Source analysis and health risk assessment of heavy metals in PM_2.5 and PM₁₀ around a textile industrial park in Changzhou

Taking a typical textile industrial park in Changzhou City, Jiangsu Province as an example, PM_2.5 and PM₁₀ samples were collected in the surrounding areas. Through the microwave pretreatment method, the contents of Sb, Co, V, Pb, Cd, As, Cu, Ni, and Cr in PM_2.5 and PM₁₀ were obtained using the inductively coupled plasma mass spectrometer (ICP-MS). The characteristics and seasonal variation of heavy metal concentrations in summer and winter were analyzed, and the sources and health risks of heavy metals were evaluated using the positive definite matrix factor model (PMF) and the US EPA health risk assessment model. The results showed that the mean values of PM_2.5 around the textile industrial park in summer and winter were 64.41 and 109.29 μg/m³, respectively, and the mean values of PM₁₀ were 89.08 and 146.65 μg/m³, respectively. Both PM_2.5 and PM₁₀ concentrations were higher in winter than in summer. PM_2.5 content in winter was about 1.70 times that in summer, and PM₁₀ content in winter was about 1.65 times that in summer. Particulate matter around the textile industrial park exceeded the standard, with the maximum over-standard multiple being 33.3 times of the reference concentration limit of the Ambient Air Quality Standard (GB 3095-2012), and the levels of metal elements in winter were greater than in summer. PMF model analysis showed that the main sources of heavy metals in PM_2.5 and PM₁₀ in the surrounding areas of the textile industrial park were road dust and industrial emissions, contributing 59.7% and 64.2% in summer and winter, respectively. The health risk model showed that in winter, exposure to the PM_2.5 and PM₁₀ had a non-carcinogenic risk to children, and the total non-carcinogenic risk value were 1.13 and 1.20, respectively. The carcinogenic risk indexes of Cr and As were not within the threshold range (10⁻⁶-10⁻⁴), which was at an unacceptable level.