The haze has returned to peninsular Malaysia with four areas recording unhealthy Air Pollutant Index levels in the Klang Valley and the worse is yet to come.
As in previous years, several hotspots in central Sumatra in Indonesia are causing the haze.
Both the Department of Environment and Indonesian authorities expect the situation to worsen with the hot and dry spell in the Riau district of Sumatra set to peak over the next two weeks.
Air quality in Klang Valley deteriorated progressively on Friday with four locales noting unhealthy API readings as of 5 p.m. local time (4 p.m. Jakarta time).
They were Port Klang (147), Kuala Selangor (129), Shah Alam (120) and Cheras (105).
Most of the 51 areas monitored by DOE also showed increases, with several places in the Klang and Kinta valleys hovering at the edge of unhealthy API readings of more than 100.
The DOE classifies API readings of between 0 and 50 as Good, 51-100 (Moderate), 101-200 (Unhealthy), 201-300 (Very Unhealthy) and more than 301 as Hazardous.
“With the relatively dry weather in several northern and east coast states in the peninsula, the haze is expected to continue over the next few days,” said the DOE in a statement.
Indonesian daily The Jakarta Post, reported recently that peat and forest fires in the district were causing the haze and more fires were expected.
Satellite image reports issued by the ASEAN Specialised Meteorological Centre (ASMC) showed an increase in hotspots in Sumatra from 67 on Tuesday to 122 on Wednesday.
The centre reported a decline in the number of hotspots in the Riau district because of cloud cover over the satellite but noted that the south-westerly wind had blown the haze towards peninsular Malaysia.
Meantime, the DOE has activated its action plan to curb open burning and peat fires as well as step up enforcement on exhaust fumes from motor vehicles and factories.
The Meteorological Department's Fire Danger Rating System also reported that almost the entire country was at high risk of fires from the hot and dry weather.
The Fine Fuel Moisture Code (FFMC) chart on the department's website rated the ignition potential of many parts of the country as “extreme”.
The code, which is a numerical rating for moisture content of litter and other cured fine fuels (grass, bushes, dried leaves), is used as an indicator of potential for fires to start and spread in an area.
It is affected by temperature, relative humidity, rainfall and wind speed.
In Selangor, one case of peat fire was recorded on Friday in Pulau Kempas, Kuala Langat, where firemen fought to keep it under control.
Health Department director general Hasan Abdul Rahman said people should drink more water while high-risk patients with respiratory problems should seek early treatment if symptoms developed.
He also urged the public to visit the Health Ministry's website at www.moh.gov.my for health advice on coping with haze.