摘要：Objectives. Arsenic contamination of groundwater is a severe public health crisis in Bangladesh, where the population is exposed to arsenic in drinking water through tube wells used for groundwater collection. In this study, we explored the association between socioeconomic status and arsenic toxicity. Methods. We used baseline data from 11438 men and women who were recruited into the Health Effects of Arsenic Longitudinal Study (HEALS), a prospective cohort study on the health effects of arsenic exposure in Bangladesh. We conducted analyses with logistic regression and generalized estimating equations. Results. We found a strong dose–response association with all measures of arsenic exposure and skin lesions. We also found that the effect of arsenic was modified by land ownership on a multiplicative scale, with an increased risk among non–land owners associated with well water arsenic ( P =.04) and urinary total arsenic concentrations ( P =.03). Conclusions. Our study provides insight into potentially modifiable host characteristics and identifies factors that may effectively target susceptible population subgroups for appropriate interventions. Beginning in the 1970s, hand-pumped tube wells were installed in Bangladesh to provide a source of pathogen-free groundwater for consumption. Since then, the number of tube wells within the country has exponentially increased, and these wells are the population’s primary source of drinking water. Unfortunately, the groundwater in Bangladesh has been naturally contaminated with high levels of arsenic, a phenomenon discovered only after decades of exposure and an epidemic of arsenical skin lesions. 1 , 2 Many of the human health effects of arsenic have been proven, and arsenic has been classified as a human carcinogen. 3 Epidemiologic evidence has shown a significant association between the consumption of arsenic through drinking water and cancers of the skin, lung, bladder, liver, and kidney. 4 – 8 Premalignant skin lesions are an early manifestation and hallmark of arsenic toxicity and may indicate increased future risk for arsenic-related cancer. 9 However, there is evidence of marked interindividual variability in arsenic-induced premalignant skin lesions and cancer. 9 It has been suggested that differential susceptibility to arsenic-induced skin lesions may be attributed to host characteristics 10 , 11 ; therefore, because of the magnitude of the arsenic problem in Bangladesh, a thorough examination of potentially modifiable host characteristics is warranted. Socioeconomic status (SES) has been identified as an important determinant of health across a broad range of health issues. 12 SES is a multidimensional construct that includes education, occupation, income, wealth, and residence. However, the measure of this construct in less-developed countries creates a challenge because adequate data may not be available. Therefore, the examination of several measures of SES is advantageous because it increases the likelihood that some dimension of the SES construct is captured. No previous studies of arsenic exposure have explicitly examined effect modification by SES in arsenic toxicity. We sought to determine whether selected SES indicator variables modify the association between various measures of arsenic exposure and premalignant skin lesions among 11438 men and women in Araihazar, Bangladesh.
