By Matt Leingang
The Cincinnati Enquirer

Denis Boudreau will be at the US Bank Arena tonight for the motorcycle ice-racing series. His job: to make sure no fan becomes nauseated.

CARBON MONOXIDE

Q: What is carbon monoxide? A: Carbon monoxide is a colorless, odorless, poisonous gas. Q: What are the symptoms of CO poisoning? A: The initial symptoms of CO poisoning are similar to the flu (but without the fever). They include headache, fatigue, shortness of breath, nausea and dizziness. Q: What should you do to prevent CO poisoning? A: Make sure appliances are installed according to manufacturers' instructions and local building codes. Install a CO detector/alarm that meets the requirements of the current UL standard 2034 or the requirements of the IAS 6-96 standard. A carbon monoxide detector/alarm can provide added protection, but is no substitute for proper use and upkeep of appliances that can produce CO. Source: U.S. Consumer Product Safety Commission

Boudreau, a senior environmental safety specialist with the Cincinnati Health Department, monitors the air at indoor sporting events for potentially dangerous levels of carbon monoxide, a colorless, odorless, poisonous gas produced by the incomplete combustion of carbon-based fuels.

Tonight's show poses less of the carbon monoxide threat, said Anthony Barlow, the promoter and the sport's three-time indoor quad ice racing champion. The motorcycles used in these races run on methanol, an alcohol fuel that emits less carbon monoxide than gasoline-fueled counterparts.

"We think about the issue, sure," Barlow said. "But we watch how much our engines smoke, and the arenas these days are better ventilated than they used to be."

For the past 10 years, Boudreau has attended almost every tractor pull and monster truck rally in this city.

Cincinnati's health department was one of the first in the country to take this step - a move that wasn't without controversy. Critics, including former arena management, said the agency was overreacting.

Public health officials say oversight is hit or miss. The U.S. Environmental Protection Agency regulates outdoor air quality only, and it's hard to know how many local health departments set standards.

"There's not a national system to monitor this," said Stephen Redd, chief of air pollution and respiratory control for the National Center for Environmental Health, which is part of the U.S. Centers for Disease Control and Prevention.

The federal Occupational Safety and Health Administration doesn't have jurisdiction over these events because there's not a direct employer-employee relationship, a spokesman said. The entertainers and professional athletes are considered independent contractors.

Carbon monoxide, which can be fatal at high levels, is difficult to detect with the senses. Indoor sporting events pose a health hazard to spectators if gasoline-powered engines burn for long periods of time in arenas that lack adequate ventilation, Boudreau said.

And it has happened. In 1996, about 70 people became ill with fatigue, headaches and dizziness after an ice-sweeping machine spit out exhaust fumes in a poorly ventilated Seattle arena, according to a CDC report.

During Cincinnati events, Boudreau moves around the concourse level of the arena with a hand-held electronic chemical sensor.

Promoters agree to stop or slow shows on the floor if necessary. Fire department and arena officials are also on hand to open doors and windows to let in fresh air.

E-mail mleingang@enquirer.com