Photo: Ling Low

How do we measure haze?

Singapore uses the PSI (Pollutant Standards Index), a standard developed for measuring pollutants by the United States Environmental Protection Agency (USEPA). Malaysia uses API (Air Pollutant Index). Both have similar categories: a reading of 0-50 is considered ‘good’, 51- 100 ‘moderate’, 101-200 ‘unhealthy’, 201-300 ‘very unhealthy’. A reading above 300 is ‘hazardous’.

What is the main pollutant in haze?

PM10 is the dominant pollutant in haze, and this is what is mostly measured to determine the PSI or API reading.

What happens in a state of emergency?

If the reading is above 500 in Malaysia, a state of emergency is declared in those areas. According to emergency guidelines, schools and non-essential civil service offices and workplaces are closed, including factories, plantations, construction sites, quarries and earthwork sites.

Who is responsible for the haze?

The current haze in Malaysia is caused by slash and burn in Indonesia, an illegal practice of clearing forested land for timber and palm oil plantations. Some of the land where fire ‘hotspots’ have occurred belongs to Malaysian and Singaporean companies. Sime Darby, the world’s biggest listed palm oil producer, has denied that fires have occurred in their operating areas.

What can we do about the haze?

Cloud seeding is one method of clearing the air, where rain is artificially induced by implanting clouds with particles that induce water droplets. But this method requires existing clouds in order to work. Cloud seeding also cannot control where the rain falls, which means it is hard to target to small areas. Finally, it only provides a temporary relief if winds continue to blow haze over.

How does the haze affect health?

Haze particles can irritate the eyes, nose and throat. For healthy people, this should resolve itself if exposure is limited. For those who have heart or lung diseases such as asthmatic conditions, it can be more serious.

According to the Ministry of Health in Singapore, ‘long-term’, inhaling haze particles can lead to heart attacks, strokes and reduced lung development and chronic respiratory diseases. But it is not clear what is considered ‘long-term’.

How can we stay healthy?

The Ministry of Health in Singapore advises using N95 masks, except for children and pregnant women in their second and third trimester. Staying indoors to limit exposure is common advice, as well as drinking water to keep hydrated. If you fall unwell, seek the advice of your GP.

Ling Low