Association of blood mercury levels with non-melanoma skin cancer in the United States using NHANES data from 2003-2016

Abstract

PDS 63: Chemicals and metals: health effects, Exhibition Hall (PDS), Ground floor, August 27, 2019, 10:30 AM - 12:00 PM Background/Aim: Some studies have reported that mercury is associated with an increased risk of lung and esophageal cancers. However, few epidemiological studies investigated mercury exposure in relation to skin cancer risk. Mercury inactivates glutathione peroxidase (GPX) and lower GPX activity is associated with increased risk of skin cancer. Therefore, we investigated the association between blood mercury levels and skin cancer. Methods: We used National Health and Nutrition Examination Survey (NHANES) data from 2003 through 2016. Our exposures of interest were blood total (tHg), inorganic (iHg), and methyl mercury (MeHg). The main outcome was a reported diagnosis of non-melanoma skin cancer. We included participants aged ≥18 having information on exposures, outcome, and covariates (age, sex, race, BMI, smoking history, and income). We conducted logistic regression analysis adjusting for above covariates and survey year. Results: Among 30,103 participants, the median age was 48, 52% were female, 46% Non-Hispanic White, and 21% Non-Hispanic Black. A total of 477 subjects reported diagnosis of non-melanoma skin cancer; 95% of whom were Non-Hispanic White. Median levels of tHg and MeHg were 0.9 µg/L and 0.6 µg/L, respectively. A 1 µg/L increase in blood tHg was associated with 6% increased odds of non-melanoma skin cancer (OR: 1.06; 95% CI: 1.02, 1.09). Compared to subjects with tHg ≤ 0.46 µg/L, subjects with tHg >1.72 µg/L had approximately double the odds of non-melanoma skin cancer (OR: 1.93, 95% CI: 1.31, 2.84). Similarly, subjects with MeHg > 1.43 µg/L had 1.8 times greater odds of non-melanoma skin cancer (OR: 1.82, 95% CI: 1.18, 2.79) compared to subjects with MeHg ≤ 0.21 µg/L. Conclusions: We found that higher blood tHg and MeHg levels were associated with higher prevalence of non-melanoma skin cancer. Our findings add to the limited evidence from epidemiologic studies supporting the role of mercury exposures in skin cancer.