从组分和性质角度谈污染地块中石油烃的人体健康风险评估

石油烃的人体健康风险评估是污染地块土壤污染风险评估过程中的最常见的问题之一,其远比单一污染物的评估复杂和困难.但我国缺乏针对性的评估方法,实际操作中存在较多误区.因此,对于石油烃概念、性质的归纳总结以及对其健康风险评估方法的研究和探索,具有重要的意义.本文介绍了石油烃的基本概念,分析了不同馏分性质间的关系,回顾并分析了其分析测试方法及人体健康风险评估方法的适用要求及优缺点,提出了指示剂法与分馏法相结合采用典型样品馏分占比进行总体评估的工作方法,进而针对我国当前面临的问题,提出了后续的研究和发展建议.     

Understand the local and regional contributions on air pollution from the view of human health impacts

• PM_2.5-related deaths were estimated to be 227 thousand in BTH & surrounding regions. • Local emissions contribute more to PM_2.5-related deaths than PM_2.5 concentration. • Local controls are underestimated if only considering its impacts on concentrations. • Rural residents suffer larger impacts of regional transport than urban residents. • Reducing regional transport benefits in mitigating environmental inequality. The source-receptor matrix of PM_2.5 concentration from local and regional sources in the Beijing-Tianjin-Hebei (BTH) and surrounding provinces has been created in previous studies. However, because the spatial distribution of concentration does not necessarily match with that of the population, such concentration-based source-receptor matrix may not fully reflect the importance of pollutant control effectiveness in reducing the PM_2.5-related health impacts. To demonstrate that, we study the source-receptor matrix of the PM_2.5-related deaths instead, with inclusion of the spatial correlations between the concentrations and the population. The advanced source apportionment numerical model combined with the integrated exposure–response functions is used for BTH and surrounding regions in 2017. We observed that the relative contribution to PM_2.5-related deaths of local emissions was 0.75% to 20.77% larger than that of PM_2.5 concentrations. Such results address the importance of local emissions control for reducing health impacts of PM_2.5 particularly for local residents. Contribution of regional transport to PM_2.5-related deaths in rural area was 22% larger than that in urban area due to the spatial pattern of regional transport which was more related to the rural population. This resulted in an environmental inequality in the sense that people staying in rural area with access to less educational resources are subjected to higher impacts from regional transport as compared with their more resourceful and knowledgeable urban compatriots. An unexpected benefit from the multi-regional joint controls is suggested for its effectiveness in reducing the regional transport of PM_2.5 pollution thus mitigating the associated environmental inequality.     

Contamination levels and human health risk assessment of toxic heavy metals in street dust in an industrial city in Northwest China

This study investigated the content, distribution, and contamination levels of toxic metals (Cd, Cr, Cu, Pb, and Zn) in street dust in Lanzhou, an industrial city in Northwest China. Meanwhile, the risk these metals posed to the urban ecosystem and human health was also evaluated using the potential ecological risk index and human exposure model. Results showed that concentrations of these metals in the dust are higher than the background value of local soil, with Cu having the highest levels. The districts of Anning and Xigu had the most extreme levels of contamination, while Chengguan and Qilihe districts were lightly contaminated, which can be partly attributed to human activities and traffic densities. In comparison with the concentrations of selected metals in other cities, the concentrations of heavy metals in Lanzhou were generally at moderate or low levels. Heavy metal concentration increased with decreasing dust particle size. The pollution indices of Cr, Cd, Cu, Pb, and Zn were in the range of 0.289–2.09, 0.332–2.15, 1.38–6.21, 0.358–2.59, and 0.560–1.83 with a mean of 1.37, 1.49, 3.18, 1.48, and 0.897, respectively. The geo-accumulation index (I _geo) suggested that Zn in street dust was of geologic origin, while Cd, Cr, Pb, and Cu were significantly impacted by anthropogenic sources. The comprehensive pollution index showed that urban dust poses a high potential ecological risk in Lanzhou. Non-carcinogenic and carcinogenic effects due to exposure to urban street dust were assessed for both children and adults. For non-carcinogenic effects, ingestion appeared to be the main route of exposure to dust particles and thus posed a higher health risk to both children and adults for all metals, followed by dermal contact. Hazard index values for all studied metals were lower than the safe level of 1, and Cr exhibited the highest risk value (0.249) for children, suggesting that the overall risk from exposure to multiple metals in dust is low. The carcinogenic risk for Cd and Cr was all below the acceptable level (< 10⁻⁶).

     

Effects of a lead- and cadmium-resistant fungal strain on the absorption of heavy metals by Vetiveria zizanioides北大核心CSCD

A two-factor randomized complete block experiment was used to explore the remediation by a plant-microorganism combination on soils contaminated by lead (Pb) and cadmium (Cd). Factor A was the amount of fungi, for which four values were considered, namely, 0, 1, 3, and 5 g. Factor B was the level of contamination by lead and cadmium, for which six values were considered, namely, Cd0Pb0, Cd10Pb400, Cd20Pb600, Cd30Pb800, Cd50Pb1200, and Cd80Pb1800 (data in units of mg/ kg). The results showed that the resistant fungi promoted the growth of vetiver (Vetiveria zizanioides). At weights of 1, 3, and 5 g, the resistant fungi increased the biomass of vetiver by 41.9%, 74.9%, and 71.7% respectively. The resistant fungi stimulated the absorption of lead and cadmium by both the aerial and underground parts of vetiver. In the presence of 80 mg/kg of Cd2+ and 1 800 mg/kg of Pb2+, the contents of lead in the aerial parts of vetiver were increased by 120.6%, 265.4%, and 242.9%, while the lead content in the underground parts were increased by 110.3%, 278.2%, and 266.2%, after the addition of 1 g, 3 g, and 5 g of fungi, respectively. The content of cadmium in the aerial parts increased by 113.2%, 238.3%, and 217.3%, while the content of cadmium in the underground parts increased by 103.1%, 298.8%, and 274.4%, after the addition of 1 g, 3 g, and 5 g of fungi, respectively. The addition of fungi strengthened the effect of V. zizanioides to remediate soils contaminated by lead and cadmium, and the remediation after the addition of 3 g of fungi was better than that after treatment with 1 g and 5 g of fungi. The combination of resistant fungi and the heavy metal enrichment plant, vetiver, under different concentrations of lead and cadmium showed that the fungi had a significant effect on the remediation of soils contaminated by lead and cadmium. © 2018 Science Press. All rights reserved.     

丙烯腈诱导的氧化应激对大鼠肝脏内质网应激信号通路的影响

为探讨丙烯腈(acrylonitrile,ACN)诱导的大鼠肝脏氧化损伤对内质网应激(endoplasmic reticulum stress,ERS)信号通路的影响,我们将50只SPF级成年雄性SD大鼠按体重随机分为5组,每组10只。各组分别以12.5、25.0、50.0 mg·kg~(-1)ACN灌胃染毒,N-乙酰半胱氨酸(N-acetylcysteine,NAC)干预组先用300.0 mg·kg~(-1)NAC灌胃30 min后再灌50.0 mg·kg~(-1)ACN,对照组以0.5 mL·(100 g)~(-1)的玉米油灌胃,1次·天~(-1),6天·周~(-1),共计13周。染毒结束后,检测肝脏组织氧化还原酶活力及丙二醛(malondialdehyde,MDA)含量,GRP78、CHOP及caspase-12 mRNA及蛋白表达水平。结果显示:低、中ACN组大鼠肝脏GSH含量显著低于对照组(P0.05);低ACN组大鼠肝脏GSH-Px活力、SOD活力及MDA含量均显著高于对照组(P0.05);中、高ACN组大鼠肝脏CAT活力明显低于对照组(P0.05)。NAC干预后可逆转ACN诱导的大鼠肝脏GSH含量、MDA含量及SOD活力的变化。RT-PCR结果显示,高ACN组大鼠肝脏GRP78、CHOP、caspase-12 mRNA表达水平与对照组比较均升高(P0.05)。NAC干预后,CHOP、caspase-12 mRNA表达水平与高ACN组比较均降低(P0.05)。Western Blot结果显示,高ACN组大鼠肝脏GRP78、CHOP、caspase-12蛋白表达水平与对照组比较均升高(P0.05),NAC干预后可逆转以上作用。结果表明,ACN慢性染毒对大鼠肝脏的氧化损伤可激活ERS信号通路,NAC可减轻氧化损伤的程度而阻断ERS信号通路,这可能是ACN产生肝脏毒性的机制之一。     

草甘膦对非靶标生物的毒性研究进展

随着现代农业的飞速发展,农药的使用越来越广泛。草甘膦作为全球销量最大的农药除草剂,在自然环境中广泛存在,其对生态环境和人类健康的影响越来越受到人们的关注。文中从水生/两栖动物、土壤生物、哺乳动物以及人群等4个方面对除草剂草甘膦对非靶标生物的毒性研究概况进行综述,并对该领域未来发展趋势做了简要分析与展望,以期为草甘膦的生态安全和环境风险评价提供数据资料,为其合理使用提供理论指导。     

一种准分布式内加热刚玉管FBG渗流速率监测方法

岩土体中的渗流是引发各种地质灾害的重要因素。针对现有渗流监测技术的不足,提出了一种基于光纤布拉格光栅FBG的准分布式内加热刚玉管FBG渗流监测方法;介绍了该方法的原理;发明了一种新型内加热刚玉管渗流传感器;推导出了温度特征值与渗流速率之间的关系,并通过砂性土室内模型试验对此关系进行了率定。试验结果表明:(1)本方法对砂性土中渗流速率进行监测是可行的;(2)利用刚玉管封装的新型传感器具有很好的监测性能;(3)在给定加热功率条件下,一定渗流速率范围内,温度特征值与渗流速率间存在线性关系,渗流速率越大,温度特征值越小;(4)一定加热功率条件下的渗流速率监测存在相应的测试量程,提高给定加热功率可提高监测量程。     

河南省大气污染现状及其控制对策分析

河南省近年大气污染问题突出,灰霾天气频发,已经影响到居民正常生活。通过调查河南省2012年环境空气质量现状及2003—2012年变化趋势、2012年能源消费结构现状及2005—2012年能源消费结构变化趋势,分析河南省能源消费结构对环境空气质量的影响,根据河南省目前环境空气质量和能源消费结构存在的问题,提出推进产业结构调整、加快能源结构调整、实施大气污染物协同控制、严格节能环保准入条件等措施。     

Cathode ray tube (CRT) recycling: current capabilities in China and research progress

It is estimated that approximately 6,000,000 scrap TVs and 10,000,000 personal computers are generated each year in China. Cathode ray tubes (CRTs) from these machines consist of 85% glass (65% panel, 30% funnel and 5% neck glass). The leaded glass (funnel-24%, neck-30%) may seriously pollute the environment if it is not properly disposed of. In this paper, the past, current and future status of CRT dismantling technologies as well as the CRT glass recycling situation in China are presented and discussed. Recycling technology for waste CRTs in China is still immature. While the conventional CRT dismantling technologies have disadvantages from both economic and environmental viewpoints, some of the new and emerging treatments such as automatic optical sorting facilities that have been applied in developed countries offer advantages, and therefore should be transferred to China in the next few years to solve the CRT pre-processing problem. Meanwhile, because the demand for CRT glass closed-loop recycling is extremely limited, the authorities should take effective measures to improve CRT glass recycling rates and to facilitate a match to local conditions. Moreover, we also provide a broad review of the research developments in recycling techniques for CRT cullet. The challenge for the future is to transfer these environmentally friendly and energy-saving technologies into practice.