SINGAPORE — The health impact of the haze should not be underestimated and doctors have urged Singaporeans to take precautions against prolonged exposure to the poor air quality, which has plunged to hazardous levels in recent days.
In particular, they cited the record levels of PM2.5 concentration, or very fine particulate matter.
They added that while the Pollutant Standards Index (PSI) reading of PM10 concentration — which was updated more regularly until today — tend to dominate the headlines, Singaporeans should pay attention to the PM2.5 reading as well.
For example, the PM2.5 concentration went up to about 304 μg/m3 at 4pm yesterday, way past its normal levels of between 20 and 40 μg/m3.
The PM2.5 concentration reading measures small particles of less than 2.5 microns in diameter, which can slip past the nasal passages into the lungs and blood streams, potentially creating an entire host of problems from heart attacks to stroke and even brain damage in extreme cases.
In comparison, the PM10 concentration reading tracks particles that are less than 10 microns in diameter, which get trapped in the nasal passage.
Nevertheless, the doctors stressed that the severity of conditions depends on the amount of pollutants breathed in by a person, so the exposure during normal commuting would not be considered too hazardous.
Associate Professor Philip Eng, a Senior Consultant in respiratory medicine, said: “The much smaller PM2.5 particles can go anywhere in the body, any organs. This can trigger inflammation of the blood vessels and lead to heart attacks, even in people with no history of heart disease.”
He added that inflammation could occur in unborn fetuses and these children have a higher risk of developing asthma after they are born.
Mount Elizabeth Respiratory Consultant Ong Kian Chung said one of the effects could even be brain damage, occurring at a similar level to people with Alzheimer’s disease. “But the effect is dose dependent. How long people need to be breathing in the polluted air to suffer such hazardous effects is not known,” he said.
Dr Ong added that, for average office workers, the PSI levels of beyond 300 do not pose a threat so severe that they have to stop working or work from home. “But for people who work outside, such as delivery drivers, it is hazardous, as they work outside all day long. Their number of working hours should be limited and they must be made to wear N95 masks,” he said.
The doctors also recommended that people wear N95 masks and close all windows and doors at home to bring down their exposure to the haze.
But Dr Lee Lay Tin, Head of Occupational Health Department at Tan Tock Seng Hospital, cautioned that these masks are only effective if they are of the correct size and fit. She advised those with respiratory ailments to consult their doctors on the use of respirator masks before buying them.
She said as much as 60 per cent of the haze particles may penetrate indoors, depending on air flow, and using air-conditioning and closing windows and doors may bring down the level.
On the use of air purifiers, she noted that they “may help reduce levels of smaller airborne allergens, particles, or, in some cases, gaseous pollutants in a home”. “However, air cleaners may not reduce adverse health effects, particularly in sensitive populations such as children, people with asthma and allergies, and the elderly. They also need to be properly maintained to be effective,” she said.
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