OTTAWA — A new report by the NAFTA environmental agency shows that the United States has been doing a better job than Canada in cutting toxic pollution -- but the releases on both sides of the border remain large.

The report, Taking Stock, shows that close to three million tonnes of toxic chemicals were produced as waste by North American industry in 2003, with roughly a quarter of that amount released directly to the air.

Almost 11 per cent of toxic chemicals released in 2003 were known or suspected carcinogens, while eight per cent were known to cause developmental or reproductive harm.

U.S. manufacturing facilities cut their releases of toxics by 21 per cent between 1998 and 2003, while Canadian manufacturers cut releases by 10 per cent.

The annual report by the Commission for Environmental Co-operation is considered the most authoritative data source on pollution trends in North America, and has for a number of years shown Canada to be lagging its main trading partner in pollution control.

Across North America, total releases and transfers of toxic chemicals fell eight per cent from 2002 to 2003.

Average air pollution releases per facility were about 20 per cent higher in Canada than the United States, possibly reflecting the fact that the U.S. has legally binding air quality regulations under its Clean Air Act, while Canada has no equivalent legislation.