Relationship between ambient PM2.5 exposure and blood cadmium level in children under 14 years in Beijing, China

Ambient PM2.5 pollution is a global environmental problem. PM2.5 can act as a carrier of heavy metals. However, the relationship between PM2.5 exposure and blood cadmium (Cd) level in children was less understood. Based on the data of hourly collected PM2.5 and blood Cd level of 13,626 children aged 0-14 years from Apr. 2008 to Feb. 2013 in Beijing of China, we investigated the short-term effects of PM2.5 exposure on blood Cd level. Generalized linear mixed models (GLMMs) were utilized to explore the potential association between PM2.5 exposure and blood Cd level of children. The results showed that the mean blood Cd level was 0.64 mu g/L. There was a significant association between PM2.5 exposure and blood Cd level (P < 0.05). Age was negatively associated with blood Cd level (P < 0.05), and the younger children were more sensitive to Cd from PM2.5 exposure. There wasn't a significant difference in PM2.5 concentration between heating and non-heating seasons in winter (P > 0.05); there was also no gender difference of children on blood Cd level (P > 0.05). The present study demonstrates the importance of controlling the PM2.5 bound Cd exposure, and environmental countermeasures should be implemented stringently to reduce their impact on children's health.