KUALA LUMPUR: Haze continues to affect the capital despite recent rain, as winds carry smoke and pollutants into the country while high humidity and water vapour contribute to poor visibility.
The Batu Muda and Cheras monitoring stations recorded unhealthy Air Pollutant Index (API) readings of 156 and 155 respectively at noon today.
Kuala Lumpur Department of Environment (DoE) director Sharifah Zakiah Syed Sahab said the rain was caused by natural weather conditions, not cloud seeding, and had only slightly reduced haze particles in areas where it fell.
"Winds are still carrying haze into the country, causing API readings to remain high in most areas," she told the New Straits Times.
She said Malaysia was currently in the monsoon transition phase, which typically brings thunderstorms, heavy rain and strong winds to the west coast and interior of the peninsula.
Although PM2.5 concentrations and API readings had decreased after the rain, poor visibility could make the haze appear more severe than the readings suggested, she added.
PM2.5 refers to fine particles measuring 2.5 micrometres or smaller that can penetrate deep into the lungs.
Sharifah Zakiah said high humidity and water vapour could trap dust and reduce visibility, particularly in the morning and after rain.
"This may lead people to assume that API readings should be higher than those recorded by DoE monitoring stations," she said.
She said PM2.5 remained the main pollutant at both Batu Muda and Cheras, with readings lower than before but still above pre-haze levels.
Despite the persistently unhealthy readings, the latest API trend showed a decline, she added.
The transboundary haze has affected Malaysia's air quality since Aug 8 and is expected to gradually ease over the next two weeks as wind patterns change, Deputy Natural Resources and Environmental Sustainability Minister Syed Ibrahim Syed Noh said on Tuesday.
A cloud-seeding operation was conducted in Kuala Lumpur, Putrajaya and Selangor last month to mitigate the impact of the haze.
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