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A chamberless field exposure system for determining the effects of gaseous air pollutants on crop growth and yield.
1990
Runeckles V.C. | Wright E.F. | White D.
Assessment of kitchen emissions using a backpropagation neural network model based on urinary hydroxy polycyclic aromatic hydrocarbons
2020
Gan, Dong | Huang, Daizheng | Yang, Jie | Zhang, Li’e | Ou, Songfeng | Feng, Yumeng | Peng, Yang | Peng, Xiaowu | Zhang, Zhiyong | Zou, Yunfeng
Kitchen emissions are mixed indoor air pollutants with adverse health effects, but the large-scale assessment is limited by costly equipment and survey methods. This study aimed to discuss the application of backpropagation (BP) neural network models in the assessment of kitchen emissions based on the exposure marker. A total of 3686 participants were recruited for the kitchen survey, and their sleep quality was measured by the Pittsburgh sleep quality index (PSQI). After excluding the confounders, 365 participants were selected to assess their urinary hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) concentrations by ultra-high-performance liquid chromatography/tandem mass spectrometry. Two BP neural network models were then set up using the survey and detection data from the 365 participants and used to predict the total urinary OH-PAHs concentrations of all participants. The total urinary OH-PAHs and 1-hydroxy-naphthalene (1-OHNap) concentrations were significantly higher among the 365 participants with poor sleep quality (global PSQI score > 5; P < 0.05). Results from internal and external validation showed that our model has high credibility (model 2). Further, the participants with higher predicted total urinary OH-PAHs concentrations were associated with the global PSQI score of >5 (odds ratio (OR) = 1.284, 95% confidence interval (CI) = 1.082–1.525 for participants with predicted total urinary OH-PAHs concentrations of over 1.897 μg/mmol creatinine in model 1, and OR = 1.467, 95% CI = 1.240–1.735 for participants with predicted total urinary OH-PAHs concentrations of over 2.253 μg/mmol creatinine in model 2) after adjusting for the confounders. Findings suggest that the BP neural network model is suitable for assessing kitchen emissions, and the urinary OH-PAHs concentrations can be taken as the model outlay.
Show more [+] Less [-]Impacts of electrokinetic isolation of phosphorus through pore water drainage on sediment phosphorus storage dynamics
2020
Tang, Xianqiang | Li, Rui | Hinton, William | Wu, Xingyi
Pore water is a crucial storage medium and a key source of sediment phosphorus. A novel equipment based on electrokinetic geosynthetics (EKGs) was used for isolating phosphorus from eutrophic lake sediments through pore water drainage. Three mutually independent indoor group experiments (A, B, and C) were conducted to investigate the effects of voltage gradient (0.00, 0.25, and 0.50 V/cm) on pore water drainage capacity, phosphorus removal performance, sediment physicochemical properties, and phosphorus storage dynamics. The average reduction in the sediment moisture and total phosphorus content was 2.5%, 4.3%, and 4.6% and 28.15, 75.95, and 112.65 mg/kg after 6 days of treatment for A, B and C, respectively. Efficient pore water drainage through gravity and electroosmotic flow and electromigration of phosphate were the main drivers of sediment-dissolved and mobilized phosphorus separation. A high voltage gradient facilitated the migration of pore water and the phosphorus in it. The maximal effluent total phosphorous (TP) concentration was up to 27.9 times that in the initial pore water samples, and negligible effluent TP was detected when the pore water pH was less than 2.5. The TP concentration was exponentially and linearly related to the pH and electronic conductivity of the electroosmotic flow, respectively. The migration of H⁺ within the sediment matrix promoted the liberation of metals bounded to phosphorus, particularly of Ca–P and Fe–P. Pore water drainage through an EKG resulted in Ex–P separation of up to 87.50% and a 13.84 mg/kg decrease in Ca–P and 125.35 mg/kg accumulation of low mobile Fe–P in the weak acid anode zone.
Show more [+] Less [-]Spatial distribution of lead contamination in soil and equipment dust at children's playgrounds in Beijing, China
2019
Peng, Tianyue | O'Connor, David | Zhao, Bin | Jin, Yuanliang | Zhang, Yunhui | Tian, Li | Zheng, Na | Li, Xiaoping | Hou, Deyi
Lead contamination is widespread across China, posing a serious public health concern. In quantifying child lead exposure, established health risk assessment (HRA) approaches often take into account residential soil lead levels. However, this may not constitute a significant exposure source for children in urban mainland China, where the population mainly dwell in high-rise buildings without back or front yards. In this setting, children's playgrounds may represent a more probable exposure source. The present study analyzed lead levels in settled dust on playground equipment and in surficial soils at 71 playgrounds in Beijing, China. Our results reveal that the average playground dust lead concentration was 80.5 mg/kg, more than twice the average soil lead concentration of 36.2 mg/kg. It was found that there are differences in statistical and spatial distributions for lead in playground dust and soils. Lead levels in equipment dust were largely consistent across Beijing, with elevated levels detected at locations in the main city area, the newly developed Tongzhou District, and the rural counties. Whereas average soil lead concentrations were higher at playgrounds in the main city area than other areas of Beijing. Statistical analysis suggests that the lead content in dust and soil may derive from different natural and anthropogenic sources. Equipment dust lead may be associated with long-distance atmospheric transportation and deposition. Whereas lead in soil is more likely to be associated with local traffic. This study also found that, in certain areas of Beijing, the risk of blood lead levels (BLLs) exceeding safe levels was up to 6 times higher when based on dust exposure than when based on playground soil exposure. The results of this study suggests that HRA undertaken for children in urban mainland China should pay closer attention to children's playgrounds as a lead exposure source, and, in particular, playground equipment dust.
Show more [+] Less [-]Direct and potential risk assessment of exposure to volatile organic compounds for primary receptor associated with solvent consumption
2018
Wang, Di | Yu, Han | Shao, Xia | Yu, Hongbing | Nie, Lei
Rapid development of industrial production has stimulated the growth of consumption of raw and auxiliary materials including organic paints, among which volatile organic compounds (VOCs) are proved harmful to the population who inhale the polluted air based on epidemiologic studies. Therefore, new types of environment-friendly paints were developed to replace solvent-based paints (SBPs). Nevertheless, new types of paints containing VOCs failed to replace SBPs entirely due to certain disadvantages. Hence, five kinds of paints were employed in simulation experiments to assess the health risk of primary receptor including three kinds of water-based paints (WBPs) and two kinds of SBPs. Conclusions showed that mean TVOC concentration in breathing zone of primary receptor ranged from 9.5 to 13.6 mg/m³ and 3.4 × 10³ to 1.4 × 10⁴ mg/m³ for WBPs and SBPs, respectively. Assessments of non-cancer risk concluded that nearly one third quantified compounds exceeded corresponding thresholds for WBPs, and the maximum risk value was 101.33; for SBPs, the maximum risk value reached 50760.20, and twenty-two compounds exceeded the reference limits. The calculation of cancer risk values showed that seventeen compounds were higher than acceptable limit amongst which 1,2-dibromoethane had maximum values of 1.27 × 10⁻² to 3.24 × 10⁻² for WBPs; for SBPs, all quantified compounds exceeded the acceptable limit, and 82.61% VOCs were distributed in a scope larger than 1 × 10⁻³. Additionally, a removal efficiency of 60% was considered for primary receptor with personal protective equipment, and subsequent results confirmed its inability of lowering the risk resulted from hazardous VOCs. The calculated potential health risk could be applied to estimate the total health risk for both primary and secondary receptor based on consumed materials. The finding suggested that WBPs could improve VOCs exposure condition and reduce the direct and potential health risk significantly for primary receptor, although they might dissatisfy acceptable limit.
Show more [+] Less [-]Tracing perfluoroalkyl substances (PFASs) in soils along the urbanizing coastal area of Bohai and Yellow Seas, China
2018
Meng, Jing | Wang, Tieyu | Song, Shuai | Wang, Pei | Li, Qifeng | Zhou, Yunqiao | Lü, Yonglong
With the shift of fluorine chemical industry from developed countries to China and increasing demand for fluorine chemical products, occurrence of perfluoroalkyl substances (PFASs) in production and application areas has attracted more attention. In this study, 153 soil samples were collected from 21 cities along the urbanizing coastal area of the Bohai and Yellow Seas. PFASs in this area were relatively higher, compared with other study areas. The concentrations ranged from 2.76 to 64.0 ng g−1, and those in most sites were between 2.76 and 13.9 ng g−1, with a predominance of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Among the 21 coastal cities, contaminations of PFASs in Zibo, Nantong and Binzhou were elevated, which was likely affected by local fluorine chemical plants, equipment manufacturing and chemical industry, respectively. The total emissions of PFOA and PFOS were similar, with amount of 4431 kg and 4335 kg, respectively. Atmospheric deposition was the largest source, accounting for 93.2% of total PFOA and 69.6% of PFOS, respectively. In addition, due to application of aqueous film-forming foams (AFFFs) and sulfluramid, disposal of sewage sludge and stacking of solid waste, emission of PFOA and PFOS to soil was 1617 kg, accounting for 9.29% of the whole China. In general, pollution in Jiangsu, Shandong and Tianjin was more serious than those in Liaoning and Hebei, which was consistent with industrialization level and size of industrial sectors emitting PFASs.
Show more [+] Less [-]A state-of-the-art review on capture and separation of hazardous hydrogen sulfide (H2S): Recent advances, challenges and outlook
2022
Chan, Yi Herng | Lock, Serene Sow Mun | Wong, Mee Kee | Yiin, Chung Loong | Loy, Adrian Chun Minh | Cheah, Kin Wai | Chai, Slyvester Yew Wang | Li, Claudia | How, Bing Shen | Chin, Bridgid Lai Fui | Chan, Zhe Phak | Lam, Su Shiung
Hydrogen sulfide (H₂S) is a flammable, corrosive and lethal gas even at low concentrations (ppm levels). Hence, the capture and removal of H₂S from various emitting sources (such as oil and gas processing facilities, natural emissions, sewage treatment plants, landfills and other industrial plants) is necessary to prevent and mitigate its adverse effects on human (causing respiratory failure and asphyxiation), environment (creating highly flammable and explosive environment), and facilities (resulting in corrosion of industrial equipment and pipelines). In this review, the state-of-the-art technologies for H₂S capture and removal are reviewed and discussed. In particular, the recent technologies for H₂S removal such as membrane, adsorption, absorption and membrane contactor are extensively reviewed. To date, adsorption using metal oxide-based sorbents is by far the most established technology in commercial scale for the fine removal of H₂S, while solvent absorption is also industrially matured for bulk removal of CO₂ and H₂S simultaneously. In addition, the strengths, limitations, technological gaps and way forward for each technology are also outlined. Furthermore, the comparison of established carbon capture technologies in simultaneous and selective removal of H₂S–CO₂ is also comprehensively discussed and presented. It was found that the existing carbon capture technologies are not adequate for the selective removal of H₂S from CO₂ due to their similar characteristics, and thus extensive research is still needed in this area.
Show more [+] Less [-]The combined effects of macrophytes and three road salts on aquatic communities in outdoor mesocosms
2021
Coldsnow, Kayla D. | Relyea, Rick A.
Because of environmental and societal concerns, new strategies are being developed to mitigate the effects of road salt. These include new deicers that are alternatives to or mixtures with the most common road salt, sodium chloride (NaCl), improved techniques and equipment, and biotic mitigation methods. Using outdoor mesocosms, we investigated the impacts of NaCl and two common alternatives, magnesium chloride (MgCl₂) and calcium chloride (CaCl₂) on freshwater communities. We also investigated the mitigation ability of a common macrophyte, Elodea. We hypothesized that road salt exposure reduces filamentous algae, zooplankton, and macrocrustaceans, but results in increases in phytoplankton and gastropods. We also hypothesized that MgCl₂ is the most toxic salt to communities, followed by CaCl₂, and then NaCl. Lastly, we hypothesized that macrophytes mitigate some of the effects of road salt, specifically the effects on primary producers. We found that all three salts reduced filamentous algal biomass and amphipod abundance, but only MgCl₂ reduced Elodea biomass. MgCl₂ had the largest and longest lasting effects on zooplankton, specifically cladocerans and copepods, which resulted in a significant increase in phytoplankton and rotifers. CaCl₂ increased ostracods and decreased snail abundance, but NaCl increased snail abundance. Lastly, while we did not find many interactions between road salt and macrophyte treatments, macrophytes did counteract many of the salt effects on producers, leading to decreased phytoplankton, increased filamentous algae, and altered abiotic responses. Thus, at similar chloride concentrations, NaCl alternatives, specifically MgCl₂, are not safer for aquatic ecosystems and more research is needed to find safer road management strategies to protect freshwater ecosystems.
Show more [+] Less [-]Volatile organic compound (VOC) emissions and health risk assessment in paint and coatings industry in the Yangtze River Delta, China
2021
Mo, Ziwei | Lü, Sihua | Shao, Min
Solvent use and paint consumption are significant source sectors of volatile organic compounds (VOCs) emissions in China. The occupational painters have high risk of health effect due to exposure to high VOCs concentration. However, the toxic components in coating environment have not been carefully identified, and the health risks of VOCs exposure have not been sufficiently assessed. This study collected air samples from nine workshops of three major coating sectors in the Yangtze River Delta of China, namely cargo container coating, ship equipment coating, and furniture coating, to evaluate the non-cancer and cancer risk of toxic VOCs exposure to occupational painters under a normal working condition. The results show that the container coating had highest cancer risk (2.29 × 10⁻⁶–5.53 × 10⁻⁶) exceeding the safe limit of 1.0 × 10⁻⁶, while non-cancer risk of all workshops was lower than acceptable level of 1. Ethylbenzene and 1,2-dichloropropane should be targeted for priority removal during the container coating process in attempt to reduce adverse health effect on the occupational painters. This study helps better understand the health risk of VOCs exposure in coating workshops in China and provides information for policy-makers to formulate possible control of specific toxic compounds during coating process.
Show more [+] Less [-]Factor diagnosis and future governance of dangerous goods accidents in China’s ports
2020
Chen, Jihong | Zheng, Huiying | Wei, Ling | Wan, Zheng | Ren, Ruisi | Li, Jie | Li, Haoqiang | Bian, Wentao | Gao, Manjia | Bai, Yun
Dangerous goods are particularly hazardous, as they can be flammable, explosive, and toxic. These characteristics make them vulnerable to accidents, and such mishaps during port operations can lead to massive economic losses and even deaths. It is, therefore, necessary and important to analyze and study the dangerous goods accidents at ports, so as to identify major factors and prevent them. Formal concept analysis (FCA) is a powerful tool for rule extraction. This paper introduces FCA along with relevant documents and case studies to analyze the dangerous goods accidents at China’s ports, building a concept lattice model of dangerous goods accidents at China’s ports, and reduces the condition attributes to come up with three key attributes of dangerous goods accidents at China’s ports: warehousing management, facilities and equipment, goods registration and extract four effective diagnostic rules for dangerous goods accidents at ports. This paper proposes corresponding governance strategies to the rules of dangerous goods accidents, which can significantly prevent and manage dangerous goods accidents at China’s ports in the future. In the future, the concept scale can be introduced to study the problem that the influencing factor is multi-valued attribute so as to expand the scope of research.
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