Cadmium exposure and tobacco consumption: Biomarkers and risk assessment

Abstract

To investigate whether cadmium has an independent role in diseases associated with tobacco consumption, epidemiology data were reviewed, biomonitoring data were analyzed, and probabilistic risk assessment (PRA) was performed. Results from previous epidemiology studies have indicated that there are adverse health effects potentially in common between cadmium exposure and tobacco consumption. Analysis of publically available biomonitoring data showed that blood (B-Cd) and urine (U-Cd) cadmium were higher in cigarette smokers compared with smokeless tobacco (SLT) consumers, and B-Cd and U-Cd in SLT consumers were not significantly different than in non-consumers of tobacco. Comparison with previously established biomonitoring equivalent (BE) values indicated that B-Cd and U-Cd in the majority of these cigarette smokers and SLT consumers did not exceed the blood and urine BEs. Results of the PRA showed that the mean hazard estimate was below a generally accepted regulatory threshold for SLT consumers, but not for cigarette smokers. In total, this evaluation indicated that cadmium exposures in tobacco consumers differed by product category consumed; cadmium in tobacco may not be associated with tobacco consumption related diseases; if cadmium in tobacco contributes to tobacco consumption related diseases, differences in hazard and/or risk may exist by product category.

Biomarkers of Tobacco Exposure: Summary of an FDA-Sponsored Public Workshop

“…Tobacco is no longer a major source of arsenic due to the termination of arsenic pesticide use during tobacco cultivation (83). In cross-sectional studies, biomarkers of cadmium and lead are elevated in smokers compared to non-smokers (84–86). Blood cadmium distinguishes clearly between current and non-current smokers while the dose-response relationship between urine cadmium and CPD is more subtle.…”

“…For example, BE for cadmium in urine and blood samples is based on a dose that indicates kidney effects preceding kidney damage. In an NHANES study in which blood and urinary cadmium levels were obtained from smokers, smokeless tobacco users, and non-consumers of tobacco, a higher percentage of smokers than smokeless tobacco users exceeded the BE of 1.5μg/L urine and 1.7μL blood (84). Higher percentages of smokers and smokeless tobacco users exceeded the BE for urinary cadmium than non-consumers of tobacco products; however, the percentages of smokeless tobacco users and non-users who exceeded the BE for blood cadmium were similar (84).…”

Toxic Metal Concentrations in Cigarettes Obtained from U.S. Smokers in 2009: Results from the International Tobacco Control (ITC) United States Survey Cohort

“…Biomonitoring studies show that smokers have substantially higher Cd and Pb levels [15,16,17], and bioaccumulation of metals has also been demonstrated in those chronically exposed to tobacco smoke pollution (also known as second-hand smoke) [15,16,18]. Because the use of arsenic-containing pesticides has declined, smoking no longer appears to represent a major exposure pathway for As [19].…”

Assessment of concentration and toxicological (Cancer) risk of lead, cadmium and chromium in tobacco products commonly available in Bangladesh

“…The users of tobacco take in substantial levels of heavy metals in their body via inhalation, although these chemical elements are present in low amounts but exhibit high toxicity [7,8]. Bioaccumulation of metals also occurs in people due to chronic exposure to tobacco smoke via inhalation, also known as passive smoking [[9], [10], [11], [12]]. Lead and cadmium concentrations were described to be significantly higher in four out of five lobes, while the concentrations of chromium have been found to be significantly higher in all five lobes of smokers' lungs than in nonsmokers' [13].…”