A new study reports that elevated levels of blood mercury are associated with an increased prevalence of nonmelanoma skin cancer (NMSC).
The most common human malignancy, NMSC has continued to rise in incidence in recent years. A better understanding of risk factors, including blood mercury levels, is needed in order to aid in prevention and improve patient outcomes. While a number of epidemiological studies have investigated the link between cancer risk and occupational exposure to mercury, little research had been conducted regarding this association in the general population until now.
In their study now published in the British Journal of Dermatology, a team of researchers led by first author J. Rhee, MD, of the Department of Dermatology at Warren Alpert Medical School of Brown University, used data from the National Health and Nutrition Examination Survey (NHANES) on 29,413 participants, 468 of whom had been diagnosed with NMSC. Of the evaluated individuals, 46% were non-Hispanic white, and 21% were non-Hispanic black. The researchers analyzed the link between high blood mercury and NMSC using information on blood total mercury (tHg), inorganic mercury (iHg), and methylmercury (MeHg).
Among the overall study population, participants with a tHg level of more than 1.74 µg L-1 (the highest quartile) had nearly twice the risk of developing NMSC compared with those who had a tHg level at or below 0.47 µg L-1 (the lowest quartile), with an odds ratio of 1.79. Individuals with an MeHg level in the highest quartile (more than 1.44 µg L-1) also had a substantially increased risk of being diagnosed with NMSC compared with those in the lowest quartile (at or below 0.21 µg L-1), with an odds ratio of 1.74. The association between blood mercury levels and NMSC was similar between men and women, and it was slightly stronger among non-Hispanic white individuals. Results were consistent after adjusting for sun exposure and occupations with an increased risk of mercury exposure.
"We conducted the first study to examine the association between blood mercury levels and skin cancer among a general and representative population in the USA," conclude Dr. Rhee and colleagues in their publication. "Our findings add to the limited data from epidemiological studies supporting the role of mercury exposure in skin cancer."
For More Information
Rhee J, Vance TM, Lim R, et al (2020). Association of blood mercury levels with nonmelanoma skin cancer in the U.S.A. using National Health and Nutrition Examination Survey data (2003-2016). Br J Dermatol. [Epub ahead of print] DOI:10.1111/bjd.18797
Image credit: Markus Schober and Elaine Fuchs. Courtesy of the National Cancer Institute