Environmental Public Health Journal 2014 | BCIT Institutional Repository

Environmental Public Health Journal 2014

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Air quality at bus stop microenvironments in a Metro Vancouver urban and suburban area
BACKGROUND Those commuters waiting in small-scale transportation microenvironments, such as bus stops, can be exposed to levels of pollution higher than what is registered by ambient air quality monitoring stations. In addition, historically, those commuting in urban areas experience greater exposure to air pollutants than those commuting in suburban or rural areas, due to the nature of the environment. Little quantitative research has been conducted in the Metro Vancouver area regarding air quality in small scale transportation microenvironments. OBJECTIVES The aim of this study was to assess the differences in commuter exposure during AM Peak and PM Peak periods between an urban (Vancouver) and suburban (Ladner) bus stop. Furthermore, results were to be compared to the Metro Vancouver 24 hour rolling average objective as well as nearby Lower Fraser Valley (LFV) Ambient Air Quality Monitoring Network stations. METHODS The author measured particulate matter (PM) 2.5 (particulate matter ≤ 2.5 μm in aerodynamic diameter), using the DustTrakTM Aerosol Monitor 8520 between January 6, 2014 and January 21, 2014 on 12 weekdays, from 6:30am to 7:00am and 5:00pm to 5:30pm, at Stop #55165 Northbound Harvest Dr at Ladner Trunk Rd in Ladner, BC and from Stop #50043 Burrard Stn Bay1 in Vancouver, BC. In addition, meteorological conditions, traffic density, bus volume, and other observations were taken during sampling periods. RESULTS The author found that average PM2.5 exposures were highest during the morning in Ladner (μ=34.38667μg/m3) and lowest during the morning in Vancouver (μ=13.44 μg/m3). In addition, there was a statistically significant difference (p<0.05) between Vancouver AM and the other groups (Ladner AM, Ladner PM [μ=28.07778 μg/m3], and Vancouver PM [μ=30.16667 μg/m3]), but the other groups were not significantly different from each other. Furthermore, the author found that the Vancouver AM average (μ=13.44 μg/m3) was below the Metro Vancouver 24 hour rolling average (25μg/m3) while all other groups (Ladner AM, Ladner PM, and Vancouver PM) exceeded this average. Lastly, when comparing all groups to the AM and PM hourly averages of their respective LFV Air Quality Monitoring Network stations (Ladner AM and PM vs. Tsawwassen AM and PM and Vancouver AM and PM vs. Kitsalano AM and PM), the author found that all groups averages exceeded the hourly averages of their respective stations. CONCLUSION Commuters’ peak hour exposures were significantly influenced by different microenvironments and were found to be higher than the ambient PM2.5 levels registered by the respective LFV Air Quality Monitoring Network stations. In order to address this, Metro Vancouver should implement personal exposure assessments, especially near roadways, to obtain actual levels of exposure to pollutants, such as PM2.5, by their residents. In this way, acute and chronic health outcome risks to air pollution can be better understood., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014, Published., Peer reviewed, air pollution, PM2, bus stop, commuting, microenvironment, personal exposure, ambient air, urban, suburban, Metro Vancouver
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., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, holding times, gastric, bladder, test strips, Ion Chromatography, e.coli
Bluetooth’s impact on radiation emissions
Introduction: Cellphone usage has increased leaps and bounds over the past decade. With the growing popularity of cellphones come numerous studies on the effects of mobile radiation on human health. Cellphone radiation has been associated with many health implications such as: sleep deprivation, hearing loss, slower sperm, cancers and tumors to name a few; however, more research is needed to confirm these claims. Purpose: The purpose of this research is to determine the Bluetooth impact on radiation levels when it is paired with a cellphone. This is a two-fold process: firstly, to determine radiation levels emitted by the pairing of a cellphone and a Bluetooth headset and comparing it to a control group of the cellphone alone and secondly, comparing the radiation emissions of a paired cellphone with the associated paired Bluetooth headset. Methods: An Extech RF EMF strength meter was used to measure the radiation emission levels (μW/cm2) of various phone types by Apple and Samsung when they were unpaired and paired with a LG HBM-220 Bluetooth device. The radiation emissions of the paired Bluetooth were also measured. Results: There was a statistically significant increase in radiation emissions (μW/cm2) observed in a cellphone paired with a Bluetooth when compared to an unpaired cellphone. This was statistically significant as the p-value (0.00026) was less than the 0.05 and 0.01 values and the power was near 100 % (99.8%). When comparing the paired cellphone with the associated paired Bluetooth, the Bluetooth emitted much more radiation than the cellphone. This data was statistically significant as well as the p-value was at 0.00000 and the power at 100%. Discussion: The findings in this study suggest that Bluetooth headsets increase radiation emissions; however, it is important to note that only one Bluetooth headset model (LG HBM-220) was tested. The results also conflict with Health Canada claims that Bluetooth headsets decrease radiation emissions. More research is needed to confirm the results found in this study. A key limitation of this study was that only Samsung and Apple Inc. brands were tested. Additionally, the equipment used to measure radiation levels (Extech RMF meter) was subject to background radiation sources. Conclusion: The pairing of a LG HBM-220 Bluetooth to a cellphone increases radiation emissions in both the cellphone and Bluetooth when compared to an unpaired cellphone. These increases in emissions when paired would results in additive effects to one’s body., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, Bluetooth, cellphone, EMF radiation, Apple, Samsung
The CO2 and PM2.5 levels in Downtown Vancouver at peak (5 p.m.) and off-peak (12 a.m.) hours
The effects of air pollution and global warming on human health have reached a dangerous level and this situation has become a critical environmental concern all over the world. The aim of the study was to explore levels of PM2.5 and CO2 emitted from the combustion engines of the road vehicles. The reason for choosing PM2.5 as one of the variables in this study is that it easily penetrates the lungs alveoli and is transmitted to other body organs by blood circulation. Exposure to PM2.5 from a few hours to a few weeks can cause serious cardiovascular diseases (CVDs), including death. The longer the exposure, the higher the risk for cardiovascular mortality. On the other hand, decrease in PM2.5 levels reduces cardiovascular mortality. Studies also show that PM2.5 is associated with diabetes, hypertension, and heart failure. The reason for choosing CO2 was its being as one of the six greenhouse gases leading to the climate change or global warming that threatens human health all over the world. Traffic emissions are the major source for both PM2.5 and CO2. That is why to understand the extent of the PM2.5 and the CO2 emissions from fossil fuel burning and thus their impact on human life is important. Studies show that while air pollution is high during peak hours, it is lower during off-peak hours. Moving from this fact, the discrepancies between peak and off-peak hours readings of the PM2.5 and CO2 levels, which were measured in Vancouver Downtown during 30 consecutive days, were observed. Air particulates PM2.5 were measured with the Dust Trak aerosol monitor and CO2 levels with Q Trak monitor. Results showed a statistically significant difference in the median concentration of PM2.5 between 5 p.m. and 12 a.m. (p=0.018). However there was no statistically significant difference in the median concentration of CO2 between 5 p.m. and 12 a.m. (p=0.84). Measures to reduce air pollution, particularly through reducing PM2.5 and CO2 levels, especially in urban settings, can help reduce the risks of global warming (CO2 effect) and have positive effect on public health issues by preventing or reducing the risks of occurrence of many diseases, and their fatal consequences in some instances, caused or triggered by exposure to air pollution. Both national governments and international agencies should support the scientific research the results of which will inform the public health policies and regulations that will promote cleaner air and thus healthier societies by both implementing some enforcement measures and educating the public on the risks of air pollution and global warming and the relevant and available remedies. This study has been carried out to contribute to the efforts made to this end., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, PM2.5, CO2, Air pollution, Emissions, Greenhouse gases, Global warming, Traffic
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%., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, Swimming, Pool, Hygiene, Knowledge, Survey
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., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, survey, food preferences, consumers, food choice, food safety
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., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Puiblished., Peer reviewed, Food scraps, Recycling, Green bin, Metro Vancouver, Garbage
The effectiveness of ozone-chlorine treatment for reducing chloramine concentration compared to chlorine treatment in swimming pools and whirlpools
Objectives: Chloramines are by-products of chlorine disinfected swimming pools and are hazardous to people if chloramines evaporate into the air. There is evidence that chloramines cause upper respiratory tract and eye irritation. It was suspected that ozone treatment in addition to chlorine disinfection will reduce chloramine levels in the pool. The following study compared chloramine concentration in a strictly chlorine disinfected swimming pool and whirlpool (C.G. Brown) in Burnaby, BC with an ozone-chlorine disinfected swimming pool and whirlpool (Killarney) in Vancouver, BC. The study also compared each pool and whirlpool to the 1.0 mg/L combined chlorine concentration limit in the B.C. Pool Regulation. Methods: Chloramine concentrations were determined by using a Hach Pocket Colorimeter 2 Analysis System which used a DPD method of analysis. Chloramine was determined by subtracting total chlorine by the free chlorine. Thirty pool water samples were analyzed based on two samples per pool per day for fifteen days. A two sample t-test was used to compare the ozone-chlorine treated pools with the chlorine only treated pools using the Mann-Whitney U test. A z-test was used to compare all types of swimming pools and whirlpools to the 1.0 mg/L limit. Results: The chloramine concentration in both the ozone-chlorine disinfected swimming pool and whirlpool was not statistically significantly lower than in the chlorine disinfected swimming pool (p=0.263597) and whirlpool (p=0.523672). Both types of swimming pools were found to be statistically significantly greater than the 1.0 mg/L chloramine limit (p=0.000023 in the chlorine pool and p=0.00001 for the ozone-chlorine pool). Similarly, both types of whirlpools were determined to be statistically significantly greater than the 1.0 mg/L chloramine limit (p=0.000001 for the chlorine pool and p=0.000001 for the ozone-chlorine pool). Conclusion: It was determined that there was no difference between ozone chlorine treated pools and chlorine only treated pools. Environmental Health Officers can suggest other forms of secondary treatment instead of ozone since there is no significant difference compared to chlorine only treated pools in reducing chloramine concentrations. This information is also beneficial for pool operators because they can increase their flow rates for pools that use ozonation or strictly chlorination relative to what they were originally designed for., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, Chloramine, chlorine disinfection, Ozone-chlorine disinfection, swimming pools, Whirlpool
Effects of light emissions from LCD monitors on public health
Background: Evidence suggests that exposure to prolonged use of computer monitors may lead to eye discomforts such as eyestrain, blurred vision, headaches, as well as computer vision syndrome. With the increase of internet and computer use at school and work, it raises a serious concern on whether or not the users are affected negatively. Objectives: The following study focuses on estimating the risk of using computers at the British Columbia Technology of Institute (BCIT) laboratories to determine if there is sufficient room lighting (illuminance) and monitor brightness (luminance) to ensure the safety of students at the school. Methods: Illuminance and luminance were both measured by means of a calibrated Unfors Xi light detector connected to a base unit. Several areas of each environment and monitor were measured and average values were taken to ensure that the data was reliable. The data were compared to applicable standards to determine if room lighting and computer brightness at BCIT were appropriate for safe student use. Results: The average illuminance was measured to be 405.4 Lux when the recommended level is 500 Lux. The results are considered statistically significant (p-value = 2x10-6). On the other hand, the luminance measurements averaged a reading of 94.6 cd/cm2 when the recommended minimum luminance level is 80 cd/cm2 (p-value = 0.99964). Discussion: The collected data show that the illuminance inside the BCIT laboratories where testing was conducted is not sufficient while the luminance of computer screens was found acceptable. Conclusion: The measurement of the illuminance inside BCIT laboratories showed that room lighting was insufficient and alternations of the monitor's brightness were made to compensate for insufficient lighting. It is recommended to increase room lighting in the tested laboratories in order to have all areas of the laboratory sufficiently lit at all times. This is to ensure that all students at BCIT are provided with a safe and healthy environment for computer use., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, LCD, illuminance, luminance, monitors, Unfors Xi, Light
The efficacy of alcohol-based hand sanitizers used in a series, modifying the ASTM E2755 method with a shorter hand sanitizer application time
Background: Alcohol-based hand sanitizers are becoming increasingly common in healthcare settings in an effort to control communicable bacteria, viruses and fungi of health significance. Much research has been done on the effectiveness of alcohol-based hand sanitizers but few studies look at the effectiveness when combined with more typical usage, such as varying application times and amounts. Methods: We looked at the efficacy of the microbial killing power of an alcohol-based hand sanitizer when used in a series of 5 applications. ASTM E2755 was used with the modification of a shorter application time (8 seconds from the recommended 30 seconds) of the sanitizer to better reflect actual healthcare worker usage. Results: We found an increase in the amount of indicator bacteria on the gloved hands of the subjects after repeated applications. However the increase was not significant enough in that a 2-log reduction of indicator bacteria was still achieved. Using a One Sample T-Test we found a very low probability value (<0.00000), indicating that the results were statistically significant. Conclusions: There is an increase of bacteria on gloved hands after repeated use of alcohol-based hand sanitizers. The results show a decrease in their effectiveness, most likely due to a build up of various non-alcohol components in hand sanitizers. However even with the 8 second application time there was still a greater than two log reduction even after 5 serial contaminations and applications. This cautiously shows that there is significantly less danger posed by more common shorter application times than originally thought. These findings have a potential impact on hand hygiene education as other factors, such as frequency or sanitizer amounts can be safely emphasized over application times., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, Alcohol hand sanitizer, Hand hygiene, ASTM E2755, Application time, Nosocomial infections
The efficacy of ATP removal on gym contact surfaces with disinfectant wipes.
Background: Gym equipment surfaces are known to harbor a range of contaminants due to the wide range of community use of the equipment. Certain gym equipment undergoes daily sanitation, however many other equipment surfaces do not. This study measures the levels of contamination on certain gym equipment surfaces at an educational institute gym facility and determines the contamination levels after disinfectant wipes are applied. Methods: The method to obtain the data was determined by the use of the Hygiena Systemsure II ATP analyzer in conjunction with Hygiena Ultrasnap ATP surface swabs. Gym equipment (barbells, dumbbells, machine handles, cable attachments) and other surfaces (benches, floor mats) were swabbed subsequently after a random gym patron had used the equipment to capture an accurate representation of the cleanliness of the surfaces. Disinfectant wipes were then applied to the same area before being swabbed again to determine contamination levels after disinfection. Results: The results demonstrated a statistically significant difference in the reduction of ATP levels with the use of disinfectant wipes with a p-value of 0.00001 at α=0.05. Alpha error was highly unlikely with a p-value being that low. Power was 99.9%, therefore there is a strong likelihood that we are correctly rejecting the null hypothesis. Conclusion: The study can conclude that disinfectant wipes do make a significant difference in surface cleanliness levels. Equipment that does not undergo routine cleaning such as the equipment used by the hands carry a much higher contamination rate than the body contact surfaces. Gym patrons should disinfect all body contact surfaces prior to use to reduce the risk of getting an infectious disease., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, Gym, Disinfection, Ultrasnap, Hygiene, ATP, RLU
Evaluating the health and safety knowledge of body waxing providers in British Columbia
BACKGROUND: Since the deregulation of the BC Cosmetology Act in 2003, esthetics has become a voluntary-certified trade. Considering the rising popularity of more intimate body waxing services and the potential for infections and injuries associated with these services, there is concern that BC waxing service providers have varying levels of health and safety knowledge. METHODS: The health and safety knowledge of BC estheticians was analyzed by conducting a knowledge assessment survey of body waxing providers from random clusters of 50 beauty salons in Vancouver and Surrey, BC. To evaluate which parameters affected the estheticians’ knowledge scores, ANOVA, t-tests and regression analyses were used. Chi square analyses were used to determine factors associated with the level of esthetics training. RESULTS: Health and safety knowledge scores widely varied (mean = 18.8 ± 5.5 out of 36 points). Estheticians’ qualifications were not significantly associated with whether the esthetician started practicing before or after the BC Cosmetology Act deregulation. 84% held a traditional esthetics certification and 30% had BeautySafe certification; however they did not necessarily score significantly higher on the health and safety knowledge assessment. Estheticians scored higher in Vancouver than in Surrey (p=0.046). The cost of waxing (p=0.0011) and estheticians’ perceptions (p=0.020) of their own knowledge level are also positively related to their knowledge score. Age, alma mater, years of experience, and ethnicity did not show any significant relationship with an esthetician’s qualifications or knowledge scores. CONCLUSIONS: Cost of wax treatment, esthetician’s perception of health and safety knowledge and location were indicators of an esthetician’s health and safety knowledge competency. Consumers should ask the esthetician to rate their own knowledge competency, opt for the more expensive treatment and if they have the option, choose a Vancouver salon over a Surrey salon. The wide range of knowledge scores indicate a gap in health and safety standards and thus, an opportunity for health authorities and the esthetic industry to collaborate to establish such standards., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2014., Peer-reviewed article, Published., Peer reviewed, body waxing, esthetician, health, safety

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