Blood Lead Levels and Cause-Specific Mortality of Inorganic Lead-Exposed Workers in South Korea

Abstract

The objective of this study was to identify the association of blood lead level (BLL) with mortality in inorganic lead-exposed workers of South Korea. A cohort was compiled comprising 81,067 inorganic lead exposed workers working between January 1, 2000, and December 31, 2004. This cohort was merged with the Korean National Statistical Office to follow-up for mortality between 2000 and 2008. After adjusting for age and other carcinogenic metal exposure, all-cause mortality (Relative risk [RR] 1.36, 95% confidence interval [CI] 1.03–1.79), digestive disease (RR 3.23, 95% CI 1.33–7.86), and intentional self-harm (RR 2.92, 95% CI 1.07–7.81) were statistically significantly higher in males with BLL >20 μg/dl than of those with BLL ≤10μg/dl. The RR of males with BLL of 10–20 μg/dl was statistically higher than of those with BLL ≤10μg/dl in infection (RR 3.73. 95% CI, 1.06–13.06). The RRs of females with 10–20 μg/dl BLL was statistically significantly greater than those with BLL <10μg/dl in all-cause mortality (RR 1.93, 95% CI 1.16–3.20) and colon and rectal cancer (RR 13.42, 95% CI 1.21–149.4). The RRs of females with BLL 10–20 μg/dl (RR 10.45, 95% CI 1.74–62.93) and BLL ≥20 μg/dl (RR 12.68, 95% CI 1.69–147.86) was statistically significantly increased in bronchus and lung cancer. The increased suicide of males with ≥20 μg/dl BLLs, which might be caused by major depression, might be associated with higher lead exposure. Also, increased bronchus and lung cancer mortality in female workers with higher BLL might be related to lead exposure considering low smoking rate in females. The kinds of BLL-associated mortality differed by gender.

Possible changes of New-Generation inflammation markers with occupational lead exposure

“…Kimetal. 31) conducted a cohort study evaluating the association of BLL with mortality of inorganic Pb-exposed workers, and the result was consistent with the studies showing that BLL was associated with major depression and other psychological disorders. Authors especially draw attention to the increased suicide of males with !…”

Urinary Lead Concentration Is an Independent Predictor of Cancer Mortality in the U.S. General Population

“…No association was found between blood lead concentration and cancer death rate in a cohort of 533 females enrolled in the study of Osteoporotic Fractures in U.S. from 1986 to 1988 ( 11 ). Because blood lead concentration of workers with occupational lead exposure is thought to be higher [often considerably over 80 µg/dL ( 33 )] than that of general population ( 17 ), numerous occupational reports have examined the contribution of lead exposure to mortality of lead-exposed workers. However, the results from occupational studies are also controversial and inconclusive.…”

“…Because of limited epidemiological evidence, the IARC Working Group categorized inorganic lead compounds as “probably” human carcinogens (group 2A) ( 15 ). Recently, several epidemiological studies have illustrated the association of blood lead concentration and death rate due to cancer in numerous populations, including U.S. adults ( 14 , 16 ), lead-exposed workers in South Korea ( 17 ) and Australia ( 18 ). However, whether urinary lead, as the most non-invasive and accessible way for lead measurement in human, is associated with cancer mortality has never been explored in the general population.…”

The effect of leaded gasoline on elderly mortality: Evidence from regulatory exemptions

“…We selected cardiovascular, IHD, and respiratory mortality because of the existing associational evidence that EBLLs are related to cardiovascular mortality and reduced respiratory function (Pirkle et al, 1985;Lustberg and Silbergeld, 2002;Jurdziak et al, 2015;Lanphear et al, 2018). We included deaths of despair because higher levels of blood or bone lead are associated with higher rates of drug addition, psychiatric symptoms such as depression and panic attacks, and suicide risk (Rhodes et al, 2003;Fishbein et al, 2008;Bouchard et al, 2009;Kim et al, 2015).…”