KUALA LUMPUR, Oct 22 — The Air Pollutant Index (API) readings issued by the Department of Environment (DOE) remain the government’s official reference for determining air quality and managing haze.
Natural Resources and Environmental Sustainability Minister Datuk Seri Arthur Joseph Kurup said the official API was calculated based on the concentrations of six major pollutants monitored around the clock through 68 automatic air quality monitoring stations nationwide.
He said the stations used measurement equipment and technical methods recognised by the United States Environmental Protection Agency, with procedures in place to ensure the accuracy and reliability of the data.
“Station operations include equipment maintenance, calibration, instrument performance checks and quality assurance procedures to ensure that the data used to calculate the official API are accurate and reliable,” he said during the Minister’s Question Time in the Dewan Rakyat today.
Arthur was answering a question from Manndzri Nasib (BN-Tenggara), who wanted to know how the government ensured that Malaysia’s official API readings were accurate, transparent and trusted by the public.
He said the stations operated under a Quality Assurance Project Plan (QAPP), which included daily automated zero and span checks, periodic calibration using standard gases traceable to international metrology standards under the National Institute of Standards and Technology, and regular performance audits.
Data collected were also monitored continuously through the Environmental Data Centre to detect changes in readings, assess equipment performance and enable corrective action in the event of disruptions or irregularities.
Arthur said the official API was updated hourly, while the calculations for PM2.5 and PM10 were based on their 24-hour moving average concentrations, in line with World Health Organisation standards and practices adopted by international environmental agencies.
On differences between official API readings and those displayed on platforms such as the Air Quality Index (AQI) and other independent applications, he said these did not necessarily mean that the official readings were inaccurate.
“Differences may arise because these platforms use different scales, thresholds, categories, averaging periods, update times and data sources,” he said, adding that some also relied on low-cost sensors or estimates derived from models and satellite data.
He explained that satellite data measured particle concentrations in the atmosphere rather than actual air quality at ground level, where people breathe.
Such readings could also be affected by cloud cover and atmospheric humidity.
Meanwhile, Arthur said the ministry was open to improving the National Haze Action Plan to ensure that coordination mechanisms and protective measures remained relevant as haze conditions changed.
“This is important to ensure that the actions of the various agencies are better coordinated, particularly when API readings reach unhealthy or very unhealthy levels, to protect public health and well-being,” he said.
On measures to address haze and open burning, Arthur said the government maintained a zero-tolerance approach towards open burning.
The DOE had taken 3,433 enforcement actions related to open-burning incidents between August and October this year, he added. — Bernama