Why has the air quality in the UAE been so poor this week?

Visibility has fallen because of a sandstorm coming from Iran

A sandstorm engulfs Dubai's Burj Khalifa. AFP

Dubai has been ranked highly in a global index for an unwelcome reason this week: it has been named among the top 10 most polluted cities in the world.

The designation by the air purifier company IQAir, which refers to current conditions rather than the long-term average, results from an increase in pollution that has cut visibility.

The key factor behind the conditions in Dubai and other parts of the UAE is that the country is “under the influence of a massive dust storm originating in Iran”, said Dr Diana Francis, a researcher who leads the environmental and geophysical sciences lab at Khalifa University in Abu Dhabi.

The dust storm is causing, Dr Francis explained, a rise in the concentration of particulate matter (PM), along with other knock-on effects.

“So an increase in PM concentrations, as well as of secondary pollutants resulting from interactions between primary pollutants and dust aerosols, is expected to affect the UAE and Dubai in particular [because it is downwind of the area emitting dust] for a few days,” she said.

What is the forecast?

In an update published on Thursday, the UAE’s National Centre of Meteorology (NCM) said that easterly winds bringing in dust and sand over the sea were continuing. In some areas, the NCM said, visibility was less than 3,000 metres.

Tying in with this, IQAir said in an online update that Dubai was experiencing “very poor air quality due to regional dust and emissions”. On Wednesday morning, the city was ranked by the company as the third most polluted major city in the world as a result of the dusty conditions, behind only Kolkata and Beijing.

According to IQAir, the average air quality index (AQI) in Dubai last year was 97. However, at 4pm on Thursday the live AQI published by the US Consulate recorded a reading of 202, which translates to “very unhealthy”.

For comparison, at the same time the US Embassy in New Delhi gave an AQI of 155, which is classified as “unhealthy”, while the US embassy in Islamabad was recording an AQI of 89, which is described as “moderate”. Simultaneously the US embassy in Beijing recorded an AQI of 97, which also falls into the “moderate” category.

In the current conditions the NCM has suggested that UAE residents should keep doors and windows closed, wear a face mask and keep vehicle windows closed.

How common is this?

Sandstorms are a fact of life in the Gulf region and are especially common in the summer and during transition periods, such as when strong winds hit as temperatures rise between winter and spring.

A report published in 2017 by Emirates Wildlife Society-WWF indicated that sandstorms could become more frequent during the summer as a result of climate change.

In addition to the silica crystals or sand that they carry, sandstorms can also bring bacteria, viruses, dust mites and fungi.

While dust storms are a regular hazard, average levels of pollution in the UAE are improving, according to scientists.

As reported in The National earlier this year, factors such as a transition to renewable energy and tougher controls in air quality have been credited with reductions in the levels of pollution.

The work, by Dr Francis and colleagues at Khalifa University, used data from Nasa satellites to assess pollution from nitrogen dioxide (NO2) and sulphur dioxide (SO2).

The study looked at information from 2003 to 2023 and found that earlier on during this period, pollution levels were increasing before a decline in more recent years as efforts to improve air quality took effect.

Tying in with what has been seen this week, it is not just what is happening in the UAE that is affecting the long-term pollution trends: reductions in SO2 emissions from Iran were also said to be a factor behind the improvements.