Air pollution fears at holy sites

Originally published 21 July 2014 on Nature Middle East.

Air quality in holy sites of Saudi Arabia sharply deteriorates during the pilgrimage seasons, exposing pilgrims to dangerous gases.

Pilgrims visiting the holy sites of Saudi Arabia, including Mecca, are being exposed to significant air pollution, with high levels of combustion tracer carbon monoxide (CO) and volatile organic compounds (VOCs) detected in samples, a new study shows.

Several one-minute air samples were taken from Mecca and the central pilgrimage route, which extends to Mina, Arafat, and Muzdalifah, during the main Hajj season – the largest annual Muslim gathering in the world. Those samples revealed elevated CO levels of 57 parts per million by volume (ppmv) – exceeding the maximum average concentration deemed acceptable by the US Environmental Protection Agency (US EPA).

The study, a collaboration by a team from University of California at Irvine (UC Irvine) and King Abdulaziz University, started during the pilgrimage season in 2012 with a survey focusing on measuring carbon dioxide (CO2), methane (CH4), CO, and 96 speciated C1-C10 VOCs. It revealed that the major VOC sources came from vehicular exhaust and petrol evaporation.

Nature Middle East, July 2014.