Geographic and Sociodemographic Differences in Cadmium Exposure in the Multi-Ethnic Study of Atherosclerosis (MESA)

Smoking is the primary source of cadmium (Cd) exposure, however, there are unexplained differences in urinary Cd (uCd) levels that persist by sociodemographic characteristics. We characterized uCd levels across geographic regions and sociodemographic categories to better identify sources and contributors. We include 6729 adults from the Multi-Ethnic Study of Atherosclerosis (MESA) with uCd measured at the baseline exam (2000-2002) and covariate information. Percentage difference (95% confidence interval) of uCd levels were computed by established factors using linear regression models. The overall median (IQR) of uCd was 0.53 (0.36, 0.80) μg/g creatinine. uCd levels differed significantly by age, sex, cigarette use, and race/ethnicity, not by study site or dietary factors. In fully adjusted models, participants > 62 years (mean age) had 20% (16%, 22%) higher uCd levels compared to those ≤ 62 years; females had 71% (67%, 76%) higher uCd compared to males. Compared to never smoking, participants with current and former cigarette use had 46% (40%, 52%) and 9% (6%, 13%) higher uCd, respectively. Chinese and Hispanic participants had 81% (73%, 89%) and 6% (2%, 9%) higher uCd, respectively, compared with White participants. Chinese participants had higher levels than other self-reported race/ethnicities, particularly among younger participants, females, never smoking or other tobacco product use, and those born outside of the United States. Smoking continues to have important implications for Cd burden among the general population. Our results highlight non-smoking Chinese women and Chinese participants born outside the US are a particularly vulnerable subgroup affected by higher long-term Cd exposure and body burden.