The Irving Oil oil refinery has had three malfunctions in the last month causing a grey, gritty dust to layer parts of Saint John. ((Courtesy of Peter Searle))

A clean air activist is calling on the New Brunswick government to strengthen air quality monitoring after a series of malfunctions at the Irving Oil refinery left parts of Saint John covered in a gritty dust.

Three times this month, some homes and cars in east Saint John were covered in a grey, gritty material called catalyst.

The material came from a processing unit at Saint John's Irving Oil refinery.

Gordon Dalzell, a member of the Citizens Coalition for Clean Air, said the Department of Environment should impose tough air quality rules and enforce stricter regulations on the emission of the materials that were released by the refinery.

Dalzell said he was shocked that the province's air quality monitors didn't register any of the recent releases from the refinery.

The Department of Environment has two air quality monitors near the refinery, one in the Champlain Heights area and the other in Forest Hills. The department is investigating why the monitors did not pick up any of the catalyst.

Dalzell said the provincial government should be doing a better job of monitoring the material.

But the government's monitors only measure fine particulate matter, not larger particles.

An environment department official said fine particulate matter is of greatest concern to human health because it can get into people's lungs.

That's why the department uses that type of monitor in the Saint John area.

But the president of the New Brunswick Lung Association and an environmental engineer in Houston have both expressed concerns about larger releases.

In Burnaby, B.C., after a similar release from the refinery there, officials recently added a monitor that measures both fine and coarser material.

Dalzell said he also thinks catalyst should be regulated separately, instead of being lumped together with other particulate matter because it contains metals.