Search

The ubiquity of microplastics (MPs) in natural surroundings leads to inevitable human exposure. MPs are reported to be present in daily food products, viz. bottled water, sea salt, packaged foods, beverages, fruits, crops, fishes, and sea foods, mainly due to their unique physical and chemical characteristics, leading to their human exposure across all age groups. In terrestrial environments, soil serves as a potential route of MP exposure to plant communities through plastic mulching, which can have implications on crops and transfer to human trough food chain. Consumption of MPs by aquatic organisms also causes a potential health hazards along food chain through trophic transfer. MPs are also reported to transfer from mother to child via placenta and breast milk. Additionally, MPs can trigger immune responses and hypersensitivity, and induce cellular, gastrointestinal, and developmental cytotoxicity. The aim of the present review is to provide a comprehensive idea on MP exposure through daily food items and their possible health concerns with plausible toxicity pathways. Future research should be oriented toward examining multi-level trophic transmission of MPs. Further, more in vivo studies should be conducted to understand the underlying mechanisms of MP uptake, retention, and depuration in the human body. [ABSTRACT FROM AUTHOR]

Environmental perception serves as a powerful tool for identifying community needs and potential within their surroundings. This study assessed tourists' environmental perception regarding solid waste and its impact on the Hurtado Balneary, located in Valledupar, Colombia. The investigation delved into the environmental attitudes and behaviors of 769 balneary users by employing a combination of observation, photographic documentation, and a comprehensive 21-question online survey. The findings are 98.8% of participants acknowledged the adverse effects of solid waste on the environment, with 98% demonstrating a willingness to participate in waste management efforts. Furthermore, 42.13% exhibited limited awareness regarding waste management practices, reflecting a concerning lack of public interest and commitment (41.61%). Statistically significant disparities (p > 0.05) emerged 59% of waste items were not appropriately disposed of in designated receptacles. Reasons for this included a lack of a sense of belonging (50.2%) and inadequate environmental education (45.6%). Ninety-six percent expressed the need for river conservation signage, while 59.8% did not undertake any form of environmental training. The study's implications extend beyond the Hurtado Balneary, potentially informing solid waste management strategies in other aquatic environments. This investigation aligns with three Sustainable Development Goals: SDG 12, emphasizing responsible consumption and production; SDG 13, addressing climate action; and SDG 15, advocating for life on land and below water. [ABSTRACT FROM AUTHOR]

Introduction: An instance of fish deaths in marine waters surrounding some communities in Bonny and Andoni Local Government Areas in Rivers State was reported in March-April 2020. This study investigated trace metals hazard in muscle of Tilapia (Sarotherodon melanotheron) and Silver Catfish (Chrysichthys nigrodigitatus) from Okulu River, Rivers State, Nigeria. Materials and Methods: Tissues of 24 samples of Sarotherodon melanotheron and Chrysichthys nigrodigitatus obtained from the river were analyzed using atomic adsorption spectrophotometer, and the health risk was estimated based on estimated daily intake (EDI), target hazard quotient (THQ), and total target hazard quotient (TTHQ). Results: The concentration (mg/kg) of iron, zinc, manganese, copper, cadmium, lead, and chromium in both species ranged 4.00 – 197.30, 9.20 – 35.30, 0.20 – 5.00, 0.00 – 73.10, 0.00 – 1.30, 0.00 – 54.70, and 0.00 – 0.50, respectively. The EDI of trace metals resulting from the consumption of both fish species was higher than the permissible tolerance intake (PTI) mg/day/60kg body weight. The THQ and TTHQ were < 1, indicating that the consumption of this food fish portends no known health concern. However, the carcinogenic risks exceeded the threshold level of 10-6 - 10-4, thus, reflecting carcinogenic tendency. Based on the results obtained, it must be ensured that the effluents discharged into open water bodies meet the recommended limits. Conclusion: There is a need to create awareness among consumers of food fish in the study area. There should be periodic monitoring of trace metals in surface waters and its food fish population to forestall potential health impact on humans.

Mining in the Kizel coal basin (Perm Region, Russia) ceased 20 years ago; however, AMD with high levels of total iron (Fetotal) and trace elements still affects the rivers. In this study, we attempted to estimate inter-annual and seasonal variability of AMD-related surface water contamination using Sentinel-2 images from 2016 to 2019. The acid mine water index (AMWI), which is a normalized difference of spectral reflectance in the red and blue bands, was calculated from Sentinel-2 images. We compared the AMWI values with measured Fetotal concentrations in the surface water. A statistically significant (at a 0.05 significance level) Spearman's rank correlation between AMWI and Fetotal concentration was found for 5 out of 7 surface water sampling points. We found that surface water contamination reaches a seasonal maximum in July, 1–1.5 months after the end of the snowmelt high water period. Excessive summer rainfalls also contributes to increased contamination, causing contamination to possibly spread more than 200 km from the AMD sources. In contrast, arid summer conditions were associated with a substantially decreased AMD discharge and Fetotal concentrations in the surface water. The main uncertainties in our results are associated with the effect of contaminated bottom and bank sediments and suspended sediments on the spectral characteristics of the water surface, and the relatively coarse (10 m) spatial resolution of Sentinel-2 images. However, despite the data and method limitations, our results show that Sentinel-2 images have substantial potential for monitoring AMD-related contamination of surface water. [ABSTRACT FROM AUTHOR]

Despite the fact that there are tens of thousands of thermal baths in existence, knowledge about the occurrence of pharmaceutically active compounds (PhACs) in untreated thermal wastewater is very limited. Because used thermal water is typically legally discharged into surface waters without any treatment, the effluent poses environmental risks for the receiving water bodies. The aim of this study was to show the occurrence patterns and spatiotemporal characteristics of 111 PhACs in thermal wastewater. Six thermal water outflows of different thermal baths were tested in different seasons in the Budapest metropolitan region (Hungary), and diurnal analysis was performed. After solid-phase extraction, the samples were analysed and quantified by coupling supercritical fluid chromatography and mass spectrometry to perform simultaneous multi-residue drug analysis. The results confirm that water discharge pipes directly transport pharmaceuticals into surface water bodies; 34 PhACs were measured to be over the limit of quantification at least once, and 21 of them were found in more than one water sample. The local anaesthetic drug lidocaine, antiepileptic carbamazepine, analgesic derivative tramadol and illicit drug cocaine were detected in more than half of the samples. Caffeine, metoprolol and bisoprolol (cardiovascular drugs), benzoylecgonine (cocaine metabolite), diclofenac (NSAID), citalopram (antidepressant) and certain types of hormones also have a significant frequency of 30-50%. However, the occurrence and concentrations of PhACs vary according to the season and number/types of visitors. As demonstrated by the diurnal fluctuation, drug contamination of thermal waters can significantly vary, even for similar types of baths; furthermore, the quantity and types of some pollutants rapidly change in the discharged thermal wastewater. [ABSTRACT FROM AUTHOR]

Due to favourable hydrogeological and climatic conditions there are many sources of mine water in Slovakia. The total discharge of mine water is about 1.80 m³.s-1. 14 mining-deposit regions with 1 041 sources have been identified in Slovakia. Mine drainage represents a risk for the environment especially because of the high concentrations of heavy metals. The most of the discharges drain into surface water where they deteriorate the quality of the local streams. However, the quality and quantity of mine water differ from site to site. To minimize negative effects, it is necessary to understand the composition of mine drainage. The worst situation is at the site Smolník. Smolnícky potok Creek in the profile below the deposit is contaminated by iron, manganese, aluminium, zinc and copper. Mine water in Slovakia have approximately neutral pH, except from the Pech shaft (<5) and the New gallery (<6) in the Smolník site. The most commonly the contamination of surface water is caused by arsenic (Horná Nitra, Dúbrava, Pezinok, Špania Dolina, Slovinky, Kremnica site), copper (Dúbrava, Špania Dolina, Rudňany, Slovinky, Smolník, Novoveská Huta site), antimony (Dúbrava, Pezinok, Špania Dolina, Rudňany, Slovinky site) and other elements -- zinc, manganese, aluminium, iron, mercury. [ABSTRACT FROM AUTHOR]

The microbiological and chemical drinking water quality of 20 vulnerable Finnish small groundwater supplies was studied in relation to environmental risk factors associated with potential sources of contamination. The microbiological parameters analyzed included the following enteric pathogens: Giardia and Cryptosporidium, Campylobacter species, noroviruses, as well as indicator microbes (Escherichia coli, intestinal enterococci, coliform bacteria, Clostridium perfringens, Aeromonas spp. and heterotrophic bacteria). Chemical analyses included the determination of pH, conductivity, TOC, color, turbidity, and phosphorus, nitrate and nitrite nitrogen, iron, and manganese concentrations. Giardia intestinalis was detected from four of the water supplies, all of which had wastewater treatment activities in the neighborhood. Mesophilic Aeromonas salmonicida, coliform bacteria and E. coli were also detected. None of the samples were positive for both coliforms and Giardia. Low pH and high iron and manganese concentrations in some samples compromised the water quality. Giardia intestinalis was isolated for the first time in Finland in groundwater wells of public water works. In Europe, small water supplies are of great importance since they serve a significant sector of the population. In our study, the presence of fecal indicator bacteria, Aeromonas and Giardia revealed surface water access to the wells and health risks associated with small water supplies.

Public crude oil fields in Wonocolo sub-district were active from 1942 until now and have inadequately operated. The aims of this research were to measure the level of total petroleum hydrocarbon (TPH) pollution and their distribution in soil and surface water at the Wonocolo public crude oil fields. Twelve composite soil samples were collected from uncontaminated and contaminated sites of old well (OW), transportation line (T), and refinery area (R) at the depths of 0-30 cm, 30-60 cm, and 60-90 cm. The composite surface water sample was obtained from two points with different distances from the river side. TPH from soil and surface water samples were extracted using soxhlet and gravimetric method. Quantification of TPH was performed using Fourier Transform Infrared (FT-IR) Spectrometer. From the results of this study, it was concluded that soils and surface water are contaminated by TPH of 119.80-107,190 μg/g and 211,025.73 μg/L, respectively. TPH is clearly located in the upper of 0-30 cm depth at OW, T, and R sites (52,328.14-107,189.63 μg/g). These concentrations exceeded the soil quality standard of TPH and classified as category A for human hazard risk. The findings from this study show that there are considerable health risks which are potentially poisonous to humans in the local area. We recommend that remediation could be conducted using biological methods to reduce TPH pollution level. [ABSTRACT FROM AUTHOR]

This study aimed to develop and validate a Dynamic in-River Agrochemical Fate and Transport (DRAFT) model simulating one-dimensional advective and dispersive pesticide transport processes under unsteady flow regime in a riverine system. The DRAFT model was coupled with two other modeling components, the PCPF-B model and the land use based tank model, which simulated hydrological/pesticide process in paddy fields and hydrological process in other land uses such as city, agricultural field and forest, respectively. The PCPF-B/DRAFT model was fed with the spatial information of the target catchment by incorporating the Geographical Information System (GIS). For the model validation, a full catchment monitoring data of a rice herbicide, mefenacet, along the Kose River, Fukuoka, Japan was utilized. After model calibration, hourly river discharge and daily mefenacet concentration were simulated by the PCPF-B/DRAFT model at individual observed points of the Kose River and model performance was evaluated by graphical assessment and multiple statistical indices (e.g. Nash-Sutcliffe efficiencies were 0.84–0.86 for streamflow and 0.16–0.72 for herbicide, respectively). The predicted mefenacet concentrations were strongly affected by: (1) water managements practiced in rice fields and (2) intensive rainfall events. The former concentrations were characterized by broad peak while for the latter the peak concentration was sharp and narrow. We used the PCPF-B/DRAFT model to further evaluate the applications of 7 days of water holding period after herbicide application in paddy fields, which was shown to effectively reduce the total loss of mefenacet from 18.9 to 12.8% of applied mass. Consequently, the broad peak concentrations of mefenacet in the Kose River decreased remarkably while the water management practice was less effective to reduce the sudden and sharp peak concentration resulting from intensive rainfall events. [ABSTRACT FROM AUTHOR]

The Meenachil, the only river that flows through the heart of the Kottayam district of Kerala state, India was selected for the study. The present study has been carried out with an objective to systematically examine the prevalence of indicator and pathogenic microorganisms and to compare the microbiological quality of the river water during the pre-monsoon and post-monsoon seasons. Water samples from 44 different sites during pre-monsoon and post-monsoon seasons were collected for the analysis. During the pre-monsoon period, the faecal coliform count ranged from 230 to 110,000 MPN/100 ml while there was a variation from 200 to 4600 MPN/100 ml during the post-monsoon period. When the faecal streptococci count was analysed, it ranged from 140 to 110,000 MPN/100 ml during the pre-monsoon and 70 to 4600 MPN/100 ml during the post-monsoon seasons, respectively. All the samples collected were found to have total viable count (TVC) higher than those prescribed by Bureau of Indian Standards (ISI 1991). Total viable counts were found in the range of 1.1 × 102 to 32 × 102 cfu/ml in the pre-monsoon and 1.0 × 102 to 26 × 102 cfu/ml in the post-monsoon. The presence of faecal indicator bacteria, Escherichia coli and potentially pathogenic bacteria, Vibrio cholerae, Vibrio parahaemolyticus and Salmonella enterica in the Meenachil River indicates that the bacteriological quality of the Meenachil River is poor. Moreover, it sheds light to the fact that raw sewage is being dumped into the Meenachil River. Urban runoffs and effluents of rubber factories appear to be the important sources of faecal contamination in the river. From this study, we conclude that these water bodies pose significant public health hazards. Adequate sanitary infrastructure will help in preventing source water contamination. Besides this, public health education aimed at improving personal, household and community hygiene is urgent. [ABSTRACT FROM AUTHOR]

There are many locations for traditional gold mining in Indonesia. One of these is in Murung Raya District, Central Kalimantan Province. Mining activities involving the application of traditional gold processing technology have a high potential to pollute the environment, especially surface water. Therefore, this study aims to determine the impact of gold mining and processing on surface water quality around the mine site. Based on the results of field surveys and laboratory analysis, our data shows that the concentration of mercury (Hg) and Cyanide (CN) has reached 0.3 mg/L and 1.9 mg/L, respectively, in surface water. These values exceed the drinking water quality standards of Indonesia and WHO. Many people who live in the mining area use surface water for daily purposes including drinking, cooking, bathing and washing. This scenario is very dangerous because the effect of surface water contamination on human health cannot be immediately recognized or diagnosed. In our opinion the dissemination of knowledge regarding the treatment of gold mining wastewater is urgently required so that the quality of wastewater can be improved before it is discharged into the environment

A holistic risk assessment of surface water (SW) contamination due to lead-210 (Pb-210) in oil produced water (PW) from the Bakken Shale in North Dakota (ND) was conducted. Pb-210 is a relatively long-lived radionuclide and very mobile in water. Because of limited data on Pb-210, a simulation model was developed to determine its concentration based on its parent radium-226 and historical total dissolved solids levels in PW. Scenarios where PW spills could reach SW were analyzed by applying the four steps of the risk assessment process. These scenarios are: (1) storage tank overflow, (2) leakage in equipment, and (3) spills related to trucks used to transport PW. Furthermore, a survey was conducted in ND to quantify the risk perception of PW from different stakeholders. Findings from the study include a low probability of a PW spill reaching SW and simulated concentration of Pb-210 in drinking water higher than the recommended value established by the World Health Organization. Also, after including the results from the risk perception survey, the assessment indicates that the risk of contamination of the three scenarios evaluated is between medium-high to high. [ABSTRACT FROM AUTHOR]

Cities in developing countries encounter rapid waves of social transformation and economic development where the environment is mostly a neglected aspect. The Katari watershed encompasses mining areas, El Alto city (one of the fastest growing urban areas in South America and the biggest in the Altiplano) as well as agricultural areas. Its outlet is Cohana Bay, one of the most polluted areas of Lake Titicaca. Here we propose an integrative approach (hydrological, physicochemical, chemical and bacterial data) to understand the pollution problem of this developing area, in which a variety of anthropogenic activities takes place. Both mining and urban areas appear to be sources of metal pollution. Nutrient and bacterial contaminations are mainly related to urban and industrial discharges. These situations have impacts in the basin from the mining area down to Cohana Bay of Lake Titicaca. Pollutant concentration patterns are highly influenced by seasonal hydrology variations. The poor quality of surface waters in the basin represents a risk for human and animal populations, as well as for the quality of aquifers located underneath El Alto city. [ABSTRACT FROM AUTHOR]

Leachate emission from uncontrolled municipal solid waste landfills (referred to as waste sites in the present study) is a major threat to the environment and living beings in its vicinity. Surface water contamination potential resulting from leachate may be used as one of the criteria for prioritization of sites for remediation purposes. The existing hazard rating systems that prioritize waste sites considering surface water contamination potential as one of the criteria are mainly suited for the developed countries where these were developed initially. In developing countries like India, the set of conditions differ from those in developed countries, and therefore the existing systems may not be suitable for developing countries. Thus in the present study, an improved system is proposed to assess surface water contamination potential from MSW sites. The system is based on the concept of Source, Pathway and Receptor. The proposed system employs parameters derived from the review of existing rating systems and selects their best and worst values based on literature review, design standards and field conditions. The importance weights of the system parameters have been decided based on expert judgment using Delphi technique. Sensitivity analysis of the system shows that the improved system is more sensitive than the existing systems for the site conditions encountered in developing countries. Monte Carlo analysis of the proposed system confirms the spread of the scores obtained from the system over the full scale of 0-1000. The improved system is compared with existing systems by applying it to waste sites from metropolitan cities of India and performing clustering analysis on the rating scores. The clustering analysis shows that the rating scores from the improved system are less clustered as compared to the scores from the existing systems. This demonstrates that the improved system makes a better tool to distinctly prioritize the waste sites for remediation purpose. [ABSTRACT FROM AUTHOR]

Copyright of Ecological Engineering / Inżynieria Ekologiczna is the property of Polish Society of Ecological Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Identifying sources of nitrogen input and nitrogen yield to waterways are important aspects of watershed management. A Soil and Water Assessment Tool (SWAT) model was developed for the Cibolo and Dry Comal Creek watersheds in south central Texas, USA to assess how individual nitrogen source categories contribute to nitrogen yield. The model includes nitrogen inputs from atmospheric deposition, fertilizer, manure, a wastewater treatment plant (WWTP), and on-site sewage facilities (OSSFs). Model calibration was successful with all model performance parameters rated satisfactory or better except for percent bias (PBIAS) during the streamflow calibration period in Cibolo Creek. The high PBIAS value likely resulted from the model underestimating streamflow during two flood events coupled with potential measurement errors for the observed streamflow values during the floods. The largest contributors to nitrogen input were livestock (42.0 %), atmospheric deposition (26.8 %), deer (9.9 %), and farm fertilizer use (9.7 %). The largest contributors to nitrogen yield were atmospheric deposition (56.3 % of nitrogen yield), livestock (25.9 %), and the WWTP (7.1 %). The difference in ranking between nitrogen inputs and nitrogen yields occurred because the percentage of nitrogen input that becomes nitrogen yield varied with source. The WWTP (100 % of the WWTP nitrogen input became nitrogen yield) was highest because it directly discharged to the waterway. The WWTP was followed by feral hogs (8.0 %), atmospheric deposition (5.8 %), and waterfowl (2.1 %). These results provide a source-by-source assessment of nitrogen inputs and their corresponding yields allowing watershed managers to better assess nitrogen management strategies. [ABSTRACT FROM AUTHOR]

Long-term monitoring of the content of perchloroethylene (PCE) in a river ecosystem affected by groundwater contamination was performed at a site in the Czech Republic. The quality of surface water was monitored quarterly between 1994 and 2013, and fish were collected from the affected ecosystem to analyse the content of PCE in their tissue in 1998, 2011 and 2012. Concentrations of PCE (9-140 μg/kg) in the tissue of fish collected from the contaminated part of the river were elevated compared to the part of the river unaffected by the contamination (ND to 5 μg/kg PCE). The quality of surface water has improved as a result of groundwater remediation during the evaluated period. Before the remedial action, PCE concentrations ranged from 30 to 95 μg/L (1994-1997). Following commencement of remedial activities in September 1997, a decrease in the content of PCE in the surface water to 7.3 μg/L (1998) and further to 1 μg/L (2011) and 1.1 μg/L (2012) led to a progressive decrease in the average concentration of PCE in the fish muscle tissue from 79 μg/kg (1998) to 24 (2011) and 30 μg/kg (2012), respectively. It was determined that the bioconcentration of PCE does not have a linear dependence because the decrease in contamination in the fish muscle tissue is not directly proportional to the decrease in contamination in the river water. The observed average bioconcentration factors were 24 and 28 for the lower concentrations of PCE and 11 for the higher concentrations of PCE in the river. In terms of age, length and weight of the collected fish, weight had the greatest significance for bioconcentration, followed by the length, with age being evaluated as a less significant factor. [ABSTRACT FROM AUTHOR]

The quality of surface waters/groundwater of a geographical region can be affected by anthropogenic activities, land use patterns and fecal pollution sources from humans and animals. Therefore, the development of an efficient fecal pollution source tracking toolbox for identifying the origin of the fecal pollution sources in surface waters/groundwater is especially helpful for improving management efforts and remediation actions of water resources in a more cost-effective and efficient manner. This review summarizes the updated knowledge on the use of fecal pollution source tracking markers for detecting, evaluating and characterizing fecal pollution sources in receiving surface waters and groundwater. The suitability of using chemical markers (i.e. fecal sterols, fluorescent whitening agents, pharmaceuticals and personal care products, and artificial sweeteners) and/or microbial markers (e.g. F + RNA coliphages, enteric viruses, and host-specific anaerobic bacterial 16S rDNA genetic markers) for tracking fecal pollution sources in receiving water bodies is discussed. In addition, this review also provides a comprehensive approach, which is based on the detection ratios (DR), detection frequencies (DF), and fate of potential microbial and chemical markers. DR and DF are considered as the key criteria for selecting appropriate markers for identifying and evaluating the impacts of fecal contamination in surface waters/groundwater. [ABSTRACT FROM AUTHOR]

Heavy metal concentrations in surface water and soil samples around Gümüşköy Silver Mine, located in Köprüören Basin, were determined to evaluate the anthropogenic level of contamination due to mining activities. The mean concentrations of As, Pb, Sb and Cd in 12 soil samples came out to be 1193, 844, 66 and 19 ppm, respectively. Soil pollution assessment was carried out by using geoaccumulation index ( Igeo), enrichment factor (EF) and pollution index (PI). Igeo, EF and PI suggest anthropogenic pollution of As, Pb, Sb and Zn in the areas where there is leakage of these heavy metals from the waste pools of the silver mine facility. Water samples collected from the surface waters also have elevated concentrations of these heavy metals. The contaminants are most probably transported by surface waters in the rainy season. [ABSTRACT FROM AUTHOR]

Nutrient pollution in surface and ground water is one of the world’s most widespread, costly and challenging environmental problems, resulting in serious environmental and health issues. This study investigated the removal of low concentration nutrients from synthetic solution simulating slightly nutrient polluted water. Continuous-flow filtration column and hydroponic wetland experiments were conducted to investigate the impact of operating conditions and using zeolite and calcium silicate hydrate (CSH) as functional filtration substrates. The interactions between phosphorus (PO 4 3− -P) and nitrogen (NH 4 + -N and total nitrogen) with hydroponic plants, CSH and zeolite at different hydraulic loading rates (HLR) were found to have significant impacts on nutrient removal. During filtration column experiments, CSH was highly effective for PO 4 3− -P removal and achieved an average removal efficiency greater than 90%. Zeolite removed more NH 4 + -N than CSH, achieving an average removal of 77%. Longer filtration time improved nutrient removal, and the optimal retention time was found to be 12 h. The wetland testing demonstrated nutrient uptake by hydroponic plants played a major role in removal of PO 4 3− -P and NH 4 + -N during plant growth season. Installation of CSH and zeolite functional substrates was critical to ensure stable overall nutrient removal in hydroponic wetlands. The functional substrates provided complementary physical–chemical sorption capacity for PO 4 3− -P and NH 4 + -N, especially when the plants uptake varied between growth and harvest seasons. Higher HLR reduced slightly the overall nutrient removal in wetlands. Throughout the testing period of 70 days, hydroponic wetlands showed no advantage in organic nitrogen removal compared to subsurface flow constructed wetlands. The total nitrogen percent removal was below 30% in both wetland units probably due to lack of microbiological activities in the wetlands resulting from low organic matter in synthetic influent water. [ABSTRACT FROM AUTHOR]

The water quality of the northern Caspian Sea has not been well-known, and its contamination can adversely affect the health of swimmers and seashore residents. The study sought to determine the contamination state of the Caspian Sea in Kazakhstan and quantify human health risks coming from the existing heavy metals concentration. The Caspian Sea was found to be "fairly to marginally" contaminated (24 < CCME-WQI < 64), with Cd influencing the index significantly. Concentrations of Cd and Pb increase over time (seasonal Kendall test, p-values = 2–4 %) in sites near oil fields and ports, suggesting the significant role of anthropogenic sources in causing diverse pollution events. Pb demonstrated the highest variability and number of outliers (4.3 % of all samples with coefficients of variation reaching up to 175 %). The principal component analysis further revealed that various discharges from oilfields and upstream transport could contribute to the contamination by heavy metals and their concentrations. Contamination is associated with up to 6 % cancer risk for adults. The long exposure duration of swimmers in water increases risks by up to 18 %, indicating the local population is at a higher risk. In conclusion, statistical tests and analysis indicate the presence of anthropogenic sources, and risk assessment reveals swimming can contribute to cancer risk. [Display omitted] • Surface water quality was studied in the Kazakhstan's coastline of the Caspian Sea. • Human health risk assessment was conducted for swimming scenario. • Water quality can be categorized as fair to marginal according to index analysis. • Risks were acceptable without an extreme concentration or exposure duration. • Oil fields, upstream transport, and seaports were possible contamination sources. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ambiente e Água is the property of Revista Ambiente e Agua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years there have been a number of waterborne outbreaks of cryptosporidiosis in some major urban centers in Ireland. The Irish Environmental Protection Agency has adapted and modified the qualitative 'Scottish Water Directions' to help prevent such outbreaks. When this risk assessment method was applied to three small agricultural river catchments in Ireland, the results suggested an equal risk of water contamination for each catchment. A survey was conducted in each catchment focusing on agricultural activity and surface waters. Fecal samples were collected from 1-8-week-old calves along with associated slurry and dung from beef and dairy farms and water samples were collected monthly at the outlet of the three catchments. Two of the catchments had much higher infection rates among neonatal calves as well as higher oocyst contamination of surface waters than the remaining one. It was concluded that the qualitative risk assessment could be more robust if cognizance was taken of the temporal and epidemiological aspects of cryptosporidiosis in beef and dairy herds. [ABSTRACT FROM AUTHOR]

To address the uncertainty associated with microbial transport and surface water contamination events, we developed a new comprehensive stochastic framework that combines processes on the microscopic (single microorganism) and macroscopic (ensembles of microorganisms) scales. The spatial and temporal population behavior is modeled as a nonhomogeneous Poisson random field with Markovian field dynamics. The model parameters are based on the actual physical and biological characteristics of the Cryptosporidium parvum transport process and can be extended to cover a variety of other pathogens. Since soil particles have been shown to be a major vehicle in microbial transport, a U.S. Department of Agriculture approved erosion model (Water Erosion Prediction Project) is incorporated into the model. Risk assessment is an integral part of the stochastic model and is conducted using a set of simple calculations. Poisson intensity functions and correlations are computed. The results consistently indicate that surface water contamination events are transient, with traveling high peaks of microorganism concentrations. Correlations between microorganism populations at different points in time and space reach relatively significant levels even at large distances from one another. This information is aimed to assist water resources management teams in the decision-making process to identify the likely timing and locations of high-risk areas and thus to avoid collection of contaminated water. [ABSTRACT FROM AUTHOR]

Many environmental and health problems come from the presence of metals in surface water. Effectiveness of a new commercial tannin-based flocculant has been tested in order to remove Zn2+, Ni2+ and Cu2+ by coagulation–flocculation process. pH has been adjusted in order to evaluate the real heavy metal removal due just to flocculant effect and not to hydroxide precipitation. At least a 75% of metal removal has been reported in every case, depending on pH value. Flocculant doses have been reported to be about 100–150ppm. [Copyright &y& Elsevier]

Abstract: Diffuse nitrogen pollution caused by irrigated agriculture is quantified for the Pocochay stream located in the Aconcagua watershed in the Valparaíso region, Chile. The study area has an extent of 93 km2 with 36 km2 under irrigation. It is representative for the central part of Chile where intensive irrigation is prevailing and predominantly taking place in the alluvial plains of river systems with water sources from the Andes Mountains. Water quality and discharge were monitored biweekly at several points of the Pocochay main stream from December 2003 to June 2006. The study was supported by an agricultural survey and remote imagery interpretation in order to retrieve data on cropping pattern and actual fertilizer uses in the sub-watersheds. Nitrate – N concentration in the Pocochay stream ranged from 1.3 to 10.1 mg L−1 with a mean of 4.8 mg L−1. Other nitrogen species showed very low concentrations. At average, around 52 kg N ha−1 a−1 are drained from the study area as compared to 167 kg N ha−1 a−1 applied as fertilizer to the fields. Even though nitrate concentrations in the Pocochay do not reach alarming levels yet, the impact of irrigated agriculture on surface water quality is obvious and makes a case for introducing best management practices to avoid aggravation of contamination. [Copyright &y& Elsevier]

A previously developed Cryptosporidium transport model is solved numerically to investigate the transport and interactions between Cryptosporidium, water and surface sediment and to estimate the risk of surface water contamination by Cryptosporidium. The primary objective of this study is to expand the work of Yeghiazarian (Ph.D. dissertation, Cornell University )where the analytical solution of the Cryptosporidium transport model was obtained for a simple case of specific attachment of Cryptosporidium oocysts to fine soil particles wherein some parameters have zero values. However, some studies have shown several cases where these parameters are not zero. This necessitated further study to generate a solution to the complete Cryptosporidium transport model. Utilizing the finite difference method, the Cryptosporidium transport model is solved numerically for the general case of a system with any parameter values. Previously, first- and second-order reliability methods (FORM and SORM) were employed for risk assessment using analytical transport results (Yeghiazarian, Ph.D. dissertation, Cornell University, ), but in this work, FORM and SORM are applied to the numerical solution of the Cryptosporidium transport model to estimate the risk of Cryptosporidium contamination in surface water. The risk of surface water contamination is estimated by the probability that the Cryptosporidium concentration in surface water at a given time and location exceeds a safety threshold. The numerical solution is interfaced with the general-purpose reliability code, CALREL, to estimate the probability of failure on one hillslope. The sensitivity of system reliability to process parameters is reported. [ABSTRACT FROM AUTHOR]

The article presents abstracts of several studies on environmental geochemistry. Some of the abstracts presented include "Biogeochemical Cycling of Nutrients in Karstic Catchments, Southwestern China: Linkages to Changes of Eco-Environments," by Congqiang Liu and "Emerging Organic Contamination in China," by Guibin Jiang and colleagues.

Pesticide pollution of surface waters was studied in a 49.7 km2 catchment in Germany. The loads were differentiated into point source (PSP) and non-point source pollution (NPSP). The contribution of runoff, interflow, groundwater, drainage and spray drift to river contamination was defined as NPSP. Pesticides discharged into the river via wastewater treatment plants and sewer overflows were considered as PSP. Hydrology and pesticide loads were studied on the scale of the entire catchment and in two sub-catchments not influenced by PSP. River discharges and concentrations of 19 pesticides were measured at four locations over 447 days. The total load detected in the entire catchment amounted to 3249 g active ingredient (a.i.). The stream flow data were separated into base and direct flow applying a non-linear reservoir separation algorithm. Single rainfall events leading to runoff and interflow dominated NPSP in the sub-catchments. For the sub-catchment Rossberg 87% and for Leidenhofen 71% of the pesticide load could be attributed to direct flow. This corresponded to 14 and 34% time of peak flow events for Rossberg and Leidenhofen, respectively. For the entire catchment only 15% of the NPSP was transported with direct flow with 49% attributed to base flow. The difference between the entire and the sub-catchment contribution was attributed to dilution, hysteresis and merging effects. Applying a digital recursive filter technique for hydrograph separation confirmed the results of the non-linear reservoir separation algorithm. The impact of the hydrograph separation technique on the hydrological characterisation of pesticide loads was insignificant. The results emphasise the dynamic nature of pesticide transport and its complex interaction between size and position of source areas along a stream flow network.The measured loads in the sub-catchments were scaled up to the entire catchment as an estimate for the total NPSP. The fraction of the area treated with a pesticide was found not to be an appropriate scaling factor. Research is required to develop adequate methods to scale detailed measurements of pesticide loads from small scales up to catchments with complex drainage systems. [Copyright &y& Elsevier]

Tailings-derived mine drainage water that is neutral in character, has a high electrical conductivity and contains elevated sulphate, chloride and nickel concentrations, has caused deterioration in groundwater and surface water quality in the mining area of Hitura in Western Finland. This deterioration, and thereby the location of the contaminant plume, was recognized in the water chemistry in the form of a gradual change in ion composition from Ca-HCO3-type water towards a Mg-SO4-rich type. It was possible to define the extent of the pollution by using cluster analysis to distinguish between hydrochemically different regimes and performing an electrical sounding survey. The results indicated that contamination is most intense close to the tailings impoundment and is related to an esker complex running across this area. Nevertheless, the water in the eastern and southern parts of the area upgradient of the hydraulic head is uncontaminated and suitable for water supply purposes. [ABSTRACT FROM AUTHOR]

The occurrence of two herbicides (diuron and simazine) in receiving surface waters is related to their seasonal applications within an urban catchment. Comparisons of herbicide concentrations within baseflow and during rainfall conditions provide an insight into pollutant transport processes following application to urban surfaces. Two storm events, with different hydrological characteristics, are described. The maximum recorded herbicide concentrations reached 238.4 and 2.23 μg/l for diuron and simazine, respectively, with the former corresponding to an application loss of 45.1% with respect to the diuron recently applied to the urban catchment. The factors influencing the extent of application losses to receiving waters of herbicides applied to urban substrates are discussed. [Copyright &y& Elsevier]