The effects of air pollution on respiratory and cardiovascular health.

Today, air pollution is one of the critical problems in metropolitans and necessary preparations are needed for confronting this crisis. The present study was based on the goal of determining the relationship of air pollutant levels with the rate of emergency admissions for respiratory and cardiovascular patients.

Methods:

In the present retrospective cross-sectional study, all respiratory and cardiovascular patients, referred to emergency department during 2012, were assessed. The meteorological and air pollution data were collected. Information regarding the numbers and dates (month, day) of admission for respiratory and cardiovascular diseases was achieved from the hospital's electronic registration system. The relation of air pollution and respiratory and cardiovascular admissions were analyzed by generalize additive model (GAM).

Results:

5922 patients were assessed which included 4048 (68.36%) cardiovascular and 1874 (31.64%) respiratory. Carbon monoxide (CO) level was an independent risk factor of cardiovascular disease on the same day (RR=1.49; 95% CI: 1.25- 1.77; P<0.001), the day before (RR=1.22; 95% CI: 1.02- 1.45; P=0.03), and the last two days (RR=1.3; 95% CI: 1.09- 1.54; P<0.001). The same process was repeated for ozone (O3). In addition, the O3 level on the same day (RR=1.49; 95% CI: 1.25- 1.77; P<0.001), the day before (RR=1.22; 95% CI: 1.02- 1.45; P=0.03), the last two days (RR=1.3; 95% CI: 1.09- 1.54; P<0.001), and the last week (RR=1.004; 95% CI: 1.0007-1.008; P=0.02) were independent risk factors of respiratory admissions. The increased level of particulate matter less than 2.5 micrometers in diameter (PM2.5) like O3 led to growth in the admissions to emergency department.

Conclusion:

The findings of the present study suggested that rising levels of CO and O3 during two days leads to a significant increase in cardiovascular admission on the third day. Furthermore, increase in O3, PM2.5, nitrogen dioxide (NO2), and CO levels causes a rise in respiratory admissions to emergency department.

Key Words: Air pollutant, patient admission, cardiovascular disease, respiratory disease