Diesel Emission Regulations Won’t Protect Health

Published September 14, 2010

Dr. Stephen Maxwell’s invited editorial, “Another View: No serious dispute over diesel’s role in dirty air” in the Sunday, Aug. 22, 2010 edition was wrong. We are compelled to respond and correct the record.

The California Air Resources Board (CARB) decision to declare diesel small particulate emissions a toxic air pollutant in the late 90s was based on a handful of weak studies of railroad workers exposed to diesel locomotive emissions, not hundreds of studies as Dr. Maxwell claims. Dr. Eric Garshick, the lead author of the research on railroad workers, told the CARB expert panel not to use his studies because they were not reliable. They ignored his advice.

No state in the United States has declared diesel emissions toxic for good reason–there are no studies to justify such an action. The debate on diesel and fine-small particle health effects became so contentious that the CARB convened a scientific symposium on fine-small particle air pollution February 26, 2010. Dr. Enstrom and 4 other distinguished, nationally known scientists appeared to oppose the CARB position represented by CARB scientists. Enstrom’s group included Roger McClellan, formerly chair of the US EPA Clean Air Scientific Advisory Committee, Robert Phalen, currently chair of the US EPA Fine-Small Particle Air Pollution Scientific Advisory Committee, Suresh Moolgavkar, nationally known epidemiologist at University of Washington, and Fred Lipfert, renowned and distinguished air pollution effects epidemiologist.

During the symposium, titled “Estimating Premature Deaths from Long-term Exposure to PM 2.5,” found at http://www.cal-span.org/cgi-bin/archive.php?owner=CARB-PM2.5&date=2010-02-26, Dr. Michael Jerrett of University of California, Berkeley, epidemiologist, appearing for CARB, admitted that his recent California specific study of fine-small particles showed no relationship to premature deaths at all. So Dr. Jerrett’s findings were identical to Dr. Enstrom’s 2005 findings. Dr. Maxwell was apparently unaware of this agreement? CARB failed to inform him he was on a fool’s mission, defending a CARB position that its own scientists could not defend? CARB claims its new air regulations will save thousands of lives when its research doesn’t show any lives will be saved. Dr. Maxwell should rethink his opinion, in light of the evidence. CARB regulations will cause economic hardship, unemployment, and poor health in California, for no good reason.


Skip Brown CEO, Delta Construction Co, Sacramento, CA
John Dale Dunn MD JD, Brownwood, TX
Jerome Arnett, Jr. MD, Pulmonologist, Elkins Chest Clinic, Elkins, WV

Letter to the editor submitted on September 14, 2010 to, but not published by, the Sacramento Bee