Microbial risk assessment for recreational use of the Chicago area waterway system

A microbial risk assessment was conducted to estimate the human health risks from incidental contact recreational activities such as canoeing, boating and fishing in the Chicago Area Waterway System (CAWS) receiving secondary treated, but non-disinfected, effluent from three municipal water reclamation plants. Actual concentrations of the pathogens (pathogenic E. coli [estimated], Giardia, Cryptosporidium, adenovirus, norovirus, enteric virus) detected from the waterway field data collection at locations upstream and downstream of the effluent outfall during dry and wet weather conditions within the recreation season were included in the risk assessment. The results under the current treatment scheme with no disinfection indicated that the total expected gastrointestinal illness (GI) rate per 1000 incidental contact recreational exposure events during combined weather (dry and wet) conditions ranged from 0.10 to 2.78 in the CAWS, which is below the eight illnesses per 1000 swimmers considered tolerable by the United States Environmental Protection Agency. Wet weather conditions contribute to elevated pathogen load to the CAWS; therefore this study determined that disinfecting the effluents of three major WRPs that discharge to the CAWS would result in an extremely small reduction in the aggregate recreation season risk to incidental contact recreators.     

重庆市男男性行为人群新型毒品使用现状及其影响因素分析

目的 了解男男性行为人群（men who have sex with men, MSM）新型毒品使用现状及其影响因素。方法 采用方便抽样的方法对重庆市MSM进行自填式匿名问卷调查,采用二分类非条件logistic回归对该人群新型毒品使用进行影响因素分析。结果 本研究共招募合格调查对象1 151例。调查对象以35岁以下青壮年、未婚、重庆户籍、高中以上文化程度、服务或个体职业及较高收入水平者为主。18.9%的调查对象报告近6个月使用过新型毒品,Rush为MSM最常使用的新型毒品,占17.7%。logistic回归显示,年龄≤35岁（OR = 2.232, 95% CI: 1.218～4.090）、月收入≥3 000元（OR = 1.652, 95% CI: 1.051～2.596）、性角色为被插入方（OR = 1.874, 95% CI: 1.154～3.043）或双重性角色（OR = 2.462, 95% CI: 1.612～3.761）、初次肛交年龄＜18岁（OR = 1.664, 95% CI: 1.144～2.422）及近6个月发生过群交性行为（OR = 13.597, 95% CI: 7.341～25.183）是MSM使用新型毒品的影响因素。结论 重庆市MSM使用新型毒品情况比较普遍,应根据使用人群的社会人口学及行为特征制定针对性的干预策略,从而降低该人群中艾滋病及其他性传播疾病的感染风险。     

Exposure analysis of five fish-consuming populations for overexposure to methylmercury

Mercury, in the form of methylmercury, is found in a myriad of fish species consumed by recreational and subsistence fishers around the world. Many agencies have attempted to address the issue of mercury consumption, resulting at times in the placement of advisories on waterways used for fishing. In this study, consumption rates of three Native American populations and two recreational fishing populations consuming freshwater or saltwater fish species were examined. These consumption rates were combined with fish contamination data to assess the level of exposure to methylmercury and to determine if any of these populations exceed a derived tolerable daily intake (TDI) for methylmercury (0.035 to 0.08 microg/kg/day). The TDI is unlikely to result in adverse health effects and is based on scientific studies investigating sensitive endpoints in children of mothers who consume fish over prolonged periods of time. Results from the exposure analysis indicate that many within the Native American populations exceed the TDI. This occurs even though the mercury concentrations in certain fish species are comparable to concentrations found in fish from open waters where "background" levels are assumed. Recreational anglers consuming freshwater species have exposure levels below the TDI as do nearly all anglers consuming saltwater species. Similar populations or populations having comparable consumption patterns of fish with equal or higher mercury levels in other areas will also exceed the TDI level for mercury. The public health implications of this exposure analysis are discussed.     

Recreational Use of Erectile Dysfunction Medications in Undergraduate Men in the United States: Characteristics and Associated Risk Factors

Mounting evidence indicates that erectile dysfunction medications (EDMs) have become increasingly used as a sexual enhancement aid among men without a medical indication. Recreational EDM use has been associated with increased sexual risk behaviors, an increased risk for STIs, including incident HIV infection, and high rates of concomitant illicit drug use. The aim of the present study was to investigate the characteristics and associated risk factors for recreational EDM use among young, healthy, undergraduate men. A cross-sectional sample of 1,944 men were recruited from 497 undergraduate institutions within the Unites States between January 2006 and May 2007. The survey assessed patterns of EDM use, as well as demographic, substance use, and sexual behavior characteristics. Four percent of participants had recreationally used an EDM at some point in their lives, with 1.4% reporting current use. The majority of recreational EDM users reported mixing EDMs with illicit drugs and particularly during risky sexual behaviors. Recreational EDM use was independently associated with increased age, gay, or bisexual sexual orientation, drug abuse, lifetime number of sex partners, and lifetime number of “one-night stands.” Recreational EDM users also reported a 2.5-fold rate of erectile difficulties compared to nonusers. Overall, recreational use of EDMs was associated with sexual risk behaviors and substance abuse; however, a relatively small proportion of undergraduates reported using EDMs. Results also suggest that a sizable portion of recreational EDM users are heterosexual men, and that use does not solely occur within the environments of venues that cater to men having sex with men.     

A wide range of activity duration cutoffs provided unbiased estimates of exposure to computer use

Integrative computer usage monitors have become widely used in epidemiologic studies to investigate the exposure-response relationship of computer-related musculoskeletal disorders. These software programs typically estimate the exposure duration of computer use by summing precisely recorded durations of input device activities and durations of inactivity periods shorter than a predetermined activity duration cutoff value, usually 30 or 60 sec. The goal of this study was to systematically compare the validity of a wide range of cutoff values. Computer use activity of 20 office workers was observed for 4 consecutive hours using both a video camera and a usage monitor. Video recordings from the camera were analyzed using specific observational criteria to determine computer use duration. This observed duration then served as the reference and was compared with 238 estimates of computer use duration calculated from the usage monitor data using activity duration cutoffs ranging from 3 to 240 sec in 1-sec increments. Estimates calculated with cutoffs ranging from 28 to 60 sec were highly correlated with the observed duration (Spearman's correlation 0.87 to 0.92) and had nearly ideal linear relationships with the observed duration (slopes and r-squares close to one, and intercepts close to zero). For the same range of cutoff values, when the observed and estimated durations were compared for dichotomous exposure classification across participants, minimal exposure misclassification was observed. It is concluded that activity duration cutoffs ranging from 28 to 60 sec provided unbiased estimates of computer use duration.     

High volume hydraulic fracturing operations: potential impacts on surface water and human health

High volume, hydraulic fracturing (HVHF) processes, used to extract natural gas and oil from underground shale deposits, pose many potential hazards to the environment and human health. HVHF can negatively affect the environment by contaminating soil, water, and air matrices with potential pollutants. Due to the relatively novel nature of the process, hazards to surface waters and human health are not well known. The purpose of this article is to link the impacts of HVHF operations on surface water integrity, with human health consequences. Surface water contamination risks include: increased structural failure rates of unconventional wells, issues with wastewater treatment, and accidental discharge of contaminated fluids. Human health risks associated with exposure to surface water contaminated with HVHF chemicals include increased cancer risk and turbidity of water, leading to increased pathogen survival time. Future research should focus on modeling contamination spread throughout the environment, and minimizing occupational exposure to harmful chemicals.     

PCP exposure for the Canadian general population: a multimedia analysis.

Pentachlorophenol (PCP) is ubiquitous in the Canadian environment, as a result of the large quantities used in the wood preservation and wood protection industries. In the past decade, agricultural and wood protection applications of PCP in Canada have been sharply curtailed. A multimedia approach was used to update estimates of PCP exposure of the members of the general population in Canada, based on currently available information. A detailed review of PCP concentrations reported in air, water, foods, household dust, and soil was performed. PCP intake estimates for infants, toddlers, school-age children, and adults in Canada were calculated. Estimates were made for people with average intakes of air, water, foods, household dust, and soil, as well as for recreational anglers and aboriginal subsistence fishermen, who were expected to have higher intakes. The current estimated intake by all of these populations is well below the Acceptable Daily Intake (ADI) of 6 micrograms/kg bw/day. The average members of the general population have an estimated intake via all routes of 0.05 micrograms/kg bw/day; most exposure is calculated to occur via food (dairy products, grains and cereals and meats) and indoor air. Recreational anglers are estimated to be exposed to only marginally more PCP per day (roughly 2%) than the general population. In contrast, aboriginal subsistence fisherman, because of their very high consumption of fish and fish products, experience the highest exposure to PCP through food; their estimated intake of PCP is almost twice that of the general population.     

锰的人体暴露水平与控制措施

锰在空气、水、土壤中均能检出,在自然界分布广泛但不均匀,地下水中锰含量较地表水的高,南方土壤中锰含量较北方的高;锰矿开采冶炼及含锰制品（汽油添加剂三羟基甲基戊基锰、锰焊条等）的使用会对周围环境造成锰污染。这都会使人体暴露在高锰环境中,而人体对锰的过量暴露会引起神经系统损伤。本文综述报道锰在我国的人体暴露水平、健康危害,以及控制措施。     

People living in disadvantaged areas faced greater challenges in staying active and using recreational facilities during the COVID-19 pandemic

This study aimed to understand the perceived effects of the COVID-19 pandemic on physical activity, recreation walking, and use of recreational facilities; and if the COVID-19 pandemic amplified disparities in physical activity, recreational walking, and use of recreational facilities related to the levels of neighborhood disadvantage. Recreational walking and the use of neighborhood streets and green spaces significantly decreased in high deprivation areas but not in low deprivation areas during the pandemic. While COVID-19 has negatively affected overall recreational activities, the inequitable impact on recreational walking and use of outdoor recreational facilities has been more evident in disadvantaged neighborhoods with greater deprivation.     

Comparative pathway analysis of radiocesium in the Hudson River Estuary: environmental measurements and regulatory dose assessment models

This work summarizes the measurements and associated environmental dosimetry of reactor-released 137Cs and 134Cs and weapons-produced 137Cs in samples of water, shoreline sediment and fish collected from 1971 to 1980 in the Hudson River Estuary. Trends observed in annual mean concentrations and the resultant dose implications for man from each source are discussed. The human exposure pathways examined are: fish consumption, water consumption, swimming and recreational use of the shoreline. Based on environmental measurements, a maximum, adult, whole-body, 50-y committed effective dose equivalent (CEDE) of 0.79 mu Sv (79 mu rem) is estimated from fish consumption in 1971, the year of maximum reactor discharge of the radiocesiums. For comparison, during the period 1974-79, mean estimates (+/- 1 SD) of the CEDE based on environmental measurements and attributed to other pathways are as follows: consumption of indigenous fish species caught downstream of the reactor outfall, 0.05 +/- 0.02 mu Sv (5 +/- 2 mu rem); consumption of fresh water sampled upstream of the reactors, 0.02 +/- 0.03 mu Sv (2 +/- 3 mu rem); and swimming, 10(-4) +/- 10(-4) mu Sv (0.01 +/- 0.01 mu rem). In addition, external, whole-body exposure resulting from recreational use of the shoreline 1.6 km downstream of the reactors is estimated to be 1.2 X 10(-8) C kg-1 (46 +/- 11 mu R yr-1). The above dose estimates are based on consumption factors of 3.9 and 803 kg y-1 (fish and water, respectively) and on usage factors of 50 and 140 h y-1 (swimming and shoreline recreation, respectively). Differences in dose estimates obtained from these long-term environmental measurements and from assessment models currently recommended for use by the U.S. Nuclear Regulatory Commission (NRC) are discussed.     

藻毒素的人类健康效应及危险性评估

藻毒素可能通过饮水、娱乐用水等途径对人类健康产生不利影响,但是,国际上尚未制订藻毒素的正式指导值.该文介绍了有关藻毒素的人类健康效应、暴露途径、可能的指导值及其计算方法.这不仅为进行危险性管理提供依据,而且有助于制定不会对人类产生危险性的正式指导值.同时,有助于改善饮水供应的安全性.     

A sea change ahead for recreational water quality criteria

The United States Environmental Protection Agency is committed to developing new recreational water quality criteria for coastal waters by 2012 to provide increased protection to swimmers. We review the uncertainties and shortcomings of the current recreational water quality criteria, describe critical research needs for the development of new criteria, as well as recommend a path forward for new criteria development. We believe that among the most needed research needs are the completion of epidemiology studies in tropical waters and in waters adversely impacted by urban runoff and animal feces, as well as studies aimed to validate the use of models for indicator and pathogen concentration and health risk predictions.     

江滩型地区洪灾与居民血吸虫感染关系

目的 探讨洪灾与血吸虫病流行关系。方法 通过1999年5-11月试区人群暴露方式、人数、次数和时间及人群洪为前后血吸虫病感染率和感染度的调查进行综合分析。结果 试区人群暴露方式共3类11种，总暴露率53.55%。汛期暴露人灵敏，次数及暴露时间显增多。洪灾后人群血吸虫感染率和感染度显增高；暴露组与非暴露组血吸虫感染率和感染度差异有显性。结论 洪灾增加人群暴露和感染，必须针对不同人群和不同暴露方式，加强健康教育和控制发病。     

A sea change ahead for recreational water quality criteria

The United States Environmental Protection Agency is committed to developing new recreational water quality criteria for coastal waters by 2012 to provide increased protection to swimmers. We review the uncertainties and shortcomings of the current recreational water quality criteria, describe critical research needs for the development of new criteria, as well as recommend a path forward for new criteria development. We believe that among the most needed research needs are the completion of epidemiology studies in tropical waters and in waters adversely impacted by urban runoff and animal feces, as well as studies aimed to validate the use of models for indicator and pathogen concentration and health risk predictions.     

Are microbial indicators and pathogens correlated? A statistical analysis of 40 years of research

Indicator organisms are used to assess public health risk in recreational waters, to highlight periods of challenge to drinking water treatment plants, and to determine the effectiveness of treatment and the quality of distributed water. However, many have questioned their efficacy for indicating pathogen risk. Five hundred and forty cases representing independent indicator–pathogen correlations were obtained from the literature for the period 1970–2009. The data were analyzed to assess factors affecting correlations using a logistic regression model considering indicator classes, pathogen classes, water types, pathogen sources, sample size, the number of samples with pathogens, the detection method, year of publication and statistical methods. Although no single indicator was identified as the most correlated with pathogens, coliphages, F-specific coliphages, Clostridium perfringens, fecal streptococci and total coliforms were more likely than other indicators to be correlated with pathogens. The most important factors in determining correlations between indicator–pathogen pairs were the sample size and the number of samples positive for pathogens. Pathogen sources, detection methods and other variables have little influence on correlations between indicators and pathogens. Results suggest that much of the controversy with regards to indicator and pathogen correlations is the result of studies with insufficient data for assessing correlations.     

综合性医院抗菌药物应用管理成效

目的 通过综合干预促进抗菌药物的临床合理应用。方法 成立医院抗菌药物使用管理专家咨询组，制定各专业抗菌药物使用规范，进行抗菌药物应用培训和检查，统计病原菌分布及耐药性变迁；随后分别抽取2000、2002、2004年出院病历的10％，分析抗菌药物使用和病原菌送检率。结果 采用上述措施后，预防和治疗性使用指征的构成比明显提高（P〈0．01）；除内科外各科抗菌药物联用比例降低（P〈0．01）；病原菌送检率明显提高（P〈0．05）。结论 通过临床医师、药剂师、检验和感染管理人员等的共同参与，可以达到控制和合理使用抗菌药物的目的。     

Development of a process-based model to predict pathogen budgets for the Sydney drinking water catchment

In drinking water catchments, reduction of pathogen loads delivered to reservoirs is an important priority for the management of raw source water quality. To assist with the evaluation of management options, a process-based mathematical model (pathogen catchment budgets - PCB) is developed to predict Cryptosporidium, Giardia and E. coli loads generated within and exported from drinking water catchments. The model quantifies the key processes affecting the generation and transport of microorganisms from humans and animals using land use and flow data, and catchment specific information including point sources such as sewage treatment plants and on-site systems. The resultant pathogen catchment budgets (PCB) can be used to prioritize the implementation of control measures for the reduction of pathogen risks to drinking water. The model is applied in the Wingecarribee catchment and used to rank those sub-catchments that would contribute the highest pathogen loads in dry weather, and in intermediate and large wet weather events. A sensitivity analysis of the model identifies that pathogen excretion rates from animals and humans, and manure mobilization rates are significant factors determining the output of the model and thus warrant further investigation.     

Development of a process-based model to predict pathogen budgets for the Sydney drinking water catchment

In drinking water catchments, reduction of pathogen loads delivered to reservoirs is an important priority for the management of raw source water quality. To assist with the evaluation of management options, a process-based mathematical model (pathogen catchment budgets - PCB) is developed to predict Cryptosporidium, Giardia and E. coli loads generated within and exported from drinking water catchments. The model quantifies the key processes affecting the generation and transport of microorganisms from humans and animals using land use and flow data, and catchment specific information including point sources such as sewage treatment plants and on-site systems. The resultant pathogen catchment budgets (PCB) can be used to prioritize the implementation of control measures for the reduction of pathogen risks to drinking water. The model is applied in the Wingecarribee catchment and used to rank those sub-catchments that would contribute the highest pathogen loads in dry weather, and in intermediate and large wet weather events. A sensitivity analysis of the model identifies that pathogen excretion rates from animals and humans, and manure mobilization rates are significant factors determining the output of the model and thus warrant further investigation.     

Surveillance data from swimming pool inspections--selected states and counties,United States,May--September 2002

Swimming is the second most popular exercise activity in the United States, with approximately 360 million annual visits to recreational water venues (1). This exposure increases the potential for the spread of recreational water illnesses (RWIs) (e.g., cryptosporidiosis, giardiasis, and shigellosis). Since the 1980s, the number of reported RWI outbreaks has increased steadily (2). Local environmental health programs inspect public and semipublic pools periodically to determine compliance with local and state health regulations. During inspections for regulatory compliance, data pertaining to pool water chemistry, filtration and recirculation systems, and management and operations are collected. This report summarizes pool inspection data from databases at six sites across the United States collected during May 1--September 1, 2002. The findings underscore the utility of these data for public-health decision making and the need for increased training and vigilance by pool operators to ensure high-quality swimming pool water for use by the public.     

茶氨酸延缓运动性疲劳及其作用机制研究

目的:研究茶氨酸延缓运动性疲劳的作用,并探讨相关的机制。方法:160只小鼠分成4组,三个剂量组分别以茶氨酸5.6、8.4和12.6mg/(kgbw?d)灌胃,对照组以等量蒸馏水灌胃,连续30d。实验期末进行负重游泳试验,测定血清尿素氮(BUN)、肝糖原及脑组织中5-羟色胺(5-HT)、多巴胺(DA)、去甲肾上腺素(NE)等单胺类神经递质含量。结果:中、高剂量组的负重游泳时间和肝糖原含量均显著高于对照组(P<0.05);运动后中剂量组BUN增加量显著低于其他各组,休息60min后各剂量组BUN含量明显低于对照组(P<0.05);运动前、后各剂量组5-HT含量低于对照组,运动前中剂量组和运动后中、高剂量组DA含量高于对照组,运动前各剂量组和运动后中剂量组DA/5-HT比值高于对照组,差异均有显著性(P<0.05)。结论:茶氨酸具有延缓运动性疲劳作用,其机制可能与茶氨酸增加脑组织中DA含量,抑制5-HT的合成和释放等效应有关。