Arthur Kurup says differences between official API readings and independent air-quality apps reflect varying methods, data sources and averaging periods.
KUALA LUMPUR: Differences between Malaysia’s official Air Pollutant Index (API) readings and those displayed by independent air-quality applications do not necessarily mean pollution levels are being understated, Natural Resources and Environmental Sustainability Minister Datuk Seri Arthur Joseph Kurup said.
He said discrepancies could arise because different platforms use varying pollution thresholds, measurement periods, update frequencies and data sources.
“Differences in readings do not necessarily indicate that the official API readings are inaccurate or that air pollution levels have been lowered.
“Instead, these platforms may use different scales, including thresholds, categories, averaging periods, update times and data sources,” he told the Dewan Rakyat today.
Arthur was responding to Manndzri Nasib (BN-Tenggara), who asked how the government ensured the accuracy of official readings and whether haze information could be made easier for the public to understand.
He said the Department of Environment (DOE) operated 68 automatic monitoring stations nationwide, which continuously measured six major air pollutants using internationally recognised equipment and procedures.
“Official API readings are updated every hour, while calculations for PM2.5 and PM10 are based on 24-hour moving average concentrations.
“This method takes into account exposure to air pollution over that period and is consistently applied in determining the country’s air-quality status,” he said.
Arthur explained that some independent platforms relied on low-cost sensors, satellite measurements or model-based estimates, which could produce different results.
“Satellite data measures particle density in the atmosphere rather than actual air quality at ground level, where people breathe.
“Satellite data also has limitations because it can be affected by clouds and atmospheric humidity,” he said.
He stressed that the DOE’s API remained the government’s official reference for air-quality assessments and haze management, adding that efforts were underway to provide clearer explanations of pollution categories, trends and appropriate health precautions.
In a supplementary question, Richard Rapu (GPS-Betong) highlighted the absence of an automatic air-quality monitoring station in Betong, Sarawak, and sought a commitment to establish one.
Arthur acknowledged gaps in monitoring coverage, particularly in Sarawak, and said efforts would be made to increase the number of stations to improve the accuracy and coverage of air-quality readings.
He also highlighted MetMalaysia’s MyCMAQ forecasting system, which can predict potential air-pollution and haze conditions up to five days ahead.
Meanwhile, responding to Abdul Latiff Abdul Rahman (PN-Kuala Krai) on legal action against transboundary haze, Arthur said any proposed legislation must be enforceable rather than introduced merely for appearances.
“The main challenge in implementing legislation with a cross-border element is obtaining sufficient evidence to determine the source of pollution and those responsible,” he said.
He explained that identifying fire locations, land ownership and links to haze in Malaysia could involve another country’s jurisdiction, confidential information and issues of sovereignty.
“If we are going to introduce such a law, we must ensure that it has an impact and can be enforced, rather than merely for optics,” he said.