2308 - The Urinary 1-Hydroxypyrene Biomarker in Street Janitors Exposed to Air Quality Changes Associated with Religious Events in Madinah, Saudi Arabia

Abstract

Background Madinah is the second most important Muslim holy city in Saudi Arabia. Exceptionally during holy months, traffic congestion and consequent air emission of several pollutant compounds mainly carcinogenic Benzo[a]pyrene (BaP) is expected to reach high levels at certain places. Inhalation of air BaP emissions is the main route of entry into the human body. Therefore, the aim of the present study was to assess a biomarker of exposure to air BaP which is urinary 1-hydroxypyrene (1-OHP) among janitors and find out the relation between this biomarker with daily exposure to air BaP, some traffic and weather factors. Methods The study was performed during one Islamic calendar year from 1/4/1438 – 30/3/1439 (December 2016 to November 2017), in Madinah City. The research was designed to include three traffic locations with high traffic density and two control locations with low traffic activity. Daily breathing-zone air BaP was measured using PM2.5 personal samplers at the five locations. Daily volumes of traffic (cars, medium and heavy-duty vehicles) were recorded in the five studied locations. Daily weather recordings of temperature, % humidity, wind speed, precipitation and dust were obtained at these locations. Twenty male participants (street janitors) each were recruited in the study from the five studied locations (total = 100) aged from 25-35 years old. Two urine samples were obtained from each participant after the work shift and in the early morning to measure 1-OHP. Statistical analysis was done using descriptive statistics, two-way ANOVA, time series analysis and plots. Statistical significance was taken as p Results Urinary 1-OHP was significantly higher in the high traffic locations compared to those in the control locations. Time series analysis was conducted for mean urinary 1-OHP as the independent variable using ARIMAX model. The input variables included BaP, weather and traffic factors. The best fit model was ARIMAX model (1,1,1)(0,0,1)7. The only significant predictor for urinary 1-OHP was air BaP in the model (p Conclusions As the main source of air BaP comes from medium and heavy vehicles, air BaP might have a hazardous impact upon the health of residents at traffic locations and to lesser extent on visitors to Madinah. Finally, the management of the vehicular air pollution in the city of Madinah should be a high-priority concern for the Saudi Government which could include replacing older polluting vehicles with newer less polluting vehicles and encouraging sustainable private and public transport.