Related Experiment Video
Updated: Feb 19, 2026

Measuring Carbon Content in Airway Macrophages Exposed to Carbon-Containing Particulate Matters
Published on: July 12, 2024
Rainfall-Associated Bronchospasm Epidemics: The Epidemiological Effects of Air Pollutants and Weather Variables
Kambiz Masoumi1, Maryam Haddadzadeh Shoushtari2, Arash Forouzan1
1Department of Emergency Medicine, Imam Khomeini General Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Background:
This study compares different risk factors in patients visiting a hospital during five rainfall-associated bronchospasm epidemics in Ahvaz and those visiting on other occasions.
Methods:
This case-control study was conducted on 5307 patients with bronchospasm admitted to the Emergency Department of Imam Khomeini Hospital in Ahvaz (Iran) from late October to December (as the epidemic) and 916 patients admitted from late January to March (as the nonepidemic) in 2011 to 2015.
Results:
A total of the 41.7% of the cases and 48.8% of the controls had episodes of bronchospasm, suggesting a significant difference between the two groups (P < 0.001). The mean concentrations of PM10, NO, NO2, and NO pollutants (except O3) were significantly higher in the nonepidemic periods (P < 0.05). The adjusted analysis showed a direct significant relationship between emergency respiratory admissions and each unit of increase in NO and SO2 concentration during the epidemic periods and NO2 concentration during the nonepidemic periods. During the epidemic periods, a direct and significant relationship was also observed between respiratory admissions and each unit of increase in relative humidity and evaporation.
Conclusion:
The results suggest that certain pollutants and weather variables are associated with the risk of emergency respiratory admissions during epidemic periods.
Related Concept Videos
Asthma-I: Introduction
Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Antiasthma Drugs: β2-Adrenoceptor Agonists
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce...
Asthma-III: Symptoms and Complications
Classification of Asthma
Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...

