Exposure to particulate air pollution (PM2.5PM_{2.5}PM2.5) is a major environmental risk factor linked to the development of non-communicable respiratory and cardiovascular diseases.
A clinical study investigated the acute impact of different microenvironments on lung function. Five groups of healthy volunteers were exposed to five distinct urban environments with different average PM2.5PM_{2.5}PM2.5 concentrations for 4 hours.
The percentage change in their Forced Expiratory Volume in 1 second (FEV1FEV_1FEV1) was measured before and after the exposure.
The table below shows the results.
| Environment | Rural park | Urban residential | Roadside | Industrial zone | Underground subway |
|---|---|---|---|---|---|
| Average PM2.5PM_{2.5}PM2.5 concentration (μg m−3\mu\text{g}\text{ m}^{-3}μg m−3) | 8 | 25 | 45 | 85 | 120 |
| Percentage change in FEV1FEV_1FEV1 (%) | +0.4 | -1.5 | -3.8 | -7.2 | -11.5 |
Which environment is most likely to cause the greatest acute impairment of lung function?
Roadside
Industrial zone
Underground subway
Urban residential
