Pollution characteristics and health risk assessment of PM2.5-bound arsenic: a 7-year observation in the urban area of Jinan, China.

The aim of the study was to analyze the temporal trends, pollution sources, and carcinogenic health risks associated with PM2.5-bound arsenic (As). A total of 588 PM2.5 samples were collected in Jinan during January 2014-December 2020. The content and distribution characteristics were determined for As and Al in PM2.5, and the pollution sources were identified based on enrichment factors (EFs). The health risk of inhalation exposure to As was estimated using the risk assessment methods recommended by the United States Environmental Protection Agency (US EPA). The annual average concentration of As in PM2.5 was 4.5-17.5 ng m-3, which was 0.8-2.9 times higher than the limit ruled by the European Union and China's Ambient Air Quality Standards (6 ng m-3). From 2014 to 2020, the As concentration gradually decreased from 17.5 to 4.9 ng m-3. After 2017, the concentration was close to the level required by the atmospheric quality standard (6 ng m-3). The PM2.5 and arsenic concentrations in the heating season were significantly higher than those in the non-heating season. The EF of As ranged from 144 to 607, which was higher than 10. The cancer risk of As in PM2.5 decreased to the lowest values (heating season 1.0 × 10-5 and non-heating season 7.1 × 10-6, respectively) in 2019. As in Jinan mainly came from anthropogenic pollution. The level of As pollution has been significantly reduced in recent years, but there is still a high risk of carcinogenesis. Air pollution control strategies and guidelines need to be implemented in urban areas, especially during the heating season in winter and spring.

Pollution characteristics and chronic health risk assessment of metals and metalloids in ambient PM2.5 in Licheng District, Jinan, China.

PM2.5 samples were collected at the Wangsheren primary school site in Licheng District of Jinan, China, during 2016. Eleven metals and metalloids including Al, As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sb and Se in PM2.5 were measured by inductively coupled plasma-mass spectroscopy. The annual average mass concentration of PM2.5 was found to be 88.7 µg m-3. The highest PM2.5 concentrations were obtained during the heating seasons of winter and spring. The concentrations of metals and metalloids in PM2.5 were in a descending order of Al, Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg and Be. The enrichment factors showed that Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg originated from anthropogenic sources. Factor analysis indicated that the main sources of the metals were coal combustion dust, soil dust, metallurgical industry, brake abrasion of vehicles and other mixed sources. Coal combustion dust was the primary source of metal pollution in PM2.5. Non-carcinogenic risks associated with exposure through the respiratory system were between 6.30 × 10-4 and 7.62 × 10-1, which were lower than the safe limit (1). The carcinogenic risks of Cr, As and Cd were 3.17 × 10-5, 1.52 × 10-5, 2.22 × 10-6, respectively, which were higher than the precautionary criterion (10-6/year). This study indicates that the air pollution of PM2.5 is of public health concern in Licheng District of Jinan, particularly related to potential carcinogenic metals of As, Cr and Cd. Intervention action is needed to reduce the emission sources of these elements, especially coal combustion in winter heating season.