenic (< 50 μg/L), the level relevant for most populations, are limited. We evaluated the association of arsenic exposure with respiratory health in American Indians from the Northern Plains, the Southern Plains and the Southwest United States, communities with environmental exposure to inorganic arsenic through drinking water.MethodsThe Strong Heart Study is a prospective study of American Indian adults. This analysis used urinary arsenic measurements at baseline (1989–1991) and spirometry at Visit 2 (1993–1995) from 2132 participants to evaluate associations of arsenic exposure with airflow obstruction, restrictive pattern, self-reported respiratory disease, and symptoms.ResultsAirflow obstruction was present in 21.5% and restrictive pattern was present in 14.4%. The odds ratio (95% confidence interval) for obstruction and restrictive patterns, based on the fixed ratio definition, comparing the 75th to 25th percentile of arsenic, was 1.17 (0.99, 1.38) and 1.27 (1.01, 1.60), respectively, after adjustments, and 1.28 (1.02, 1.60) and 1.33 (0.90, 1.50), respectively, based on the lower limit of normal definition. Arsenic was associated with lower percent predicted FEV1 and FVC, self-reported emphysema and stopping for breath.ConclusionLow-moderate arsenic exposure was positively associated with restrictive pattern, airflow obstruction, lower lung function, self-reported emphysema and stopping for breath, independent of smoking and other lung disease risk factors. Findings suggest that low-moderate arsenic exposure may contribute to restrictive lung disease.

Highlights

Arsenic exposure via drinking water is a well-established lung carcinogen [1,2,3]
We examined the association of low-moderate arsenic exposure with respiratory health in American Indians from the Northern Plains, the Southern Plains and the Southwest United States, communities with environmental exposure to inorganic arsenic through drinking water
As study site proportion is known from the original cohort, the withdrawal of the Tribal Nation was adjusted for by weighting the remaining participants, with approximately 1/3 of weight for each center (33.0% AZ, 33.6% OK, 33.4% North Dakota and South Dakota (ND/SD)); the use of the statistical weight is to reduce bias introduced by drop-out [9]

Summary

Introduction

Water arsenic > 100 μg/L has been associated with non-malignant respiratory effects, including respiratory symptoms and worse lung function tests. Powers et al Environmental Health (2019) 18:104 association between high levels of arsenic exposure with respiratory symptoms, non-malignant respiratory illness, and reduced lung function [5]. We examined the association of low-moderate arsenic exposure with respiratory health in American Indians from the Northern Plains, the Southern Plains and the Southwest United States, communities with environmental exposure to inorganic arsenic through drinking water. We evaluated the association of arsenic exposure with respiratory health in American Indians from the Northern Plains, the Southern Plains and the Southwest United States, communities with environmental exposure to inorganic arsenic through drinking water

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Results

Discussion

Conclusion