Rain helps lessen impact of haze from Sumatra fires

Audrey Tan, Straits Times AsiaOne 29 Aug 15;

SINGAPORE - Rain in the past few days helped to ease hazy conditions in Singapore, with the air quality in the moderate range as of 7pm yesterday.

Despite the haze that blanketed South Sumatra's provincial capital of Palembang on Wednesday, the rain has helped maintain air quality here, said Dr Erik Velasco, a research scientist from the Singapore-MIT Alliance for Research and Technology.

"The winds have been blowing from the south-south-east direction. If the winds switch a little bit to the west and the fires continue in Sumatra, we could expect a more intense smoke-haze.

"Fortunately, we have experienced some rain that has helped to maintain the air quality at moderate levels," he said.

As at 7pm yesterday, the National Environment Agency (NEA) said the 24-hour Pollutant Standards Index (PSI) was in the moderate range, hovering between 64 and 70. Under such conditions, normal activities can be carried out.

Two hot spots were detected in Sumatra yesterday, said NEA, with smoke plumes and haze visible in the southern half of the Indonesian island.

For today, the weather agency expects thundery showers in the late morning and early afternoon. But occasional slight haze from Sumatra might be on the cards this afternoon, if the winds shift briefly to blow from the south, it added. Overall, air quality for the next 24 hours is expected to be in the moderate range.

Dr Velasco said the frequent rain last week had lessened the impact of the fires in Indonesia.

"Two weeks ago, a massive number of hot spots were detected in Kalimantan, but the PSI rose only to moderate levels."

Noting that weather forecasts for Riau, Indonesia, showed "weak possibilities of rain", he said: "We should cross our fingers for rain in the whole region - in Singapore and Malaysia, to attenuate the smoke-haze impact, and in Indonesia, to stop the fires."

The severe smoke-haze that Singapore experienced in 2013 was triggered by two months of dry weather in the region.

The PSI had then reached hazardous levels.

But associate professor Richard Webster from Nanyang Technological University's School of Physical and Mathematical Sciences warned that if the levels of fires and wind conditions are similar to 2013, PSI readings could be just as bad for short periods.

"Because this year is an El Nino year, some have predicted that the haze could be particularly bad due to warmer temperatures, although this appears not to have occurred so far," he said.

When is the haze dangerous (and other important haze facts)
The Straits Times AsiaOne 29 Aug 15;

Singapore may not have autumn, winter, summer or spring but people now joke that we have our own four seasons; hot, wet, flood and haze.

While the flood is localised to certain parts of the island, there's no escaping the haze for any of us when it hits.

The haze situation in Singapore is caused by winds bringing in smoke from the forest fires in Sumatra, usually during the period of May to October.

Authorities in the South-East Asia region are working with their Indonesian counterparts to combat this haze problem, but for the time being, it looks like the haze will remain an annual event for the foreseeable future.

We've grown so used to the haze that it's quickly become the butt of jokes.

However, the air we end up breathing may contain particulate matter, carbon monoxide, dirt and other pollutants that affect our health.

Dr. Muhammad Iqbal, who runs his own practice, The Cliniq, cautions, "The main potential danger of the haze is respiratory illness although it can also affect the eyes and skin. Asthmatics are definitely at a higher risk but I have also been seeing many children and babies who are down with breathing problems. These are the susceptible groups, along with the elderly."

When Is The Haze Considered Unhealthy?

The National Environment Agency (NEA) measures air pollution levels through a system called the Pollutant Standards Index (PSI). A PSI value in the range of 0 to 50 is considered 'Good' while a PSI value in the range of 101 to 200 is considered 'Unhealthy'. Anything above 300 is considered 'Hazardous'.

When the air quality reaches 'Unhealthy' levels, it is more likely to trigger mild aggravation of respiratory illness symptoms among those suffering from chronic lung or heart ailments. For others, it may affect you by triggering coughs, eye irritation and sneezing. The NEA has summarised the air quality categories as based on PSI and how they affect your general health.