Human-made pollution greater threat to Middle East than desert dust

A new study discredits conventional thinking about the Arabian Peninsula’s air quality. 

For years scientists had assumed that the primary contributor to elevated air pollution across the Middle East was dust from the desert. Now an international team of researchers at King Abdullah University of Science & Technology (KAUST) believes this may be wrong, and anthropogenic pollutants are the leading cause. 

Human-made particulate matter is distinct from less harmful coarse dust particles that naturally occur in the region’s air due to wind and sand. This means the behaviour and actions of people in the region have a greater impact on the atmosphere compared with landscape and weather conditions, effecting climate change and also leading to an estimated 745 preventable fatalities in every 100,000 excess deaths in the region. 

‘Previous modeling studies on air quality across the Middle East tend to overestimate the fraction of the desert dust, obscuring the contribution to poor air quality from anthropogenic sources,’ said Sergey Osipov of the Max Planck Institute (MPI) for Chemistry, whose team worked on the project with KAUST’s Georgiy Stenchikov and Alexander Ukhov, and colleagues from King Saud University and The Cyprus Institute.

‘Such models produce semicorrect answers for the wrong reason, because they poorly represent a significant component of anthropogenic fine particle pollution in the region,’ he continued. The lack of observational data, according to Osipov, has ‘significantly hindered our ability to model the chemical composition of the atmosphere in the region.’

To address this problem, this new study saw the tram collect measurements taken at sea as part of the international collaboration, Air Quality and Climate in the Arabian Basin. These figures were taken over a two month period in summer 2017 during a variety of ambient conditions, including low and heavy pollution levels, and dust storms.

Data was then analysed, providing comprehensive constraints on the dust size distribution, facilitating more realistic simulations of mass flux and life cycle of dust. From this, the team could model a far more accurate chemical composition of the aerosol, with some 53% made up of particulate matter from human-made, or anthropogenic, sources.

You can read the full study here. Separate research, published in the journal Nature Sustainability in June 2020, suggested that desert air pollution was causing an 18% increase in infant mortality.

Image: KAUST