Blood lead levels and their associated risk factors in Chinese adults from 1980 to 2018.

In China, studies on lead exposure to grownup are scarce compared to children, although relevant disease burdens for adults are much severe than that in developed countries. The present study evaluated blood lead levels (BLLs) in Chinese adults by data mining using Monte Carlo simulation. A total of 115 scientific studies published between January 1980 and March 2021 reflecting 45,514 Chinese adults were included in the study. After a continuous increase in Chinese adult BLLs from 1980-1983 (GM 74.84 µg/L) to 1994-1996 (GM 92.27 µg/L), BLLs began to decline from 2000--2002 (GM 80.32 µg/L) to 2016-2018 (GM 21.57 µg/L). This decline implied that the lead phase-out policy in gasoline was effective over the past two decades. The study indicated that North, South, and Southwest China were still relatively high compared to other regions in the past decade. Statistical analysis showed that BLLs of males (GM 68.45 µg/L) were higher than females (GM 56.51 µg/L), smokers (GM 80.96 µg/L) higher than nonsmokers (GM 58.95 µg/L), and populations over 40 (GM 40.43 µg/L) higher than younger populations (GM 40.37 µg/L). The significantly positive correlation between the concentrations of PM2.5 and topsoil lead and BLLs in Chinese adults indicated that air and soil pollution affect adult BLLs. Taken together, our results showed that strict lead control strategies and regular bio-monitoring are needed to maintain low BLLs in the population.

Blood lead levels of Chinese children from 1991 to 2020: Based on Monte Carlo simulation.

Chinese children have been exposed to high level of lead due to polluted air, dust, contaminated foods and water, etc. In this research, we investigated published blood lead levels (BLLs) reflecting 1,057,832 Chinese children aged at 0-12 and teenagers aged at 13-18 in the past 30 years (1991-2020). The data mining and estimation were performed innovatively by Monte Carlo simulation to remedy the skewed distribution-induced bias. The temporal trend of Chinese children's BLLs showed an obvious decrease in the past decades from 88.74 µg/L (Geometric SD = 4.09) during 1991-1995 to 27.32 µg/L (Geometric SD = 4.18) during 2016-2020. This study also indicated that children's BLLs of Yunnan, Guizhou, Shanxi were at relatively high levels and most provinces showed a downward trend. Chinese boys aged at 1-18 years old had higher BLLs (GM: 44.03 µg/L) compared to girls (GM: 41.32 µg/L) (p < 0.001). At different age groups, Chinese children's BLLs were 42.04 µg/L (1-3 years old), 52.88 µg/L (4-6 years old), 50.49 µg/L (7 and above years old), respectively. Although the BLLs of Chinese children exhibited a continuous declined trend in the past 30 years, it was still higher than that in developed countries, which indicated that more efforts are needed in children's BLLs control.