Due to the characteristics of ozone-depleting and high global warming potential, chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) have been restricted by the Montreal Protocol and its amendments over the world. Considering that China is one of the main contributors to the emission of halocarbons, a long-term atmospheric observation on major substances including CFC-11 (CCl₃F), CFC-12 (CCl₂F₂), HCFC-22 (CHClF₂), HCFC-141b (CH₃CCl₂F), HCFC-142b (CH₃CClF₂) and HFC-134a (CH₂FCF₃) was conducted in five cities (Beijing, Hangzhou, Guangzhou, Lanzhou and Chengdu) of China during 2009–2019. The atmospheric concentrations of CFC-11, CFC-12, HCFC-141b and HCFC-142b all showed declining trends on the whole while those of HCFC-22 and HFC-134a were opposite. A paired sample t-test showed that the ambient mixing ratios of HCFC-22 and HFC-134a in cities were 41.9% and 25.7% higher on average than those in suburban areas, respectively, while the other substances did not show significant regional differences. The annual emissions of halocarbons were calculated using an interspecies correlation method and the results were generally consistent with the published estimates. Discrepancies between bottom-up inventories and the estimates in this study for CFCs emissions were found. Among the most consumed ozone depleting substances (ODSs) in China, CFCs accounted for 75.1% of the ozone depletion potential (ODP)-weighted emissions while HCFCs contributed a larger proportion (58.6%) of CO₂-equivalent emissions in 2019. China's emissions of HCFC-141b and HCFC-142b contributed the most to the global emission (17.8%–48.0%). The elimination of HCFCs in China will have a crucial impact on the HCFCs phase-out in the world.

Hydrochlorofluorocarbons (HCFCs) are used as temporary substitutes for chlorofluorocarbons and other ozone-depleting substances because they have reduced ozone depletion and global warming potentials. The consumption and production of HCFCs are regulated via the Montreal Protocol and its amendments till 2013, with a complete phase-out being scheduled by 2030 for Article 5 parties (developing countries). To better understand the characteristics and emissions of HCFCs in the Yangtze River Delta (YRD), which is the largest metropolitan area in China, weekly flask samples were collected at the Lin'an regional background station located in the YRD from 2011 to 2018 and measured for four HCFCs (HCFC-22, HCFC-141b, HCFC-142b, and HCFC-124). The HCFC-132b and HCFC-133a measurements began in 2018. The ambient mixing ratios of the HCFCs exhibited higher concentrations and larger variabilities than those at the Shangri-la regional background station at similar latitudes in southwest China. The HCFC emissions in the YRD were estimated based on the tracer ratio method using CO and HFC-134a as tracers, and were comparable within the uncertainties. Our results are generally consistent with previous estimates obtained using top-down approaches. HCFC-22 and HCFC-141b contributed 52% ± 23% and 41% ± 24% of the total ODP-weighted (CFC-11-equivalent) HCFC emissions from the YRD, respectively, whereas HCFC-22 contributed the most (83% ± 36%) to the total CO₂-equivalent HCFC emissions from the YRD. The cumulative ODP-weighted and CO₂-equivalent emissions of HCFCs from the YRD accounted for 25% ± 15% and 20% ± 11% of the national corresponding totals, respectively, for 2011–2017. The HCFC-141b emissions from the YRD contributed approximately half of the total Chinese emissions. HCFC-133a emissions in the YRD accounted for approximately one-fifth of the global total in 2018. Thus, the YRD is an important contributor of HCFC emissions on national and global scales.

Regional- and national-scale emissions of chlorofluorocarbons (CFCs), especially in Eastern China, are of great concern to environmentalists and policy makers. To determine the source-sink dynamics of coastal salt marshes for CFC-11 and CFC-12 in the local atmosphere, we studied a coastal salt marsh in Northern Jiangsu Province, taking measurements of the atmospheric concentrations and fluxes of CFC-11 and CFC-12 using static flux chambers in August (growing season) and December (non-growing season) of 2013, and along both creek-side and vegetated transects. We observed unexpectedly high concentrations of CFC-11 (676.5 × 10⁻¹²) and CFC-12 (794.6 × 10⁻¹²) in the salt marsh in 2013, with predominantly non-local emissions. Overall, the study salt marsh acted as a net sink for CFC-11 and CFC-12, with the average flux ranging from −11.4 μg m⁻² h⁻¹ to 5.0 μg m⁻² h⁻¹ for CFC-11 and from −7.4 μg m⁻² h⁻¹ to 0.7 μg m⁻² h⁻¹ for CFC-12. This clearly indicates that the high concentrations of CFC-11 and CFC-12 measured in the atmosphere were not caused by local emissions; terrigenous sources most likely act as the main exogenous input pathway. Our study suggests that salt marsh ecosystems may be worthy of attention as sinks for CFC-11 and CFC-12; as such, the ecological restoration of salt marshes is critical to better offset increasing CFC-11 and CFC-12 emissions.

Spatiotemporal distributions of volatile halogenated organic compounds (VHOCs) were investigated in the marine boundary air and surface seawater of the Changjiang (Yangtze River) estuary and its adjacent East China Sea in two cruises from March 11, 2015 to March 21, 2015 and from July 9, 2015 to July 20, 2015. Results revealed that the concentrations of released chlorofluorocarbons (CFCs) such as CFC-12, CFC-11, and CFC-114 in China decreased, suggesting that limitations set by the Chinese government on CFCs production and consumption have taken effect. Atmospheric concentrations of CFCs were affected by local industrial sources of emission and transport of terrestrial pollutants from coastal areas to varying degrees. Seasonal variations in atmospheric VHOCs were probably due to seasonal differences in prevalent monsoon and biogenic production. In the study periods, the investigated area was an essential source of atmospheric CH3Br and CH3I but was a net sink of CFC-12, CFC-11, and CH3Cl.

Temporal and spatial distribution patterns of volatile halogenated organic compounds (VHOCs), such as dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), trichlorotrifluoroethane (CFC-113), and methyl iodide (CH3I), in the Changjiang (Yangtze River) estuary and its adjacent marine area were measured during two cruises from 21 February to 10 March 2014 and from 10 to 21 July 2014. VHOC concentrations showed seasonal variation with higher values during winter. VHOC distributions evidently decreased along the freshwater plume from the river mouth to the open sea and from inshore to offshore regions. VHOC distributions were obviously influenced by the Changjiang runoff, anthropogenic inputs, and biological release of phytoplankton. The study area was a net sink for CFC-12 and CFC-11, but a net source for atmospheric CH3I during the study periods.

This study investigates the composition and concentrations of volatile organic compounds (VOCs) in air-conditioned office space and low-level waste (LLW) repository sites of nuclear power plants located in Taiwan. Air samples were collected in the office space and technical rooms of administration buildings of the three nuclear power plants and in LLW repository site using canisters. Thirty-six toxic organic compounds including aromatics, CFCs and chlorinated hydrocarbons were identified and quantified using gas chromatograph/mass spectrometer (GC/MS). The results indicated that the concentrations of most determined species were similar to that in urban areas; however, the air at the LLW building contained abundant trichlorotrifluoroethane (CFC-113), trichloroethylene, toluene, 1,2,4-trimethylbenzene and CFC-12 in concentrations markedly higher than the background levels. Only toluene and 1,2,4-trimethylbenzene were detected with low concentrations in the air of LLW repository site. In addition, comparison of the ambient air concentration at several major industries and urban atmosphere revealed that the nuclear power plants emitted and/or leaked higher concentration of chlorinated hydrocarbons among them.

The goal of this study is to use life cycle assessment (LCA) tool to assess possible environmental impacts of different municipal solid waste management (MSWM) scenarios on various impact categories for the study area Dhanbad City, India. The scenarios included in the present study are collection and transportation (denoted as S1); baseline scenario consisting of recycling, open burning, open dumping, and finally unsanitary landfilling without energy recovery (denoted by S2); composting and landfilling (denoted by S3); and recycling and composting followed by landfilling of inert waste without energy recovery (denoted by S4). One ton of municipal solid waste (MSW) was selected as the functional unit. The primary data were collected through sampling, surveys, and literatures. Background data were obtained from Eco-invent data of SimaPro 8.1 libraries. The scenarios were compared using the CML 2 baseline 2000 method, and the results indicated that the scenario S1 had the highest impact on marine aquatic ecotoxicity (1.86E + 04 kg 1,4-DB eq.) and abiotic depletion (2.09E + 02 kg Sb eq.). S2 had the highest impact on global warming potential (9.42E + 03 kg CO₂ eq.), acidification (1.15E + 01 kg SO₂ eq.), eutrophication (2.63E + 00 kg PO₄³⁻ eq.), photochemical oxidation (2.12E + 00 kg C₂H₄ eq.), and human toxicity (2.25E + 01 kg 1,4-DB eq.). However, S3 had the highest impact on abiotic depletion (fossil fuels) (2.71E + 02 MJ), fresh water aquatic ecotoxicity (6.54E + 00 kg 1,4-DB eq.), terrestrial ecotoxicity (3.36E − 02 kg 1,4-DB eq.), and ozone layer depletion (2.73E − 06 kg CFC-11 eq.). But S4 did not have the highest impact on any of the environmental impact categories due to recycling of packaging waste and landfilling of inert waste. Landfilling without energy recovery of mixed solid waste was found as the worst disposal alternative. The scenario S4 was found as the most environmentally suitable technology for the study area and recommended that S4 should be considered for strategic planning of MSWM for the study area.

The biological degradation of volatile halogenated hydrocarbons (chlorocarbons (VCCs) and chlorofluorocarbons (CFCs)) was investigated under simulated conditions of landfills in laboratory test digesters. Fully halogenated VCCs (tetrachloroethylene, 1,1,1-trichloroethane, tetrachloromethane and dichloromethane) and CFCs (trichlorofluoromethane (R11), dichlorodifluoromethane (R12) and 1,1,2-trichlorotrifluoroethane (R113)) were degraded under anaerobic conditions in addition to the methanogenic bacteria in municipal solid waste (MSW) and organic wastes. These substances showed different degradation reactions in the simulated acid and methanephases of MSW landfills. It is assumed that R11 and R113 could be decomposed completely under methanogenic conditions. Dichlorofluoromethane (R21) was oberved as the reductive degradation product of R11 and was further degraded during the methanephase, but hardly at all under acid conditions. Chlorodifluoromerhane (R22) as a degradation product of R12 was not degraded, even not in the methanephase. In the acidphase, R11 was the only CFC to be dechlorinated, although only in small quantities. The degradation products of tetrachloroethylene differed under the various environmental conditions. In the acidphase, 1,1-dichloroethylene was detected as the only dichloroethylene, whereas in particular cis-1,2-dichloroethylene but also trans-1,2-dichloroethylene, 1,1-dichloroethylene and vinyl chloride could be detected as metabolites in the methanephase. Dichloromethane and chloroethane, as metabolites of 1,1,1-trichloroethane, could hardly be degraded at all in the acidphase. The degradation of VCCs and CFCs is largely independent of the substrate used. The investigations have demonstrated that the measured biodegradation rates (0.3–15 mg/m³ ₘₐₜₑᵣᵢₐₗ ᵥₒₗ./h) cannot be improved considerably since they are limited by the inhibiting effect of the substances and their degradation products.