环境内分泌干扰物对哮喘发生影响研究进展

环境内分泌干扰物对全球环境和生物方面的影响越来越受到重视,其可能通过影响神经中枢和免疫系统及激活相关丝裂原活化蛋白激酶通路而增加哮喘发生。本文以近年来各类内分泌干扰物相关毒理学研究资料为依据,综述其可能对哮喘产生的影响。     

Immunotoxicity of pesticides: a review

The intricate balance that is the hallmark of the immune system shows vulnerability to any chemical, including pesticides, that can cause structural and functional alterations to the system. The immunotoxic effects of xenobiotics include: histopathologic effects in immune tissues and organs; cellular pathology; altered maturation of immunocompetent cells; changes in B and T cell subpopulations; and functional alterations of immunocompetent cells. Pesticides, including fungicides, herbicides, and insecticides, are the only class of chemicals deliberately released into the environment because of their toxicity. Around the world, millions of people are exposed to pesticides at work and/or in their home. This article reviews evidence, from animal and human studies, on the effects of pesticides on the immune system.     

环境内分泌干扰物邻苯二甲酸二丁酯的生物降解特性

以邻苯二甲酸二丁酯 (DBP)为唯一碳源驯化活性污泥 ,并在恒温摇床中用驯化污泥对DBP进行降解试验。以研究环境内分泌干扰物DBP的生物降解特性。结果表明 ,48h内DBP可降解 90 % ,其降解的最适条件是 :温度为 2 5～ 3 5℃ ,pH值为 6 0～ 8 0 ,停留时间 (HRT)为 12～ 2 4h ,浓度在 3 0 0mg L以下。DBP生物降解过程符合酶促一级反应动力学模型     

Reproductive effects of the endocrine disruptor fenarimol on a Baltic amphipod Monoporeia affinis

An endocrine disruptor, the fungicide fenarimol, was investigated regarding its effects on reproduction and hormone (ecdysteroid) levels in the deposit-feeding amphipod Monoporeia affinis. In addition, the influence of food shortage, both by itself and in combination with fenarimol, on reproduction was examined. Field-collected amphipods were exposed in flow-through microcosms during the period of sexual maturation and mating in four treatment series: Control with low food, fenarimol with low food, control with high food, and fenarimol with high food. Fenarimol was added at a concentration of 0.3 mg/L in two pulses/ week. Results show that fenarimol has a negative effect on fertilization rate and male mating ability. Results were supported by a tendency toward delayed male sexual development. Food shortage decreased weight in both sexes and retarded female oocyte development. Higher ecdysteroid levels were recorded in males than in females, and food shortage increased male ecdysteroid levels. No effect of fenarimol exposure on ecdysteroid levels was observed. No synergistic effects of fenarimol and food shortage could be distinguished in any variable examined. Thus, M. affinis was vulnerable to reproductive impairment by fenarimol, with effects on the next generation (i.e., a disturbed sexual development and fertilization ability). Food shortage has negative effects on M. affinis, but it does not enhance the effects of fenarimol.     

Multi-factorial influences on sex ratio: a spatio-temporal investigation of endocrine disruptor pollution and neighborhood stress

Background:

It is suggested the declining male birth proportion in some industrialized countries is linked to ubiquitous endocrine disruptor exposure. Stress and advanced parental age are determinants which frequently present positive findings. Multi-factorial influences on population sex ratio are rarely explored or tested in research.

Objectives:

To test the hypothesis that dual factors of pollution and population stress affects sex proportion at birth through geographical analysis of Central Scotland.

Methods:

The study incorporates the use of Geographical Information Systems (GIS) tools to overlay modeled point source endocrine disruptor air emissions with “small-area” data on multiple deprivation (a proxy measurement of stress) and birth sex. Historical review of regional sex ratio trends presents additional data on sex ratio in Scotland to consider.

Results:

There was no overall concentration in Central Scotland of low sex ratio neighborhoods with areas where endocrine disruptor air pollution and deprivation or economic stress were high. Historical regional trends in Scotland (from 1973), however, do show significantly lower sex ratio values for populations where industrial air pollution is highest (i.e. Eastern Central Scotland).

Conclusions:

Use of small area data sets and pollution inventories is a potential new method of inquiry for reproductive environmental and health protection monitoring and has produced interesting findings.     

Multi-factorial influences on sex ratio: a spatio-temporal investigation of endocrine disruptor pollution and neighborhood stress

Abstract

Background:

It is suggested the declining male birth proportion in some industrialized countries is linked to ubiquitous endocrine disruptor exposure. Stress and advanced parental age are determinants which frequently present positive findings. Multi-factorial influences on population sex ratio are rarely explored or tested in research.

Objectives:

To test the hypothesis that dual factors of pollution and population stress affects sex proportion at birth through geographical analysis of Central Scotland.

Methods:

The study incorporates the use of Geographical Information Systems (GIS) tools to overlay modeled point source endocrine disruptor air emissions with “small-area” data on multiple deprivation (a proxy measurement of stress) and birth sex. Historical review of regional sex ratio trends presents additional data on sex ratio in Scotland to consider.

Results:

There was no overall concentration in Central Scotland of low sex ratio neighborhoods with areas where endocrine disruptor air pollution and deprivation or economic stress were high. Historical regional trends in Scotland (from 1973), however, do show significantly lower sex ratio values for populations where industrial air pollution is highest (i.e. Eastern Central Scotland).

Conclusions:

Use of small area data sets and pollution inventories is a potential new method of inquiry for reproductive environmental and health protection monitoring and has produced interesting findings.     

固定化微生物降解环境内分泌干扰物DBP

目的 研究固定化微生物降解环境内分泌干扰物邻苯二甲酸二丁酯(DBP)的生物特性。方法 将驯化活性污泥用聚乙烯醇包埋，并制成固定化小球。增殖培养后，在不同溶解氧、pH值、温度下对不同浓度的DBP水样进行降解试验。结果 固定化微生物增殖培养后对DBP的降解率较游离活性污泥高，并且对温度、pH值的适应范围变宽，其降解过程符合酶促一级反应动力学模型。结论 驯化获得的DBP降解优势菌群经固定、增殖培养后能有效降解底物DBP，且为酶促一级反应。     

Toxicity of pesticides to aquatic microorganisms: a review

Microorganisms contribute significantly to primary production, nutrient cycling, and decomposition in estuarine eco-systems; therefore, detrimental effects of pesticides on microbial species may have subsequent impacts on higher trophic levels. Pesticides may affect estuarine microorganisms via spills, runoff, and drift. Both the structure and the function of microbial communities may be impaired by pesticide toxicity. Pesticides may also be metabolized or bioaccumulated by microorganisms. Mechanisms of toxicity vary, depending on the type of pesticide and the microbial species exposed. Herbicides are generally most toxic to phototrophic microorganisms, exhibiting toxicity by disrupting photosynthesis. Atrazine is the most widely used and most extensively studied herbicide. Toxic effects of organophosphate and organochlorine insecticides on microbial species have also been demonstrated, although their mechanisms of toxicity in such nontarget species remain unclear. There is a great deal of variability in the toxicity of even a single pesticide among microbial species. When attempting to predict the toxicity of pesticides in estuarine ecosystems, effects of pesticide mixtures and interactions with nutrients should be considered. The toxicity of pesticides to aquatic microorganisms, especially bacteria and protozoa, is an area of research requiring further study.     

邻苯二甲酸二丁酯降解优势菌的筛选和特性研究

目的　筛选降解DBP的高效降解菌株。方法　选用环境内分泌干扰物邻苯二甲酸二丁酯 (DBP)作为唯一碳源对采集的活性污泥进行驯化 ,驯化过程中DBP浓度递增 ,10周后采用平板分离法分离出 5种菌株 ,并从中选出生长势态及降解效果最好的 1种。结果　通过正交试验 ,得到该菌株降解DBP的较优条件是 :降解时间 32h ,DBP浓度 2 0 0mg L ,摇床转速为 10 0r min ,pH7,温度为 30℃。此条件下DBP的降解率可达 95 %以上。结论　经鉴定该菌株归于假单胞菌属     

过氯酸铵毒作用及其内分泌干扰效应的研究进展

过氯酸铵(ammonium Perchlorate,AP)又名高氯酸铵,是过氯酸盐类中一种用途广泛的化工产品.最早于20世纪40年代在美国开始大规模生产,起初用于军事和国防工业,主要用于弹药的制造,随后AP广泛应用于航天与航空工业.目前,AP不仅大量应用于国防和航天航空工业,还被广泛应用到分析化学、烟花焰火、涂料、橡胶生产、皮革制造、电镀工艺、化学肥料生产以及机动车辆安全气囊的充气装置等领域[1].     

The thyroid endocrine disruptor perchlorate affects reproduction, growth, and survival of mosquitofish

The perchlorate anion--an oxidizer found in rockets, missiles, some ammunition, flares, airbags, and fireworks--occurs as a contaminant in ground and surface water in many parts of the United States. Its toxic effects include inhibition of thyroid hormone synthesis. To investigate its chronic toxicity, mosquitofish (Gambusia holbrooki) adults and fry were exposed to aqueous sodium perchlorate at 1, 10, and 100mg/L, and growth and reproductive performance (fecundity, eggs/embryos mass, and gonadosomatic index [GSI]) were determined. Five-day acute toxicity tests were also performed. Perchlorate had a stimulatory effect on fecundity, GSI, and egg/embryo mass, at least for some treatments. The LC50 of sodium perchlorate was 404 mg/L. Growth was enhanced at 1mg/L but inhibited at 10mg/L. These results suggest that, at environmentally relevant concentrations, perchlorate does not induce acutely toxic effects but may have mild stimulatory or hormetic effects on fitness parameters in this species.     

Human endometrial cell coculture reduces the endocrine disruptor toxicity on mouse embryo development

ABSTRACT: Backgrounds Previous studies suggested that endocrine disruptors (ED) are toxic on preimplantation embryos and inhibit development of embryos in vitro culture. However, information about the toxicity of endocrine disruptors on preimplantation development of embryo in human reproductive environment is lacking. METHODS: Bisphenol A (BPA) and Aroclor 1254 (polychlorinated biphenyls) were used as endocrine disruptors in this study. Mouse 2-cell embryos were cultured in medium alone or vehicle or co-cultured with human endometrial epithelial layers in increasing ED concentrations. RESULTS: At 72 hours the percentage of normal blastocyst were decreased by ED in a dose-dependent manner while the co-culture system significantly enhanced the rate and reduced the toxicity of endocrine disruptors on the embryonic development in vitro. CONCLUSIONS: In conclusion, although EDs have the toxic effect on embryo development, the co-culture with human endometrial cell reduced the preimplantation embryo from it thereby making human reproductive environment protective to preimplantation embryo from the toxicity of endocrine disruptors. Key words: Bisphenol A, Aroclor 1254, Mouse embryo, human endometrial cells, Endocrine disruptors.     

Residential pesticides and childhood leukemia: a systematic review and meta-analysis

It is a systematic review and meta-analysis of previous observational epidemiologic studies examining the relationship between residential pesticide exposures during critical exposure time windows (preconception, pregnancy, and childhood) and childhood leukemia. Searches of Medline and other electronic databases were performed (1950-2009). Study selection, data abstraction, and quality assessment were performed by two independent reviewers. Random effects models were used to obtain summary odds ratios (ORs) and 95% confidence intervals (Cis). Of the 17 identified studies, 15 were included in the meta-analysis. Exposures during pregnancy to unspecified residential pesticides insecticides, and herbicides were positively associated with childhood leukemia. Exposures during childhood to unspecified residential pesticides and insecticides were also positively associated with childhood leukemia, but there was no association with herbicides. Positive associations were observed between childhood leukemia and residential pesticide exposures. Further work is needed to confirm previous findings based on self-report, to examine potential exposure-response relationships, and to assess specific pesticides and toxicologically related subgroups of pesticides in more detail.     

Modeling impacts on populations: fathead minnow (Pimephales promelas) exposure to the endocrine disruptor 17beta-trenbolone as a case study

Evaluation of population-level impacts is critical to credible ecological risk assessments. In this study, a predictive model was developed to translate changes in fecundity of the fathead minnow (Pimephales promelas) in a short-term laboratory toxicity test to alterations in population growth rate. The model uniquely combines a Leslie population projection matrix and the logistic equation. Application of the model requires only a life table for the organism of interest, a measure of carrying capacity for the given population, and an estimation of the effect of a stressor on vital rates. The model was applied to investigate population dynamics for fathead minnow exposed to the androgen receptor agonist 17beta-trenbolone. Organismal-level responses for fathead minnows exposed to varying levels of 17beta-trenbolone were used to determine projected alterations in a population existing in a small body of water containing varying concentrations of the androgen. Fathead minnow populations occurring at carrying capacity and subsequently exposed to 0.027 microg/L of 17beta-trenbolone exhibited a 51% projected decrease in average population size after 2 years of exposure. Populations at carrying capacity exposed to concentrations of 17beta-trenbolone > or = 0.266 microg/L exhibited a 93% projected decrease in average population size after 2 years of exposure. Overall, fathead minnow populations exposed to continued concentrations of 17beta-trenbolone equal to or greater than 0.027 microg/L were projected to have average equilibrium population sizes that approached zero.     

Impact of pesticides use on human health in Mexico: a review

Pesticides having a high adverse effect on the health and environment of inhabitants of the Mexican Republic were studied to establish the main parameters to bear in mind for their use and application. The investigation showed that Mexico is the agricultural zone with the highest health damage to its population from pesticides. The valid regulation norms for the use and application of these agrochemicals were analyzed. Case histories recorded by the public health sector in Mexico were reviewed. In this way, a strong relation was found between the health problems and the pesticides applied. Finally, the study concludes that the various Mexican States appear as a risk zone because of contamination by pesticides that are permitted by the regulation norms and by others whose use is prohibited in other countries and in Mexico. This situation causes a serious effect on the health deterioration of people who are exposed to these agro-chemicals and, in some cases, leads to death.     

Evolutionary biology of plant defenses against herbivory and their predictive implications for endocrine disruptor susceptibility in vertebrates

Hormone disruption is a major, underappreciated component of the plant chemical arsenal, and the historical coevolution between hormone-disrupting plants and herbivores will have both increased the susceptibility of carnivores and diversified the sensitivities of herbivores to man-made endocrine disruptors. Here I review diverse evidence of the influence of plant secondary compounds on vertebrate reproduction, including human reproduction. Three of the testable hypotheses about the evolutionary responses of vertebrate herbivores to hormone-disrupting challenges from their diet are developed. Specifically, the hypotheses are that a) vertebrate herbivores will express steroid hormone receptors in the buccal cavity and/or the vomeronasal organ; b) absolute sex steroid concentrations will be lower in carnivores than in herbivores; and c) herbivore steroid receptors should be more diverse in their binding affinities than carnivore lineages. The argument developed in this review, if empirically validated by support for the specific hypotheses, suggests that a) carnivores will be more susceptible than herbivores to endocrine-disrupting compounds of anthropogenic origin entering their bodies, and b) diverse herbivore lineages will be variably susceptible to any given natural or synthetic contaminant. As screening methods for hormone-disrupting potential are compared and adopted, comparative endocrine physiology research is urgently needed to develop models that predict the broad applicability of those screening results in diverse vertebrate species.