MODERATE levels of air pollution (particulate matter) are currently being monitored in Ballymena, according to the Department of the Environment.
Moderate levels are also being monitored in the Armagh, Belfast, Lisburn and North Down areas while high levels of air pollution are being monitored in the Newry area.
Moderate levels of particulate matter and nitrogen dioxide are being monitored in the Derry/Londonderry area.
The DoE pointed out that this localised air pollution is likely to be associated with the build up of emissions from vehicles and home heating during the current calm, cold weather conditions experienced across Northern Ireland.
While the cold and settled weather continues through the rest of this week, there is a possibility that high or veryhigh levels of pollution could be seen in urban centres across Northern Ireland, the Department stated.
It pointed out that during periods of High Air Pollution the symptoms of people with lung or heart disease may worsen. Healthy people are unlikely to experience any ill effects.
Hourly updates on levels of particulate matter (PM10 and PM2.5), sulphur dioxide, nitrogen dioxide, ozone and carbon monoxide are available on the Department’s website: http://www.airqualityni.co.uk and the Department’s freephone helpline 0800 556677, which also offers health advice to those who may be particularly sensitive to air pollution.