What are the key air pollutants of concern?
The key air pollutants of concern include particulate matter (PM), sulphur dioxide, ozone, nitrogen dioxide and carbon monoxide. Short term exposure (i.e. continuous exposure to unhealthy daily average PSI levels over a period of a few days) to these air pollutants can cause respiratory symptoms and aggravate existing heart or lung disease. Exposure to particulate matter and sulphur dioxide may also cause irritation of the eyes, nose and throat in healthy individuals. In Singapore, the main air pollutant in the event of haze is particulate matter (PM).