The California Air Resources Board (CARB) promulgated new, stricter regulations for diesel truck emissions, last December, that significantly reduce the amount of fine particulate matter (PM 2.5) emissions allowed in the state. Diesel PM 2.5 is made up of fine particles of soot from diesel emissions that can be inhaled deeply into the lungs, and is often blamed for premature deaths. However, California’s new regulation will do nothing to improve public health, while costing millions.
California is the only state with such a diesel emissions reduction program, largely because the U.S. Environmental Protection Agency has never determined that diesel exhaust causes premature deaths. For example, the agency’s large, detailed study in 2002 failed to find that diesel exhaust causes premature deaths. As Hoover Institution Senior Fellow Dr. Henry Miller points out, the new regulations constitute an overreach by CARB—based on faulty science—that would drive business out of California.