A probabilistic QMRA of Salmonella in direct agricultural reuse of treated municipal wastewater

2015 ◽  
Vol 71 (8) ◽  
pp. 1203-1211 ◽  
Author(s):  
Yamrot M. Amha ◽  
Rajkumari Kumaraswamy ◽  
Farrukh Ahmad
Keyword(s):  
Disease Burden ◽  
Municipal Wastewater ◽  
Quantitative Polymerase Chain Reaction ◽  
Monte Carlo Analysis ◽  
World Health ◽  
Treated Wastewater ◽  
Quantitative Microbial Risk Assessment ◽  
Salmonella Spp ◽  
Salmonella Infections ◽  
Life Years

Developing reliable quantitative microbial risk assessment (QMRA) procedures aids in setting recommendations on reuse applications of treated wastewater. In this study, a probabilistic QMRA to determine the risk of Salmonella infections resulting from the consumption of edible crops irrigated with treated wastewater was conducted. Quantitative polymerase chain reaction (qPCR) was used to enumerate Salmonella spp. in post-disinfected samples, where they showed concentrations ranging from 90 to 1,600 cells/100 mL. The results were used to construct probabilistic exposure models for the raw consumption of three vegetables (lettuce, cabbage, and cucumber) irrigated with treated wastewater, and to estimate the disease burden using Monte Carlo analysis. The results showed elevated median disease burden, when compared with acceptable disease burden set by the World Health Organization, which is 10−6 disability-adjusted life years per person per year. Of the three vegetables considered, lettuce showed the highest risk of infection in all scenarios considered, while cucumber showed the lowest risk. The results of the Salmonella concentration obtained with qPCR were compared with the results of Escherichia coli concentration for samples taken on the same sampling dates.

Reclaimed municipal wastewater for forage production

2017 ◽  
Vol 75 (8) ◽  
pp. 1784-1793 ◽  
Author(s):  
Ben Said Ines ◽  
Mezghani Imed ◽  
Donyez Frikha ◽  
Chaieb Mohamed ◽  
Muscolo Adele
Keyword(s):  
Municipal Wastewater ◽  
Tap Water ◽  
Oxygen Demand ◽  
Fecal Coliforms ◽  
World Health ◽  
Treated Wastewater ◽  
Municipal Wastewater Treatment ◽  
Forage Production ◽  
Salmonella Spp ◽  
Total Coliforms

This study aims to evaluate the possibility of using reclaimed municipal wastewater for agricultural purpose. We assessed the validity of municipal wastewater treatment, analyzing its chemical characteristics before and after the biological stabilization by pond treatment (WSP). The reclaimed municipal treated wastewater (TWW) was used to irrigate Cenchrus ciliaris. Experiments were carried out in greenhouse, from July 2013 to July 2014, comparing the effects of TWW with the water normally used for irrigation (tap water, TW) on the growth and flowering parameters of C. ciliaris. During this study, total coliforms, fecal coliforms, Escherichia coli, and Salmonella spp. were detected in TW, TWW, soils and plants under irrigation. Our results evidenced that TWW increased plant growth, producing taller plants with respect to TW. Total coliforms and fecal coliforms in TWW, TW, soils and plants were under the threshold recommended by the World Health Organization (WHO). Salmonella was never found in TW, TWW, or soil and plants irrigated with TWW. The absence of pathogens suggests that the pond treatment is an effective method to reclaim wastewater, lowering biochemical oxygen demand (BOD), chemical oxygen demand (COD) and pathogens. In this respect, TWW can be used as a valid alternative to freshwater for irrigation of fodder species.

scholarly journals Quantitative Microbial Risk Analysis to evaluate health effects of interventions in the urban water system of Accra, Ghana

2010 ◽  
Vol 8 (3) ◽  
pp. 417-430 ◽  
Author(s):  
Herve Labite ◽  
Isabella Lunani ◽  
Peter van der Steen ◽  
Kala Vairavamoorthy ◽  
Pay Drechsel ◽  
...  
Keyword(s):  
Disease Burden ◽  
Water System ◽  
Reference Value ◽  
Urban Water ◽  
Quantitative Microbial Risk Assessment ◽  
Indicator Organisms ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Urban Water System ◽  
Life Years

A quantitative microbial risk assessment was applied to evaluate the microbial risks of the Accra Urban Water System (AUWS). The exposure assessment was based on the count of indicator organisms in waste water from open roadside drains and in water and sand samples from the beach. The predicted total disease burden generated in a representative catchment of the AUWS (Odaw Catchment) was 36,329 Disability Adjusted Life Years (DALYs) per year, of which 12 and 88% are caused by, respectively, shortcomings in the water supply system and inappropriate sanitation. The DALYs per person per year were above the WHO reference value. The open roadside drain had the highest contribution to the disease burden. Of four possible interventions evaluated for health risk reduction, the highest efficiency in terms of DALYs averted per euro invested would be achieved by providing covers for the open roadside drains.

scholarly journals Energy forest irrigated with wastewater: a comparative microbial risk assessment

2009 ◽  
Vol 7 (3) ◽  
pp. 413-433 ◽  
Author(s):  
A. Carlander ◽  
C. Schönning ◽  
T. A. Stenström
Keyword(s):  
Risk Assessment ◽  
Municipal Wastewater ◽  
Human Infection ◽  
Treated Wastewater ◽  
Quantitative Microbial Risk Assessment ◽  
Indicator Organisms ◽  
Giardia Infection ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Short Rotation

In this study, risks for human infection associated with irrigation of municipal wastewater on short rotation willow coppice (Salix) were evaluated in three countries. The aim was also to determine the reduction of indicator organisms and pathogens in the treatment plants. Two of the field sites were chosen for further evaluation by QMRA (quantitative microbial risk assessment) applied to three scenarios: accidental ingestions of wastewater, exposure to aerosols and ingestion of groundwater. The risks of infection for bacteria (Salmonella), virus (rotavirus) and protozoa (Giardia, Cryptosporidium) were characterised as probability of infections per exposure and number of infections per year. The highest risk for infection was associated with exposure to rotavirus in Culmore (Northern Ireland), by either accidental ingestion of wastewater or ingestion of groundwater (Pinf 8 × 10−1). For Kvidinge (Sweden) the risk for virus infection by ingestion of wastewater were in the same range (Pinf 7 × 10−1). The risk for Giardia infection differed between the two sites due to differences in concentration of this pathogen in the wastewater. The groundwater was found to have suffered faecal contamination due to the wastewater irrigation. Use of partially treated wastewater for irrigation of energy crops could be a sustainable option if site-specific recommendations are developed.

scholarly journals World Health Organization estimates of the global and regional disease burden of four foodborne chemical toxins, 2010: a data synthesis

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 1393 ◽  
Author(s):  
Herman Gibb ◽  
Brecht Devleesschauwer ◽  
P. Michael Bolger ◽  
Felicia Wu ◽  
Janine Ezendam ◽  
...  
Keyword(s):  
Burden Of Disease ◽  
Food Supply ◽  
Disease Burden ◽  
Disease Incidence ◽  
Case Fatality ◽  
World Health ◽  
Peanut Allergen ◽  
Major Pathway ◽  
Life Years ◽  
Incidence And Mortality

Background Chemical exposures have been associated with a variety of health effects; however, little is known about the global disease burden from foodborne chemicals. Food can be a major pathway for the general population’s exposure to chemicals, and for some chemicals, it accounts for almost 100% of exposure.  Methods and Findings Groups of foodborne chemicals, both natural and anthropogenic, were evaluated for their ability to contribute to the burden of disease.  The results of the analyses on four chemicals are presented here - cyanide in cassava, peanut allergen, aflatoxin, and dioxin.  Systematic reviews of the literature were conducted to develop age- and sex-specific disease incidence and mortality estimates due to these chemicals.  From these estimates, the numbers of cases, deaths and disability adjusted life years (DALYs) were calculated.  For these four chemicals combined, the total number of illnesses, deaths, and DALYs in 2010 is estimated to be 339,000 (95% uncertainty interval [UI]: 186,000-1,239,000); 20,000 (95% UI: 8,000-52,000); and 1,012,000 (95% UI: 562,000-2,822,000), respectively.  Both cyanide in cassava and aflatoxin are associated with diseases with high case-fatality ratios.  Virtually all human exposure to these four chemicals is through the food supply.  Conclusion Chemicals in the food supply, as evidenced by the results for only four chemicals, can have a significant impact on the global burden of disease. The case-fatality rates for these four chemicals range from low (e.g., peanut allergen) to extremely high (aflatoxin and liver cancer).  The effects associated with these four chemicals are neurologic (cyanide in cassava), cancer (aflatoxin), allergic response (peanut allergen), endocrine (dioxin), and reproductive (dioxin).

scholarly journals A probabilistic assessment of the contribution of wastewater-irrigated lettuce to Escherichia coli O157:H7 infection risk and disease burden in Kumasi, Ghana

2014 ◽  
Vol 13 (1) ◽  
pp. 217-229 ◽  
Author(s):  
Razak Seidu ◽  
Amina Abubakari ◽  
Isaac Amoah Dennis ◽  
Arve Heistad ◽  
Thor Axel Stenstrom ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Health Risks ◽  
Disease Burden ◽  
Infection Risk ◽  
World Health ◽  
Vegetable Production ◽  
Escherichia Coli O157 ◽  
Worst Case ◽  
E Coli ◽  
Life Years

Wastewater use for vegetable production is widespread across the cities of many developing countries. Studies on the microbial health risks associated with the practice have largely depended on faecal indicator organisms with potential underestimation or overestimation of the microbial health risks and disease burdens. This study assessed the Escherichia coli O157:H7 infection risk and diarrhoeal disease burden measured in disability-adjusted life years (DALYs) associated with the consumption of wastewater-irrigated lettuce in Kumasi, Ghana using data on E. coli O157:H7 in ready-to-harvest, wastewater-irrigated lettuce. Two exposure scenarios – best case and worst case – associated with a single consumption of wastewater-irrigated lettuce were assessed. The assessment revealed wastewater-irrigated lettuce is contributing to the transmission of E. coli O157:H7 in Kumasi, Ghana. The mean E. coli O157:H7 infection risk and DALYs in the wet and dry seasons, irrespective of the exposure scenario, were above the World Health Organization tolerable daily infection risk of 2.7 × 10−7 per person per day and 10−6 DALYs per person per year. It is recommended that legislation with clear monitoring indicators and penalties is implemented to ensure that farmers and food sellers fully implement risk mitigating measures.

Assessment of E. coli and Salmonella spp. infection risks associated with different fecal sludge disposal practices in Thailand

2009 ◽  
Vol 8 (2) ◽  
pp. 355-364 ◽  
Author(s):  
A. Yajima ◽  
T. Koottatep
Keyword(s):  
High Water ◽  
Developed Countries ◽  
World Health ◽  
Quantitative Microbial Risk Assessment ◽  
Salmonella Spp ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Risk Levels ◽  
E Coli ◽  
Fecal Sludge

The proper management of fecal sludge (FS), to block the transmission pathways of pathogens, is rarely enforced in many parts of the world. Health risks associated with different disposal practices of FS in peri-urban settings of a large metropolis in Thailand were assessed; Tha Klong sub-district with indiscriminate FS dumping, and Klong Luang sub-district which has an FS treatment system. The study showed that indiscriminate FS dumping from along the canal banks and discharge of market waste were likely the major sources of E. coli and Salmonella spp. in contamination of the canal water. The increased microbial pathogen concentrations near the FS treatment facility also indicated contamination risks from poorly designed treatment facilities. Quantitative microbial risk assessment (QMRA) indicated very high water-related infection risk levels compared to the actual locally recorded disease occurrences. These results indicated that the QMRA model needs to be modified to take account of immunological differences between populations in developed countries, where the model was developed, and developing countries. In addition, further sensitivity factors are needed to reflect different societal behavior patterns, and therefore contact with potentially contaminated water, in different sub-populations of many less developed communities.

scholarly journals Application of risk-based assessment and management to riverbank filtration sites in India

2014 ◽  
Vol 13 (1) ◽  
pp. 174-189 ◽  
Author(s):  
Rico Bartak ◽  
Declan Page ◽  
Cornelius Sandhu ◽  
Thomas Grischek ◽  
Bharti Saini ◽  
...  
Keyword(s):  
Monsoon Season ◽  
World Health ◽  
Riverbank Filtration ◽  
Total Hardness ◽  
Quantitative Microbial Risk Assessment ◽  
Aquifer Recharge ◽  
Water Safety ◽  
Life Years ◽  
Guideline Values ◽  
Management Procedures

This is the first reported study of a riverbank filtration (RBF) scheme to be assessed following the Australian Guidelines for Managed Aquifer Recharge. A comprehensive staged approach to assess the risks from 12 hazards to human health and the environment has been undertaken. Highest risks from untreated ground and Ganga River water were identified with pathogens, turbidity, iron, manganese, total dissolved solids and total hardness. Recovered water meets the guideline values for inorganic chemicals and salinity but exceeds limits for thermotolerant coliforms frequently. A quantitative microbial risk assessment undertaken on the water recovered from the aquifer indicated that the residual risks of 0.00165 disability-adjusted life years (DALYs) posed by the reference bacteria Escherichia coli O157:H7 were below the national diarrhoeal incidence of 0.027 DALYs and meet the health target in this study of 0.005 DALYs per person per year, which corresponds to the World Health Organization (WHO) regional diarrhoeal incidence in South-East Asia. Monsoon season was a major contributor to the calculated burden of disease and final DALYs were strongly dependent on RBF and disinfection pathogen removal capabilities. Finally, a water safety plan was developed with potential risk management procedures to minimize residual risks related to pathogens.

Risk assessment of treated municipal wastewater reuse in Sicily

2013 ◽  
Vol 67 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Rosa Aiello ◽  
Giuseppe L. Cirelli ◽  
Simona Consoli ◽  
Feliciana Licciardello ◽  
Attilio Toscano
Keyword(s):  
Municipal Wastewater ◽  
Irrigation System ◽  
Risk Function ◽  
Wastewater Reuse ◽  
World Health ◽  
Treated Wastewater ◽  
Treated Wastewater Reuse ◽  
Treated Municipal Wastewater ◽  
Health Organization ◽  
The Impact

In Italy, the restrictive approach for treated wastewater reuse in agriculture has led to some difficulties in promoting this practice. In order to assess the health risk associated with the use of wastewater in agriculture, an experiment was conducted in an open field near the constructed wetland (CW) system of San Michele di Ganzaria (Eastern Sicily), during the irrigation seasons 2004–2009. In particular the impact on tomato crops of drip and sub-drip irrigation with treated municipal wastewater, as well as effects of wastewater reuse on the irrigation system, main production features, hydrological soil behaviour, and microbial soil and products contamination were investigated. Notwithstanding the fact that globally CW effluents did not match microbiological standards for wastewater reuse of Italian legislation, the median infection risk (function of the recommended tolerable additional disease burden of 10−6 DALY (disability-adjusted life year) loss per person per year) suggested by the 2006 World Health Organization Guidelines for rotavirus, Campylobacter and Cryptosporidium for lettuce irrigation under unrestricted irrigation scenario was achieved.

scholarly journals Evaluation of pathogen risks using QMRA to explore wastewater reuse options: A case study from New Delhi in India

2020 ◽  
Author(s):  
Rajashree Hajare ◽  
Pawan Labhasetwar ◽  
Pranav Nagarnaik
Keyword(s):  
Water Quality ◽  
Water Reuse ◽  
Treatment Plant ◽  
Control Measures ◽  
Effluent Treatment ◽  
Treated Wastewater ◽  
Quantitative Microbial Risk Assessment ◽  
Salmonella Spp ◽  
Cryptosporidium Spp ◽  
Reuse Options

Abstract Selecting appropriate reuse for treated wastewater is a challenge. The current investigation outlines the utilization of quantitative microbial risk assessment (QMRA) to assist Effluent Treatment Plant (ETP) management to determine the best-possible reuse of treated wastewater from 11 ETPs in Delhi. Four representative pathogens: pathogenic E.coli spp., Salmonella spp., Cryptosporidium spp. and Giardia spp. were selected to characterize microbial water quality. Reuse options selected based on the survey and interaction with ETP managers include crop-irrigation, garden-irrigation, toilet-flush and industrial applications. The probability-of-infection was characterized for two exposure groups: workers and children. Water quality monitoring indicates the occurrence of pathogenic E.coli spp (100%), Salmonella spp.(63%), Cryptosporidium spp. (81%) and Giardia spp. (45%) in the treated wastewater. QMRA reveals the annual median-probability of infection above acceptable limits for pathogenic E.coli spp., Cryptosporidium spp. and Salmonella spp. The probabilities of Giardia-associated infections were low. Adults showed a 1.24 times higher probability of infection compared to children. Sensitivity analysis indicated pathogen concentration as the most critical factor. The study highlights that the existing plans for chlorination-based treatment technology may prove insufficient in reducing the risk for selected reuse options; but, alternate on-site control measures and up-grading water reuse protocol may be effective.

Pathogenic parasites and enteroviruses in wastewater: support for a regulation on water reuse

2013 ◽  
Vol 67 (7) ◽  
pp. 1512-1518 ◽  
Author(s):  
Elayse M. Hachich ◽  
Ana T. Galvani ◽  
Jose A. Padula ◽  
Nancy C. Stoppe ◽  
Suzi C. Garcia ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Water Reuse ◽  
Wastewater Treatment Plants ◽  
Immunomagnetic Separation ◽  
World Health ◽  
Treated Wastewater ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Wastewater Samples ◽  
Health Organization

Brazilian regulations for nonpotable reuse are being established using World Health Organization guidelines, however, they should be developed based on local monitoring studies. This study intended to analyze enteroviruses, protozoa and viable Ascaris sp. eggs in raw (24) and treated (24) effluents from four Wastewater Treatment Plants of São Paulo State, Brazil. The protozoa were detected with the US Environmental Protection Agency (USEPA) Method 1623 in the treated effluents and by centrifugation/Immunomagnetic Separation in the raw influent samples. Viable Ascaris sp. eggs were analyzed according to a modified USEPA method. Enteroviruses were quantified by using human rhabdomyosarcoma cells after adequate concentration procedures. All wastewater influents were positive for Giardia sp. whereas Cryptosporidium sp. was detected in 58.3% of the samples. Giardia sp. and Cryptosporidium sp. were present in 79.2 and 25.0% respectively, of the treated wastewater samples. Viable Ascaris sp. eggs were detected in 50.0 and 12.5% of influent and treated wastewater samples. Enteroviruses were isolated in the 24 raw influent samples and in 46% of the treated samples. Taking into account the densities of Giardia sp. in some treated wastewaters intended to be used as reclaimed water, Quantitative Microbial Risk Assessment studies should be conducted to establish pathogen quantitative criteria for a future Brazilian regulation for water reuse.

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