面向人体暴露评价的植物中抗生素分析进展

抗生素通过动物粪便或生物固体的施用、再生水灌溉进入农业土壤后可以被蔬菜和粮食作物吸收,从而引起人体的被动暴露。为了评估抗生素对人体暴露的健康风险,需要基于植物样品,发展灵敏、稳定且针对性强的分析方法。本文综述了植物样品中抗生素残留分析的研究进展,重点介绍了样品提取、净化等前处理方法及其仪器分析方法,并对植物样品中抗生素分析的研究方向进行了展望。     

Endocrine disruptors in bottled mineral water: total estrogenic burden and migration from plastic bottles

Background, aim, and scope  Food consumption is an important route of human exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by exposure modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination. Materials, methods, and results  In the present study, we analyzed commercially available mineral water in an in vitro system with the human estrogen receptor alpha and detected estrogenic contamination in 60% of all samples with a maximum activity equivalent to 75.2 ng/l of the natural sex hormone 17β-estradiol. Furthermore, breeding of the molluskan model Potamopyrgus antipodarum in water bottles made of glass and plastic [polyethylene terephthalate (PET)] resulted in an increased reproductive output of snails cultured in PET bottles. This provides first evidence that substances leaching from plastic food packaging materials act as functional estrogens in vivo. Discussion and conclusions  Our results demonstrate a widespread contamination of mineral water with xenoestrogens that partly originates from compounds leaching from the plastic packaging material. These substances possess potent estrogenic activity in vivo in a molluskan sentinel. Overall, the results indicate that a broader range of foodstuff may be contaminated with endocrine disruptors when packed in plastics.     

Effect of 3 years' free-air exposure to elevated ozone on mature Norway spruce (Picea abies (L.) Karst.) needle epicuticular wax physicochemical characteristics

We examined the effect of ozone (O₃) on Norway spruce (Picea abies) needle epicuticular wax over three seasons at the Kranzberg Ozone Fumigation Experiment. Exposure to 2× ambient O₃ ranged from 64.5 to 74.2 μl O₃ l⁻¹ h AOT40, and 117.1 to 123.2 nl O₃ l⁻¹ 4th highest daily maximum 8-h average O₃ concentration. The proportion of current-year needle surface covered by wax tubes, tube aggregates, and plates decreased (P = 0.011) under 2× O₃. Epistomatal chambers had increased deposits of amorphous wax. Proportion of secondary alcohols varied due to year (P = 0.004) and O₃ treatment (P = 0.029). Secondary alcohols were reduced by 9.1% under 2× O₃. Exposure to 2× O₃ increased (P = 0.037) proportions of fatty acids by 29%. Opposing trends in secondary alcohols and fatty acids indicate a direct action of O₃ on wax biosynthesis. These results demonstrate O₃-induced changes in biologically important needle surface characteristics of 50-year-old field-grown trees.     

Sorption and desorption of carbamazepine, naproxen and triclosan in a soil irrigated with raw wastewater: estimation of the sorption parameters by considering the initial mass of the compounds in the soil

The amphipod Hyalella azteca was exposed for 28 d to different combinations of Zn contaminated sediment and food. Sediment exposure (+clean food) resulted in increased Zn body burdens, increased mortality and decreased body mass when the molar concentrations of simultaneously extracted Zn were greater than the molar concentration of Acid Volatile Sulfide (SEM_Zn-AVS > 0), suggesting that dissolved Zn was a dominant route of exposure. No adverse effect was noted in the foodexposure (+clean sediment), suggesting selective feeding or regulation. Combined exposure (sediment + food) significantly increased adverse effects in comparison with sediment exposure, indicating contribution of dietary Zn to toxicity and bioaccumulation. The observed enhanced toxicity also supports the assumption on the presence of an avoidance/selective feeding reaction of the amphipods in the single sediment or food exposures. During 14 d post-exposure in clean medium, the organisms from the same combined exposure history received two feeding regimes, i.e. clean food and Zn spiked food. Elevated Zn bioaccumulation and reduced reproduction were noted in amphipods that were offered Zn spiked food compared to the respective organisms that were fed clean food. This was explained by the failure of avoidance/selective feeding behavior in the absence of an alternative food source (sediment), forcing the amphipods to take up Zn while feeding. Increasing Zn body burdens rejected the assumption that Zn uptake from food was regulated by H. azteca. Our results show that the selective feeding behavior should be accounted for when assessing ecological effects of Zn or other contaminants, especially when contaminated food is a potential exposure route.     

Proximal exposure of public schools and students to major roadways: a nationwide US survey

This study addresses the effect of urban planning and road development on the health risk of students attending schools near major roadways. The proximity of public schools and students was quantified to Interstate, US and state highways in nine large Metropolitan Statistical Areas (MSA) of the USA. In total among the surveyed schools and students, over 30% fell within 400 m of a major roadway and over 10% were within 100 m. For some MSAs almost half of the student population attended schools near (≤400m) major roadways, resulting in a potentially increased risk for asthma and other chronic respiratory problems, especially in schools representing the urban fringe locale. It was concluded that proximity of major roadways should be an important factor in considering sites for new schools and developing policies for reducing the exposure in existing schools. The findings provide an important reference point for coordinating future urban development, transportation and environmental policies.     

苯暴露的致癌风险评价

为建立苯暴露风险的定量研究方法,利用生理药代动力学(PBPK)模型与剂量—反应关系,进行苯暴露的致癌风险评价。采用美国环保署推荐的PBPK模型模拟软件,计算苯经吸收转化后进入人体的数据。将模拟得到的内剂量代入致癌风险计算公式中,得到苯暴露的致癌风险,并利用蒙特卡洛模拟方法确定风险概率分布,进行不确定性分析。最后将此健康风险评价方法应用于天津某大型石油化工企业,分析工人苯暴露下的致癌风险。结果表明,工人苯暴露的致癌风险明显超过了最大可接受风险值1×10-4,需要采取相关措施降低风险。     

污染场地土壤通用评估基准建立的理论和常用模型

污染场地土壤通用评估基准的建立与每个国家的经济水准及社会发展紧密相关.从国际相关领域的发展趋势来看,场地基准的建立基于风险基础之上.我国正在颁布污染场地风险评估技术导则(C-RAG),表明我国已选择风险基础上的污染场地管理模式.文章回顾了污染场地土壤通用评估基准建立的理论、方法及通用模型,并推荐污染场地评估的模型框架,...     

Interactive effects of O3 exposure on California black oak (Quercus kelloggii Newb.) seedlings with and without N amendment

We examined the short-term separate and combined effects of simulated nitrogen (N) deposition (fertilization) and ozone (O(3)) exposure on California black oak seedlings (Quercus kelloggii Newb.), an ecologically important tree of the San Bernardino Mountains downwind of Los Angeles. Realistic concentrations of O(3) were found to cause statistically and biologically significant negative effects on plant health, including lowered photosynthetic ability, lowered water use efficiency, and increased leaf chlorosis and necrosis. When subjected to abrupt changes in light levels, O(3)-exposed plants showed both a slower and smaller response than O(3)-free plants. Fertilized plants exhibited a significantly greater pre- to post-treatment decline in A at saturated [CO(2)] and a significantly lower level of post-treatment chlorosis than unfertilized plants. Fertilization tended to reduce plant sensitivity to O(3).     

Nickel sulfate induces numerous defects in Caenorhabditis elegans that can also be transferred to progeny

Whether the multiple biological toxicities from nickel exposure could be transferred to progeny has not been clarified. In this report, we explored the Caenorhabditis elegans to analyze the multiple toxicities of nickel and their possibly transferable properties. The nickel toxicity caused multiple biological defects in a concentration-dependent manner. Moreover, most of these toxicities could be transferred and could be only partially rescued in progeny. Some specific phenotypes in progeny were also found to exhibit no obvious rescue phenotypes or to show even more severe defects than their parents. The defects caused by nickel exposure could be classified into four groups according to their transferring properties. That is, the defects caused by nickel exposure could be largely, or partially, or unable to be rescued, or became even more severe in progeny animals. Therefore, most of the nickel exposure-caused defects can be transferred from parents to their progeny to different degrees in C. elegans.     

北京海淀区夏季交警对多环芳烃的暴露

用个人采样装置测定了北京海淀区交警夏季多环芳烃(PAHs)暴露.以16种PAHs之和计,气态和颗粒物吸附态的平均暴露浓度分别为(1 520±759)ng/m³和(148±118)ng/m³,显著高于定点对照测定结果[气态(588±228)ng/m³,颗粒物吸附态(52±50)ng/m³].交警和对照点具有致癌作用的高环化合物总暴露浓度分别是(14.9±5.9)ng/m³和(6.7±3.6)ng/m³,主要来自颗粒物吸附态暴露.暴露量具有显著的日波动特征,主要受温度和湿度影响.气态浓度与湿度正相关,与温度负相关,颗粒物吸附态浓度则与温度和湿度看不到显著相关关系.