Lead is known to have toxic effects on the cardiovascular system. Owing to its high concentration, transmission range, and absorption efficiency in organisms, inhalation of fine particulate matter (PM2.5)-bound lead (PM2.5-Pb) may cause significant cardiovascular damage. However, the contribution and adverse effects of PM2.5-Pb on workers and residents in non-ferrous metal smelting areas are not fully understood. In this work, the concentration and chemical speciation of PM2.5-Pb were analyzed to determine its pollution characteristics at a typical non-ferrous metal smelting site. A panel study conducted among factory workers revealed that PM2.5-Pb exposure makes an important contribution to the human absorption of Pb. Although the chemical speciation of PM2.5-Pb suggested poor water solubility, a high bioavailability was observed in mice (tissue average value: 50.1%, range: 31.1-71.1%) subjected to inhalation exposure for 8 weeks. Based on the bioavailability data, the relationship between PM2.5-Pb exposure and cardiovascular damage was evaluated in animal simulation experiments. Finally, a damage threshold and cardiovascular-specific risk assessment model were established for the non-ferrous metal smelting area. Our project not only accurately estimates the risk of PM2.5-bound heavy metals on the cardiovascular system but also offers a scientific basis for future prevention and therapy of PM2.5-Pb-related diseases.
Keywords: PM2.5-Pb; cardiovascular damage; health risk assessment; pollution characteristics; relative bioavailability.