Effects of ambient PM_2.5 exposure on blood lead levels in residents aged 3 to 79 years in Henan province: a cross-sectional survey in 2017 – 2019

Objective To study the effect of exposure to airborne particulate matter with an aerodynamic diameter of less than 2.5 μm (PM_2.5) on blood lead levels in residents aged 3 to 79 years in Henan province, with the aim of providing valuable insights for the prevention and control of PM_2.5 air pollution.

Methods Using stratified random sampling and a questionnaire designed by the National Institute of Environmental Health of the Chinese Center for Disease Control and Prevention, we conducted face-to-face interviews and blood lead detection among 1 152 urban and rural residents aged 3 to 79 years in 8 districts/counties under the environmental pollution monitoring program in Henan province from December 2017 to January 2019. The PM_2.5 concentration of the participant′s residence was obtained by matching the latitude and longitude of the home address with the high-resolution, high-quality near-surface air pollutant dataset for China (China High Air Pollutants CHAP dataset). The PM_2.5 exposure level of the surveyed counties/districts was divided into two levels: high and low. Multiple linear regression model was used to analyze the effect of air PM_2.5 exposure on blood lead levels of the participants.

Results The median annual average concentration of PM_2.5 at the registered home addresses of 1 114 participants was measured to be 64.56 μg/m³, while the median blood lead level was found to be 15.32 μg/L. The results of multiple linear regression analysis showed that the participants living in areas with high exposure to atmospheric PM_2.5 had an increased risk of having a high blood lead level (excessive risk ER = 26.05%, 95% confidence interval 95%CI: 18.66% – 33.89%) compared to those living in area with low exposure to atmospheric PM_2.5 ; and the increased ER of high blood level fluctuated among the participants of different age groups, with the ERs% (95%CI) of 19.41 (4.61 – 36.31), 28.01 (14.01 – 43.73), 14.89 (1.26 – 30.37), 25.79 (4.17 – 51.90), 35.00 (17.26 – 55.41), and 33.35 (16.58 – 52.54) for the participants aged 3 – 5, 6 – 11, 12 – 18, 19 – 39, 40 – 59, and 60 – 79 years, respectively.

Conclusion Exposure to ambient PM_2.5 has a positive effect on the blood lead levels in the residents aged 3 to 79 years in Henan province and the effect varies among the residents of different ages.