Computer model charts mortality from air pollutants in UAE

Out of the sands of the United Arab Emirates (UAE) has emerged a powerful economic centre. Its wealth is obvious in the towering skyscrapers and state-of-the-art desalination plants. This growth has, however, come at a cost: deadly environmental pollutants in the country are contributing to mortality, according to a computer model estimating the annual disease burden attributable to selected pollutants, and published in PLoS ONE¹.

The computer simulation, known as the Monte Carlo simulation mode, covers the country's seven emirates, or principalities, and accounts for the different levels of pollutants in different locations across the state. "[It] simulates human exposure to pollutants in outdoor air, indoor air in homes, indoor air in workplaces, drinking water, and coastal water," says Jacqueline MacDonald Gibson, an environmental scientist at the University of North Carolina–Chapel Hill, and senior co-author of the study.

Based on the results of other studies of exposure to these pollutants, researchers can use the model to estimate the number of cases of specific illnesses that could result from exposure to these pollutants, Gibson explains.

The World Health Organisation (WHO) has attributed 13 million deaths each year worldwide to risks of four categories of environmental pollution: particulate matter in outdoor air; combustion of solid fuels indoors; particulate matter and carcinogens in occupational environments; and pathogens in water. The computer simulation included the same environmental risk factors except indoor air pollution due to solid fuel use, since solid fuel is no longer used for cooking in the UAE.

Increasing health complications

[It] can be updated over time as environmental conditions change in the UAE.

Fine particles from the fumes of car exhausts contributed to 651 deaths in 2008, according to the study. This is more than all the other risk factors combined. Indoor air pollution, such as that resulting from tobacco smoke, comes in second place with 153 deaths. The third leading contributor to mortality was occupational exposures to diesel exhaust and heavy metals, with 45 estimated deaths.

Drinking polluted water caused an estimated 46,600 visits to the doctor in the Gulf state. Indoor air pollution, occupational exposures, and outdoor air pollution contributed to a similar number of visits, ranging from 15,000 to 20,000 for each.

"The study provides a scientifically sound modelling framework for assessing the health impacts due to exposure to various pollutants. The framework could well be applied elsewhere by providing location specific inputs to it," says Prashant Kumar from the University of Surrey, UK. However, Kumar adds, the study results could have been more representative had they included outdoor pollutants such as sulphur dioxide and airborne nanoparticles in the estimate.

The results provide an initial indication of the public health benefits possible in the UAE through new interventions to reduce environmental pollution. "[It] can be updated over time as environmental conditions change in the UAE, in order to keep track of changes in environmental risks to public health," says Gibson. Such updates, she adds, would provide useful information about whether health risks are increasing or decreasing.

"Although the study provides a clear indication of which pollutants have the greatest health impact in the UAE, [it] remains an assessment with large uncertainties," says Johann P. Engelbrecht from the Desert Research Institute, Nevada, USA. According to Engelbrecht, further measurements of airborne particulate matter concentrations will be necessary, since these have been identified as having the greatest impact on health in the UAE.

Sign-up to receive our e-alert update every two weeks to keep up with everything new on the portal.