Emission factors and source profiles of volatile organic compounds from typical industrial sources in Guangzhou, China

Screening characteristic VOC species, health hazards, and odor pollutants in the grain and oilseed milling industry of China

Grain and oilseed milling industries are significant sources of VOCs, leading to substantial human health risks and odor pollution. However, the VOC emission remain inadequately characterized, hindering the development of effective pollution mitigation strategies. VOC samples were collected discharged from the rapeseed oil, sesame oil, soybean oil, and wheat flour manufacturing workshops in the Pearl River Delta, China. The VOC concentrations and emission profiles were evaluated, and VOC concentrations in a nearby residential area were simulated using the CALPUFF dispersion model for health risk and odor assessments. The results revealed substantial variations in both VOC concentrations (0.4-8.3 mg m-3) and compositions among the different workshops. N-hexane was the predominant species in the extraction and refining processes at rapeseed oil (91.17%) and soybean oil factories (86.25%). Carbon disulfide (50.24%) and dimethyl sulfide (51.48%) were also important in the rapeseed oil workshop, while propanone (24.66-45.35%) was the major species in the sesame oil factory. In the wheat flour factory, the main VOCs were ethyl acetate (40.04%) and trichloromethane (29.39%). Non-cancer and cancer risks, as indicated by hazard index (HI, 9.74 × 10-6∼4.75 × 10-3) and cancer index (CI, 2.12 × 10-9∼2.78 × 10-7), both of which are much lower than the acceptable limits (HI = 1 and CI = 10-6), suggesting that the factories do not pose a significant health risk to nearby residents. The highest non-cancer risk was found in the extraction workshop of rapeseed oil, while the highest cancer risk was associated with trichloromethane from the fermentation workshop of wheat flour. The rapeseed oil industry posed the highest risk of odor pollution to nearby neighborhoods, with species such as CS2, dimethyl sulfide, and acrolein contributing most to the odor pollution, resulting in odor indices (OI) ranging from 2 to 31. These findings suggest that the high variability in VOC concentrations and compositions among the workshops is primarily due to production technologies and raw materials.

Characterization of VOCs emissions and associated health risks inherent to the packaging and printing industries in Shandong Province, China

Comprehensive volatile organic compounds (VOCs) emission control is imperative to decreasing occupational health risks and environmental impact of the packaging and printing industries. In this work, we investigated the VOCs emission characteristics and concentrations of individual contaminants generated by the packaging and printing industries, with regard to various categories, processes, and geographic regions. VOCs emissions, ozone formation potential (OFP), and associated health risks were assessed at 10 representative packaging and printing firms across several cities in Shandong Province, China. Plastic packaging enterprises had the greatest levels of unorganized VOCs emissions, consisting predominantly of oxygenated volatile organic compounds (OVOCs), followed by alkanes and halocarbons. From metal and paper packaging enterprises, OVOCs, alkanes, and aromatics were significant components of unorganized VOCs emissions. Aromatics, halocarbons, and OVOCs contributed significantly to OFP in workshops. The potential carcinogenic risk associated with VOCs in the packaging and printing industries was not significant. However, according to the findings in this study, the workshop environment may provide a comparatively elevated non-carcinogenic risk attributable to ethyl acetate, isopropanol, acrolein, 1,1,2-Trichloroethane, 1,2-Dichloropropane, and naphthalene exposure. In particular, the endocrine-disrupting and genetic toxic effects caused by benzene, toluene, styrene, and naphthalene should not be overlooked. Thus, it is essential to provide precedence to the working environment conditions of workshop laborers, while also undertaking scientific and systematic measures to mitigate the detrimental impacts of VOCs on the environment and human welfare.

Relationship between short-term exposure to sulfur dioxide and emergency ambulance dispatches due to cardiovascular disease

Background

The relationship between sulfur dioxide (SO2) and cardiovascular disease (CVD) remains inconclusive. We aimed to clarify the association between short-term exposure to SO2 and emergency ambulance dispatches (EADs) due to CVD.

Methods

We collected daily data on the number of EADs due to CVD, air pollutants, and meteorological factors between October 2013 and June 2018 in Guangzhou, China. We used the quasi-Poisson generalized additive model combined with a distributed lag nonlinear model to estimate the short-term effect of SO2 on EADs due to CVD in multivariable models. Subgroup and sensitivity analyses were also performed.

Results

A total of 37,889 EADs due to CVD were documented during the study period. The average daily SO2 concentration was 12.5 μg/m3. A significant relationship between SO2 and EADs due to CVD was found, with a relative risk of 1.04 (95% confidence interval: 1.02, 1.06) with each 10 μg/m3 increment of SO2 at lag 0-1. The relationship was stronger in males, for participants aged ≥65 years, and in the cold season; however, no significant modification by subgroup was found in the association between SO2 and EADs due to CVD. Similar results from sensitivity analyses to the main findings were observed.

Conclusions

Short-term exposure to SO2 was significantly associated with increased EADs due to CVD.

Characteristics of Volatile Organic Compounds Emitted from Airport Sources and Their Effects on Ozone Production

In recent years, commercial air transport has increased considerably. However, the compositions and source profiles of volatile organic compounds (VOCs) emitted from aircraft are still not clear. In this study, the characteristics of VOCs (including oxygenated VOCs (OVOCs)) emitted from airport sources were measured at Shenzhen Bao'an International Airport. The results showed that the compositions and proportions of VOC species showed significant differences as the aircraft operating state changed. OVOCs were the dominant species and accounted for 63.17%, 58.44%, and 51.60% of the total VOC mass concentration during the taxiing, approach, and take-off stages. Propionaldehyde and acetone were the main OVOCs, and dichloromethane and 1,2-dichloroethane were the main halohydrocarbons. Propane had the highest proportion among all alkanes, while toluene and benzene were the predominant aromatic hydrocarbons. Compared with the source profiles of VOCs from construction machinery, the proportions of halogenated hydrocarbons and alkanes emitted from aircraft were significantly higher, as were those of propionaldehyde and acetone. OVOCs were still the dominant VOC species in aircraft emissions, and their calculated ozone formation potential (OFP) was much higher than that of other VOC species at all stages of aircraft operations. Acetone, propionaldehyde, formaldehyde, acetaldehyde, and ethylene were the greatest contributors to ozone production. This study comprehensively measured the distribution characteristics of VOCs, and its results will aid in the construction of a source profile inventory of VOCs emitted from aircraft sources in real atmospheric environments.

High-solution emission characters and health risks of volatile organic compounds for sprayers in automobile repair industries

The increasing automobile repair industries (ARIs) with spray facilities have become an important volatile organic compound (VOC) pollution source in China. However, the VOC health risk assessment for long-term exposure in ARIs has not been well characterized. In this study, though sampled VOCs from 51 typical ARIs in Beijing, the relationship between emission patterns, average daily exposure concentrations (EC), and health risks was comprehensively analyzed with the health assessment method. Results showed that concentrations of 117 VOCs from the samples ranged from 68.53 to 19863.32 μg·m-3, while the ARI operator's daily VOC inhalation EC was 11.24-1460.70 μg·m-3. The organic VOC (OVOC) concentration accounted for 73.16 ~ 94.52% in the solvent-based paint workshops, while aromatics were the main VOC component in water-based paint spraying (WPS) workshops, accounting for 70.08%, respectively. And the method of inhalation exposure health risk assessment was firstly used to evaluate carcinogenicity and non-carcinogenicity risk for sprayers in ARIs. The cumulative lifetime carcinogenic risk (LCR) for 24 sampled VOCs were within acceptable ranges, while the mean hazard index (HI) for 1 year with 44 sampled VOCs was over 1. Among them, ethyl alcohol had a high carcinogenic risk in both mixed water-based paint (MP) and solvent-based paint workshops. The mean HI associated with aromatics were 2.88E - 3 and 4.30E - 3 for 1 h in MP and WPS workshops. O-ethyl toluene and acetone are VOC components that need to be paid attention to in future paint raw materials and spraying operations. Our study will provide the important references for the standard of VOC occupational exposure health limits in ARIs.