The City of Ottawa says the release of more than 2,700 kilograms of Freon-22 into the Ottawa River does not pose a risk to the drinking water because it quickly evaporates into the air, but Freon-22 released into the air carries other risks to the environment and to health, experts said Wednesday.
The chemical came from the federal government complex at Tunney's Pasture, where a heating-and-cooling plant is connected to the river. On Monday, a condenser inside the plant leaked, and for about 24 hours, Freon-22 spilled into the river. Toxicologists said most of that would have evaporated into the air.

Freon-22 is a refrigerant, the kind used in fridges and air conditioners.

"Freon's a potent greenhouse gas. So it leads to greenhouse gases in the atmosphere that would be about the equivalent of a thousand families driving their cars for a full year," said Dale Marshall, a climate-change analyst with the David Suzuki Foundation.

"There are also some other impacts in terms of the ozone layer and potentially human health impacts," Marshall said.

Public health officials said the leak poses no threat to the city's drinking water supply. But anyone in the immediate area at the time of the spill could be at risk.

"From a human health standpoint, the most likely risks would be through inhalation. If there were people in the vicinity that might have inhaled a large amount of this Freon, then they might want to consult a doctor," said Jules Blais, an environmental toxicology expert at the University of Ottawa.

However, officials with Public Works Canada would not say exactly where the chemical was released.

Without knowing that, it's impossible to know how much would have evaporated into the air, or who might have been nearby.

"Obviously, there needs to be some sort of accountability around this," Marshall said.

The exact amount of Freon released and the cause of the leak are still being investigated. Repairs are being made to the plant where the Freon leaked.

Source:  http://www.cbc.ca/canada/ottawa/story/2009/03/05/freon-leak.html