Question 1

Why the term ‘haze’ is used?

The use of the term ‘haze’ as opposed to ‘transboundary atmospheric pollution’ in ASEAN is to play down the impact of Indonesian fires even though the fires and associated haze could pose risks to human health and the environment. The usage of ‘haze’ is a diplomatic way to avoid having to confront the State that causes the problem by linking it with principles of state responsibility under international law. The perception or the term ‘haze’ therefore takes the attention away from the fires that cause the transboundary pollution.

Question 2

How is haze measured?

Air quality index (AQI) is the main parameter that is usually determined during haze episode in Southeast Asia. There are several different calculations of AQI based on different countries due to different parameters used and the different thresholds used to determine health impact of air pollutants to human health. Overall, all countries calculate their AQI based on the method suggested by the United States Environmental Protection Agency (USEPA).

The main problem with the different AQI calculations during haze episode is the breakpoints used by different countries such as Singapore Pollutants Standard Index (PSI) and Malaysian Air Pollutants Index (API) are different. The measurement of parameters such as PM2.5 increases the value of PSI compared to API calculation using PM10.