BCIT Environmental Public Health Journal
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Investigation on the cold temperature retention capacity of the 1.5 Liter Thermos® double wall vacuum stainless steel thermal container when filled to different volumes and with different types of milk
Introduction: Customers sometimes question the freshness of milk inside thermal containers in coffee shops. Milk that is kept between 4°C to 60°C can support the growth of pathogens, hence it should be kept below 4°C. Thermal containers are often advertised as being able to retain the temperature of their contents for a prolonged period of time. Yet, the extent of their temperature retention capacity is not clearly defined by the manufacturers. This study investigated the effectiveness of the 1.5 Liter Thermos® Double Wall Vacuum Stainless Steel Serving Carafe thermal container in keeping milk at ≤4°C when it was filled to different volumes and with different types of milk over a nine hour period. Methods: Four tests were carried out in this study: The 1.5L Skim Milk, The 1.5L Creamo, The 0.75L Skim Milk and The 0.75L Creamo Test. For each test, the milk was placed into the 1.5L Thermos® Double Wall Vacuum Stainless Steel Serving Carafe with the initial temperature between 3.1°C to 3.4°C. Change in temperature was recorded for nine hours using the Thermocouple data logger. Results: The descriptive data demonstrates that the mean temperatures over the nine-hour period for The 1.5L Skim Milk Test, The 1.5L Creamo Test, The 0.75L Skim Milk Test and The 0.75L Creamo Test were 4.41±0.88°C, 4.51±0.95°C, 5.59±1.52°C and 6.05±1.77°C, respectively. MANOVA results suggested that “volume”, “time”, “type of milk”, “volume and time”, “volume and type of milk”, “time and type of milk”, and “volume, time and type of milk” did have effects on the temperature retention capacity of the thermal container with p-values <0.05. The temperatures of all samples were <4°C at hour zero. All of the samples’ temperatures began to increase once they were inside the thermal container and all of the samples entered the danger zone (>4°C) after four hours. A Chi Square test was conducted to determine whether Creamo or skim milk was safer (≤4°C) from hour one to four. Results showed that 123/240 (51%) skim milk and 110/240 (46%) Creamo samples were safe, but the result was not statistically significant. Conclusion: This study’s results indicate that the tested thermal container had a better cold temperature retention capacity when it was filled up (1.5L) compared to when it was only half filled (0.75L). In addition, when the thermal container was filled with skim milk, it also had a better cold temperature retention capacity compared to Creamo. Finally, this specific thermal container was not successful in maintaining the temperature of milk out of the danger zone (≤4°C) after four hours. These results should be disseminated to Environmental Health Officers whose job it is to keep the public safe from foodborne illnesses. As well, policies should be established pertaining to time permitted to keep milk in thermal containers.
 
Sous vide salmon pasteurization temperature
Objectives: Cooking foods to a specific temperature and temperature control are often very difficult due to the frequent fluctuation of heat during the traditional dry heat (oven) cooking process. “Sous vide” cooking of vacuum-packaged foods immersed in water provides constant and controllable time and temperature measurements throughout the process. Some sous vide style foods are cooked at temperatures that are lower than 60oC for short periods of time. This presents a recognizable food safety concern including the survival of harmful bacteria as well as conditions that do not achieve pathogen reduction during either the sous vide cooking or finishing (searing) process. This research project investigated the time and temperature relationship for sous vide salmon in order to examine if pasteurization temperature was achieved if an additional searing step was performed. Methods: Temperature values were measured using data-loggers (SmartButton) for 30 samples of vacuum-packed salmon and cooked sous vide inside a circulating water bath at 50oC for 20 minutes. A one sample one tailed t-test was conducted to assess whether the internal temperature of salmon reached instantaneous pasteurization temperature of 70oC after a final searing step was performed at 220oC for 45 seconds. Results: Five out of the 30 (16.7%) salmon samples achieved 70oC after the final searing step. Statistical analyses were statistically significant, and the null hypothesis (Ho: measured internal temperature of salmon ≥ target temperature) was rejected with 100% power and a p-value of 0.00. Conclusion: These results indicate that salmon cooked sous vide style under 50oC for 20 minutes with a final searing step of 220oC for 45 seconds will likely not achieve pasteurization providing adequate pathogen reduction according to guidelines set out by BCCDC. For sous vide style cooked salmon cooked at lower temperatures for short periods, freezing for control of parasite hazards is recommended.
 
Testing for presence of radioactivity in food products imported from Japan to Canada
Following the Fukushima Nuclear accident of March 11th of 2011, many people, particularly among the general public are still skeptical about the safety of foods imported from Japan. Furthermore, currently little radiation monitoring of food happens in Canada. The present study aims to test for the presence or absence of gamma radioactivity in various food products imported to Canada from Japan. Thirty commonly imported Japanese and thirty-two additional Canadian food products were purchased from supermarkets and convenience stores in Vancouver, British Columbia. All samples were tested for gamma radiation from cesium-134 and cesium-137 using a portable gamma spectrometer, the EXPLORANIUM GR-135 Plus Identifier. All food samples tested in this experiment were found free of any detectable gamma radioactivity.
 
Are Ministry of Environment holding times for nitrate and nitrite tests in drinking water justified?
Background: Exposure to nitrate and nitrite in high concentration is associated with various health issues in humans such as methemoglobinemia, gastric and bladder cancers. Surface and ground water is vulnerable to nitrate and nitrite contamination which can have a significant impact to communities that use the water for consumption. Methods: Ion chromatography analysis of nitrate and nitrite degradation over time in well water from Abbotsford-Sumas Aquifer was performed in an analytical chemistry study. Nitrate and nitrite test strips marketed for testing drinking water were also used and results were compared to ion chromatography results. Results: Test strips used were unable to detect the level of nitrate/nitrite in the well water sample drawn from the Abbotsford-Sumas aquifer. Ion chromatography, IC, methods were able to detect measurable amounts of nitrates which resulted from concentrations of 1.17 mg/L NO3 as N to 1.13 mg/L NO3 as N from day 0 to 31 of the sampling date. The concentration decreased 0.04 mg/L NO3 as N over 31 days. Nitrites tested by IC were below the detection limit. Conclusion: In regards to nitrates, the MOE holding times are justified in that the concentrations were statistically different (p = 0.0001) from day 0 to day 31 from the sampling date indicating a change of concentration of the chemical due to time. However, the difference was not of a magnitude that may impact public health practices/policies. Test strips comparisons with EPA IC methods were non-conclusive since test strips were unable to detect measurable amounts of nitrate/nitrites. Future studies of nitrate concentrations with respect to chemical and biological components in water may lead to a greater understanding of its change in the environment and thus its association with other potential health hazards.
 
Consumer preferences concerning potentially unsafe food
BACKGROUND: Recent studies have shown that the reasons behind consumers’ preferences towards certain food products are extremely dynamic. Organic foods, raw milk products and bottled water are a few products discussed in this paper that have gone under debate regarding their safety versus their perceived health benefits. METHODS: Over 100 people participated in an exclusively online self-administered questionnaire. The questionnaire was publicized through both email and social media. Participants responded to questions regarding their food preferences of a variety of food types. RESULTS: It was found that there was a statistically significant association between education and preferences towards both milk products and organic/non-organic food products. No other demographic (setting, gender, age) were found to be associated with food preferences. It was also found that all food preferences were associated with the reasoning for that specific food preference, with the exception of cut/whole fruit. CONCLUSION: The association between food preferences and its reasoning concludes that consumers who prefer opposing products do so for extremely different reasons. Consumers that prefer the more risky food products mainly do so for taste and potential health benefits. Public health officials need to ensure that consumers that prefer riskier products thoroughly understand the risks, so that they themselves can then truly compare the benefits of taste or perceived “healthiness” with the consequences of potential contamination and illness.
 
The effectiveness of Metro Vancouver’s green bin program
Background and Aims Metro Vancouver is implementing a disposal ban on all food scraps from entering the landfills and incinerators by the year 2015. In order to prepare the city’s residents, a food scraps recycling program, known as the Green Bin Program, was initiated in 2013 for all single family households. The aim of this research project was to measure public knowledge and awareness of the program across various demographics and collect data on the general opinion of it. Methods An online survey was created using SurveyMonkey, a survey generating website, and distributed online via Facebook and e-mail. The results from these surveys were analyzed using NCSS software to determine statistical significance via a chi-squared analysis with alpha (a) = 0.05. Results There were a total of 70 respondents. Of these, 68% of the respondents indicated that the Green Bin Program should stay the way it currently is without any further changes. 8% of the respondents were in favour of stopping the program and the remaining 24% indicated that the program needed some modifications such as more education/promotional material, implementing the program into apartment complexes and more garbage pickup days to prevent pest and odor problems. Age category, location of residence, and educational background were analyzed against other variables in the survey that tested the knowledge and usefulness of the Green Bin Program. Looking at these 3 variables in relation to knowledge: there was no association between location of residence, age, and educational background, with knowledge of what could go into the green bin (p= 0.76, p= 0.53, p= 0.33, respectively). These same 3 demographic variables were also analyzed against frequency of food scraps recycling and there was a positive association between age and frequency (p= 0.037), indicating that respondents aged 19-29 were recycled food scraps more than respondents over the age of 29. However, there was no association between location/education and frequency (p= 0.32 and p= 0.10, respectively). Non demographic variables were also analyzed, such as determining if household size and garbage bin size had an effect on frequency of food scraps recycling: household size did not have a significant association (p=0.70) while garbage bin size did have a positive association (p= 0.025), showing that residences with smaller garbage bins were more likely to recycle their food scraps. Conclusion These results indicated limited knowledge of the Green Bin program and pinpointed deterrents (mostly pests and odors) from participating in it. Environmental Health Officers’ involvement would be important as educators to emphasize that certain organic wastes (like pet fecal matter) should not go into the green bin as they create health hazards. EHOs can also collaborate with the municipality to promote the program. Several participants reported recycling their food scraps; as a result, the Metro Vancouver Green Bin Program has achieved some of its aims in creating a greener and more sustainable city.
 
The risk of consuming MTGase-restructured steaks like intact steaks
Introduction: The use of transglutaminase to restructure loose pieces of meat into a fully intact piece of steak has been a concern for the public because of the potential internalization of contaminated surfaces into the aseptic center. The aim of this study was to examine if restructured steaks are safe to consume when cooked to medium rare, a common option with whole cut steaks Methods: Strips of beef were inoculated with E.coli to induce surface contamination. Steaks were restructured with transglutaminase and the altered meat. These steaks were then cooked alongside fully intact whole-cut steak samples. Each sample was then churned in a stomacher, and the resulting solution was used to detect for potential E.coli bacteria. Samples were then enriched and finally placed into the Hygiena Micro-snap Rapid Coliform and E.coli detection test to look for the presence of E.coli. Results: The Hygiena system showed that all transglutaminase restructured steaks possessed detectable levels of E.coli even after cooking to 55 degrees Celsius. On the other hand, no whole-cut steaks had traces of E.coli even when cooked to this same temperature. Conclusion: The results demonstrated that there is a substantial risk with restructured steaks and they should not be consumed undercooked. As well, proper labelling and guidelines should be developed to enable consumers to be better equipped in making decisions to consume properly consumed altered steaks.
 
Survey of the general public to determine perceptions and precautions taken when choosing personal service establishments
Objective: Personal service establishments (PSEs) include tattoo parlors, piercing shops, and beauty salons. Many of the services provided have potential to spread diseases due to the invasive nature and possibility of cross contamination if sanitation procedures are not followed. Potential infections such as nontuberculosis mycobacterium, staphylococcus aureus and blood borne infections such as Hepatitis and HIV are possible. There is concern among Environmental Health Officers (EHOs), and professionals in the industry regarding the lack of regulations and training of employees within the industry. This study investigated the criteria and safety measures the public takes when determining which personal service establishment they receive treatments from. Methods: A questionnaire was administered online through social media and Google Docs. Inferential statistical analyses determined if there were associations between certain demographic information and the responses given from participants. Results: There were six associations that were found when comparing demographic groups (age, gender and education) with the survey questions. A p value of 0.021008 was found in the association between age and perceived level of regulation of the industry, a p value of 0.014407 was found in the association between education and asking about sanitation procedures before an appointment, and a p value of 0.008668 was found in the association of education and if participant asks for references. In addition, p values of 0.028151 and 0.011739 with associations of gender and education, respectively, and the participants perceived ability to recognize bad practices during a procedure. Finally, a p value of 0.029766 was found in the association of gender and participants interest in additional information about how to choose an establishment. Conclusions: There were six hypotheses that resulted in statistically significant associations between a demographic and the survey question. Over 30 year olds chose PSEs were minimally regulated, while higher education groups were more likely to ask about sanitation and for references before a procedure. Females and people with some post secondary education felt they were more able to recognize bad practices during a procedure. Finally, females were most interested in additional information about PSEs.
 
A comparison of recreational water illness awareness and frequency of swimming
Objective: Swimming pools have potential to create health hazards that range from physical, chemical to biological. Biological concerns center on communicable diseases which can be spread through poor hygiene practices. To prevent the spread of disease, swimmers must be informed and practice appropriate hygiene. This study aims to determine whether the frequency of swimming had an influence on swimming pool hygiene knowledge. Method: Survey questions focusing on risk factors for communicable disease spread, and personal hygiene practices were developed using the pool operation handbooks, input from environmental health instructors at the British Columbia Institute of Technology, as well as past surveys from other studies. Pool patrons were surveyed at Hillcrest Community Centre in Vancouver. Scores from these tests were then analyzed in NCSS9 using one-way ANOVA tests and Two-Sample t-tests. Results: 167 validated surveys were analyzed. The most often incorrectly answered questions were in regards to the duration of avoiding swimming after diarrheal illness, pre-swim hygiene, and after bathroom use hygiene. No statistically significant difference in mean test score was found in individuals that swam more than once a week, more than once a month, or less than once a month. Statistically significant differences in mean test scores were found for individuals that read signs, and age group. Conclusion: From the data, it is observed that those who swam more frequently were not more informed on pool hygiene issues than those who swam less. The sample size (n=167) for this conclusion may be too small, since beta value was 87.5%.
 
Comparing the health risks of alfalfa sprouts and wheatgrass via detecting the presences of escherichia coli in their juices
Background: Past studies have analyzed the health risks associated with alfalfa sprout production and developed standard procedures to reduce foodborne illnesses. There have been no studies related to microgreen outbreaks, specifically wheatgrass. Wheatgrass has become a growing culinary trend and the potential health risks associated need to be evaluated. Alfalfa sprouts and wheatgrass both share the same initial growth production – pre-soak and germination. The only difference is the harvesting period. This paper evaluated the risks associated with alfalfa sprout production and compared it with wheatgrass production by contaminating both alfalfa sprouts and wheatgrass with E. coli The presences of E. coli in the plant’s juices were evaluated and compared. Method: Alfalfa sprouts and wheatgrass were grown in similar conditions, in hydroponic condition, with an additional wheatgrass in soil. The plants were grown and harvested according to its respective pre-soaking and harvesting period, as specified by the Canadian Food Inspection Agency. The plants were inoculated with Escherichia coli during the germination period, and then juiced to examine the presences of E. coli within its internal structure. The Hygiena systemSURE II luminometer was used to detect the presences of E. coli via the MicroSnap™ Enrichment and E. coli detection swabs. Results: The result showed that E. coli was present in both wheatgrass and alfalfa sprouts juice. The root systems of the food products were independent of each other. The types of growth medium used for wheatgrass were also independent of each other. Conclusion: The study found that growing microgreens should be treated similarly to sprout productions. Food facilities with wheatgrass production need to be aware of safe handling, production, and storage of wheatgrass to prevent foodborne illnesses.