Environmental Public Health Journal 2018 | BCIT Institutional Repository

Environmental Public Health Journal 2018

Bacterial growth in personal stainless steel water bottles
Background: There is a general understanding and knowledge among reusable personal water bottle users that there are hazards, such as bacterial growth, associated with poor water bottle hygiene practices. Currently, there is no information associated with outbreaks or cases of illness stemming from poor hygiene on personal water bottles. This may be due to lack of awareness that users have become ill from their own water bottle and have failed to report it. Results from previous studies on personal water bottles have indicated that there is a relationship between higher microbiological counts and the interval between cleaning times; the longer water bottles are left unclean, the higher the microbial count. Methods: 29 randomly sampled stainless steel personal water bottles were swabbed at the mouth piece and 1 brand new personal stainless steel bottle was used as a control. Personal water bottle users were provided with an in-person electronic survey at the time of sample collection. The swabs were plated following the 3M Aerobic Plate Count method and incubated for a total of 72 hours. Plates were counted after 24 hours and 72 hours. Results: There was no statistically significant difference between the aerobic bacterial levels (CFU) of personal stainless steel water bottles that were cleaned within one day and those cleaned within a month but more than one day based on the Independent Sample T-test. There was also no statistically significance difference between the aerobic bacterial levels (CFU) of bottles that were rinsed with tap water and those cleaned with soap and water based on the Independent Sample T-test. Conclusion: Based on the results, stainless steel water bottles are not required to be cleaned frequently. It also appears that there is no difference between cleaning with soap and water and just rinsing the bottles with tap water. Despite results showing no statistical difference to support more frequent cleaning and more thorough cleaning practices, these behaviours should be encouraged to prevent and minimize the risk of potential exposure to harmful pathogens., Peer reviewed, Peer-reviewed article, Published., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2018., hygiene, cleaning, aerobic plate count, sanitation, personal water bottle, aerobic bacteria
Evaluating the efficiency of chlorine removal from potable tap water using off-gassing, boiling, and filtration treatment methods
Background: One of the most frequent complaints to water distribution systems is the taste and odor of chlorine in consumer tap water. Chlorine is a common disinfectant used to inactivate and breakdown microbes and other contaminants. However, excess chlorine can result in an unpalatable chlorinous taste and odor. When water taste becomes too objectionable, consumers may search for alternative water sources, such as raw, untreated water that does not contain chemical additives. Raw, untreated water contains various contaminants, including disease-causing pathogens. To encourage consumers to drink treated tap water, and prevent disease, this study evaluated and compared the effectiveness of off-gassing, boiling and filtration as dechlorination methods for consumers to perform on their tap water. Method: Hach Method 8021 was performed to collect and analyse water samples following treatment with Off-gassing, Boiling and Filtration. Water samples were collected from BCIT SW1-1230. The Hach Pocket Colorimeter ™ II determined the free chlorine concentration of the water samples, and compared to a sample of untreated chlorinated tap water to see which method reduced chlorine concentrations the most. Results: Mean concentration of chlorine following off-gassing was determined to be 0.51 ppm, 0.24 ppm following boiling, and 0.55 ppm following filtration. It was determined that the boiling method was statistically significantly different from the mean values of chlorine concentration from the other two methods, as shown by the Kruskal-wallis test (P=0.000), and therefore was the most effective in dechlorinating tap water samples. This was further confirmed by the Scheffe’s Mutliple-Comparison Test and eyeball test. Conclusion: Based on the results, boiling water is the most effective method to dechlorinate potable tap water for consumer acceptability. The free chlorine levels found post-boiling were also found to be below the WHO’s threshold for tasting and smelling chlorine in drinking water (0.3 ppm), and above WHO’s minimum required 0.2 ppm chlorine residual. Therefore, drinking water following boiling will be safe for consumption, as well as free of chlorinous taste and smell. Public Health professionals can safely advise consumers of an effective method to encourage treated tap water consumption, and to discourage finding alternative water sources., Peer reviewed, Peer-reviewed article, Published., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2018., Free chlorine, Boiling, Off-gassing, Filtration, Dechlorination, Chlorine residual