It appears that the Chesapeake Bay will benefit from some anticipated clean air rules, at least from outside the United States.

While the debate over the EPA's proposed new air standards continues in the United States, Canada is enacting clean air rules even tougher than those being proposed here.

In fact, in a highly unusual move, Canada submitted comments on the U.S. rules, saying the EPA proposal was too lax and "will continue to result in health damages and death." Canada's comments were based on a scientific examination of the issues by its own pollution control authorities.

Canada would likely benefit from any tightening of the U.S. standards because its air is contaminated by pollution blown in from parts of this country.

Likewise, the Bay could benefit from tighter controls being enacted in Canada because part of that country, including southern Ontario's heavily populated and industrial Toronto areas, are within the "airshed" that contributes most of the nitrogen air pollution to the Chesapeake Bay.

... While new action by the United States says tough to Canada

The EPA recently agreed that a number of states will not have to curb emissions to help reduce ozone problems in downwind areas.

For months, a group of 37 states, known as the Ozone Transport Assessment Group, have been studying how to reduce the transport of nitrogen oxides, or NOx. After being emitted into the air, NOx can travel hundreds of miles, contributing to air pollution problems downwind.

Some areas of the Mid-Atlantic and Northeast, as well as some areas of the Midwest - mainly Chicago - receive so much air pollution from other states that it is almost impossible for them to meet air pollution standards on their own. Based on work done by OTAG, the EPA is expected to order additional pollution reductions for states that contribute to downwind problems.

But in a March letter to the EPA, the governors of Minnesota, North Dakota, South Dakota, Iowa and Nebraska said "there is no scientific justification" for including their states in requirements for further reductions.

A study paid for by utilities and industries in the five states showed that pollution from the region doesn't blow into the eastern United States. Rather, the study found that pollution from the states mainly blows into Canada.

In April, the EPA agreed, and exempted all those states from additional pollution reductions stemming from the OTAG process.

In addition, the EPA said it would exempt Arkansas, Florida, Kansas, Louisiana, Oklahoma and Texas because emissions from those states did not appear to contribute significantly to chronic ozone problems downwind.