Bicycle riders will gather at Manchester Center near the Fresno Area Express site on Blackstone Avenue at 7:45 a.m. Wednesday for a group ride to downtown Fresno.

It's part of a bicycle-intensive month, which will include a Fresno County Bicycle Coalition program Thursday that encourages people to ride their bikes to work. May is bike month.

How much pollution will bicycling prevent?

It depends on how old the participants' vehicles are, how far they would normally drive them to work, how they maintain their cars, how they drive, the temperature outside -- there's no simple answer.

But there are a few generalizations you can make for cars and trucks, according to the U.S. Environmental Protection Agency:

• If you drive a car that is less than 8 years old, you would prevent 31 pounds of global-warming carbon dioxide from going into the air by biking for a day. And you would prevent the release of about a tenth of a pound of nitrogen oxides, which help form ozone or smog.
• If you drive a similar-age light truck, such as a pickup, you would prevent the release of 44 pounds of carbon dioxide and 0.15 of a pound of nitrogen oxides.

Are those significant numbers? Maybe, maybe not. But most air quality regulators would tell you every bit of pollution prevention is significant, and they encourage more people to bicycle. Read between the lines: If you get enough people bicycling, it will make a dent in air pollution.