PubMed · 3832386
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K E Prescher. 1985. [Acid rain].. https://pubmed.ncbi.nlm.nih.gov/3832386/
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Chloroform (CHCl3) is a short-lived ozone-depleting substance not currently regulated under the Montreal Protocol. Due to the unique meteorological conditions in East Asia, CHCl3 emitted in this region has a greater potential to reach the stratosphere and contribute to ozone depletion. As an essential component of national CHCl3 emissions, southeastern China has attracted increasing attention. However, long-term observational data in this region remain relatively scarce, with no updates since 2020. In this study, we continuously measured atmospheric CHCl3 concentrations at a remote monitoring station in southeastern China from 1 June 2023 to 31 May 2025. Frequent concentration enhancements were observed during the monitoring period, with mixing ratios ranging from 9.3 to 134.1 ppt and an average value of 36.8 ± 19.7 ppt. Back-trajectory analysis indicated that air masses associated with elevated CHCl3 levels primarily originated from coastal industrial provinces in eastern China. Using the Potential Source Contribution Function and Concentration Weighted Trajectory methods, we identified the Yangtze River Delta (Jiangsu, Anhui, and Zhejiang Provinces) and Jiangxi Province as dominant source regions. Emissions of CHCl3 in southeastern China were estimated using the Tracer Ratio Method to be approximately 30.1 ± 5.3 Gg/yr from 2023-06-01 to 2025-05-31, indicating overall stability relative to earlier estimates and no apparent upward trend. These findings provide updated insights into the current status of CHCl3 emissions in southeastern China and highlight the need for continued monitoring and emission assessment of CHCl3 in East Asia, given its unregulated status and implications for ozone layer recovery.
This study uses the Ellenberg system of plant indicator values, along with Grime et al.'s plant growth strategy values, to investigate the nature of temporal changes in the composition of ground flora in two beechwoods in the Cotswolds region of the UK, currently receiving atmospheric inputs of nitrogen in excess of critical loads. The woods, first surveyed in the early 1960s, were resurveyed in 1998 using the original sampling protocol. Temporal changes in the abundance of individual species at Blackstable West Wood indicate changes in light over time, although decreases in sun species, and both increases and decreases in shade species suggest that this change has been patchy. Analysis of changes in plant community as represented by weighted and unweighted quadrat Ellenberg and CSR scores have yielded more significant results. Blackstable West Wood shows increases in nitrophilic, moist-soil and competitive species accompanied by a decline in stress-tolerant species. In Buckholt Top Wood there has been an increase in sun and moist-soil species, a decrease in competitive species and, when weighted Ellenberg scores are considered, an increase in acid-tolerant species. These changes indicate both the impact of woodland management by selective felling and an underlying influence of enhanced atmospheric deposition especially of nitrogen pollutants. It is concluded that quadrat mean scores are a useful tool especially where few individual species have undergone large temporal changes in abundance. However, lack of correlations between quadrat Ellenberg scores for pH and light on one hand, and their equivalents measured in the field, i.e. soil pH and surrogates for light, such as distance to the nearest tree and tree density, suggest that this approach may not be sensitive enough to pick up small-scale, within site variations. Although harder to interpret, plant strategy scores were found to be a useful additional descriptor, encapsulating a plant's response to a range of environmental factors.
Bisphenol A, an environmental contaminant, widely used as a monomer in polycarbonate plastics, has been shown to cause abnormalities in liver of rats and mice. The nature and mechanism of action of bisphenol A on liver is not clear. The aim of the present study was to investigate if bisphenol A induces oxidative stress in the liver of rats and if co-administration of vitamin C, an antioxidant, can prevent oxidative stress. Bisphenol A (0.2, 2.0 and 20 micro g/kg body weight per day) and bisphenol A+vitamin C (0.2, 2.0, 20 micro g+40 mg/kg body weight per day) was orally administered to rats for 30 days. After 24 h of the last treatment, rats were killed using overdose of anesthetic ether. Body weights of the animals and the weights of liver showed no significant changes. The activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase were decreased in mitochondrial and microsome-rich fractions of liver. The levels of hydrogen peroxide and lipid peroxidation increased in the treated rats when compared with the corresponding group of control animals. Activity of alanine transaminase, a marker enzyme of hepatic injury remained unchanged in the treated rats as compared with the corresponding control rats. Co-administration of bisphenol A and vitamin C showed no changes in the activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase and in the levels of hydrogen peroxide and lipid peroxidation as compared with the corresponding control groups. The results indicated that bisphenol A induces oxidative stress in the liver of rats by decreasing the antioxidant enzymes. Co-administration of vitamin C reversed the effects of bisphenol A-induced oxidative stress in the liver of rats.