Diesel exhaust is one of the most damaging pollutants affecting children in California, according to an advisory panel of some of the state's top scientists.
The prestigious Scientific Review Panel on Friday gave preliminary approval to a list of five toxic air pollutants that the state believes most damage people from conception to adolescence.
In addition to diesel exhaust, the list includes lead, acrolein, dioxins and polycyclic aromatic hydrocarbons. Such chemicals are largely byproducts of combustion, according to panel members.
Once the state Office of Environmental Health Hazards Assessment formally adopts the list, it will ultimately trigger a review of state regulations to ensure that there are adequate safeguards in place for children.
As a result of the designation, controls could be tightened on industrial and vehicular sources of the contaminants, including trucks, incinerators and diesel generators, which could come into heavy use this summer because of rolling blackouts caused by the energy crisis.
The panel had the difficult task--mandated by a recent state law designed to protect children's health--of choosing by July 1 only five out of a list of 200 identified toxic air contaminants.
Diesel is the most recent addition to that list of 200, and the state Air Resources Board is currently developing regulations for diesel engines. Friday's designation, if finalized, would provide more support for tightening regulations.
Diesel exhaust was placed on the tentative list because it exacerbates allergies, hurts the lungs' ability to function and worsens asthma, particularly in children, according to testimony during a hearing before the list was voted on.
Paul Blanc, an occupational physician at UC San Francisco and a panel member, noted during the hearing that freeways are hot spots for increased diesel exhaust. Census data, he said, show that poor people and children tend to live close to freeways. As a result, the toxic impacts of diesel exhaust hurt children more than adults.
In addition, diesel exhaust contains nearly all of the other chemicals on the tentative list, said John Froines, a UCLA toxicologist and panel member. "It would be hard to list the first four without listing diesel," he said after the unanimous vote.
But William Bunn, medical director for one of the largest truck and engine manufacturers in the nation, argues that the scientific picture that has unfolded during the panel's proceedings is far from complete.
In the six weeks before the panel makes its final decision, Bunn said in an interview, he and other diesel proponents will "be submitting substantial evidence on the allergy piece of the puzzle" that they hope will change the panel's mind and knock diesel off the list.