Evaluation of Carcinogenic Polyaromatic Hydrocarbon Levels in Airborne Particulates Associated with Long-Term Exposure throughout the COVID-19 Pandemic in Makkah, Saudi Arabia

Background: The effect of polyaromatic hydrocarbons (PAHs) on human health differs depending on the duration and exposure path.

Objective: This study aimed to examine the effects of PAHs on the human health risks associated with long-term exposure both before and throughout the COVID-19 pandemic.

Methodology: PM10 sampling for 24 h was conducted at six sampling sites (Al-Haram, Aziziyah, Al Nuzhah, Muzdalifah, Arafat, and Al Awali). On-site measurements were conducted from March 2020 to February 2021. PAHs were analyzed using Perkin Elmer GC/MS, which was adjusted with standard reagents for identifying 16 PAH mixtures.

Results: The 24 h average PM10 concentration showed considerable inconsistencies, exceeding the WHO standards used for median exposure (25.0 µgm^-3). The PAH intensities fluctuated from 7.67 to 34.7 ng/m³ in a suburban area, near a rush-hour traffic road, and from 6.34 to 37.4 ng/m³ close to business and light manufacturing areas. The highest carcinogenic compound levels were found in the Al-Azizia, Al Muzdalifah, and Al Nuzah areas because of the high traffic density, and the lowest concentrations were found in the Al-Haram and Arafat areas throughout the year, as a result of the COVID-19 pandemic health precautions that were undertaken by the government of Saudi Arabia involving border entry limits and limitations of the Umrah and Hajj seasons.

Conclusion: This study period is considered extraordinary as the Saudi Arabian government has undertaken successful preventive measures that have had a great effect both on the spread of the pandemic and in reducing air pollution in Makkah. More studies are required to examine PAHs' carcinogenic effects after the pandemic measures are eased across Makkah.