The Feb. 17 article "Districts Uninterested in Funds for Retrofitting Buses" overlooks the role of diesel emissions in causing human illnesses and premature death.
The cancer risks associated with diesel exhaust particles are about 10 times higher than the cancer risks from all other hazardous air pollutants combined. The average cancer risk associated with diesel emissions is 580 per million -- 80 percent of the total estimated cancer risk from all hazardous air pollutants.
Particulate matter, a major component of diesel exhaust, has been linked to a wide variety of serious health problems including upper and lower respiratory diseases such as asthma attacks and possible asthma onset, heart attacks and premature death. These problems affect the general population, not just children and drivers who occupy the buses.
However, children may have particular risks because their lungs are still maturing and because their high activity levels cause more rapid breathing with greater inspiration of diesel exhaust particles.
In addition to retrofitting engines, other actions can be taken to reduce diesel emissions, including the use of ultra-low sulfur diesel fuel and adoption of anti-idling laws.
The reduction in exposure to ambient fine-particulate air pollution results in significant improvements in life expectancy in the United States.
STANLEY J. GEYER, M.D.