Haze and mortality

Malaysiakini's recent coverage on the seasonal smogs from burning forests in Sumatra and Kalimantan has quite rightly cautioned that 'continuous hazy conditions will cause ill effects especially to those in the high-risk groups such as children, senior citizens, smokers, people who work outdoors in particular those suffering from asthma, bronchitis, pneumonia, chronic lung disease, cardiovascular problems, and allergies'.

The longer-term health effects of seasonal exposure to highly polluted air will remain conveniently ambiguous for the moment, but in fact we already have strongly suggestive data pertaining to short-term (acute) effects from such exposures, including excess mortality among the frail and elderly.

Narayan Sastry, a Princeton-trained demographer working at the Rand Corporation (a private think-tank in Santa Monica, California) published a paper entitled Forest Fires, Air Pollution, and Mortality in SE Asia in the February 2002 issue of the journal Demography (volume 39, number 1, pages 1-23).

In recent years, notable haze episodes have occurred in SE Asia in 1991, 1994, 1997, and 2002. 1997 was the worst of these, coinciding with an El Nino year which exacerbated the seasonal mid-year droughts and the ensuing fires which burned an estimated two-three percent of Indonesian land area (mostly in Sumatra and Kalimantan, but also affecting sizeable tracts in Irian Jaya, Sulawesi, Java, Sumbawa, Komodo, Flores, Sumba, Timor, Wetar as well as areas in Sarawak (west Malaysia) and Brunei).

Satellite imaging and remote sensing indicated that in Sumatra and Kalimantan alone, 45,600 sq km of vegetative cover were lost, comprising agricultural and plantations lands (50%), forest and brush (30%), and peat swamp forests (20%).

For a 15-day period in September 1997, the Air Pollution Index (API, largely based on the suspended particulates of size 10 microns and below, PM10) in Kuching, Sarawak reached or exceeded 850. The highest API reading recorded was 930, and visibility was down to about 10 metres. In Peninsular Malaysia, API readings hovered in the region of 200-300 during the same period. One hesitates to even imagine what the situation was like in the affected parts of Indonesia closer to and downwind from the infernos.

Sastry obtained daily mortality statistics from the Department of Statistics in Malaysia and correlated these with the daily API readings from the Malaysian Meteorological Department, in order to analyze the acute mortality in Kuching and Kuala Lumpur following upon days of high air pollution (defined as days when PM10 > 210 ug/m3).

His salient findings were reported thus in the professional journal: "a high air pollution day associated with the smoke haze increased the total all-cause mortality by roughly 20%. Higher mortality was apparent in two locations - Kuala Lumpur and Kuching (Sarawak) - and affected mostly the elderly. In Kuala Lumpur, non-traumatic mortality among the population aged 65-74 increased about 70% following a day of high levels of air pollution. This effect was persistent; it was not simply a moving forward of deaths by a couple of days [i.e. not s spurious "harvesting" effect].

"This finding suggests that there were real and serious health effects of the smoke haze... one implication of these results on the short-term [health] effects of the smoke haze in Malaysia is that the effects in Indonesia itself are likely to have been tremendous. The presence of significant mortality effects in Malaysian cities that are several hundred miles away from the main fires strongly supports this notion. Unfortunately, there are no appropriate health or mortality data for Indonesia to study this issue directly."

Nor was there any reliable information on morbidity (non-fatal illness episodes), or possible long-term health effects.

About 70 million people in South East Asia are affected seasonally by these recurrent smogs. The combined economic losses for Indonesia/Malaysia/Singapore due to the 1997 forest fires and smog were estimated at US$1.3 billion.

Clearly, the Asean Agreement on Trans-boundary Haze Pollution adopted in June 2002 (a regional haze monitoring and prevention mechanism) has been ineffectual.

It is time for the affected communities throughout SE Asia to demand immediate and effective action to put a stop to widespread and repeated forest burning, initially blamed on shifting cultivators and local and transmigration settlers, but now increasingly perpetrated by plantation companies using fire to clear forested (or logged) areas for rubber and oil palm planting, tree estates for pulp and paper mills, and other crops.