SHARJAH // Air pollution in Sharjah on some days reaches the same toxic levels as notoriously smog-ridden cities such as Beijing, Tokyo and Mexico City.
Scientists studying air quality in the emirate found pollutants including ethane, propane, acetylene, benzene, butane and toluene.
The concentration of benzene in particular, a known carcinogen, ranged from 0.34 parts per billion to 3.2 ppb. The average for Mexico city is 0.6ppb, for Beijing 2ppb and for Tokyo 4ppb.
Health authorities in the United States have set an exposure limit of 1 part per million in the workplace during an eight-hour working day.
The survey in Sharjah, conducted by scientists from the American University of Sharjah in collaboration with the Rosenstiel School of Marine and Atmospheric Science at the University of Miami, Florida, is focusing on specific types of pollutants known as volatile organic compounds, which contribute to smog formation.
Smog is the common name for ground-level ozone, which is formed when chemical compounds released from combustion engines react with other substances in the atmosphere in the presence of sunlight. Carbon monoxide, methane, nitrogen oxide and non-methane volatile organic compounds all contribute to forming smog.
Ground-level ozone is a public health concern and breathing it can trigger a variety of chest complaints as well as worsen asthma and bronchitis. Some volatile organic compounds have also recently been associated with cancer risk, reproductive effects and birth defects.
Preliminary results on measurements taken since last summer indicate that on some days Sharjah’s air is relatively clean, said Dr Tariq Majeed, associate professor of physics at AUS and the leader of the project. On other days, however, levels of pollutants are on par with the world’s most polluted cities.
Dr Majeed first observed the trend when looking at concentration data for ground-level ozone or smog from the meteorological station at Abu Dhabi International Airport. The analysis of the compounds that contribute to the formation of smog also show a similar trend.
The samples are being collected on weekdays between 1pm and 3pm in three areas – close to a beach, in the city centre and on top of a building on the university campus. The analysis is carried out in Miami with the collaboration of Dr Daniel Riemer.
While more data is needed to explain the large variations in the amount of air pollutants, Dr Majeed thinks this is an indication that a significant portion of the pollutants are produced abroad and carried on the wind.
Some pollutants, he said, have a long life and can travel large distances by air. The team is comparing the variations in pollution levels measured in Sharjah against atmospheric models that show the real-time movement of air masses.
Iran, Qatar and Saudi Arabia are all possible sources of the pollutants, he said. “If you look around this area, you will see a lot of petrochemical industry.”
The project continues until the end of this summer. The findings will be presented in August at the Scientific Assembly of the Committee on Space Research in Moscow.