scholarly journals The effect of cyanuric acid on the disinfection rate of Cryptosporidium parvum in 20-ppm free chlorine

2008 ◽  
Vol 7 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Joan M. Shields ◽  
Michael J. Arrowood ◽  
Vincent R. Hill ◽  
Michael J. Beach
Keyword(s):  
Public Health ◽  
Cryptosporidium Parvum ◽  
Cyanuric Acid ◽  
Free Chlorine ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Log10 Reduction ◽  
Chlorine Residual ◽  
Cryptosporidium Oocysts ◽  
Reduction Current

Cyanuric acid is used to stabilize free chlorine to reduce photodegradation in outdoor swimming pools. While there have been numerous studies examining its effect on the disinfection rates of bacteria and viruses, it is not known whether cyanuric acid can significantly impact the effectiveness of hyperchlorination for inactivating Cryptosporidium oocysts present in fecally-contaminated swimming pools. This study examined the effect of cyanuric acid on the disinfection rate of Cryptosporidium parvum under swimming pool hyperchlorination conditions (20 mg/ml free chlorine). When 50 mg/L cyanuric acid was present there was a 0.70-log10 reduction in oocyst viability after 10 hours as compared to a 3.7-log10 reduction without cyanuric acid. Aids to remediation, such as decreasing the pH to enhance the germicidal efficiency of the free chlorine and doubling the amount of free chlorine residual, were still unable to achieve a 3-log10 reduction. Current public health recommendations for hyperchlorination and pool remediation are insufficient for pools using cyanurate-stabilized chlorine to achieve a three log inactivation of the parasite.

Persistence of Pseudomonas aeruginosa in chlorinated swimming pools

1980 ◽  
Vol 26 (3) ◽  
pp. 350-355 ◽  
Author(s):  
Patricia L. Seyfried ◽  
David J. Fraser
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Free Chlorine ◽  
Swimming Pool ◽  
Phage Typing ◽  
Swimming Pools ◽  
Pool Water ◽  
Chlorine Residual ◽  
Slime Production ◽  
Water Ph

Various types of swimming pools were investigated for the quantitative isolation of Pseudomonas aeruginosa. Incidence of the organism increased when the free chlorine residual dropped below 0.4 mg/L in pool water which had a pH of 6.9–7.8. As the water pH became more alkaline the efficiency of disinfection decreased. Excessive slime production caused certain strains to become more resistant to chlorine treatment. Immunotyping and phage typing, used to study the dynamics of P. aeruginosa populations in swimming pool waters, demonstrated that high densities of the organism consisted mainly of single predominant strains.

scholarly journals Removals of cryptosporidium parvum oocysts and cryptosporidium-sized polystyrene microspheres from swimming pool water by diatomaceous earth filtration and perlite-sand filtration

2017 ◽  
Vol 15 (3) ◽  
pp. 374-384 ◽  
Author(s):  
Ping Lu ◽  
James E. Amburgey ◽  
Vincent R. Hill ◽  
Jennifer L. Murphy ◽  
Chandra L. Schneeberger ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Filtration Rate ◽  
Diatomaceous Earth ◽  
Pilot Scale ◽  
Full Scale ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Sand Filtration ◽  
Sand Filter ◽  
Cryptosporidium Parvum Oocysts

Removal of Cryptosporidium-sized microspheres and Cryptosporidium parvum oocysts from swimming pools was investigated using diatomaceous earth (DE) precoat filtration and perlite-sand filtration. In pilot-scale experiments, microsphere removals of up to 2 log were obtained with 0.7 kg·DE/m2 at a filtration rate of 5 m/h. A slightly higher microsphere removal (2.3 log) was obtained for these DE-precoated filters when the filtration rate was 3.6 m/h. Additionally, pilot-scale perlite-sand filters achieved greater than 2 log removal when at least 0.37 kg/m2 of perlite was used compared to 0.1–0.4 log removal without perlite both at a surface loading rate of 37 m/h. Full-scale testing achieved 2.7 log of microspheres and oocysts removal when 0.7 kg·DE/m2 was used at 3.6 m/h. Removals were significantly decreased by a 15-minute interruption of the flow (without any mechanical agitation) to the DE filter in pilot-scale studies, which was not observed in full-scale filters. Microsphere removals were 2.7 log by perlite-sand filtration in a full-scale swimming pool filter operated at 34 m/h with 0.5 kg/m2 of perlite. The results demonstrate that either a DE precoat filter or a perlite-sand filter can improve the efficiency of removal of microspheres and oocysts from swimming pools over a standard sand filter under the conditions studied.

scholarly journals A full-scale study of Cryptosporidium parvum oocyst and Cryptosporidium-sized microsphere removals from swimming pools via sand filtration

2015 ◽  
Vol 52 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Ping Lu ◽  
James E. Amburgey ◽  
Vincent R. Hill ◽  
Jennifer L. Murphy ◽  
Chandra Schneeberger ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Initial Dosage ◽  
Pilot Scale ◽  
Full Scale ◽  
Swimming Pool ◽  
High Rate ◽  
Swimming Pools ◽  
Sand Filtration ◽  
Continuous Feeding ◽  
Cryptosporidium Parvum Oocysts

Removal of Cryptosporidium parvum oocysts and Cryptosporidium-sized microspheres was evaluated in full-scale swimming pools via high-rate sand filtration (31–34 m/h) with coagulation. Results showed that at least 90% of C. parvum oocysts and microspheres were removed by filtration with an initial dosage of coagulant B (1.56 mg/L), D (1.9 mg/L or 305 g/m2), or F (1.56 mg/L) from each swimming pool. Filtration with an initial dosage of coagulant E (0.1 mg·Al/L) achieved 82% C. parvum oocyst removal and 97% microsphere removal. Coagulants B and F had a tendency to overdose over time with continuous feeding (based on corresponding pilot-scale experiments) and did not consistently achieve removals greater than 90% in the full-scale trials. As high as 99% of C. parvum oocysts and 98% of microspheres were removed with a continuous dosage of coagulant D. Up to 98% (1.7 log) of C. parvum oocysts and 93% (1.1 log) of microspheres were removed by continuous dosing of coagulant E at 27 m/h. Consistent oocyst and microsphere removal by aluminum-based coagulants (D and E) was achieved under the tested swimming pool conditions.

scholarly journals Cryptosporidium and Giardia in swimming pools in the Netherlands

2004 ◽  
Vol 2 (3) ◽  
pp. 191-200 ◽  
Author(s):  
F. M. Schets ◽  
G. B. Engels ◽  
E. G. Evers
Keyword(s):  
Risk Assessment ◽  
The Netherlands ◽  
Public Information ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Risk Of Infection ◽  
Cryptosporidium Oocysts ◽  
Estimated Risk ◽  
Filter Backwash Water ◽  
Giardia Cysts

The occurrence of Cryptosporidium and Giardia in indoor swimming pools in the Netherlands was studied at five locations. The backwash water from seven pool filters was analysed for the presence of Cryptosporidium oocysts and Giardia cysts for a period of 1 year. Of the 153 samples of filter backwash water analysed, 18 (11.8%) were found positive for either Cryptosporidium (4.6%), Giardia (5.9%) or both (1.3%). Oocysts and cysts were also detected in the water of one toddler pool and one learner pool. Although most of the (oo)cysts in the filter backwash water were dead, viable and potentially infectious oocysts were detected in the learner pool. On the basis of numbers of potentially infectious (oo)cysts detected in the learner pool, and assuming one visit to an infected pool per year, risk assessment indicated an estimated risk of infection with Cryptosporidium that exceeded the generally accepted risk of one infection per 10,000 persons per year. Guidelines for pool operators on how to manage faecal accidents and public information on the importance of hygiene in swimming pool complexes are recommended tools in controlling the risk of infection.

scholarly journals Inactivation of Cryptosporidium parvum under chlorinated recreational water conditions

2008 ◽  
Vol 6 (4) ◽  
pp. 513-520 ◽  
Author(s):  
Joan M. Shields ◽  
Vincent R. Hill ◽  
Michael J. Arrowood ◽  
Michael J. Beach
Keyword(s):  
Public Health ◽  
Tissue Culture ◽  
Sodium Hypochlorite ◽  
Cryptosporidium Parvum ◽  
Protozoan Parasite ◽  
Recreational Water ◽  
Log Reduction ◽  
Cryptosporidium Oocysts ◽  
Water Conditions ◽  
Control And Prevention

Cryptosporidium is a chlorine-resistant protozoan parasite and the etiological agent in many disinfected recreational water outbreaks. While previous studies have reported disinfection Ct values for Cryptosporidium parvum using sodium hypochlorite, these studies have employed conditions and procedures which are not ideal for establishing public health remediation recommendations for chlorinated recreational water venues. In the present study, free chlorine Ct values were measured at pH 7.5 using young oocysts (<1 month old) and tissue culture to determine oocyst viability. Two different oocyst isolates were used: one originating from Iowa and one from Maine (USA). This study determined that the Ct values for a 3-log reduction in oocyst viability were 10,400 (Iowa) and 15,300 (Maine) at pH 7.5. These Ct values are higher than the Centers for Disease Control and Prevention (USA) currently recommends (Ct=9,600) for achieving a 3.0-log inactivation of Cryptosporidium oocysts during remediation of recreational water venues following fecal diarrhea accidents.

scholarly journals Swimming Pool-Related Outbreak of a Rare gp60 Subtype of Cryptosporidium hominis, England, October 2016

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3152
Author(s):  
Helen Bagnall ◽  
Rachel M. Chalmers ◽  
Michelle Henderson ◽  
Stewart Sorrell ◽  
Guy Robinson ◽  
...  
Keyword(s):  
Public Health ◽  
Water Treatment ◽  
Swimming Pool ◽  
Control Measures ◽  
Reference Laboratory ◽  
Swimming Pools ◽  
Cryptosporidium Hominis ◽  
Secondary Transmission ◽  
Transmission Pathways ◽  
Gp60 Subtypes

In October 2016, Public Health England was initially notified of four cases of cryptosporidiosis among users of two swimming pools. We investigated to identify further cases, the outbreak source, and ensure the implementation of appropriate control measures. Probable primary cases had diarrhoea and reported swimming in the pools 1–12 days prior to illness; confirmed cases were verified by the reference laboratory. Secondary cases had contact with primary cases 1–12 days prior to illness. We identified twenty-two cases: eleven were primary (eight confirmed) and eleven were secondary (five confirmed). Four cases were infected with C. parvum (different gp60 subtypes); all were primary and swam at two pools. Seven primary and secondary cases were infected with C. hominis gp60 subtype IdA16, and all were associated one pool. Failings in pool water treatment and management were identified that likely contributed to the load on the filters and their efficiency. Our investigation identified a complex outbreak, with secondary transmission, involving exposures to two swimming pools. C. hominis IdA16 is rare; it has been isolated from only three previous UK cases. We hypothesize that C. hominis cases arose from a common exposure, and the C. parvum cases were likely sporadic. This investigation highlights the value of integrating epidemiology and microbiology to investigate clusters of Cryptosporidium cases, defining the extent of the outbreak and the likely transmission pathways.

scholarly journals Staphylococci in swimming pool water

1974 ◽  
Vol 73 (2) ◽  
pp. 213-220 ◽  
Author(s):  
P. B. Crone ◽  
G. H. Tee
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
Free Chlorine ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Significant Relation ◽  
Pool Water ◽  
Swimming Pool Water ◽  
Filtration Technique ◽  
Different Parts

SUMMARYDuring a period of five years 1192 water samples from swimming pools were examined for staphylococci and 338 for coliform organisms only. Eighty-nine different pools were sampled.Numbers of staphylococci, estimated by the membrane filtration technique did not bear any significant relation to either bathing load or concentration of free chlorine.Wide variation in the staphylococcal count was observed when different parts of a pool were sampled on the same occasion.The only practicable standard for pool samples in relation to staphylococci would appear to be that these organisms should be absent from 100 ml. water when the pool has been out of use during at least ten hours before sampling if filtration and chlorination are adequate.

scholarly journals Application of Water Quality Index in Assessment of Swimming Pools Water Quality in Hotels in Emerging Africa Littoral Metropolis of Warri, Delta State, Nigeria

2020 ◽  
Vol 13 (2) ◽  
pp. 91-107
Author(s):  
Obot Akpan IBANGA ◽  
◽  
Stephanie Emuobonuvie OHWO ◽  
Goodluck Mamuro OMONIGHO ◽  
◽  
...  
Keyword(s):  
Public Health ◽  
Water Quality ◽  
Water Quality Index ◽  
Quality Index ◽  
Heterotrophic Bacteria ◽  
Swimming Pool ◽  
Sub Saharan Africa ◽  
Public Health Issue ◽  
Residual Chlorine ◽  
Swimming Pools

Swimming pools in guest houses and hotels in many cities in sub-Saharan Africa have been labelled ‘beautiful irritation’ or hazard zones for public health issues due to the unwholesomeness of water. Pollution in swimming pools is therefore, not uncommon and it is a serious public health issue both at the global, regional, national and local levels. This study focused on application of water quality index in assessment of swimming pools water quality in hotels in emerging Africa littoral metropolis of Warri, Delta State, Nigeria. It used stratified random sampling technique to select five hotels with swimming pool in Warri for assessment. Temperature, pH, turbidity, free (residual) chlorine, total heterotrophic bacteria, total heterotrophic fungi, Escherichia coli and Staphylococcus aureus tested in the laboratory using scientific method of sampling. Water quality index (WQI) was computed using Weighted Arithmetic Water Quality Index (WAWQI) to evaluate in general, the quality of water in each of the five sampled swimming pools. A five-point scale (excellent, good, poor, very poor and unsuitable) was used to rank each swimming pool quality. Result showed that Wellington Hotel had the value of 2.52 and considered excellent in terms of water quality index value. Also, Brook View and Best Western Plus Hotels were classified as good water based on water quality index values of 36.9 and 39.9 respectively while BB swimming pool was ranked poor due to water quality index of 51.4. In contrast, Oasis Place Hotel swimming pool was declared unsuitable for recreational purpose due to a water quality index of 102.1. The study recommended routine and periodic surveillance of swimming pools and other recreational water sources to guarantee optimum health and wellbeing of users.

Microbiological Evaluation of Copper : Silver Disinfection Units for Use in Swimming Pools

1989 ◽  
Vol 21 (3) ◽  
pp. 267-270 ◽  
Author(s):  
Lee K. Landeen ◽  
Moyasar T. Yahya ◽  
Susan M. Kutz ◽  
Charles P. Gerba
Keyword(s):  
Pathogenic Bacteria ◽  
Silver Ions ◽  
Free Chlorine ◽  
Swimming Pools ◽  
Log10 Reduction ◽  
Bactericidal Effects ◽  
Pure Cultures ◽  
Bactericidal Activities ◽  
Low Levels ◽  
Hot Tubs

The bactericidal effects of electrolytically generated copper:silver ions on pathogenic bacteria of concern in swimming pools, hot tubs and cooling towers were evaluated in disinfection experiments. Copper:silver ion concentrations generated in well water were 400:40 µg/L, respectively. Pure cultures of Legionellapneumophila, Staphylococcusaureus, Pseudomonasaeruginosa, Escherichiacoli, and Streptococcusfaecalis, were individually tested in water containing copper:silver ions alone, copper:silver ions with free chlorine, and free chlorine alone. Greater numbers of organisms were killed after exposure to copper: silver ions with 0.2 mg/L free chlorine than in either the copper:silver ions or free chlorine alone. L. pneumophlla showed greater than a 5 log10 reduction in numbers after 7 minutes exposure to copper:silver ions with 0.2 mg/L free chlorine. In comparison, less than a 2 log10 decrease was obtained after exposure to free chlorine alone. E.coli numbers decreased over 4 log10 after 1 minute exposure to copper:silver ions with 0.2 mg/L free chlorine and less than a 3 log10 decrease after exposure to free chlorine alone. The majority of the other organisms tested showed the same effect. Electrolytically generated copper:silver ions with low levels of free chlorine appear to have greater bactericidal activities than either disinfectant alone.

Review of swimming-associated cryptosporidiosis and Cryptosporidium oocysts removals from swimming pools

2013 ◽  
Vol 48 (1) ◽  
pp. 30-39 ◽  
Author(s):  
Ping Lu ◽  
Tao Yuan ◽  
Qiyan Feng ◽  
Aiqin Xu ◽  
Jiayuan Li
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Removal Rate ◽  
Drinking Water Treatment ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Sand Filters ◽  
Pool Water ◽  
Cryptosporidium Oocysts ◽  
Swimming Pool Water

In this paper, outbreaks of cryptosporidiosis in swimming pools in the last 20 years are summarized. Cryptosporidium oocysts are very resistant to many disinfectants, including chlorine, one of the most widely-used disinfectants in swimming pools. Ozone or UV is shown to inactivate Cryptosporidium, while not effective to newly introduced Cryptosporidium and bacteria because of no residual ozone or UV in the treated swimming pool water. Additionally, swimming pool sand filters or cartridge filters are not able to effectively remove Cryptosporidium (removal rate <50%). Above 99% Cryptosporidium removals are achieved in drinking water treatment, but swimming pool water treatment is different from drinking water treatment: no coagulation is performed prior to filtration in most US swimming pools, filtration rate is four to five times higher for swimming pool water treatment compared with drinking water treatment, and the input compounds and microorganisms from bathers continuously recirculate in the swimming pool. Moreover, up-to-date Cryptosporidium or Cryptosporidium surrogate removals from swimming pools are discussed, and alternative swimming pool treatment techniques are reviewed.

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