Environmental Science and Pollution Research - Crushed waste rocks can be used as materials for backfilling goafs, so as to achieve the simultaneous goals of processing solid waste and controlling... 相似文献
This study aimed to investigate the association between pyrethroid exposure and the risk of depressive symptoms in adults in the USA. Data of participants aged ≥20 years (n = 6455) from the National Health and Nutrition Examination Survey (NHANES, 2007–2014) were included. 3-Phenoxybenzoic acid (3-PBA), an adequately detected pyrethroid metabolite, was used as a biomarker to assess pyrethroid exposure. Depressive symptoms were defined as the Patient’s Health Questionnaire (PHQ-9) total score ≥10 or use of antidepressant. Multivariable logistic regression analyses were performed to examine the association between urinary 3-PBA levels and the risk of depressive symptoms. In this study, 1150 participants (weighted frequency, 18.45%) developed depressive symptoms. Participants in the highest tertile have a higher risk of depressive symptoms than those in the lowest tertile of urinary 3-PBA and weighted OR of 1.28 (95% CI, 1.00–1.63, P=0.019). There was a nonlinear association between urinary 3-PBA and depressive symptoms (P for nonlinearity = 0.034). Mediation analysis showed the mediating effect of trouble sleeping on the association of urinary 3-PBA with depressive symptoms was 28.8% (P = 0.006). Our findings indicate that pyrethroid exposure is associated with the increased risk of depressive symptoms, and trouble sleeping may mediated this association. Further studies should be conducted to validate our findings and elucidate their underlying mechanisms.
An event-driven, urban, drinking water quality early warning and control system (DEWS) is proposed to cope with China’s urgent need for protecting its urban drinking water. The DEWS has a web service structure and provides users with water quality monitoring functions, water quality early warning functions, and water quality accident decision-making functions. The DEWS functionality is guided by the principles of control theory and risk assessment as applied to the feedback control of urban water supply systems. The DEWS has been deployed in several large Chinese cities and found to perform well insofar as water quality early warning and emergency decision-making is concerned. This paper describes a DEWS for urban water quality protection that has been developed in China. 相似文献
Plastics from waste electrical and electronic equipment (WEEE) have been an important environmental problem because these plastics commonly contain toxic halogenated flame retardants which may cause serious environmental pollution, especially the formation of carcinogenic substances polybrominated dibenzo dioxins/furans (PBDD/Fs), during treat process of these plastics. Pyrolysis has been proposed as a viable processing route for recycling the organic compounds in WEEE plastics into fuels and chemical feedstock. However, dehalogenation procedures are also necessary during treat process, because the oils collected in single pyrolysis process may contain numerous halogenated organic compounds, which would detrimentally impact the reuse of these pyrolysis oils. Currently, dehalogenation has become a significant topic in recycling of WEEE plastics by pyrolysis. In order to fulfill the better resource utilization of the WEEE plastics, the compositions, characteristics and dehalogenation methods during the pyrolysis recycling process of WEEE plastics were reviewed in this paper. Dehalogenation and the decomposition or pyrolysis of WEEE plastics can be carried out simultaneously or successively. It could be ‘dehalogenating prior to pyrolysing plastics’, ‘performing dehalogenation and pyrolysis at the same time’ or ‘pyrolysing plastics first then upgrading pyrolysis oils’. The first strategy essentially is the two-stage pyrolysis with the release of halogen hydrides at low pyrolysis temperature region which is separate from the decomposition of polymer matrixes, thus obtaining halogenated free oil products. The second strategy is the most common method. Zeolite or other type of catalyst can be used in the pyrolysis process for removing organohalogens. The third strategy separate pyrolysis and dehalogenation of WEEE plastics, which can, to some degree, avoid the problem of oil value decline due to the use of catalyst, but obviously, this strategy may increase the cost of whole recycling process. 相似文献
The prosperity of farmers is closely tied to governmental policies. The Jianghan Plain is an important region for commodity grains, cotton and edible oil for China. The trajectories of land use and land cover change (LUCC) of the study area from 1995 to 2010 were studied based on the LUCC database of the Chinese Academy of Sciences. The LUCC was characterised by a continuous decrease of arable land and continuous increase of waters and construction land. The LUCC was obviously concurrent with the implementation of related national policies. The transition to construction land was ever well controlled by ‘Notice regarding the further strengthening of land management and arable land protection’ promulgated in 1997. However, it flourished again with the ‘Rise of Central China Strategy’ taking effect since 2006. The transition of construction land to others reflects an uncommon trend, which must be strengthened with the strict implementation of the overall plan, which imposes a limited acreage quota of construction land to each district. The policies were quite contradictory to the transition of waters. LUCC related to waters is most active, which was driven by both natural forces and national policies. Just after the devastating flood of 1998, the state council of China put forward the Green Policy to govern the major rivers. As to the study area, it is mainly to ‘push over dykes to let flood through and return farmland to lakes’. In 2004, the Grain Direct Subsidy Policy was implemented, which, along with the surge in the price of rice, resulted in a strengthening trend of conversion of ponds to paddy fields. 相似文献
Aerosol optical properties from 2005 to 2008 at the Longfengshan regional background station in Northeast China were measured and analyzed. The annual mean of aerosol optical depth (AOD) at 440 nm for the four years was about 0.27 ± 0.25, 0.39 ± 0.37, 0.35 ± 0.34, and 0.38 ± 0.38, respectively, and the corresponding annual mean for the Angstrom exponent between 440 nm and 870 nm was about 1.43 ± 0.48, 1.23 ± 0.37, 1.53 ± 0.47, and 1.55 ± 0.42. The average monthly AOD440nm showed similar seasonal variation with a maximum in spring and a minimum in autumn. The monthly means of AOD at 440, 675, 870 and 1020 nm increase from the January to March with the maxima about 0.77 ± 0.04, 0.65 ± 0.04, 0.58 ± 0.06, 0.57 ± 0.07, respectively and decrease from September to February with the minima about 0.32 ± 0.12, 0.22 ± 0.09, 0.15 ± 0.08, and 0.13 ± 0.07 in January. The monthly mean of Angstrom exponent shows a minimum in March (0.97 ± 0.52) and a maximum in September (1.66 ± 0.29). Both the AOD and Angstrom exponent presents single peak distributions of occurrence frequencies. The Longfenshan data showed high AODs (>1.00) both clustering in the fine mode growth wing and the coarse mode. Two typical cases under dust and haze conditions showed that the AOD under dusty day decreased from 2.20 to 1.20 and the Angstrom exponent increased from 0.10 to 1.00. On the contrast, the AOD under haze day remained relatively stable about 0.90 and the Angstrom exponent was around 1.40. The 3-day backtrajectory analysis at Longfengshan illustrated that the air-masses near ground on the dust day were from Bohai Sea and passed through Liaodong Peninsula and Northeast plain in China. But the air-masses on 500 m AGL were originated from western Mongolia and crossed Gobi deserts, Otindag Sand Land and Horqin Sand Land in Northeast China. The air-masses at Longfengshan near ground 500 m and 1000 m AGL on the haze days were from North China Region and passed through Northeast Heavy Industrial Base in Northeast China. 相似文献