Correlation Between Air Quality and the Exacerbation of Asthma Symptoms in the Population of the United Arab Emirates

TL;DR

This study explores the link between air quality and asthma symptoms in Dubai, UAE, finding unexpected results that higher pollution levels may be linked to fewer breathing difficulties.

Contribution

This is the first pilot study in the UAE investigating the association between daily PM2.5 levels and asthma symptoms.

Findings

Higher PM2.5 levels were inversely associated with shortness of breath (SOB) in asthma patients.

No significant association was found between PM2.5 and cough, wheeze, or chest tightness.

Younger age groups reported more frequent SOB compared to older groups.

Abstract

Background

Asthma is a chronic respiratory disease, characterised by shortness of breath (SOB), wheeze, cough and chest tightness, that has a significant impact on quality of life and global health. Previous studies have demonstrated that environmental pollutants, particularly particulate matter (PM2.5), play a key role in triggering and exacerbating asthma. Despite high atmospheric air pollution in the United Arab Emirates (UAE), there is limited region-specific research evaluating its effect on asthma symptoms. This study aimed to investigate the association between daily PM2.5 levels and patient-reported asthma symptoms in adults residing in Dubai, UAE.

Methods

A retrospective observational study conducted between April to June 2024, using 284 outpatient consultation records from pulmonology clinics at a single-centre, King’s College Hospital London in Dubai, UAE. Inclusion criteria involved adults aged 18 and above, a formal diagnosis of asthma, and a minimum of one year of residency in Dubai prior to the study period. Symptoms, including SOB, cough, wheeze, and chest tightness, were extracted from electronic medical records. These symptoms were matched to daily PM2.5 data obtained from an online air quality server, known as IQAir. Associations were assessed using chi-square tests and logistic regression, adjusting for age, sex, body mass index (BMI), smoking status, allergy status, pet ownership, and consultation type.

Results

In the final analysis, 284 consultations were included. From these, 162 were male (57%) and 122 were female (43%) participants. SOB (60.9%) and cough (46.1%) were the most frequently reported symptoms. Logistic regression revealed that higher PM2.5 categories (“Unhealthy for sensitive groups”) were associated with a lower likelihood of reporting SOB (adjusted OR 0.53, 95% CI 0.29-0.98, p=0.045). No statistically significant associations were found between PM2.5 and cough, wheeze, or chest tightness. Age was independently associated with SOB, with the youngest group (18-29 years) having a higher incidence of SOB compared to older age groups.

Conclusions

Contrary to established evidence, higher PM2.5 levels were inversely associated with SOB among asthma patients in the UAE. This unexpected association should not be interpreted as suggesting a protective role of air pollution; rather, it is more plausibly explained by numerous factors, including methodological constraints such as consultation-related confounding, or patient factors, including behavioural avoidance. Furthermore, given that these results diverge from prior research, the limited sample size and statistical power should be considered when interpreting the findings. As the first pilot study in the UAE linking daily air quality with clinical asthma outcomes, it is evident that larger, long-term studies incorporating seasonal variations and additional pollutants are necessary.