Environmental Public Health Journal 2016 | BCIT Institutional Repository

Environmental Public Health Journal 2016

Blood concentrations of lead and mercury in British Columbians (2009-2010)
Background and Purpose: Adverse effects of lead and mercury on human health due to environmental and occupational exposures require a public health attention. These metals can cause severe harm to vulnerable populations such as children and pregnant women. The probability of chronic and harmful exposure is higher in occupational settings. Monitoring the levels of these two metals in blood is an important tool to identify and quantify exposure to these metals in the environment. Monitoring data provides vital information required for management of health risk posed by these metals. The purpose of this study was to perform a comparative analysis of blood lead levels and blood mercury levels within the province of British Columbia on the health services data obtained from BC Centre of Disease Control. The primary objective was to compare the levels of lead and mercury in blood among different health authorities of British Columbia. The secondary objective was to compare the levels of lead and mercury among different age groups and gender. Methods: The blood lead and mercury concentrations used for the analysis were provided by Environmental Health Services at the British Columbia Centre for Disease Control (BCCDC). The data comprised of blood analyses that were ordered by physicians during the period of 2009-2010 for reasons not disclosed. Access to this data was provided by Dr. Reza Afshari with the permission of Dr. Tom Kosastsky for the completion of this project only. Statistical analysis of data was performed using Microsoft Excel 2013 and SAS University Edition Analytic Software. Various descriptive and inferential statistical tests were performed on the data to determine the differences of blood mercury and lead levels among different genders, Health Authorities and age groups. Results: The levels of blood mercury and lead concentrations were not significantly different in males and females in province (p-value 0.5543 for mercury; p-value 0.5336 lead). However, it was found that blood levels of lead were higher in Interior Health and “Unknown” category (p<0.02), while blood mercury levels were significantly higher in coastal health authorities (highest in Vancouver Coastal Health Authority, followed by Fraser Health Authority and Vancouver Island Health Authority) (p<0.001). For both toxic metals, levels were highest in age group of 50 and above. (p<0.0001 for mercury, p<0.02 for lead). Conclusion: The statistical analysis of lead and mercury data was useful in characterizing the exposure among Health Authorities, age and sex of the people tested in province of British Columbia. Analysis of mercury data has generated clear patterns inferring association between coastal Health Authorities and elevated mercury levels. Vancouver Coastal Health had highest median mercury levels 4.02 μg/L higher than other health authorities (p<0.0001). Analysis of lead data established a pattern among physicians suggesting that they are more likely to order a test if the patient is under 18 years of age. Median levels were found to be highest in Interior Health Authority and “Unknown”, 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, 2016., Peer reviewed, Lead, Mercury, Pregnancy, Children, British Columbia, Blood lead levels, Blood mercury levels, Vancouver Coastal Health, Fraser Health, Interior Health, Northern Health, Vancouver Island Health Authority, Occupational exposure
Comparing the effectiveness between gel and foam hand sanitizers
Background: Hand sanitizers are commonly used as an alternative to washing hands with warm water and soap. There are a variety of different hand sanitizers including gel and foam and they are known to kill several bacteria. Many factors play a role in the effectiveness of hand sanitizers such as the alcohol concentration and the techniques used to apply hand sanitizers. Alcohol based hand sanitizers must have an alcohol concentration of 60 - 70% to be effective. There is currently no legislation regulating hand sanitizers and there is a lack of research focusing on differences between foam and gel hand sanitizers. This research study investigates effectiveness of gel compared to foam hand sanitizers by evaluating the prevalence of Escherichia coli (E.coli) on pigskins. Methods: To compare the hand sanitizers, microbiological sampling was completed. E.coli was introduced onto 65 pigskins. Five pigskins were used as a baseline to determine the average amount of Colony Forming Units (CFUs) of E.coli present prior to the application of hand sanitizers. One set of the 30 pigskins was applied with gel hand sanitizer, whereas the other 30 was applied with foam hand sanitizer. The pigskins were swabbed with QuickSnap swabs and plated onto 3M Petrifilms. The 65 petrifilms were incubated at 35oC for 48 hours. After incubation, the CFUs of E.coli present on the petrifilm were enumerated. The difference in CFUs was calculated to determine the reduction in E.coli and the overall effectiveness of hand sanitizers. Results: The data was analyzed by using the statistical software, NCSS. Statistical analysis showed that the findings were statistically significant and the null hypothesis (Ho: no difference in CFUs of E.coli between foam versus gel alcohol-based hand sanitizers) was rejected with a power of 0.9997 at p-value of 0.00000. This indicates that there is a difference in the ability to reduce E.coli between gel and foam hand sanitizers and gel sanitizers appeared to be more effective. Conclusion: These results indicate that there was a difference in the effectiveness between foam and gel hand sanitizers in reducing E.coli that was inoculated onto pigskins. However, consumers should be aware that hand sanitizers do not completely eliminate all pathogens. Though gel hand sanitizers are more effective, they should only be used when there are no other methods of keeping hands clean., 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, 2016., Peer reviewed, E.coli, Escherichia coli, Foam, Gel, Hand Sanitizer, Pigskin, Public health
Comparison of water quality in live shellfish retail holding tanks
Background: Water quality in live retail shellfish holding tanks are vital in increasing shellfish quality and reducing risk of shellfish-associated outbreaks. Poor holding tank water conditions may not only cause mortality of shellfish, but also allow for harmful pathogens to contaminate the shellfish, proliferate in the holding tanks, and ultimately potentially affect consumer health. Shellfish are processed and handled at a variety of levels at the retail stage. Therefore, the purpose of this research project is to compare water quality in live retail shellfish holding systems between processing plants and retail food markets. Differences may indicate a need for attention at a particular level in order to effectively and efficiently reduce mortality and disease among shellfish, and thus potentially humans as well. Methods: 30 water samples were taken from the two types of locations with the help of the Department of Fisheries and Oceans (DFO), Ministry of Agriculture, and the BCCDC. These samples were tested for parameters including temperature, pH, nitrites, turbidity, and dissolved oxygen using a LaMotte Fresh Water Aquaculture Kit and a HACH 2100P turbidimeter. A two-tailed t-test was used to compare the means of each of the parameters among the two types of locations with live shellfish holding tanks. Results: The mean values for all parameters in both retail and processing met the requirements set by the BCCDC. However, temperature and dissolved oxygen showed statistically significant differences between retail markets and processing facilities. Nitrites, pH, and turbidity showed no statistically significant differences between the two types of locations. Conclusion: Differences in dissolved oxygen may have been due to salt levels, failing recirculation systems, or high levels of organic matter from sanitation issues. Differences in temperature may have been due to differences in holding tank size, or inconsistencies from using two different thermal measuring devices. High levels of nitrites were a concern as well due to overcrowding of holding tanks. More attention may be needed for these issues, especially during certain seasons such as Chinese New Years, in order to lower the risk to public health., 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, 2016., Peer reviewed, Shellfish, Holding tanks, Water quality, Processing facility, Retail food market, Food safety, Public health
Environmental health officer’s knowledge of sensory deprivation tanks in BC
Background and Purpose: Personal service establishments are abundant such as piercing shops, tattoo parlours, spas and now float spas. Sensory deprivation tanks were popular in the 1980s and have come back as a new way to relax, reduce pain and relieve stress and to provide a complete deprivation of the senses. The sanitation of these tanks have caused concern in the public health field as bacteria and parasites can easily live and proliferate in the tank water. Environmental Health Officers (EHOs) have to keep up to date with new or returning technology in order to provide information to the public and to ensure their safety. This research project investigated EHOs with differing years of employment in the field, geographic working location and age and their knowledge of sensory deprivation tanks. Methods: A survey created in Google Forms and Survey Monkey was disseminated through e-mail who then forwarded an e-mail to all EHOs in BC. The survey asked demographic questions, health and safety, sanitation and disinfection and general knowledge of floatation tanks. A t-test and ANOVA was used to analyze the data. Results: Three comparisons were tested: first was the number of years an EHO has worked in the field and their test score; second was their age and test score; and last was their geographic location and test score. The null hypotheses were not rejected as the p-value was found to be greater than 0.05 for all of the variables analyzed. Discussion: Overall, there was weak knowledge in EHOs and due to the small sample size there was weak statistical significance between the associations found regarding the number of years an EHO has worked in the field, their age and geographic location where they work compared to their test scores. Conclusion: More information needs to be provided to all EHOs to keep them updated on new personal service establishments., 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, 2016., Peer reviewed, Floatation tanks, Sensory deprivation tanks, Environmental health officer, Knowledge, BC, Public health, Personal service establishments, PSE, Float tank, REST tank, Isolation tank
Evaluating the effectiveness of alcohol-based hand sanitizers compared to alcohol-free hand sanitizers
Background and Purpose: Hand washing is one of the most important critical control points in public premises in preventing the spread of bacteria and viruses. There is vast research on the effectiveness of alcohol-based hand sanitizers in killing germs. However, the efficacy of alcohol-free hand sanitizers lacks real-world evidence. With little to no guidelines in which one type of hand sanitizers may be more appropriate depending on the types of public premise such as food establishments, hospitals, work place, or schools, Environmental Health Officers(EHOs)/ Public Health Inspectors(PHIs) will need to educate the public and operators on the effectiveness of these hand sanitizers and their advantages and disadvantages. The purpose of the study was to compare the effectiveness of alcohol-based hand sanitizers and alcoholfree hand sanitizers by conducting statistical analyses of the reduction in mean E.coli counts. Methods: 60 pigskins were prepared (30 for alcohol-based hand sanitizers, 30 for alcohol-free hand sanitizers), which were inoculated with E. coli, then applied either alcohol-based hand sanitizers or alcoholfree hand sanitizers. After 48 hours of incubation for E.coli growth, E.coli was counted. The difference in mean E.coli counts before applying hand sanitizers and after hand sanitizers was calculated, then compared between the two hand sanitizers. Results: The mean E.coli reduction count (CFU) from alcohol-based hand sanitizers (30 samples) was 10.200; the median was 11; the standard deviation was 1.7889; the range was 5.0000. The mean E.coli reduction count (CFU) from alcohol-free hand sanitizers (30 samples) was 10.233; the median was 10.5; the standard deviation was 0.8976; the range was 3.0000. The statistical t-test resulted in p-value of 0.1034. Conclusion: There was no significant difference between the two types of hand sanitizers. Both the alcohol-based hand sanitizers and alcohol-free hand sanitizers effectively reduced the number of E.coli counts (CFU) by averages of 10.2000 (92.7% reduction) and 10.2333 (93.03% reduction) respectively. While the BC Centre for Disease Control recommends 60 percent alcohol hand sanitizers to prevent the spread of germs, this research showed that alcohol-free hand sanitizers with sulfactants, allantoin, and benzalkonium chloride (SAB) formula is just as effective in killing germs. Therefore, EHOs/PHIs can educate the public and operators on the advantages and disadvantages on the two types of hand sanitizers in preventing the spread germs during the flu season and give practical advice or guidance on which type of hand sanitizers would be most appropriate in restaurants for example., 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, 2016., Peer reviewed, Alcohol-based hand sanitizers, Benzalkonium chloride, E. coli, Alcohol-free hand sanitizers