As “fuel” for atmospheric photochemical reactions, volatile organic compounds (VOCs) play a key role in the secondary generation of ozone (O₃) and fine particulate matter (PM_2.5, an aerodynamic diameter ≤ 2.5 μm). To determine the characteristics of VOCs in a high-level ozone period, comprehensive monitoring of O₃ and its precursors (VOCs and NOx) was continuously conducted in an industrial area in Shanghai from 18 August to 30 September 2021. During the observation period, the average concentration of VOCs was 47.33 ppb, and alkanes (19.64 ppb) accounted for the highest proportion of TVOCs, followed by oxygenated volatile organic compounds (OVOCs) (13.61 ppb), alkenes (6.92 ppb), aromatics (4.65 ppb), halogenated hydrocarbons (1.60 ppb), and alkynes (0.91 ppb). Alkenes were the predominant components that contributed to the ozone formation potential (OFP), while aromatics such as xylene, toluene, and ethylbenzene contributed the most to the secondary organic aerosol production potential (SOAFP). During the study period, O₃, NOx, and VOCs showed significant diurnal variations. Industrial processes were the main source of VOCs, and the second largest source of VOCs was vehicle exhaust. While the largest contribution to OFP was from vehicle exhaust, the second largest contribution was from liquid petroleum gas (LPG). High potential source contribution function (PSCF) values were observed in western and southeastern areas near the sampling sites. The results of a health risk evaluation showed that the Hazard Index was less than 1 and there was no non-carcinogenic risk, but 1,3-butadiene, benzene, chloroform, 1,2-dibromoethane, and carbon tetrachloride pose a potential carcinogenic risk to the population.

Occupational health risk assessments of exposure to VOCs still need to be extensively studied to improve the safety standards in the industry. Based on the monitoring of organic pollutants at various workstations in a truck tire factory in Jiangsu Province, both semi-quantitative and quantitative health risk assessment methods were employed to assess health risk levels. The findings indicated that VOCs were categorized into five classes, which included alkanes, aromatics, halocarbons, carbon disulfide, and oxygenated volatile organic compounds (OVOCs). The highest concentration of total volatile organic compounds (TVOCs) was found in shaping workshop; alkanes were the most abundant class (74.2%), followed by aromatics (24.02%) and OVOCs (1.96%). Although the results of the semi-quantitative risk assessment showed that most of the organic compounds had low R values, various kinds of VOCs were detected; particularly, many harmful organic compounds (such as toluene, ethyl benzene) were detected in all the sampling sites. The quantitative risk in the calendering and vulcanizing workshop exceeded the acceptable level; both the carcinogenic risk of ethylbenzene in the tire-strip storage room, and trichloroethylene and perchloroethylene in the calendering workshop were unacceptable. Thus, the calendering and vulcanizing processes in rubber tire manufacturing should be priority-controlled processes.

Following the implementation of the Shanghai Clean Air Act, this study investigates the evolution of air pollution in central Shanghai (Putuo District) by analyzing continuous monitoring data (2016–2020) and chemical speciation of particulate matter (2017–2018). The results confirm a transition toward a “low exceedance rate and low background concentration” regime. However, short-term exceedance episodes persist, generally occurring in winter and spring, with significantly amplified diurnal variations on exceedance days. Distinct patterns emerged between PM fractions: PM₁₀ exceedances were characterized by a single morning peak linked to traffic-induced coarse particles, while PM_2.5 exceedances showed synchronized diurnal peaks with NO₂, suggesting a stronger contribution from vehicle exhaust. Source apportionment revealed that mineral components (21.61%) and organic matter (OM, 21.02%) dominated in PM₁₀, implicating construction and road dust. In contrast, PM_2.5 was primarily composed of OM (26.73%) and secondary inorganic ions (dominated by nitrate), highlighting the greater importance of secondary formation. The findings underscore that sustained PM_2.5 mitigation requires targeted control of gasoline vehicle emissions and gaseous precursors.

To clarify the emission characteristics of volatile organic compounds (VOCs) in China’s tire manufacturing industry, this study compiled enterprise distribution, permit-listed VOCs, monitoring concentrations, and annual emissions for 2023–2024 from national and provincial public platforms. Tire manufacturers were concentrated in eastern coastal provinces; Shandong, Hebei, and Jiangsu accounted for 62.39% of 702 permit-holding enterprises. Twelve VOCs in five chemical classes were listed in pollutant-control records and were not necessarily measured at every enterprise. For explicitly process-labeled non-methane hydrocarbon (NMHC) records, descriptive means ranged from 3.26 to 4.76 mg/m³; uneven coverage precludes a general ranking of processes. Reported annual VOC totals decreased from 1100.25 t in 2023 to 669.95 t in 2024, and NMHC totals decreased from 1031.03 t to 937.76 t; incomplete and unequal reporting coverage may affect these comparisons. Large enterprises contributed 62.22% of the available reported VOC total in 2024. These results describe enterprises covered by the permitting and reporting systems and do not establish national representativeness, universal compliance, causal reduction effects, or control-technology performance.

To characterize summertime ozone (O₃) pollution at the Dianshan Lake suburban site, hourly surface observations and 15 min ozone-lidar profiles were collected during June–August 2022. Monthly mean O₃ increased progressively from June through August (89.0 ± 47.4 to 102.1 ± 59.3 μg/m³), while VOCs averaged 33.9 ± 22.4 μg/m³, dominated by alkanes (53.1%), followed by aromatics (30.3%), alkenes (14.4%) and alkynes (2.3%). A representative high-O₃ episode revealed NO + HO₂ as the dominant production pathway (60.0%), whereas O₃ loss was dominated by the NO₂ + OH pathway forming HNO₃ (75.9%). Sensitivity analysis supported a VOC-limited response during the modeled 9–14 August episode; the transition in the tested joint-reduction scenarios occurred near a VOCs/NO_x ratio of 0.80 but was model-sensitive. Integrating concentrations, ozone formation potential (OFP), and OH Loss Rates (L_OH) prioritized isoprene, propylene, ethylene, m/p-xylene, toluene, and i-pentane for control. The reproduced five-factor PMF solution attributed 25.7% to gasoline vehicle exhaust, 24.6% to LPG/NG use, 21.2% to biogenic emissions, 15.1% to solvent use, and 13.4% to diesel vehicle exhaust.