06/11/2012 09:42 EDT | Updated 08/11/2012 05:12 EDT

Hamilton air quality worst in Ontario

Air quality in Hamilton is the worst in the province Monday, according to ratings from Ontario's Ministry of the Environment.

Hamilton’s air quality as of 10 a.m. is moderate, but still showing the worst ratings in Ontario.

All three areas where air quality is measured — downtown, the mountain and the west end — show the three worst ratings on Ontario's Ministry of Environment air quality index Monday morning. The ministry's forecast show air decreasing in quality later today.

The smog advisory, issued Saturday afternoon for much of Southern Ontario, has yet to be lifted.

Smog advisories are issued when air quality is poor because of ground-level ozone and particulate matter.

David Phillips, Environment Canada’s senior climatologist, told CBC Hamilton that wind is pushing chemicals from places like the Ohio Valley in the United States in Hamilton’s direction.

With lots of sun, “we have the right ingredients to cook the chemicals,” Phillips said.

Local factors, like being close to a highway, contribute too, said Phillips. On Monday morning, the wind in Hamilton was only 6 km per hour, no where near strong enough to blow any pollutants out of the city.

"This adds to the poor air quality," he said.

Phillips said we've had a grand total of seven smog days in Southern Ontario to date in 2012. Hamilton sees an average of five smog days a year, he said.

Brenda Ferguson, director of corporate affairs and communications for Today's Family Early Learning and Child Care, is trying to keep her students indoors today. "It's unfortunate and it's something that will probably be prevalent over the summer," she said.

Ian Wright, Hamilton EMS commander, is expecting more calls because of the smog and heat.

"We do typically see calls related to respiratory problems increase," he said.

Wright recommends staying indoors or planning a stop inside during your trips.

The good news is Hamilton will see some temporary releif from Monday's 30 degree heat and smog. Phillips said a thunderstorm is expected in Hamilton Monday night.

"The rain will scrub and cool the air," he said. "And the rest of the week is looking pretty good."