scholarly journals Assessing protozoan risks for surface drinking water supplies in Nova Scotia, Canada

2015 ◽  
Vol 14 (1) ◽  
pp. 155-166 ◽  
Author(s):  
Wendy Krkosek ◽  
Victoria Reed ◽  
Graham A. Gagnon
Keyword(s):  
Drinking Water ◽  
Nova Scotia ◽  
Surface Water ◽  
Quality Analysis ◽  
Water Supplies ◽  
Log Reduction ◽  
Disability Adjusted Life ◽  
Life Years ◽  
Cryptosporidium Oocysts ◽  
Giardia Cysts

Protozoa, such as Cryptosporidium parvum and Giardia lamblia, pose a human health risk when present in drinking water. To minimize health risks, the Nova Scotia Treatment Standards for surface water and groundwater under the direct influence of surface water require a 3-log reduction for Giardia cysts and Cryptosporidium oocysts. This study determined the protozoan risk of municipal surface source waters in Nova Scotia, through the use of a pre-screening risk analysis of water supplies, followed by subsequent water quality analysis of the seven highest risk supplies. The water supplies were monitored monthly for 1 year to obtain baseline data that could be used for a quantitative microbial risk assessment (QMRA). The QMRA model outcomes were compared to the Health Canada health target of 10−6 disability-adjusted life years/person/year. QMRA modeling shows that the treatment facilities meet the required log reductions and disability-adjusted life year target standards under current conditions. Furthermore, based on the results of this work, Nova Scotia should maintain the current 3-log reduction standard for Giardia cysts and Cryptosporidium oocysts. The results of this study show that a pre-screening step can help to inform water sources that are particularly vulnerable to protozoan contamination, which can lead to more focused, cost-effective sampling, and monitoring programs.

Comparison of three methods to concentrate Giardia cysts and Cryptosporidium oocysts from surface and drinking waters

2010 ◽  
Vol 62 (1) ◽  
pp. 196-201 ◽  
Author(s):  
Helmi Karim ◽  
Skraber Sylvain ◽  
Leblanc Laurence ◽  
Hoffmann Lucien ◽  
Cauchie Henry-Michel
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Type ◽  
Standard Protocol ◽  
Recovery Rates ◽  
Drinking Waters ◽  
Cryptosporidium Oocysts ◽  
Giardia Cysts

In this study, three methods commercialized by Pall (Envirochek HV), Idexx (FiltaMax) and Whatman (Cryptest) to concentrate Giardia cysts and Cryptosporidium oocysts from surface and drinking waters were compared according to the EPA standard protocol. Twenty litres of surface and 100 litres of drinking waters were inoculated with 103 (oo)cysts before being concentrated by filtration. Our results show that recovery rates of Giardia cysts from surface water was significantly higher using FiltaMax (91 ± 12%) than Cryptest (57 ± 9%) or Envirochek HV (60 ± 4%) while recovery from drinking water was equivalent using FiltaMax (84 ± 7%) or Cryptest (78 ± 7%) but lower using Envirochek HV (34 ± 29%). Recovery of Cryptosporidium oocysts from surface water was significantly higher using Envirochek HV (65 ± 5%) than using FiltaMax (45 ± 7%) or Cryptest (50 ± 7%) while recovery rates from drinking water was equivalent using either FiltaMax (48 ± 8%), Cryptest (57 ± 4%) or Envirochek HV (64 ± 22%). Finally, regardless of the water type, all methods tested allowed recovery rates superior to 24% complying with the EPA standard protocol. Timing, material and practicability associated with each method are discussed.

scholarly journals First investigations into the prevalence of Cryptosporidium and Giardia spp. in Hungarian drinking water

2007 ◽  
Vol 5 (4) ◽  
pp. 573-584 ◽  
Author(s):  
J. Plutzer ◽  
M. H. Takó ◽  
K. Márialigeti ◽  
A. Törökné ◽  
P. Karanis
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Raw Water ◽  
Forest Environment ◽  
Water Supplies ◽  
Purification Method ◽  
Cryptosporidium Oocysts ◽  
River Danube ◽  
Drinking Water Samples ◽  
Giardia Cysts

Safe drinking water is a top priority in preventing disease outbreaks and is of general concern to everyone. This study examines the occurrence of Cryptosporidium and Giardia in Hungarian drinking water supplies for the first time. A total of 76 raw and drinking water samples were examined using the U.S. EPA Method 1623. From these 15 of 34 (48.4%) raw water samples tested positive for Giardia and 7 (26.6%) for Cryptosporidium. Twelve of 45 (26.7%) drinking water samples were positive for Giardia and 6 (13.3%) for Cryptosporidium. Overall, Giardia cysts and/or Cryptosporidium oocysts were detected in 48% of the raw water samples and 35% of the drinking water samples. The highest levels in drinking water were found to be 3 oocysts/100 litres of Cryptosporidium and 63.6 cysts/100 litres for Giardia, enough to cause giardiasis. The highest levels in raw water were 1,030 cysts/100 litres for Giardia and 50 oocysts/100 litres for Cryptosporidium and higher oocyst densities were associated with source water receiving effluents from sewage treatment plants or originating from a forest environment. In addition to this monitoring, riverbank filtrated water and raw water from the River Danube in Budapest were monitored in order to ascertain protozoan removal efficiency of riverbank filtration (RBF). A total of 157 samples, including 87 samples from the River Danube and 70 samples post RBF, were examined. Cryptosporidium and Giardia were detected regularly in the river water but never in riverbank filtered water suggesting the effectiveness of RBF as a purification method. The occurrence of Cryptosporidium oocysts and Giardia cysts in the investigated water supplies may require the water utilities and water authorities in Hungary to apply additional monitoring and treatment and/or watershed controls.

scholarly journals Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain

2007 ◽  
Vol 102 (3) ◽  
pp. 882-882
Author(s):  
D. Carmena ◽  
X. Aguinagalde ◽  
C. Zigorraga ◽  
J. Crespo ◽  
J. Ocio
Keyword(s):  
Drinking Water ◽  
Northern Spain ◽  
Water Supplies ◽  
Cryptosporidium Oocysts ◽  
Giardia Cysts

scholarly journals Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain

2007 ◽  
Vol 102 (3) ◽  
pp. 619-629 ◽  
Author(s):  
D. Carmena ◽  
X. Aguinagalde ◽  
C. Zigorraga ◽  
J.C. Fernández-Crespo ◽  
J.A. Ocio
Keyword(s):  
Drinking Water ◽  
Northern Spain ◽  
Water Supplies ◽  
Cryptosporidium Oocysts ◽  
Giardia Cysts

scholarly journals A water contamination incident in Oslo, Norway during October 2007; a basis for discussion of boil-water notices and the potential for post-treatment contamination of drinking water supplies

2008 ◽  
Vol 7 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Lucy Robertson ◽  
Bjørn Gjerde ◽  
Elisabeth Furuseth Hansen ◽  
Teresa Stachurska-Hagen
Keyword(s):  
Drinking Water ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Post Treatment ◽  
Capital City ◽  
Water Supplies ◽  
Cryptosporidium Oocysts ◽  
Treatment Contamination ◽  
Giardia Cysts

Over a 5 day period in October 2007 a boil-water notice was served on the majority of Oslo, capital city of Norway, as a result of a combination of bacteriological findings (coliforms, intestinal enterococci, and E. coli), and very low numbers of Cryptosporidium oocysts and Giardia cysts in 10 L water samples taken from the water distribution network. The water source had been regularly monitored for these parasites and generally found to be negative. Over 460,000 residents were affected by the boil-water notice, as were many thousands of businesses. Despite an extensive outbreak of waterborne giardiasis in Bergen, Norway during 2004/2005, occurrence of parasites in Norwegian drinking water supplies has apparently continued to be considered to be of minimal relevance by Norwegian health authorities. Here we describe the background and occurrence of the episode in Oslo, including the species of Cryptosporidium detected, and use this event, in conjunction with incidents from other countries, as a basis to discuss the following issues: 1) under which circumstances should the occurrence of Cryptosporidium oocysts and Giardia cysts in water supplies trigger the issue of a boil-water notice, and 2) the possibilities and probabilities of post-treatment contamination events in the water distribution network.

scholarly journals Balancing the risks and benefits of drinking water disinfection: disability adjusted life-years on the scale.

2000 ◽  
Vol 108 (4) ◽  
pp. 315-321 ◽  
Author(s):  
A H Havelaar ◽  
A E De Hollander ◽  
P F Teunis ◽  
E G Evers ◽  
H J Van Kranen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Disinfection ◽  
Disability Adjusted Life Years ◽  
Risks And Benefits ◽  
Disability Adjusted Life ◽  
Life Years ◽  
Drinking Water Disinfection

scholarly journals Adoption of a microbial health-based target for Australian drinking water regulation

2015 ◽  
Vol 13 (3) ◽  
pp. 662-670 ◽  
Author(s):  
Joanne O'Toole ◽  
Martha Sinclair ◽  
Katherine Gibney ◽  
Karin Leder
Keyword(s):  
Drinking Water ◽  
Water Quality Management ◽  
Bacterial Pathogen ◽  
Diarrhoeal Disease ◽  
Water Regulation ◽  
Disability Adjusted Life Years ◽  
Common Goal ◽  
Disability Adjusted Life ◽  
Life Years ◽  
Target Values

The health-based targets of 1 in 10,000 for infection and 10−6 disability adjusted life years (DALYs) per person per year are increasingly being considered, or have already been adopted, to define microbial safety targets for water. The aim of this paper is to convey information about how these two targets compare by converting each of the target values to a common metric. The metric chosen for viral (rotavirus and norovirus) and protozoan (Cryptosporidium) reference pathogens is the estimated maximum number of annual drinking water-associated cases of acute diarrhoeal disease tolerated. For the reference bacterial pathogen Campylobacter, sequelae to acute diarrhoeal illness have also been considered in estimating the tolerable number of cases for the DALY target. Also investigated is whether non-compliance with targets would be detected as a waterborne disease outbreak by the health surveillance system in an extreme hypothetical situation whereby all tolerable cases per annum occurred as a single event. The paper highlights that verification of compliance with targets cannot be demonstrated by the absence of reported drinking water-associated outbreaks alone and concludes that introduction of a quantitative health-based outcome for drinking water in Australia would help improve water quality management by providing a common goal directly linked to health outcomes.

scholarly journals Groundwater Quality Analysis of Domestic Water Sources from Hand Dug Wells In Gwallameji, Bauchi State

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Olufunmilayo I Ndububa ◽  
Abubakar U Ardo
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Health Workers ◽  
Water Sources ◽  
World Health ◽  
Quality Analysis ◽  
Domestic Water ◽  
Water Supplies ◽  
Environmental Interventions ◽  
Dug Wells

Lack of access to safe and adequate domestic water supplies contributes to poverty levels through the economic costs of poor health and the high proportion of household expenditure on safe water supplies. Gwallameji, a community on the outskirts of Bauchi town has no access to municipal water supply from Bauchi town, groundwater water, mainly hand dug wells are used as domestic water sources. The quality of water available from these hand dug wells  in the community were determined by the physical, chemical and biological parameters of the water samples collected from domestic water points in the community. The results from the water samples were compared with World Health Organization (WHO) Standards for Drinking Water. High levels of Nitrate and Chromium above recommended levels from the standard were found in all water samples. Concentrations of Calcium highest value of 213mg/l and Magnesium a highest value of 22.02 mg/l at levels higher than recommended levels for drinking water were also obtained in all samples. It was recommended that restrictions on farming activities with use of fertilizers and location of latrines around domestic water sources should be enforced. Hand dug wells should be at a distance of at least 30m from soak away pits and pit latrines. Well lining and cover should be provided for all hand dug wells to reduce contamination of water from these sources. Increased and continued environmental interventions through public health education by community based health workers, awareness and sensitization campaigns should be carried out for improved household and community sanitation in the area.

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