Objectives: Pathogens are introduced into foods, surfaces, and hands by our surrounding environment which includes soil, air, and fecal contamination. It can be due to improper handling, cleaning, washing or sanitizing. Sanitizers are applied to surfaces in order to kill all the vegetative cells of microbes. Health Canada regulates the types, uses and concentration of the sanitizers. These sanitizers are chemically formulated to kill microbes and hence there is a rising concern about toxicity associated with their use. People are moving away from regulated sanitizers to natural alternatives. This research project examined the efficacy of vinegar, one of the natural alternatives, as a sanitizer.
Methods: 3M Quick Swabs were used to collect coliform samples from a plastic cutting board before and after inoculating it with coliform culture and subsequently cleaning it with vinegar. A one tail paired t-test was conducted to assess whether the coliform counts were reduced after cleaning with vinegar.
Results: For all 30 samples there was a reduction in the number of coliforms when comparing before and after cleaning with vinegar. Results show that there is a significant difference in the mean numbers of coliforms before and after cleaning with vinegar; p <0.0001.
Conclusion: These results indicate that undiluted vinegar when used for cleaning food contact surface significantly reduces the coliform counts but not to the safer levels for human exposure., 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, Sanitizer, Vinegar, Food contact surfaces, Alternatives, Efficacy
Objectives: The average person living in North America is exposed to hundreds of chemical ingredients, including those that are harmful to human health, through application of personal care products. The manufacture of personal care products is largely untested and unregulated at a government level; legislation is not as prescriptive as the public would expect it to be. This shifts the responsibility to consumers to use their own discretion when purchasing personal care products. The purpose of this research was to assess the knowledge of the Canadian general public regarding ingredients in personal care products to determine if they have enough knowledge to avoid harmful substances.
Methods: A knowledge assessment survey was conducted to two different groups in Canada. The first group consisted of the general public who did not have a background in toxicology or dermatology, and the second group consisted of Public Health Inspectors in Lower Mainland B.C. The test scores from the knowledge assessment were compared between the two groups to determine if there was a significant difference in the means.
Results: The survey was completed by 39 Public Health Inspectors and 91 members of the general public. The mean score was 3.0256 for the Public Health Inspectors and 1.846 for the general public; the test score was out of 10. Statistical analyses showed that the mean test scores were significantly different and the null hypothesis (Ho: mean test score of the Public Health Inspectors = mean test score of the general public) was rejected at α= 0.05.
Conclusion: The result showed that both groups had low level of knowledge regarding the ingredients in personal care products that are widely used in Canada. Even the chemical ingredients that are known or suspected to be dangerous to human health or have adverse effects on the environment were not recognized. Exposure to potentially hazardous chemicals can be prevented or reduced by setting a legal requirement of a maximum concentration, imposing marketing restrictions or requiring better labelling of hazardous ingredients to improve public awareness of potential risk., 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, 2017., Peer reviewed, chemical ingredients, Personal care products, Cosmetic, Toxic, Xenobiotics, Preservatives
Background: The public perceives seafood generally as a healthy food. Studies have shown that consumption of fish is associated with healthy heart function. However, the benefits of consuming seafood may also come with some risks, which may not be well-known by the public. Seafood can potentially contain contaminants that originate from the natural environment or pollutants from human activity. The contaminants of interest that were focused on in this study include lead, mercury, organophosphates, and domoic acid.
Methods: The study utilized a KAP (Knowledge, Attitude, and Practice) survey to evaluate the knowledge, attitude, and practices regarding these contaminants between the general public and those working in the seafood industry. Nominal data was analyzed by the chi-square test while numerical data was analyzed by the t-test.
Results: The data obtained did not show a statistically significant difference between the general public and the seafood industry (p-values greater than significance level of 0.05 on all parameters) in their knowledge, attitude, and practice regarding seafood contaminants.
Conclusion: There was no difference between the general public and the seafood industry in their knowledge, attitude, and practice regarding seafood contaminants. Although the attitude data was not significant, the effects of some chemical contaminants (organophosphates and domoic acid) were generally incorrectly perceived by both groups unlike biological contaminants. Additional research will be required, but results from this study show that educational intervention by the government or health authorities may be needed., 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, 2017., Peer reviewed, Organophosphates, Seafood, Contaminants, Knowledge, Attitude, Practice, Perception, Domoic acid, Lead, Mercury
Objectives: There is an increasing desire in the culinary industry to use sous vide to prepare meals at low internal temperatures to enhance flavour, texture, and quality. The sous vide method uses specific time and temperature combinations to allow for sufficient microbial destruction. The BCCDC’s Guidelines for Restaurant Sous Vide Cooking Safety in British Columbia suggests time and temperature combinations to help ensure that the required log10 reductions of pathogens are achieved. Concerns for public safety arise when chefs deviate from the guidelines, and therefore may not achieve the appropriate log10 reductions. This study looked at a commonly used sous vide duck breast recipe and determine whether appropriate the appropriate log10 reductions were met. It also examine the efficacy of the sear step and resting period in achieving the log10 reductions.
Methods: After calibration, two batches of 15 duck breasts were prepared using the sous vide method for 80 minutes at 58ºC, the breasts were then seared on a 200°C frying pan for 2 minutes each side, and then subjected to a 4 minute rest period at room temperature. The internal temperature of the breasts was continuously measured using SmartButton thermometers. This data was entered into the AMI Process Lethality Determination Spreadsheet to calculate the log10 reductions. The log10 reductions were analyzed using a one-sample t-test to assess whether the recipe achieved the required 7.0 log10 reductions.
Results: The results showed 14% of the 29 duck breasts achieved a 7.0 log10 reduction after the sous vide step of 80 minutes at 58 ºC. The null hypothesis (Ho: measured log10 reductions of duck breasts = 7.0 log10 reductions) was rejected with 100% power and a p-value of 0.00. The mean was 5.13, therefore it seems as though the log10 reductions were significantly lower than 7.0 log10 reductions. After the sear and the resting period, 52% of 27 duck breasts achieved a 7.0 log10 reduction. Statistical analyses showed that the null hypothesis could not be rejected. The p-value was 0.97 and the power was 0.413. Disregarding cumulative effects, the median log10 reductions achieved only by the sear step was 0.43, and the median log10 reductions achieved solely by the resting period was 0.35.
Conclusion: Due to lack of normality one cannot confidently say this recipe will achieve 7.0 log10 reductions. However, due to the high log10 reductions achieved, it seems plausible for another recipe to provide adequate log10 reductions while maintaining acceptable quality. The sous vide step should be used for the majority of the log10 reductions. Due to a wide variability in the results, the sear and resting period should only be used for small increases in log10 reductions., 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, 2017., Peer reviewed, Sous vide, Duck breast, Temperature, SmartButton, Public health, Sear, Foodborne illness
Background and Purpose: The 2011 Fukushima Daiichi nuclear reactor incident in Japan resulted in the release of large quantities of radioactive material into the Pacific Ocean through deposition from the atmosphere and liquid discharges from the nuclear facility. Public misconceptions and the scarcity of radiation monitoring along the west coast of Canada have create doubt within the population regarding the safety of the ocean. A radiation survey along some of Vancouver’s beaches was completed to determine whether radioactivity from Fukushima has reached our local shores.
Methods: Radiation surveys were conducted at three different locations; Sunset, Spanish Banks and Jericho Beach in Vancouver, British Columbia. Gamma radiation levels were measured using both the Radeye, GR 135 Plus EXPLORANIUM survey meters. At each beach, 30 samples of water, sand and various different artifacts including algae, stones and logs were each surveying. If the radiation detected exceed 0.05μSv/Hr the identification function of the GR 135 Plus EXPLORANIUM would be used to determine if it was from natural or artificial sources. The radiation levels were compared to the expected normal background levels (between 0.05μSv/Hr- 1.0 μSv/Hr) as well as to observed if there was any sufficient differences between the mediums under investigation.
Results: The radiation levels along all three beaches did not exceed normal background levels (between 0.05μSv/Hr- 1.0 μSv/Hr). Furthermore, characteristic radionuclides released from this incident, specifically Cesium 134 and Cesium 134, were not detected. There was no sufficient difference between the radiation levels observed from the sand, water and different artifacts (logs, stones, and algae)
Conclusion: It was concluded that the radiation levels along the beaches, Jericho, Spanish Banks and Sunset Beach do not present an additional risk to the public visiting this area as a result of this incident., 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, 2017., Peer reviewed, Fukushima Daiichi, Cesium 134, Cesium 137, Gamma, Radiation, Vancouver beaches
Background and Purpose: Outbreaks of enteric diseases in schools and daycares are common. It is possible that these outbreaks could be propagated via fomites in school settings, such as playground equipment that is not regularly cleaned. Studies thus far have provided conflicting results on the level of contamination present on fomites in the school setting. This project is intended to assess the level of microbial contamination present on elementary school playground surfaces as a result of hand contact from school children. Methods: Two categories of elementary school playground equipment were sampled in this study; those that are likely to see regular hand contact from children and those that were not likely see hand regular hand contact from children. 30 surfaces of each category were swabbed and the media will be plated and incubated to enumerate total coliforms and E. coli.
Results: The mean number of total coliforms on high hand contact surfaces was 0.2333 cfu/100cm2, while the mean number of total coliforms on low hand contact surfaces was 0.2667 cfu/100cm2. The t-test analysis of total coliform results produced a p-value of 0.5566. The mean number of E. coli on high hand contact surfaces was 1.1333 cfu/100cm2, while the mean number of E. coli on low hand contact surfaces was 4.9000 cfu/100cm2. The t-test analysis of E. coli results produced a p-value of 0.8019. Discussion: Neither results for total coliforms or E. coli indicated significantly different numbers on high or low hand contact surfaces. This indicates that these total coliform and E. coli may not be present as a result of hand contact.
Conclusion: These results do not support the deposition of coliforms or E. coli on playground equipment as a result of hand contact. However, there is still concern due to the number of samples positive for E. coli. These results suggest the need for practices such as regular hand washing in the school setting after using the playground, regular cleaning of playground materials and EHO inspections of school grounds., 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, Playgrounds, Schools, Surface sampling, Sanitation, Total coliforms, Escherichia coli, Abbotsford
Objectives: Kombucha tea is becoming an increasingly popular food item within the Vancouver area. The tea is prepared through fermentation at room temperature during which acidic by-products are produced lowering the overall pH of the tea. Though the pH eventually reaches levels below 4.6, many health authorities prevent the sale of kombucha in farmers markets due to potential food safety issues. The initial pH before fermentation is around 5.5 and is then left at room temperature to ferment. As a result, this process potentially could allow for food borne illness causing organisms to survive and proliferate within the sugared tea. This research project will investigate the relationship of pH and time during fermentation at both room and refrigeration temperatures. Fermentation within a refrigerator could provide a safer alternative fermentation method
Methods: The pH was measured using a pH meter for 30 samples at both room and refrigeration temperatures providing a total of 60 samples. The pH was measured periodically every twelve hours for a total of 120 hours. The data was analyzed using a linear regression model to determine if the pH change over time was statistically significant. The time at which the pH dropped below 4.6 was also noted for food safety purposes
Results: At room temperature the pH steadily decreased in a linear fashion throughout the entire sampling period, dropping below 4.6 within 12 hours. The pH decreased in a nearly identical fashion when fermented in a refrigerator for the first 72 hours of sampling. After the 72 hour mark the pH stabilized at approximately 3.75, whereas the pH at room temperature continued to decrease down to 3.10 after the full sampling period
Conclusion: The results indicate that kombucha tea becomes a non-potentially hazardous food within the first 12 hours of fermentation. The pH dropped below 4.6 after 12 hours at which point no food borne illness causing bacteria are able to survive and proliferate within the tea. The observed decrease in pH during the first 72 hours within a refrigerator is unlikely to have resulted from the fermentation process and therefore is not a feasible practice. Fermentation at room temperature appears to be a relatively safe process if home brewers are able to measure the pH change and carry out the process in a sanitary manner, 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, 2017., Peer reviewed, Kombucha, Fermentation, pH, Temperature, Refrigeration, Tea
Background and Purpose: Seafood makes up a significant portion of the diets of people around the world. Especially fatty fish such as salmon and herring, seafood items contain numerous nutritional benefits including omega-3 fatty acids which studies have shown aid in cognition and memory. However, due to natural and anthropogenic sources of pollution, contaminants such as mercury which studies suggest decreases cognitive functioning if consumed in excess bioaccumulate in marine life including various fish and shellfish species. The purpose of this study was to categorize participants into either the “fish” group (more fish than shellfish consumed) or the “same” group (either more shellfish than fish consumed or equal amounts of fish and shellfish consumed) via a seafood frequency questionnaire, and to administer a memory test to the participants to determine whether there is a significant difference in mean memory test scores between the groups.
Methods: 31 participants were randomly selected at BCIT to participate in the study. Participation was voluntary and participants were given written and oral instructions on how to complete both the seafood frequency questionnaire and memory test. Memory test scores were based on the length of the longest digit sequence that the participant was able to recite upon hearing the examiner list the sequence. The highest possible score was a 10, while the lowest possible score was a 1.
Results: The mean memory test scores of the groups, “fish” (more fish than shellfish consumed) and “same” (either more shellfish than fish consumed or equal amounts of fish and shellfish consumed), were 5.83 and 5.92, respectively. The median memory test scores of the groups, “fish” and ”same”, were both equal to 6. The standard deviations of the groups, “fish” and “same”, were 1.2004901 and 0.9540736, respectively. The ranges of the groups, “fish” and “same”, were 4 (minimum) to 8 (maximum) and 5 (minimum) to 8 (maximum). From the non-parametric Wilcoxon Rank sum test, the P-value was found to be >0.05 at α = 0.05.
Conclusion: The results of this study suggest that diets relatively high in fish are neither positively nor negatively correlated with memory. However, the limitations of this study in combination with the various studies that contradict this study’s findings illustrate the need for further research., 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, Memory, Seafood, Shellfish, Fish, PCBs, Mercury, Brain, Neurodevelopment, DHA, EPA, Omega-3 fatty acids
