Measuring the Concentration of Volatile Organic Compounds (VOCs), Carbon Monoxide, and Particulate Matters in Underpass of Emam Reza Holy Shrine, Mashhad (Shirazi Parking)

The purpose of this study is to measure airborne contaminants including volatile organic compounds (VOCs), carbon monoxide (CO), and suspended particles of less than 10 microns (PM10) from April to November 2016. Over the course of 8 months, 144 samples were collected for pollutants VOC, CO and PM10 with two replicates per month at three stations. The pollutants were measured at one oclock in the evening. VOC and CO measurements were performed by the American-made Multi-RAE direct reading device and the Haz-Dust EPAM5000 Hazard Particle Measurement, in accordance with the US Environmental Protection Agency (EPA) standards. The air quality index (AQI) for pollutants (VOC, CO, and PM10) was calculated using linear correlation methodology according to the National Open Air Quality Standards (NAAQS). The results showed that the highest concentration of CO pollutants was related to the center of Shirazi parking with an average of 22.31 ppm, and the lowest was related to parking exit from Imam Reza Street with a mean of 7.5 ppm and then the parking entrance from Shirazi Streets with a concentration of 8 ppm. The concentration of carbon monoxide and PM10 at Shirazi parking station was higher than the standard of Iran Department of Environment (9 ppm, 150 μg/m3). The air quality index for carbon monoxide for all months except November and the air quality index for PM10 for June and September were higher than the standard. In addition, the highest concentration of volatile organic compounds was reported in September and, in general, contamination was higher during the warm period than the cold period.