Correlation of ambient particulate matters (PM₁₀, PM_2.5) with respiratory hospital admissions: a case-crossover study in Urmia, Iran

Abstract

Exposure to high concentrations of ambient particulate matters (PMs) has a strong potential to cause adverse respiratory outcomes. Recent PMs increase due to the drying of Urmia Lake remains a major health challenge in the west of Iran. This study was conducted to assess the correlation of the exposure to PM₁₀ and PM_2.5 on respiratory hospitalization in Urmia, Iran. Daily hospital admissions and air pollutants data were collected during the study period. Conditional logistic regression models were used to estimate the risks of hospitalization in exposure to PMs. There was a significant adverse effect between PM₁₀ and asthma hospitalization based on the adjusted and unadjusted models. In the adjusted model, an interquartile range (IQR) increment of PM₁₀ and PM_2.5 increased the risk of admissions for asthma by [1.124 (1.062-1.191)] and [1.117 (1.055-1.184)], respectively. The estimated odds ratio for females was 1.5 times higher than males. A comparison of the associated risks of PM_2.5 indicates a significant increase in the group aged 18-60 and >60 years. Not including asthma, a significant correlation was found between all causes of hospitalization and exposure to PM_2.5 during cold seasons. Taken together, the results provide important insights into that exposure to ambient PMs were associated with an increased risk of respiratory hospitalization.

Highlights

• A case-crossover design was used to evaluate the correlation of PMs and hospital admissions.

• Conditional logistic regression models were used to estimate the risks.

• The estimated odds ratio for females was 1.5 times higher than males.

• A significant correlation was found between hospitalization and PM_2.5 exposure during cold seasons.

• Group aged 18–60 years and >60 years were faced at more risks in exposure to PM_2.5.

Keywords:

• Air pollution
• particulate matters
• hospital admission
• case-crossover
• respiratory diseases

Compliance with ethical standards

The local Ethical Review Committee of Tabriz University of Medical Sciences approved this study (IR.TBZMED.VCR.REC.1397.148).

Disclosure statement

There is no potential conflict of interest for any of the authors concerning this study.

Data availability statement

The datasets generated during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This work was supported by the Office of the Vice-Chancellor for Research of Tabriz University of Medical Sciences (Grant No. 60048).