The environment department’s air pollutant index (API) showed figures ranging from 108 at 7am to a peak of 120 at 5pm in Petaling Jaya before easing slightly to 116 at 10pm, still within the “unhealthy” range.

Readings of between 101-200 are regarded as “unhealthy” and 201-300 as “very unhealthy”.

The API figures showed poor air quality in Segamat from 12pm to 5pm, with figures of 103 to 110 but the air quality had improved to “moderate” levels by 6pm. However by 10pm the API in the area had climbed back up to 107.

However, the US-based website, IQAir reported poor air quality at 10 locations in Malaysia, with the figure for Petaling Jaya reaching as high as 166.

At 10pm, IQAir reported an “unhealthy” air quality index figure of 164 for Petaling Jaya and 156 for Segamat district in Johor.

The site also reported poor air quality regarded as “unhealthy for sensitive groups” in Kedah, Penang, Selangor, Negeri Sembilan, Johor and Labuan.

The localities were: Banting, Selangor (145); Seremban, Negeri Sembilan (136); federal territory of Labuan (132); Prai, Penang (123); Shah Alam, Selangor (123); Kuala Selangor, Selangor (120); Parit Sulong, Johor (120); Alor Setar, Kedah (117).

The website’s figures are from real-time reporting based on the US air quality index, while Malaysia uses its own API which gives an average figure for a locality over a 24-hour period.