Genesis of epizootics involving introduced species of helminths,mammals, and mollusks

The functioning of two foci of helminth diseases caused by trematodes Apophallus muehlingi and Rossicotrema donicum has been studied in the Volga Delta. The origin of these foci is related to the expansion of species ranges of Lithoglyphus snails, intermediate hosts of trematodes. Introduced mammal species, the raccoon dog Nyctereutes procyonoides and American mink Mustela vision, are involved in the circulation of the invasion.     

中国地表臭氧浓度估算及健康影响评估

在PM2.5浓度逐年下降的背景下,臭氧浓度不降反升,臭氧已成为中国暖季的主要污染物之一.基于大数据关联分析思路,构建并开发了极限梯度提升(XGBoost)臭氧浓度估算模型,用以估算2019年中国每日最大8 h平均臭氧浓度(O3_8h),用于人类暴露评估.该模型输入地面监测站点数据、高分辨率遥感卫星数据、气象数据、排放清...     

Seeing,believing, and behaving: Heterogeneous effects of an information intervention on household water treatment

Providing information about environmental health risks only sometimes induces protective action. This raises questions about whether and how risk information is understood and acted upon, and how responses vary across contexts. To characterize such variation, we stratified a randomized experiment related to household water quality across two periurban areas in Cambodia. When we showed specific evidence of water contamination to lower-SES households who were initially more optimistic about water safety, they altered their beliefs about health risk and increased their demand for a treatment product. However, demand for the treatment product among higher and initially more pessimistic SES households did not change significantly. These findings highlight the importance of better understanding heterogeneity in the specific drivers of responses to health risk information.     

肠道微生物受环境污染的影响及其对宿主疾病的调控作用

宿主肠道内存在的大量微生物与其健康状况直接相关,这些微生物是人和动物健康成长不可或缺的。肠道微生物通过多种途径调节人体生理功能的同时也受到人体内外环境的影响。因此,分析建立肠道微生物、相关疾病的产生原因和作用机制以及环境影响因子之间的联系具有重要意义。本文首先针对肠道微生物对人体的物质与能量代谢、先天和获得性免疫、胃肠道功能等方面的影响进行综述。然后重点分析了近年来有关肠道微生物对环境污染所致健康效应的影响及作用机制的研究进展。以期加深肠道微生物与人类健康之间相互作用机理的理解,并为环境毒理学与肠道微生物之间关系的研究提供新的思路。     

Per- and polyfluoroalkyl substances and obesity,type 2 diabetes and non-alcoholic fatty liver disease: a review of epidemiologic findings

Abstract

Per- and polyfluoroalkyl substances, a group of fluoro-surfactants widely detected in the environment, wildlife, and humans, have been linked to adverse health effects. A growing body of literature has addressed their effects on obesity, diabetes and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. This review summarizes the brief historical use and chemistry of per- and polyfluoroalkyl substances, routes of human exposure, as well as the epidemiologic evidence for associations between exposure to per- and polyfluoroalkyl substances and the development of obesity, diabetes and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. We identified 22 studies on obesity and 32 studies on diabetes, while only 1 study was found for non-alcoholic fatty liver disease/non-alcoholic steatohepatitis by searching PubMed for human studies. Approximately two-third of studies reported positive associations between per- and polyfluoroalkyl substances exposure and the prevalence of obesity and/or type 2 diabetes. Causal links between per- and polyfluoroalkyl substances and obesity, diabetes and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, however, require further large-scale prospective cohort studies combined with mechanistic laboratory studies to better assess these associations.     

Neurologic features of chronic minamata disease (organic mercury poisoning) and incidence of complications with aging

Abstract

To elucidate the neurologic features of chronic Minamata disease, and the incidence of complications with aging, we studied 80 patients with documented Minamata disease (organic mercury poisoning) from 1986 to 1994 (mean age: 63 years). Of the cardinal neurologic findings, sensory impairment was seen with highest frequency in 98.8% of patients limited to the extremities in 86.3%. Impairment of lower extremity coordination was observed in 60%, constriction of the visual field in 51.9%, and retrocochlear hearing loss in 41%. To assess age‐related complications, patients were separated into three groups by age: Group I (10 to 39 years); Group II (40 to 69 years); Group III (≥7 0 years). The incidences of hypertension and cerebrovascular diseases, organic ophthalmologic disorders (including cataracts), presbyacusis, and cervical spondylosis deformans increased significantly with age. Compared with a preceding survey (1981 to 1985, 171 patients, mean age: 63.5 years), the incidences of complicated hypertension and cataracts had decreased, whereas those of cerebrovascular disease and retinitis pigmentosa remained unchanged. The incidences of abnormal brain computed tomography (CT), presbyacusis, cervical spondylosis deformans, and positive tests for urine sugar also increased. The incidences of these complications other than retinitis pigmentosa were similar to those in the general population. These results accurately reflect the recent epidemiological disease tendencies in Japan toward a decreased incidence of hypertension and an increased incidence of diabetes.     

Control of bacterial speck of tomato by copper and ethylenebisuithiocarbamate fungicides: Their efficacy and residues on leaves

Abstract

Field studies were conducted to determine the synergism, persistence, and efficacy of a tank‐mix spray of cupric hydroxide and mancozeb for control of bacterial speck of tomato. The increased efficacy of the cupric hydroxide‐mancozeb mixture could not be attributed to the formation of a bacteriostatic compound in the tank mixture nor to a greater persistence of the mixture on the tomato foliage.     

Dissolution of beryllium in artificial lung alveolar macrophage phagolysosomal fluid

Dissolution of a lung burden of poorly soluble beryllium particles is hypothesized to be necessary for development of chronic beryllium lung disease (CBD) in humans. As such, particle dissolution rate must be sufficient to activate the lung immune response and dissolution lifetime sufficient to maintain chronic inflammation for months to years to support development of disease. The purpose of this research was to investigate the hypothesis that poorly soluble beryllium compounds release ions via dissolution in lung fluid. Dissolution kinetics of 17 poorly soluble particulate beryllium materials that span extraction through ceramics machining (ores, hydroxide, metal, copper-beryllium [CuBe] fume, oxides) and three CuBe alloy reference materials (chips, solid block) were measured over 31 d using artificial lung alveolar macrophage phagolysosomal fluid (pH 4.5). Differences in beryllium-containing particle physicochemical properties translated into differences in dissolution rates and lifetimes in artificial phagolysosomal fluid. Among all materials, dissolution rate constant values ranged from 10⁻⁵ to 10⁻¹⁰ g cm⁻² d⁻¹ and half-times ranged from tens to thousands of days. The presence of magnesium trisilicate in some beryllium oxide materials may have slowed dissolution rates. Materials associated with elevated prevalence of CBD had faster beryllium dissolution rates [10⁻⁷-10⁻⁸ g cm⁻² d⁻¹] than materials not associated with elevated prevalence (p < 0.05).     

Monitoring of Biofilm-associated Legionella pneumophila on Different Substrata in Model Cooling Tower System

Cooling towers have the potential to develop infectious concentrations of Legionella pneumophila. Legionella counts increases where biofilm and warm water temperatures are present. In this study, biofilm associated L. pneumophila and heterotrophic bacteria were compared in terms of material dependence. Model cooling tower system was experimentally infected by L. pneumophila standard strain and monthly monitored. Different materials were tested for a period of 180 days. The lowest L. pneumophila and heterotrophic plate counts were measured on plastic polymers, whereas L. pneumophila and heterotrophic bacteria were accumulated rapidly on galvanized steel surfaces. It can be concluded that selection of plastic polymers, as a manufacturing material, are suitable for recirculating water systems.     

果树缺铁失绿症矫治方法简述

本文简单评述了果树缺铁失绿症的多种矫治方法及其效果,以供各地在矫治果树失绿症时参考。