The City of Windsor is being criticized for not practising what it preaches.

During smog advisories, the city asks people to suspend activities requiring gasoline-powered equipment.

But a local environmentalist recently caught city employees mowing grass on a smog day, and he's not impressed.

Derek Coronado said the city has a leadership role in fighting air pollution.

Under its environmental master plan, it does encourages people not to use gas-powered lawn mowers when air quality is poor. But last week, Coronado noticed the city doing just that.

Windsor was under smog and humidex advisories Friday.

"These machines, in particular, are very dirty. For example the environmental protection agency did an analysis that showed a one hour operation of a lawn mower is equivalent to driving a car for 320 km," Coronado said.

Jan Wilson, the city's head of recreation, said the city does scale back the use of their gasoline-powered equipment on smog days, but because of events such as soccer tournaments like the one at Ford Test Track this weekend, crews have to mow the grass.

However, moments after interviewing Wilson, CBC News cameras caught a city employee cutting the front lawn of the parks building on McDougall Street. Later Friday, three mowers were caught cutting grass at the WFCU Centre.

One city worker CBC News spoke to said he's been mowing on smog days for years.

Coronado said it's a matter of credibility. He is aware the city contracts out some of its work. But he said that's no excuse because stipulations about smog days could be included in agreements.

Coronado plans to discuss the issue with city officials.

"The issue is, there's supposed to be certain responses that the city engages in based on years of its environmental master plan and before that, its air quality action plan," Coronado said. "Some of those issues include reducing the use of gas powered equipment such as lawn mowers."