BCIT Environmental Public Health Journal
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209 research outputs found
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Comparing carbon dioxide levels within urban transport microenvironments during rush hour and non-rush traffic
Introduction: Commuters spend countless hours within tightly confined spaces with limited ventilation that may be filled with many contaminants. By analyzing if there is a significant difference between levels of carbon dioxide between rush and non-rush hour conditions, it can be determined if some commuters are subjected to poorer levels of air quality during certain times of the day. Objectives: The primary objective of this study is to understand whether there are significant ventilation deficiencies during rush compared to non-rush hour times in urban transport microenvironments. Methods: Analysis of urban transport microenvironments was done using the TSI brand QTrak Indoor Air Quality (IAQ) Monitor to gather data on carbon dioxide at 1-minute intervals on the 99 B-line express bus that runs between Broadway and Commercial Skytrain Station and the Broadway and Cambie Street Skytrain Station. Results: A one tailed T-test was done on the NCSS 9 statistical software to compare if rush hour urban microenvironments had significantly higher concentrations of carbon dioxide than when compared to non-rush hour. Statistical analysis determined that since the P-value was well above the alpha level of 0.05 (i.e. P<0.05), it gives reason to accept the null hypothesis, which states that rush hour concentrations were not higher than non-rush hour. Conclusion: Statistical analysis determined that the overall concentrations of carbon dioxide during rush hour were not significantly higher than non-rush hour times. This result may have been attributed to conditions and factors during data collection that could not be controlled by the researcher. Due to the length of the route, exposure times were found to be within time-weighted averages as set out by the American Conference of Industrial Hygienists (ACGIH), though it was still not within the recommended limit of 1000 ppm as set out by the American Society of Heating, Refrigeration and Air-Conditioning (ASHRAE).
 
Disinfection efficacy studies on three different disinfection methods in health care facilities by ATP method
Objectives: Nosocomial infection has always been a significant topic in the field of public health. The disinfection procedures involved in health care facilities are extremely important to prevent potential transmission of diseases. Therefore, this study was performed to compare the disinfection efficacy between three different disinfection methods (Accel wipes, Hubscrub industrial washer, and Steam vapor) on three pieces of non-critical medical equipment: wheelchairs, mattresses and bath chairs. Methods: The method used to evaluate the disinfection efficacy compared the reduction of contaminants count in the relative light unit using ATP monitoring methods. 30 samples of each of the three types of medical equipment were swabbed pre-disinfection and post-disinfection using the three disinfection methods. The recorded reduction number was then converted using log transformation. Statistical analysis was conducted using NCSS to assess differences between the disinfection methods. Results: The mean log-reduction of disinfection for Accel wipes, Hubscrub, and steam vapor were 1.067, 1.490, and 1.485 respectively. Steam vapor and Hubscrub displayed statistically significantly better disinfection efficacy compared to Accel wipes in terms of log reduction (overall p=0.000002). Conclusion: Hubscrub and steam vapor are better disinfectants compared to Accel wipes in terms of mean log reduction values; however, all three disinfection methods demonstrated effectiveness when cleaning and disinfecting non-critical medical equipment. For critical medical equipment, steam vapor and Hubscrub industrial washing are effective while Accel wipes do not meet the standards of high-level disinfection. As a result, combination usages of all three disinfection methods are recommended at health care facilities based on the categories of the medical equipment.
 
Electronic cigarettes: conducting vapor analysis for heavy metals from two different types of e-cigarettes
Background: Since 2011, the popularity of electronic cigarettes in North America has increased dramatically. However, with a lack of scientific data performed on long term health effects and the limited number of short term studies, it is difficult for Environmental Health Officers to effectively educate the public on concerns relating to the health and safety of the general public. The increase of teenage users demonstrates the need for better government legislation and enforcement, in order to prevent the re-glamorization of smoking in younger generations. Therefore, the following study conducted a chemical analysis on artificially inhaled vapor from two different types of e-cigarettes (disposable and rechargeable), to determine if any heavy metal concentrations; specifically cadmium, chromium, lead and arsenic, are detectable. Methods: The vapor from one of two e-cigarette types was artificially inhaled through a cellulose filter cassette by a personal sampling pump. A two tailed t-test was performed to determine if there were any differences between the heavy metals and the type of e-cigarette used in the study. Results: There was no statistical significant difference in heavy metal concentration by the type of e-cigarette used (for cadmium the p-value was 0.00, and power was 0.00, for chromium the p-value was 0.181220, and power was 0.008976342, for lead the p-value was 0.333711, and power was 0.001825742, for arsenic the p-value was 0.00, and power was 0.00). Conclusion: Based on the results, it was determined that there was no statistical significance between disposable e-cigarettes and rechargeable e-cigarettes with respect to concentration of the four heavy metals of interest (eg. cadmium, chromium, lead and arsenic). Although there was no statistical significance between the types of e-cigarettes used, the average concentration of chromium (IV) from the rechargeable e-cigarette was 0.13mg/m3, which is ten times the recommended 8-hour time weighted average (TWA) set by the BC Occupational Health and Safety Regulations. Hence, further studies must be conducted to determine if the average concentration found in this study truly reflects the concentration found in inhaled vapor from rechargeable e-cigarettes. Furthermore, environmental health officers can provide the public with the concentration found in this study and warn of potential health risks associated with e-cigarettes until further studies are released.
 
Mitigating hand contamination at recycling depots: are hand wash stations in Metro Vancouver meeting public health standards?
Background and Purpose: Although the number of recyclers and amount of accepted materials and their contaminants has increased over the decades, the adequate provision of hand washing equipment to mitigate the transfer of infectious agents at recycling depots has not been well studied. Minimal Standard (MS) depots and STAR-Rated (SR) depots are inspected by Encorp Pacific (Canada) auditors, not health inspectors, and claim to provide adequate hand hygiene equipment. This study compared the adequate provision of essential hand washing equipment at MS and SR depots in Metro Vancouver to determine if they met public health standards. Methods: Inspections of presence/absence of essential hand washing equipment (tap with running water, soap in soap dispenser, hand drying equipment and signage) were carried out at 35 depots throughout Metro Vancouver (Vancouver West End to Abbotsford). Depots recorded with all components were assigned a Pass grade; depots with any one missing component or more were assigned a Fail grade. MS/SR and Pass/Fail grade was analyzed using Chi-squared test on NCSS 9 Statistical Software (NCSS). Results: Of the 35 depots surveyed, fails were present in both MS depots and SR depots. Very few depots had signage. Main reasons for Fails included broken hand dryers and lack of soap. All depots with hand wash stations had running water. Pearson’s Chi-square results for observed Pass/Fail and MS/SR depots compared to expected values were unable to reject null hypothesis (P-value 0.911 > 0.05) even when provision of signage was excluded as a criterion (P-value 0.537 > 0.05). Conclusion: There was no association between depot standard rating and provision of essential hand washing equipment. Lack of signage failed 74.3% of depots but excluding signage from the criteria failed 34.3% of depots. Hand washing is important in mitigating risk of infection from hand contamination from household recyclables and those sorted from waste. Inspecting depots and educating operators from a public health viewpoint may increase provision of essential hand washing equipment and increase hand washing compliance in public users.
 
The effect of Foodsafe Level 1 Training on inspection report results
Abstract: Food handlers equipped with food safety knowledge prevent foodborne illnesses. This study examined the relationship between worker Foodsafe level 1 training and critical violations reported on inspection results of non-chain restaurants in the Burnaby Fraser Health region. A total of 25 food service establishments with no critical violations on their routine inspections and 25 that had at least one critical violation participated in the telephone survey. Using the Mann-Whitney U two tailed t-test, it was shown that food service establishments with no critical violations on inspections had no significantly (p = 0.72) different proportions of Foodsafe level 1 trained staff than those with at least one critical violations on inspections. This study suggested that having more food handlers with food safety training does not impact how well restaurants score on inspections.
 
The effectiveness of smartphone temperature sensors for ambient temperature monitoring
Background: Heat-related illness during extreme weather events is a leading cause of death and morbidity among vulnerable populations. Heat health alert systems are crucial in preventing serious impacts due to extreme heat, however its efficacy is limited by available atmospheric temperature data. A study was conducted to determine the accuracy of a silicon band-gap sensor integrated into certain models of smartphones when compared to a well-documented thermistor themperature sensor. Methods: Ambient temperature readings were taken at a location chosen within Burnaby, BC, using both a Met One sensor and a Sensirion sensor integrated into a smartphone. The data was then analyzed using a dependent T-test for paired samples to determine whether there was a significant difference between the grouped readings. Results: According to the results of the dependent T-test with data adjusted to a calibration curve, it was determined that there was no difference between the readings taken by the Met One and the Sensirion sensors, t(30)= -0.68, p=0.5 (95% CI, -0.04 to 0.02). Conclusions: Although further research is needed, the results of this study suggest that temperature sensors found in smartphones may be a smaller, lower-cost, and more accessible alternative to some of the higher-end models currently used to measure ambient temperature for the purposes of public health planning and policy-making.
 
A study on the public perception of waste-to-energy facilities in Metro Vancouver
BACKGROUND: Metro Vancouver is proposing a second waste-to-energy (WTE) facility to be built within the regional district. WTE facilities are used to reduce the volume of waste going to landfill sites. With Metro Vancouver’s desire to become the Greenest City in the World by 2020, WTE facilities are one option to achieve this goal. The proposal is currently in its second phase, and is looking for an ideal location. However, there are debates over whether the use of WTE facilities is an ideal method of municipal waste disposal. The aim of this research project was to measure the public knowledge and opinion of WTE facilities across various demographics. METHODS: A survey regarding knowledge and opinion of WTE facilities was generated and distributed online via social media platforms. Microsoft Excel and NCSS software were used to analyze the data to determine statistical significance. RESULTS: There were a total of 111 respondents. Demographic information was analyzed against the respondent’s knowledge score of WTE facilities. There is no statistically significant difference between educational background, age group, or place of residence and attaining a particular knowledge score of WTE facilities (p=0.51, p=0.31, p=0.22 respectively). The results indicated a limited knowledge of WTE facilities in the general public, with a mean score of 3.6 out of a maximum of 5. 59% of respondents indicated that they felt neutral towards WTE facilities, while 24% believed they were the most desirable method of managing municipal waste, and 21% believed they were least desirable. CONCLUSION: Results suggests that WTE facilities are not well understood, and not enough knowledge has been provided to the public in order for them to formulate a consensus on supporting or rejecting the use of WTE facilities. In such cases, the Environmental Health Officer (EHO) can act as an educator to help the public make an informed decision on the effects of WTE facilities and the consequences of different methods of handling municipal solid waste.
 
Determining a relationship between licensing status and semi-quantitative risk score for BC dairy processing plants
Background: Following the 2014 Gort’s Gouda Cheese Escherichia coli O157:H7 outbreak which resulted in one death and 28 illnesses, an examination of dairy processing plants (DPP) within British Columbia (BC) was undertaken. The intent of this examination was to efficiently allocate resources to ensure a lower likelihood of future outbreaks occurring in a BC DPP and to improve current knowledge regarding DPP practices. A risk-based approach to assessing inspection activities for DPPs was undertaken. As such, the purpose of the project was to create a semi-quantitative tool to assess inherent risk factors of DPPs, after which it would be used to determine appropriate inspection frequencies for these plants based on their risk scores. Finally, a comparison between provincially licensed and federally registered dairies was conducted in order to examine if there was a difference in risk between the two licensing statuses. Methods: A semi-quantitative approach was used to characterize responses to a survey (Shi, 2014) conducted by the BCCDC between August and December 2014. This survey was sent to all DPPs (n=54) operating in BC. Each survey question related to increasing information on conditions found in DPPs, after which a semi-quantitative assessment approach was used to assign a total risk inherent to each DPP due to the conditions found in the facility. The DPPs were then ranked against each other with respect to their risk scores in order to assess which facility was considered of higher risk. Facilities were grouped by their licensing status, provincially licensed or federally registered, and then compared against one another using a two variable t-test in NCSS 10. Semi-quantitative risk assessment was done using an Excel tool designed specifically for the present study. Results: Complete data was obtained for 85%(n=46) of DPPs, with an equal number of provincial and federal DPPs used in the evaluation. Dairies were ranked against one another with respect to their total risk score. A statistically significant difference (p=0.036) was found when comparing the inherent risk of provincial and federal DPPs, with federally registered dairies showing a lower total inherent risk score. Conclusion: The information obtained from this study provided the BCCDC with a standardized risk-based inspection approach. Ranking of DPPs with respect to their inherent risk also allows inspectors to gain better understanding of present day dairies and their high risk issues. This reassessment allows for the development of more efficient inspection schedules in order to effectively allocate inspection resources and to increase the ability for inspectors to capture and prevent risks which would lead to foodborne illnesses.
 
Kimchi: determining the rapidity of acidification depending on temperature
Background: The increasing number of kimchi consumers in Metro Vancouver raises food safety concerns over the kimchi being out in the ambient temperature. Although kimchi is known to have lactic acid pro-ducing bacteria as its normal flora, environmental health officers have no specific reference to the change in pH with respect to time. The purpose of this study was to understand the rate at which kimchi ferments at different temperatures and determine whether kimchi is a hazardous food or not. Methods: Freshly made kimchi at researcher’s residence were divided into two groups; 4 oC and 25 oC. 30 samples for each set with equal amounts were left at these two different conditions. PH and temperature were measured at the time of separation and for three weeks weekly using the Waterproof Palm pH analyzer. Results: There was a steeper decline in the 25 oC set compared to 4 oC. It took some time between 22 hours and 34 hours for 25 oC set to show a drop in pH. On the other hand, 4 oC set did not show a significant decline in pH within the time period of the experiment.
 
Accuracy of swimming pool test kits
Background: Pool Chemistry is important to allow those using it to feel comfortable through pool water being physically clean and biologically safe. Operators and health inspectors use test kits to ensure that pool water chemistry is correct and will not cause irritation or problems to both the patrons and the pool recirculation system. This study investigates the accuracy of the three commonly used pool test kits available in the market (Taylor, HACH, and ColorQ). Parameters tested are Free Available Chlorine (FAC), Total Chlorine (TC), and pH. Methods: Using artificial pool water with known concentrations of FAC, TC, and pH, 30 samples were taken for the three different parameter from the three test kits. The indicated concentrations and pH on the test kits were then recorded and used to compare with the known standards. Results were analyzed using the statistical software NCSS. One sample t-tests were performed to indicate whether or not the test kit as accurate in reading different parameters of pool chemistry. Results: Taylor Test Kit: Readings for FAC (2.6ppm) showed 2.4ppm, TC (2.7ppm) showed 2.43ppm, and pH (7.1) showed 7.1. HACH Test Kit: Readings for FAC (2.8ppm) showed 3.5ppm, TC (3.0ppm) showed 3.5ppm, and pH (7.1) showed 6.97. ColorQ Test Kit: Readings for FAC (2.7ppm) showed 3.0ppm, TC (3.0ppm) showed 3.0ppm, and pH (7.0) showed 6.96. Conclusion: All three test kits have accurate readings for pH levels. However, the test kits do not provide accurate readings for FAC and TC which would make it difficult to calculate CC in pool waters. Although the FAC and TC readings are inaccurate, they are able to provide operators and health inspectors with brief information regarding pool water chemistry.