Variation of microorganism concentrations in urban stormwater runoff with land use and seasons

Stormwater runoff samples were collected from outfalls draining small municipal separate storm sewer systems. The samples were collected from three different land use areas based on local designation (high-density residential, low-density residential and landscaped commercial). The concentrations of microorganisms in the stormwater runoff were found to be similar in magnitude to, but less variable than, those reported in the stormwater National Pollutant Discharge Elimination System (NPDES) database. Microorganism concentrations from high-density residential areas were higher than those associated with low-density residential and landscaped commercial areas. Since the outfalls were free of sanitary wastewater cross-connections, the major sources of microorganisms to the stormwater runoff were most likely from the feces of domestic animals and wildlife. Concentrations of microorganisms were significantly affected by the season during which the samples were collected. The lowest concentrations were observed during winter except for Staphylococcus aureus. The Pearson correlation coefficients among different indicators showed weak linear relationships and the relationships were statistically significant. However, the relationships between indicators and pathogens were poorly correlated and were not statistically significant, suggesting the use of indicators as evidence of the presence of pathogens is not appropriate. Further, the correlation between the concentration of the traditionally monitored indicators (total coliforms and fecal coliforms) and the suggested substitutes (enterococci and E. coli) is weak, but statistically significant, suggesting that historical time series will be only a qualitative indicator of impaired waters under the revised criteria for recreational water quality by the US EPA.     

Genotoxicity in native fish associated with agricultural runoff events

The primary objective of the present study was to test whether agricultural chemical runoff was associated with in-stream genotoxicity in native fish. Using Sacramento sucker (Catostomus occidentalis), we combined field-caging experiments in an agriculturally dominated watershed with controlled laboratory exposures to field-collected water samples, and we coupled genotoxicity biomarker measurements in fish with bacterial mutagenicity analysis of water samples. We selected DNA strand breakage as a genotoxicity biomarker and Ames Salmonella mutagenicity tests as a second, supporting indicator of genotoxicity. Data from experiments conducted during rainfall runoff events following winter application of pesticides in 2000 and 2001 indicated that DNA strand breaks were significantly elevated in fish exposed to San Joaquin River (CA, USA) water (38.8, 28.4, and 53.6% DNA strand breakage in year 2000 field, year 2000 lab, and year 2001 field exposures, respectively) compared with a nearby reference site (15.4, 8.7, and 12.6% DNA strand breakage in year 2000 field, year 2000 lab, and year 2001 field exposures, respectively). Time-course measurements in field experiments supported a linkage between induction of DNA strand breakage and the timing of agricultural runoff. San Joaquin River water also caused significant reversion mutation in two Ames Salmonella tester strains. Salmonella mutagenicity corroborated in-stream effects, further strengthening a causal relationship between runoff events and genotoxicity. Potentially responsible agents are discussed in the context of timing of runoff events in the field, concordance between laboratory and field exposures, pesticide application patterns in the drainage, and analytical chemistry data.     

城市土壤重金属研究进展

基于文献计量法探究城市土壤重金属研究的热点、修复技术与关键问题。城市土壤重金属污染是能有效反映城市环境污染状况的重要指标之一,城市土壤重金属生态地球化学、环境风险和污染修复是目前研究的热点和焦点。城市土壤与重金属微界面过程及机制、城市土壤重金属生物有效性及其健康风险以及城市土壤重金属复合污染效应、作用机理及其污染控制是目前城市土壤重金属研究有待解决的关键科学问题。城市土壤重金属研究仍然是今后环境科学研究的热点方向,而我国西部地区的研究有待加强。     

Gardening work and heavy metals in urban environment

Urban soil may be a source of occupational exposure to various pollutants in gardening and land cultivation. This paper presents data of a one-year follow-up of lead, cadmium, nickel, chromium, and vanadium in the environment of the city of Bologna. Samples of soil and leaves were collected at three locations; gardens from the inner-city high-traffic area, parks in moderate-traffic area, and parks in suburban, low-traffic area. The top and deeper layers of soil and leaves were mainly polluted by lead at all locations, which corresponded to the traffic density. Personal samplers recorded greater concentrations of airborne metals than did the area samplers but the values kept below the threshold limit established by the American Conference of Governmental Industrial Hygienists for the working environment. Due to cumulative nature and interactive effects of toxic metals with other toxic and essential elements, long-term exposure to metals in the urban environment may be a health risk for occupationally exposed gardeners.     

Assessment of heavy metals in the treated wastewater of Suez ponds,Egypt

Levels of the heavy metals Cd, Pb, Cu and Zn were measured in treatment Suez ponds for both systems; the American (ASP) and French (FSP) system ponds are within the limits established which were sublethal for both phytoplankton and fish. The mean values of heavy metals in water during the period of investigation (1990-92) were 0.46, 2.21, 0.23 and 1.30 ppb in ASP and 0.47, 2.07, 0.22 and 1.20 ppb in FSP, respectively, where Cu and Cd recorded the lowest values, and Pb had higher value than Zn. As a result of the encountered data, the treatment processes of the fishponds water were found to be suitable for aquaculture and agriculture.     

哈尔滨地区野生黄鼠脑组织中重金属含量检测

目的检测野生环境中黄鼠脑组织重金属铅、砷、汞含量。方法解剖分离捕获的哈尔滨道里、香坊2区13~24月龄野生黄鼠大脑组织,将大脑皮层和其他部分分离,应用原子荧光光度计检测大脑皮层组织内铅、砷、汞含量。结果 道里区野生黄鼠脑组织中的重金属铅、砷、汞含量分别为(49.4±32.5)、(46.7±28.5)、(4.271±1.786)μg/kg;香坊区野生黄鼠脑组织中重金属铅、砷、汞含量分别为(90.1±45.0)、(23.0±18.0)、(4.740±0.952)μg/kg;2区野生黄鼠脑组织内铅、汞含量差异无统计学意义(P>0.05);与香坊区比较,道里区野生黄鼠脑组织中砷含量较高,差异有统计学意义(P<0.05)。结论 哈尔滨地区野生黄鼠脑内可检出重金属铅、砷、汞,其负荷对环境重金属污染具有指示作用。     

Levels and patterns of fecal indicator bacteria in stormwater runoff from homogenous land use sites and urban watersheds

Routine stormwater monitoring programs focus on quantification of average fecal indicator bacteria (FIB) concentration at the terminal watershed discharge point. While important for permit compliance, such monitoring provides little insight into relative bacteria levels from different land use types or the mechanisms that influence FIB concentrations. The goal of this study was to quantify the relative levels and flux patterns of Escherichia coli, enterococci, and total coliforms from representative land use (LU) types. Bacteria concentrations were measured over the entire storm duration from 8 different LU types over 13 storm events in 5 southern California watersheds during the 2000–2005 storm seasons. In addition, runoff samples were collected from 8 bottom of the watershed mass emission (ME) sites. Intra-storm and intra-season patterns were investigated in order to identify mechanisms that influence patterns of FIB concentrations. Mean FIB event mean concentrations (EMCs) at LU sites ranged from 10³ to 10⁵ MPN/100 ml. Recreational (horse stables) LU sites contributed significantly higher storm EMCs than other LU types. Early season storms repeatedly produced higher EMCs than comparably sized late season storms. For most storms sampled, the highest bacterial concentrations occurred during the early phases of stormwater runoff with peak concentrations usually preceding peak flow.     

Traffic-related air pollution is associated with atopy in children living in urban areas

Traffic emissions are a major source of air pollution in Western industrialized countries. To investigate the association between traffic-related air pollution and parameters of atopy, we studied 317 children 9 years of age living near major roads in two urban areas and one suburban area of a city in West Germany. Atopic sensitization was analyzed by skin-prick testing and determination of allergen-specific serum immunoglobulin E. Parents recorded allergic symptoms in a symptom diary, and physicians assessed allergic diseases. Personal NO2 exposure and NO2 concentrations in front of each child's home were measured. Outdoor NO2 was a good predictor for traffic exposure but a poor predictor for NO2 exposure at the personal level. Atopy was found to be related to outdoor NO2 (odds ratio for the association between symptoms of allergic rhinitis and outdoor NO2 = 1.81; 95% confidence interval = 1.02-3.21) but not to personal NO2 (odds ratio for the association between symptoms of allergic rhinitis and personal NO2 = 0.99; 95% confidence interval = 0.55-1.79). When the analysis was restricted to urban areas, we found that hay fever, symptoms of allergic rhinitis, wheezing, sensitization against pollen, house dust mites or cats, and milk or eggs were associated with outdoor NO2. The results indicate that traffic-related air pollution leads to increased prevalence of atopic sensitizations, allergic symptoms, and diseases.     

武汉淡水鱼中重金属含量分析及安全性初步研究

以中国南方湖泊中的淡水鱼及其生活环境为研究对象,采用ICP-OES法对主要经济鱼种体内的重金属含量进行了研究,具体研究对象选择了武汉市周边具有代表性的湖泊———南湖、东湖和野芷湖,对湖泊底积物、湖水和主要淡水鱼采用ICP-OES法分别测定锌、铜、铅、铬、镉等重金属元素的含量。分析结果表明:野芷湖和东湖湖水中铜和镉含量分别为10.0μg/L和5.4μg/L,超过了国家规定的淡水养殖水域的水质标准。三个湖底泥中的镉含量分别为0.95mg/L、1.07mg/L、1.13mg/L,均超过无公害水产品产地环境要求。鱼类不同组织器官对各种重金属积累能力明显不同,主要分布于鳞片、鳃中,其食用部分各种重金属含量均低于人体卫生消费标准。     

Determination of heavy metals in crayfish by ICP-MS with a microwave-assisted digestion treatment

Contamination of the American red crayfish, from the Guadiamar riverside, is due to the disastrous toxic spill that occurred on 25 April 1998 in the mining area of Aznalcóllar-Los Frailes, Spain. A high concentration of heavy metals in the waters from the mine pool and their spill to the river Guadiamar was the cause of the destruction of a great number of animal and vegetable organisms. An ICP-MS method for the total determination of heavy metals (Cu, Zn, Pb, and Cd) in whole bodies of American red crayfish (Procambarus clarkii) was used. Metals were extracted from the matrix in a closed-vessel microwave digestion system with nitric acid and hydrogen peroxide. A study of the uncertainty of the method for the determination of metals was carried out; at a concentration of 5 microg/L, the uncertainty was below 34%.     

广州市场食用鱼中5种重金属含量分析及评价

目的:评价市场上常见食用鱼的重金属(锌、铅、镉、铜、铬)污染状况和食用安全性。方法:采用硝酸-高氯酸消化和火焰原子吸收法对广州市场21种鱼中重金属含量进行分析及评价。结果:21种鱼中重金属含量符合以下规律:必需微量元素锌、铜、铬含量较高,非必需微量元素铅含量较低,镉未检出;根据《NY 5073-2006无公害食品水产品中有毒有害物质限量》,所测样品的铅、镉、铜未超标;鳗鱼中的铬含量超过"人体消费卫生标准"。结论:鳗鱼中的铬含量较高,经常食用存在潜在危害,应引起有关部门重视。     

Factors associated with rotavirus diarrhoea in children living in a socially diverse urban centre in Brazil

A case-control study, aimed at identifying factors associated with rotavirus diarrhoea cases presenting to health facilities, was conducted in children from low-income and middle-low-income families in Brazil. Cases were 390 children with diarrhoea and rotavirus in stools; controls were 1674 children without diarrhoea presenting to the same facilities. Data were collected by questionnaire and observations during home visits. Explanatory variables were grouped according to a conceptual model of causation. The ORs by non-conditional logistic regression and population-attributable fractions were calculated. Socioeconomic factors contributed a third of cases, followed by contact with diarrhoea cases and by not being breast fed. In cases aged <1 year, not being breast fed was the main determinant, followed by socioeconomic factors, and crowding and contact outside the home; in older children, socioeconomic factors followed by contact inside and outside the home were the main determinants. Environmental and sanitation variables were not associated with diarrhoea in the final model, and socioeconomic factors were only partly mediated by proximal variables. Transmission of rotavirus appears to be mostly by person-to-person contact, and shows marked social differentials not explained by the biological factors studied. The rotavirus vaccine is unlikely to protect against the full range of circulating genotypes of rotavirus, and understanding rotavirus epidemiology remains essential to the development of control policies.     

脐带血重金属负荷与孕妇、新生儿健康关系

目的了解一般孕妇人群重金属铅、镉、铬、镍的暴露水平,以及对孕妇及新生儿健康产生的影响。方法在汕头市中心医院招募20～35岁非职业暴露健康待产孕妇,测量身高、体重、血压、心率等身体指数,采集静脉血测量红细胞、白细胞、血红蛋白及血小板等生化指标。产后采集脐带血,应用石墨炉原子吸收法检测重金属铅、镉、铬及镍的含量。产后测量新生儿身长、体重、头围、胸围、胎龄及Apgar评分。以Pearson相关分析方法统计分析重金属暴露水平与孕妇、新生儿健康关系。结果共调查55对孕妇及其新生儿,孕妇平均年龄（29．63±4．48）岁,BMI为24．91±3．60;新生儿BMI为12．64±1．38,Apgar评分（9．24±0．83）分（10分为满分）。研究人群脐带血铅、镉、铬、镍的中位浓度分别为45．92、0．61、23．27、7．50ug／L。按目前通用标准,脐带血中铅超标率为7．27％（4／55）,镉、铬各有1例超标,血镍无超标。血镉与血铬、血镍之间存在着相关性,在体内协同存在（r值分别为0．466、0．299）。血铅与孕妇血红蛋白呈负相关（r=-0．519）;血镉与孕妇血压呈正相关（收缩压：r=0．313,舒张压：r=0．372）;血铬与孕妇血小板呈负相关（r=-0．288）。血铅与新生儿Apgar评分呈负相关（r=-0．530）;而血镉与新生儿体重、BMI指数呈负相关（r值分别为-0．311及-0．372）。结论受检孕妇人群血铅存在一定水平的超标,而其他重金属的超标率较低。在目前暴露水平下,显示已对孕妇及其新生儿健康产生一定影响,其确切的健康危害作用需大样本研究作进一步评估。     

Evaluation of pollution of an urban area by level of heavy metals in snow cover

The goal of this study was to systematize various methodological approaches to evaluating the contamination of the snow cover with heavy metals (HM) by using Kazan, an industrial city with diversified industry, as an example. The findings suggest that it is necessary to characterize the contamination of the snow cover by the actual entrance of an element per area unit of the snow cover for a definite period of time rather than by the concentration of TM in the volume unit of snow water (mg/l), which minimizes the uncertainties with spatial and temporary snow cover variations. The index of the maximum allowable entrance, which is of practical value, may be used to objectively calibrate the pollution of the snow cover, by estimating the amount of a coming element and its toxicity.     

Urinary heavy metals and associated medical conditions in the US adult population

Health effects of heavy metals have been widely investigated, but further evaluation is required to comprehensively delineate their toxicity. Using data from the 2007-2008 National Health and Nutrition Examination Survey, a multivariate logistic regression analysis was performed on 1,857 adults to examine the relationship between urinary heavy metals and various medical conditions. Cardiovascular diseases were correlated to cadmium (OR: 4.94, 95% CI: 1.48-16.56) and lead (OR: 5.32, 95% CI: 1.08-26.21). Asthma was related to tungsten (OR: 1.72, 95% CI: 1.15-2.59) and uranium (OR: 1.52, 95% CI: 1.01-2.28). Hepatotoxicity was associated with molybdenum (OR: 3.09, 95% CI: 1.24-7.73) and uranium (OR: 4.79, 95% CI: 1.74-13.19). Surprising inverse relationships occurred for excessive weight with lead (OR: 0.72, 95% CI: 0.52-0.98), reduced visual acuity with cobalt (OR: 0.65, 95% CI: 0.44-0.95) and cesium (OR: 0.52, 95% CI: 0.35-0.77). This study supports some previous evidence of potential relationships and provides insights for future research.     

An outbreak of waterborne giardiasis associated with heavy water runoff due to warm weather and volcanic ashfall

From mid-June through early August 1980, an outbreak of gastrointestinal illness in Red Lodge, Montana affected approximately 780 persons, as estimated from attack rates of 33 per cent and 15 per cent in urban and rural residents, respectively. Giardia lamblia was identified in stool specimens from 51 per cent of 47 persons with a history of untreated gastrointestinal illness and in 13 per cent of 24 specimens from asymptomatic persons (p = .00045, Fisher's Exact Test). The epidemic curve was bimodal with peaks in mid-June and mid-July. Each peak occurred about three weeks after an episode of very heavy water runoff resulting from warm sunny weather and snow darkened by ashfall from the Mt. St. Helens volcanic eruption of May 18, 1980. Unfiltered and inadequately chlorinated surface water was supplied by the city water system, which was implicated as the vehicle of transmission in the outbreak. Water systems providing unfiltered surface water are more likely to become contaminated during periods of heavy water runoff.     

In vivo removal of a few heavy metals in certain tissues of the fish Notopterus notopterus

An evaluation was made of the comparative efficiency of five metal-binding agents (NTA, EDTA, DDTA, DTPA, and DDC) in vivo in mobilization of the Cr, Ni, and Hg from the liver, kidney, gills, and brain of the freshwater fish Notopterus notopterus. The maximum and significant (P < 0.001) mobilization of chromium by DTPA (54.68%) and EDTA (36.56%) was observed. However, in the cases of nickel and mercury, the significant (P < 0.01 and P < 0.001, respectively) mobilizations observed were 56.57% by DDC, and 45.52% by EDTA. In general, no definite correlation between the chemical structure or molecular weight of the chelators and their ability to remove the metals from the biological system was observed.     

Distribution of bacteria in tropical freshwater fish and ponds

Bacteriological examination of the various organs (liver, kidney, intestine and inner muscle) of four freshwater fish species belonging to the family cyprininae reared in experimental ponds were compared to those reared in conventional pond. A total of 16 bacterial species were recovered from the water samples and the various organs of the fish. The intestines of all the fish species harboured the most number of different bacterial species. No bacteria was found in the muscle of any of the fish. In general, the bacterial species isolated from the intestine were also found in the water samples from the ponds. The common species found in the intestine of the fish belonged to seven Gram negative bacterial species: Aeromonas hydrophila, Citrobacter freundii, Escherichia coli, Enterobacter aerogenes, Klebsiella sp., Pseudomonas sp, Vibrio anguillarum and three Gram positive bacterial species: Bacillus sp., Listeria and Staphylococcus. The presence of the former group of bacteria which are members of the family Enterobacteriaceae and Vibrio-Aeromonas is a cause for concern as these organisms are potential enteropathogens, and any mishandling of the fish can lead to the transmission of the pathogen to humans. The type of bacterial species present in the water of the conventional ponds were similar to those found in the experimental ponds.