SYDNEY, Jan. 10 (Xinhua) -- Australian health authorities have issued an air quality warning for Sydney City as the east coast of Australia succumbs to the grip of an intense heat wave.
The mercury is expected to tip 47 degrees Celcius as parts of New South Wales state by weeks suffer from a hot air mass built up over central and western Australia lingering in front of a low-pressure trough.
"There's not enough cold air further south to push this heat around, so it's just hanging around for days, and days and days until this low pressure trough comes through," Weatherzone meteorologist Kim Westcott told Xinhua on Tuesday.
"We've got some showers with it which will cool things down a little bit, (but) looking into next week, we may see heat returning and recirculating around.
"It's not over and done with once this air pressure cools the air mass a little, it's got a fair bit of cloud ... it will stop the direct heating (but) the air doesn't have sufficient time to really cool."
Health authorities urged people with respiratory issues to stay indoors as high ozone pollution levels, created from car exhaust and industrial fumes become worse on hot, still days.
"Ozone levels are higher outdoors than indoors, so parents should limit the time their children with asthma play outside as they are more susceptible to the effects of ozone pollution," NSW Health director of Environmental Health Branch Ben Scalley said in a statement.
While the chemical in the upper atmosphere is great for protecting from harmful ultraviolet radiation, at ground level it can cause lung, throat, eye and nose irritations, and may worsen chronic respiratory diseases.
The high temperatures come with an increased risk for wildfires. Authorities have warned farmers and pastoralists to increase firebreaks along their properties after more than 5,500 hectares of land was burnt in recent fires.
