Diesel exhaust from big rigs probably causes lung cancer, says to a new report from the Environmental Protection Agency.
“Overall, the evidence for a potential cancer hazard to humans resulting from chronic inhalation exposure to (diesel exhaust emissions) is persuasive,” said the report.
The EPA concluded that it was long-term inhalation exposure that posed the greatest risk of lung cancer and other lung damage. Short-term exposure can cause irritation and inflammatory symptoms, and there is also emerging evidence that diesel can make existing allergies and asthma worse, said the report.
But the Diesel Technology Forum slammed the report as “an appraisal of past diesel technology.”
“The report does note that that its findings are based on exposures to engines which did not meet today’s high emissions standards,” said DTF executive director Allen Schaeffer, “and which occurred in the workplace settings of another era.
“While the report focused on the past, the future is clean diesel. Diesel trucks and buses built today are more than eight times cleaner than just a dozen years ago. Thanks to state-of-the-art engine designs, cleaner burning fuels and effective emissions controls systems, diesel technology had progressed by quantum leaps over the past 30 years – and will continue to improve its emissions performance in the future.”
While the EPA reported that in some urban areas diesel exhausts account for as much as 25 percent of airborne microscopic soots, the DTF pointed out that according to the EPA’s own figures, the levels of diesel particulates in the atmosphere dropped by over 37 percent between 1990 and 1998. And by 2007, said Schaeffer, diesel manufacturers will reduce truck and bus emissions by 90 percent from today’s levels.
The EPA report said its “health hazard conclusions are based on exposure to exhaust from diesel engines built prior to the mid-1990’s. The health hazard conclusions, in general, are applicable to engines currently in use, which include many older engines.”
Those conclusions “will need to be reevaluated” after new, cleaner diesels replace those older ones, said the EPA.
The EPA oversees diesel emission levels under the Clean Air Act. In August the EPA, with support from the White House, fought off moves by some diesel engine makers to postpone introducing the October 1 emission laws which lower the amount of nitrous oxide gasses truck exhausts can release into the air.