黄浦江上游工业废水对程序外DNA合成的影响

用SD大鼠原代肝细胞作程序外DNA合成(UDS)试验,检测黄浦江上游水源保护区9家工厂的工业废水,结果表明,在不同时间采集的9家工厂的两批工业废水UDS试验均呈阳性,并且呈剂量—反应关系。这说明9家工厂的工业废水有潜在的致突变作用和致癌作用,对这些工业废水的排放应加以控制。     

Safer alternatives assessment: the Massachusetts process as a model for state governments

In 2006 the Massachusetts Toxics Use Reduction Institute conducted a study to determine if states could identify safer alternatives to five chemicals of concern. The chemicals investigated included di (2-ethylhexyl) phthalate (DEHP), formaldehyde, hexavalent chromium, lead and perchloroethylene. First, the Institute developed a methodology for assessing alternatives to these five chemicals that allowed it to quickly determine priority uses and alternatives to assess and to research the pertinent decision criteria, which included performance, technical, financial environmental and human health parameters. The methodology included important feedback from stakeholders in the state, which helped to focus and enhance the value of the work. Second, the Institute implemented the methodology over a ten month period. Based on the activities conducted by the Institute, safer alternatives were identified for each of the priority uses associated with the five chemicals studied. This report summarizes the methodology employed and provides examples of the results for one of the five chemicals, namely DEHP. The experience of the Institute and the information contained in this report indicates that alternatives assessment was a useful approach to organizing and evaluating information about chemicals and alternatives.     

Erionite series minerals: mineralogical and carcinogenic properties

Erionite is a human and animal carcinogen and one of the most toxic minerals known. Erionite deposits have been reported in many countries; however, it is only in the area of three villages of Cappadocia, Turkey, that environmental exposure to erionite has been demonstrated to be the cause of an epidemic of the disease mesothelioma. In the USA, no cases of mesothelioma have been reliably proven to be the result of erionite exposure, though the possibility exists. Erionite samples from three villages of the Cappadocia region were characterized mineralogically and compared with three different standards from the USA. Micro morphological details of erionite minerals using a high-resolution field-emission SEM showed that microstructures of "bundles", "fibers", and "fibrils" are important physical properties of fibrous erionite minerals. Typical lung burden of erionite and asbestos fibers were compared in terms of number of fibers. Assuming the lung burden of fibers in a human mesothelioma victim is about 1 mg, and the hazardous fibers are approximately 1 mum in diameter and 10 mum long, that milligram contains approximately 40 million asbestos and 50 million erionite fibers. These microstructures of erionite minerals draw attention to the concepts of surface area or surface-area-to-volume ratio and their relationship to the carcinogenicity of the mineral. The larger surface area creates a wider platform for mineral-cell interaction and thus more possibilities of proliferative transformation of mesothelial cells. Consequently, understanding the exact mineralogical properties will help determination of the true carcinogenic mechanism(s) of the mineral for prevention and possibly treatment of malignant mesothelioma.     

Physicochemical and toxicological characteristics of nanoparticles in aerosols in southern Thailand during recent haze episodes in lower southeast Asia

Transboundary haze from biomass burning is one of the most important air pollutions in Southeast Asia. The most recent serious haze episode occurred in 2015. Southern Thailand was affected by the haze during September to October when the particulate matter concentration hit a record high. We investigated physical and chemical characteristics of aerosols, including concentration and aerosol size distribution down to sub-micron sizes during haze episodes in 2013 and 2015 and, for reference, an insignificant haze period in 2017. The highest total suspended particulates and PM₁₀ levels in Hat Yai city were 340.1 and 322.5 µg/m³. The mass fractions were nanoparticles (< 100 nm) 3.1%-14.8% and fine particles (< 1 µm) 54.6%-59.1%. Polycyclic aromatic hydrocarbon size distributions in haze periods peaked at 0.75 µm and the concentrations are 2-30 times higher than the normal period. High molecular weight (4-6 ring) PAHs during the haze episode contribute to about 56.7%-88.0% for nanoparticles. The average values of benzo(a)pyrene toxic equivalency quotient were 3.34±2.54ng/m³ in the 2015 haze period but only 0.89±0.17 ng/m³ in 2017. It is clear that particles smaller than 1 µm, were highly toxic. Nanoparticles contributed 19.4%-26.0% of total BaP-TEQ, whereas the mass fraction is 13.1%-14.8%. Thus the nanoparticles were more carcinogenic and can cause greater health effect than larger particles. The fraction of BaP-TEQ for nanoparticles during 2017 non-haze period was nearly the same, while the mass fraction was lower. This indicates that nanoparticles are the significant source of carcinogenic aerosols both during haze and non-haze periods.     

First report on development of quantitative interspecies structure-carcinogenicity relationship models and exploring discriminatory features for rodent carcinogenicity of diverse organic chemicals using OECD guidelines

Different regulatory agencies in food and drug administration and environmental protection worldwide are employing quantitative structure-activity relationship (QSAR) models to fill the data gaps related with properties of chemicals affecting the environment and human health. Carcinogenicity is a toxicity endpoint of major concern in recent times. Interspecies toxicity correlations may provide a tool for estimating sensitivity towards toxic chemical exposure with known levels of uncertainty for a diversity of wildlife species. In this background, we have developed quantitative interspecies structure-carcinogenicity correlation models for rat and mouse [rodent species according to the Organization for Economic Cooperation and Development (OECD) guidelines] based on the carcinogenic potential of 166 organic chemicals with wide diversity of molecular structures, spanning a large number of chemical classes and biological mechanisms. All the developed models have been assessed according to the OECD principles for the validation of QSAR models. Consensus predictions for carcinogenicity of the individual compounds are presented here for any one species when the data for the other species are available. Informative illustrations of the contributing structural fragments of chemicals which are responsible for specific carcinogenicity endpoints are identified by the developed models. The models have also been used to predict mouse carcinogenicities of 247 organic chemicals (for which rat carcinogenicities are present) and rat carcinogenicities of 150 chemicals (for which mouse carcinogenicities are present). Discriminatory features for rat and mouse carcinogenicity values have also been explored.     

美欧环境内分泌干扰物研究框架

欧美于20世纪90年代开始系统研究环境内分泌干扰物（EDs)，为此成立了专门的工作机构负责EDs研究的规划与协调工作。研究框架包括确认EDs对人类和生态效应的方法，剂量一效应关系模型以及检测环境暴露水平等。研究对环境威胁最大受试物的主要毒理学终点有致癌性，生殖发育毒性，神经毒性和免疫毒性，目前危险评价的新进展是应用定量结构活性关系（QSAR）模型预测化学物的安全性。