Cadmium exposure in US adults, research based on the National Health and Nutrition Examination Survey from 1988 to 2018.

Cadmium (Cd) is a widespread environmental contaminant that has a wide range of adverse effects on human health. We described the distribution of blood Cd levels (BCLs) and urinary Cd levels (UCLs) in US adults aging ≥ 18 years over a 30-year period by using data from the National Health and Nutrition Examination Survey (NHANES) III and continuous NHANES (1999-2018). Geometric mean (GM) and 95% confidence intervals (CI) were calculated among participants with valid BCLs (n=47889) or UCLs (n=33003). The prevalence of BCLs ≥ 0.5, ≥ 1.0 ug/L and UCLs ≥ 0.5, ≥ 1.0 ug/g creatinine were estimated. The results showed that for men and women, respectively, GM BCLs declined from 0.458 and 0.472 ug/L in 1999-2000 to 0.252 and 0.330 ug/L in 2017-2018, while GM UCLs declined from 0.266 and 0.376 ug/g creatinine in 1988-1991 to 0.145 and 0.231 ug/g creatinine in 2015-2016. The estimated prevalence of UCLs ≥ 0.5 ug/g creatinine among men and women declined from 31.96 and 45.34% during 1988-1991 to 7.88 and 18.73% in 2015-2016. Higher Cd exposure was associated with females, older age, poverty, lower education, and smoking. These results indicate that Cd exposure in US adults has declined over the past 30 years. However, there are still approximately 7.88% US men and 18.73% US women being exposed to Cd at levels reported to show toxic effects on kidneys.