The air quality in five towns in three states dropped close to unhealthy levels Wednesday.
The Department of Environment reported higher-than-normal Air Pollutant Index (API) readings for Port Klang (97), Nilai (92), Banting (82), Bukit Rambai in Malacca (87) and Muar (84).
An area's air quality reaches an unhealthy level when its API hits 101, a very unhealthy level at 201 and hazardous when it exceeds 301.
The air quality of an area is considered good if its API reading is between 0 to 50.
Director of air quality unit Kalsom Abdul Ghani attributed the decrease in visibility in various parts of the country to southwesterly winds blowing haze from open burnings in Sumatra hotspots.
"It occurred under transboundary conditions due to the wind, which normally takes this direction at this time of the year,” Kalsom said.
