Previous studies have consistently reported an increase in mortality risk, even at low levels of blood lead. The average blood lead concentration in the Korean population has steadily decreased but is still higher than that of developed countries. The purpose of this study was to examine the associations between mortality and blood lead concentrations for adults in Korea. We used the Korea National Health and Nutrition Examination Survey (2008–2013) linked Cause of Death data, which are followed by 2018. A total of 7308 subjects who aged over 30 at the baseline examination were included in the analyses. Cox proportional hazard model was used to estimate the hazard ratios of mortality from non-accidental causes and cancer mortality. The estimated hazard ratios (95% CI) for comparison of the second and third tertile group with the lowest tertile group were 2.01 (1.20, 3.40) and 1.91 (1.13, 3.23) for non-accidental mortality and 3.42 (95% CI: 1.65, 7.08) and 2.27 (95% CI: 1.09, 4.70) for cancer mortality, respectively. The dose–response relationship also showed significant increase in the risk of mortality at blood lead level between 1.5 and 6.0 μg/dL. Our findings suggest that potent policies to lower lead exposure are required for the general Korean population.

Despite enormous investment in air-quality regulations, there are only a few studies about the health effects of the air-quality regulations. By applying synthetic control methods to controlled-interrupted time-series analysis, this study aimed to test whether air-quality regulations implemented in Seoul metropolitan area since 2005 had reduced cardiovascular mortality rate in Seoul and Incheon. Each synthetic control for Seoul and Incheon was constructed to predict the counterfactual cardiovascular mortality rate through synthetic control methods. By using a synthetic control as a control group in controlled-interrupted time-series analysis, we tested whether the air-quality regulations had changed the trend of cardiovascular mortality rate in Seoul and Incheon after the intervention. The results showed a significant slope change in cardiovascular mortality rate in Seoul (coefficient: −0.001, 95% confidence interval (CI): −0.0015, −0.0004) and Incheon (coefficient: −0.0006, 95% CI: −0.0012, 0). This study suggests additional evidence that air-quality regulations implemented in the Seoul metropolitan areas since 2005 had beneficial effects on cardiovascular mortality rate in Seoul and Incheon.