A Meta-analysis of Arsenic Exposure and Lung Function: Is There Evidence of Restrictive or Obstructive Lung Disease?

Abstract

Purpose of review: Hundreds of millions of people worldwide are exposed to arsenic via contaminated water. The goal of this study was to identify whether arsenic-associated lung function deficits resemble obstructive- or restrictive-like lung disease, in order to help illuminate a mechanistic pathway and identify at-risk populations. Recent findings: We recently published a qualitative systematic review outlining the body of research on arsenic and non-malignant respiratory outcomes. Evidence from several populations, at different life stages, and at different levels of exposure showed consistent associations of arsenic exposure with chronic lung disease mortality, respiratory symptoms, and lower lung function levels. The published review, however, only conducted a broad qualitative description of the published studies without considering specific spirometry patterns, without conducting a meta-analysis, and without evaluating the dose-response relationship. Summary: We searched PubMed and Embase for studies on environmental arsenic exposure and lung function. We performed a meta-analysis using inverse-variance weighted random-effects models to summarize adjusted effect estimates for arsenic and forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio. Across nine studies, median water arsenic levels ranged from 23 to 860 μg/L. The pooled estimated mean difference (MD) comparing the highest category of arsenic exposure (ranging from >11 to >800 μg/L) versus the lowest (ranging from <10 to <100 μg/L) for each study for FEV1 was −42 (95% confidence interval (CI): −70, −16) mL and for FVC was −50 (95%CI: −63, −37) mL. Three studies reported effect estimates for FEV1/FVC, for which there was no evidence of an association; the pooled estimated MD was 0.01 (95%CI: −0.005, 0.024). This review supports that arsenic is associated with restrictive impairments based on inverse associations between arsenic and FEV1 and FVC, but not with FEV1/FVC. Future studies should confirm whether low-level arsenic exposure is a restrictive lung disease risk factor in order to identify at-risk populations in the US.

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

“…More recently, water arsenic > 100 μg/L has been associated with non-malignant respiratory effects, including respiratory symptoms and worse lung function tests. A recent meta-analysis identified an association between arsenic exposure and reduced forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) with a preserved ratio (in subset of 3 studies reporting FEV1/FVC), indicating a possible association with restrictive lung disease [4]. The studies in the meta-analysis included a wide range of exposure levels, with arsenic often 10 times higher than the World Health Organization guideline/United States Environmental Protection Agency standard of 10 μg/L in drinking water.…”

Toxic metal exposure as a possible risk factor for COVID-19 and other respiratory infectious diseases

“…However, even subtoxic doses of arsenic may significantly affect respiratory functions. Particularly, a recent meta-analysis demonstrated that arsenic exposure is associated with restrictive impairments in lung function including reductions in forced expiratory volume in one second (FEV1), forced vital capacity (FVC) ( Sanchez et al, 2018 ). Another study has demonstrated that As-associated FVC reduction is observed on males ( Khan et al, 2020 ).…”

Inequalities in Public Water Arsenic Concentrations in Counties and Community Water Systems across the United States, 2006–2011

“…2018 ; Moon et al. 2017 ; Sanchez et al. 2018 ), and water contaminant present in many aquifers in the United States.…”