Environmental Public Health Journal 2014 | BCIT Institutional Repository

Environmental Public Health Journal 2014

Determining the time required to disinfect a sponge contaminated with Escherichia coli, using a commercial microwave
Background: Disinfection and sanitation are important in areas where food is involved. Thorough cleaning is a necessity to prevent growth of harmful pathogens that could affect human health. Sponges used for cleaning can serve as a vehicle for cross-contamination on food preparation surfaces. There are various methods that could be used to disinfect contaminated sponges. The usage of a microwave is one suggested method. Objective: The purpose of this study was to determine if the Scotch-BriteTM Brand, cellulose sponges contaminated with E.coli (105 cfu/ml) could be disinfected using a microwave set at three timings (30 seconds, 1 minute, and 2 minutes). Methods: The Hygiena MicroSnap was used to detect the presence (or absence) of E.coli in sponges after microwave heating. The relative light units (RLU) indicated in the monitor determined whether there were any remaining coliforms in the sample after microwaving. Results: Statistical analysis was conducted using Microsoft Excel and NCSS. After heating sponges for 30 seconds, 100% of the samples detected no E.coli. After heating for 1 minute, 70% of the samples had no E.coli present. After heating for 2 minutes, 100% of the samples detected no E.coli. The p-value of 0.03567 concludes that the results were statistically significant at the 5% significance level. Discussion: The results of this study indicate that sponges contaminated with E.coli can be disinfected using microwave heating. EHOs, food establishment operators, and the general public can use this knowledge to re-use their old sponges and avoid further cross-contamination. Conclusions: The results indicate that microwave time is associated with the presence or absence of E.coli in a sponge. However, E.coli was present in 3 samples microwaved at 1 minute. This suggests further studies are required to confirm the findings of this study. In addition, further studies are required to determine what specific time is sufficient to completely eliminate the E.coli in a contaminated sponge., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Peer reviewed, E.coli, sponge, disinfection, microwave, MicroSnap, cross-contamination, EHO
The effectiveness of ozone-chlorine treatment for reducing chloramine concentration compared to chlorine treatment in swimming pools and whirlpools
Objectives: Chloramines are by-products of chlorine disinfected swimming pools and are hazardous to people if chloramines evaporate into the air. There is evidence that chloramines cause upper respiratory tract and eye irritation. It was suspected that ozone treatment in addition to chlorine disinfection will reduce chloramine levels in the pool. The following study compared chloramine concentration in a strictly chlorine disinfected swimming pool and whirlpool (C.G. Brown) in Burnaby, BC with an ozone-chlorine disinfected swimming pool and whirlpool (Killarney) in Vancouver, BC. The study also compared each pool and whirlpool to the 1.0 mg/L combined chlorine concentration limit in the B.C. Pool Regulation. Methods: Chloramine concentrations were determined by using a Hach Pocket Colorimeter 2 Analysis System which used a DPD method of analysis. Chloramine was determined by subtracting total chlorine by the free chlorine. Thirty pool water samples were analyzed based on two samples per pool per day for fifteen days. A two sample t-test was used to compare the ozone-chlorine treated pools with the chlorine only treated pools using the Mann-Whitney U test. A z-test was used to compare all types of swimming pools and whirlpools to the 1.0 mg/L limit. Results: The chloramine concentration in both the ozone-chlorine disinfected swimming pool and whirlpool was not statistically significantly lower than in the chlorine disinfected swimming pool (p=0.263597) and whirlpool (p=0.523672). Both types of swimming pools were found to be statistically significantly greater than the 1.0 mg/L chloramine limit (p=0.000023 in the chlorine pool and p=0.00001 for the ozone-chlorine pool). Similarly, both types of whirlpools were determined to be statistically significantly greater than the 1.0 mg/L chloramine limit (p=0.000001 for the chlorine pool and p=0.000001 for the ozone-chlorine pool). Conclusion: It was determined that there was no difference between ozone chlorine treated pools and chlorine only treated pools. Environmental Health Officers can suggest other forms of secondary treatment instead of ozone since there is no significant difference compared to chlorine only treated pools in reducing chloramine concentrations. This information is also beneficial for pool operators because they can increase their flow rates for pools that use ozonation or strictly chlorination relative to what they were originally designed for., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, Chloramine, chlorine disinfection, Ozone-chlorine disinfection, swimming pools, Whirlpool
The efficacy of ATP removal on gym contact surfaces with disinfectant wipes.
Background: Gym equipment surfaces are known to harbor a range of contaminants due to the wide range of community use of the equipment. Certain gym equipment undergoes daily sanitation, however many other equipment surfaces do not. This study measures the levels of contamination on certain gym equipment surfaces at an educational institute gym facility and determines the contamination levels after disinfectant wipes are applied. Methods: The method to obtain the data was determined by the use of the Hygiena Systemsure II ATP analyzer in conjunction with Hygiena Ultrasnap ATP surface swabs. Gym equipment (barbells, dumbbells, machine handles, cable attachments) and other surfaces (benches, floor mats) were swabbed subsequently after a random gym patron had used the equipment to capture an accurate representation of the cleanliness of the surfaces. Disinfectant wipes were then applied to the same area before being swabbed again to determine contamination levels after disinfection. Results: The results demonstrated a statistically significant difference in the reduction of ATP levels with the use of disinfectant wipes with a p-value of 0.00001 at α=0.05. Alpha error was highly unlikely with a p-value being that low. Power was 99.9%, therefore there is a strong likelihood that we are correctly rejecting the null hypothesis. Conclusion: The study can conclude that disinfectant wipes do make a significant difference in surface cleanliness levels. Equipment that does not undergo routine cleaning such as the equipment used by the hands carry a much higher contamination rate than the body contact surfaces. Gym patrons should disinfect all body contact surfaces prior to use to reduce the risk of getting an infectious disease., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, Gym, Disinfection, Ultrasnap, Hygiene, ATP, RLU