Risk assessment of exposure to BTEX in the Holy City of Makkah

Millions of pilgrims visit Makkah every year in order to perform Hajj and/or Umrah. The high volume of road traffic during the Hajj season and the month of Ramadan emits large amount of chemicals into the atmosphere. Among these chemicals, volatile organic compounds (VOCs) are of a major concern for human health. The aim of the present study is to analyse the concentrations of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) and assess their impact on human health. Samples of BTEX were collected in Makkah City at three different locations namely: Al-Shbaikah, Al-Aziziah and Mina during Hajj season 1431H (November 2010) using activated charcoal tubes and a vacuum pump. The concentrations (microgram per cubic meter) ranged from 3.2 to 34.0, 8.1 to 52.4, 6.2 to 42.0 and 1.9 to 21.5 for Benzene, Toluene, Ethylbenzene and Xylene, respectively. The total concentrations of BTEX varied from 26.9 to 219.9 mu g/m(3). Both cancer and non-cancer health risks due to BTEX inhalation were assessed, and the results varied in both time and space within Makkah. The estimated cancer risk of BTEX per million people was 0.03-1.07 at Al-Shbaikah, 0.02-0.40 at Al-Aziziah and 0.02-1.16 at Mina. Children (6-8 years) and boys (12-14 years) were found to be at most risk.