The study, which used a new method to track so-called "fugitive emissions" from pieces of equipment at an unidentified Alberta refinery, finds such releases of gases such as benzene are up to 18 times higher than previously thought.

Although air quality around the refinery remained within provincial guidelines, the report's author said any reduction in such emissions is worth making.

"Anything you can do to reduce emissions to the air is a good thing," said Allan Chambers, who wrote the report for the Alberta Research Council.

Chambers' report looked at releases of methane, benzene and other hydrocarbons from leaking equipment and vents that are currently estimated using a combination of lab tests and mathematical modelling.

But the new study, published last month in an academic journal, used a type of laser to measure actual releases from the refinery.

The laser was positioned downwind of the site and its beam shot in a cross-section of the facility's plume. The diffraction and reflection pattern was then examined to measure what was truly in the air.

The results, averaging a week's worth of data over an entire year, were sobering.

Emissions of benzene, a known carcinogen, were 18 times higher than estimated for a total of 40 tonnes per year. Emissions of methane, a highly potent greenhouse gas, were found to be nine times higher than estimated, or 2,400 tonnes a year.

So-called volatile organic compounds, a major cause of smog, were underestimated by a factor of 15.

Chambers said those results are likely to be similar countrywide.

"You could consider this refinery pretty typical," he said. "It's quite likely other refineries in North America are in a similar position, that they're emitting quite a bit more than the (current methods) suggest."

Refineries also pay an economic price for such leakage. Chambers calculated that at $40 a barrel, the refinery is losing about $3.1 million per year.

The current price of oil is a little over $100 a barrel.

As well, cutting off all the leaks would reduce the facility's total methane emissions by five per cent.

The laser technology, known as Differential Absorption Light Detection, or DIAL, is in common use in Europe. Chambers said its absence in North America is due to fact few companies supply it and no governments require it.

"When you start talking methods that you require industry to do, then you need to have the equipment available, you need to have companies that can supply the service, and you need to protocols so you have consistent results," Chambers said.

"It's a chicken-and-egg situation. You can't write regulations when nobody can provide the service."

However, both the U.S. Environmental Protection Agency and Environment Canada - which helped fund Chambers' study - are re-examining methods used to estimate fugitive emissions, said Chambers.

As well, Houston, Texas, is also considering the DIAL system.