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 Legionella pneumophila as a Health Hazard to Miners: A Pilot Study of Water Quality and QMRA

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1528
Author(s):  
Valerie Madera-García ◽  
Alexis L. Mraz ◽  
Nicolás López-Gálvez ◽  
Mark H. Weir ◽  
James Werner ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Health Hazard ◽  
Ventilation System ◽  
Sprinkler System ◽  
Dust Control ◽  
Quantitative Microbial Risk Assessment ◽  
Mining Operations ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Life Years

Legionella pneumophila (L. pneumophila), the causative agent of legionellosis, is an aquatic bacterium that grows in warm water. Humans are only presented with a health risk when aerosolized water containing L. pneumophila is inhaled. In mining operations, aerosolized water is used as dust control and as part of the drilling operations, a currently ignored exposure route. This study characterized L. pneumophila concentrations in the mine’s non-potable water and the relationship between L. pneumophila and chlorine concentrations. These concentrations informed a quantitative microbial risk assessment (QMRA) model to estimate the infection risk to miners exposed to aerosolized water containing L. pneumophila. Fourteen water samples were collected from seven locations at a mine and analyzed for temperature, pH, chlorine, and L. pneumophila serogroup. Most samples (93%) tested positive for L. pneumophila cells. The faucet from the sprinkler system on the adit level (entrance to the underground mine levels) showed the highest concentration of L. pneumophila (8.35 × 104 MPN/L). Disability adjusted life years (DALYs) were estimated in the QMRA model and showed that the risk for all miners was significantly lower (p < 0.0001) with the ventilation system on than when the system was off. Our study showed that the use of a ventilation system at the adit level of the mine reduced the risk of infection with aerosolized L. pneumophila.

scholarly journals Quantitative microbial risk assessment (QMRA) for water re-use via aquifers

2009 ◽  
Vol 30 (1) ◽  
pp. 20
Author(s):  
Declan Page ◽  
Simon Toze
Keyword(s):  
Risk Assessment ◽  
Reclaimed Water ◽  
Managed Aquifer Recharge ◽  
Urban Water ◽  
Quantitative Microbial Risk Assessment ◽  
Aquifer Recharge ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Wide Range ◽  
Potential Risks

Worldwide, there is an increasing interest in the recharge of aquifers as a method for augmenting urban water supplies. Managed aquifer recharge (MAR) can utilise a variety of non-traditional source waters including urban stormwater and reclaimed water from sewage effluent. However, these alternate water sources may contain a wide range of pathogenic hazards that pose risks to human health. Hence the safe use of recycling water via aquifers requires potential risks to be reduced to acceptable levels. This article outlines the approach recommended by the draft Australian Guidelines for Water Recycling (AGWR) (Phase 2C Managed Aquifer Recharge) to quantify the aquifer treatment using a quantitative microbial risk assessment (QMRA) approach.

Practical applications of quantitative microbial risk assessment (QMRA) for water safety plans

2010 ◽  
Vol 61 (6) ◽  
pp. 1561-1568 ◽  
Author(s):  
P. W. M. H. Smeets ◽  
L. C. Rietveld ◽  
J. C. van Dijk ◽  
G. J. Medema
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Quantitative Microbial Risk Assessment ◽  
Indicator Organisms ◽  
Water Safety ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Log Reduction ◽  
Yearly Average ◽  
Water Safety Plans

The absence of indicator organisms in drinking water does not provide sufficient guarantee for microbial safety. Therefore the water utilities are implementing water safety plans (WSP) to safeguard drinking water quality. Quantitative microbial risk assessment (QMRA) can be used to provide objective quantitative input for the WSP. This study presents several applications of treatment modelling in QMRA to answer the risk managers questions raised in the WSP. QMRA can estimate how safe the water is, how much the safety varies and how certain the estimate of safety is. This can be used in the WSP system assessment to determine whether treatment is meeting health-based targets with the required level of certainty. Quantitative data analysis showed that short events of only 8 hours per year can dominate the yearly average health risk for the consumer. QMRA also helps the design of physical and microbial monitoring. The study showed that the required monitoring frequency increases with increasing treatment efficacy. Daily monitoring can be sufficient to verify a treatment process achieving 2 log reduction of pathogens, but a process achieving 4 log reduction needs to be monitored every 15 minutes. Similarly, QMRA helps to prepare adequate corrective actions by determining the acceptable ‘down time’ of a process. For example, for a process achieving 2.5 log reduction a down time of maximum 6 hours per year is acceptable. These applications illustrate how QMRA can contribute to efficient and effective management of microbial drinking water safety.

scholarly journals Quantitative microbial risk assessment to estimate health risks attributable to water supply: Can the technique be applied in developing countries with limited data?

2006 ◽  
Vol 4 (1) ◽  
pp. 49-65 ◽  
Author(s):  
Guy Howard ◽  
Steve Pedley ◽  
Sarah Tibatemwa
Keyword(s):  
Risk Assessment ◽  
Developing Countries ◽  
Drinking Water ◽  
Water Supply ◽  
Disease Burden ◽  
Quantitative Microbial Risk Assessment ◽  
Limited Data ◽  
Water Supplies ◽  
Microbial Risk Assessment ◽  
Microbial Risk

In the 3rd edition of its Guidelines for Drinking-Water Quality (2004) (GDWQ) the World Health Organization (WHO) promotes the use of risk assessment coupled with risk management for the control of water safety in drinking water supplies. Quantitative microbial risk assessment (QMRA) provides a tool for estimating the disease-burden from pathogenic microorganisms in water using information about the distribution and occurrence of the pathogen or an appropriate surrogate. This information may then be used to inform decisions about appropriate management of the water supply system. Although QMRA has been used to estimate disease burden from water supplies in developed countries, the method has not been evaluated in developing countries where relevant data may be scarce. In this paper, we describe a simplified risk assessment procedure to calculate the disease burden from three reference pathogens – pathogenic Escherichia coli, Cryptosporidium parvum and rotavirus – in water supplies in Kampala, Uganda. The study shows how QMRA can be used in countries with limited data, and that the outcome can provide valuable information for the management of water supplies.

Enteric virus presence in green vegetables and associated irrigation waters in a rural area from Argentina. A quantitative microbial risk assessment

LWT ◽  
2021 ◽  
Vol 144 ◽  
pp. 111201 ◽  
Author(s):  
Prez Verónica Emilse ◽  
Victoria Matías ◽  
Martínez Laura Cecilia ◽  
Giordano Miguel Oscar ◽  
Masachessi Gisela ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Rural Area ◽  
Enteric Virus ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Irrigation Waters
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