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.

Occupational exposure to polybrominated diphenyl ethers or decabromodiphenyl ethane during chemical manufacturing: Occurrence and health risk assessment.

Field investigations were conducted on a decabrominated diphenyl ether (BDE-209) manufacturing plant and a decabromodiphenyl ethane (DBDPE) manufacturing plant, and worker exposure to polybrominated diphenyl ethers (PBDEs) or DBDPE was assessed. Workshop air was collected and tested to measure levels of external exposure to corresponding chemicals via air inhalation. Paired human serum and urine samples taken from 202 workers were tested to assess levels of internal BFR exposure. Levels of BDE-209 in air for the BDE-209 plant ranged from 10.6 to 295 µg m-3, accounting for at least 99% of the total PBDEs in the workshop air, and those of DBDPE in air samples from the DBDPE plant ranged from 12.7 to 435 µg m-3. Maximum estimated daily intakes (EDIs) of BDE-209 and DBDPE accumulated via air inhalation exceeded the corresponding RfD level recommended by the U.S. Environmental Protection Agency, indicating that for some workers, occupational exposure is likely to create significant health problems. The levels of BDE-209 measured in serum taken from BDE-209 workers ranged from 0.202 to 57.1 µg g-1 lw, and those of DBDPE in serum taken from DBDPE workers ranged from 0.087 to 54.4 µg g-1 lw. These values are several orders of magnitude higher than those detected in general areas and e-waste recycling sites. BDE-209 and DBDPE were detected in all of the urine samples with median levels of 1.12 and 8.6 ng mL-1, respectively, and levels of BDE-209 and DBDPE in the urine were significantly and positively correlated with those observed in the serum.

[Risk assessment and risk control for occupational exposure to chemical toxicants from an isophorone nitrile device].

OBJECTIVE: Risk assessment and risk control for occupational exposure to chemical toxicants were performed on an isophorone nitrile device with an annual production of 5,000 tons, based on improved Singaporean semi-quantitative risk assessment method, with consideration of actual situation in China and in the present project. METHODS: With the use of engineering analysis and identification of occupational hazards in the improved Singaporean semi-quantitative risk assessment method, hazard rating (HR) and risk assessment were performed on chemical toxicants from an isophorone nitrile device with an annual production of 5,000 tons. RESULTS: The chemical toxicants in the isophorone nitrile device were mainly isophorone, hydrocyanic acid, methanol, phosphoric acid, sodium hydroxide, and sodium cyanide; the HR values were mild hazard (2), extreme hazard (5), mild hazard (2), mild hazard (2), moderate hazard (3), and extreme hazard (5), respectively, and the corresponding exposure rating (ER) values were 2.09, 2.72, 2.76, 1.68, 2.0, and 1.59, respectively. The risk of chemical toxicants in this project was assessed according to the formula Risk = [HR×ER](1/2). Hydrocyanic acid was determined as high risk, sodium hydroxide and sodium cyanide as medium risk, and isophorone, methanol, and phosphoric acid as low risk. Priority in handling of risks was determined by risk rating. The table of risk control measure was established for pre-assessment of occupational hazards. CONCLUSION: With risk assessment in this study, we concluded that the isophorone nitrile device with 5,000 ton annual production was a high-occupational hazard device. This device is a project of extreme occupational hazard. The improved Singaporean semi-quantitative risk assessment method is a scientific and applicable method, and is especially suitable for pre-evaluation of on-site project with no analogy.