The EPA Chokes on Smog

Hazy.

Photographer: Mark Ralston/AFP/Getty Images

The world's focus on global warming can make it easy to forget that the stuff that belches from smokestacks and exhaust pipes hurts more than just the climate. It also harms human health. So it makes little sense to move aggressively against greenhouse gases but timidly against good old-fashioned smog.

That's why the U.S. Environmental Protection Agency's decision Thursday on the maximum acceptable level of smog is so disappointing. Smog causes or worsens asthma, heart disease and other ailments, especially among children. Yet the agency has chosen to impose the loosest standards it could, dismissing the warnings of its own scientific advisory panel. For a government otherwise committed to the environment, it's a remarkable misstep.

Smog, also called ground-level ozone, forms when nitrogen oxides and so-called volatile organic compounds -- all released from manufacturing and energy plants, automobile exhaust and other sources -- react with sunlight. The Clean Air Act directs the Environmental Protection Agency to limit smog, and update that limit every five years.

In 2008, the agency set it at 75 parts per billion, and public health and environmental advocates promptly sued, noting that the EPA's Clean Air Scientific Advisory Committee recommends 60 to 70 parts per billion. A judge gave the agency until Thursday to issue a new standard.

The new limit of 70 parts per billion is an improvement, but still "provides little margin of safety for the protection of public health, particularly for sensitive subpopulations," the advisory committee wrote last year to EPA Administrator Gina McCarthy. "Our policy advice is to set the level of the standard lower than 70 ppb within a range down to 60 ppb."

Why did McCarthy disregard the EPA's own scientists? Perhaps to avoid antagonizing industry, especially manufacturers and energy producers, who spent the past year warning that tighter rules would be the costliest in U.S. history, risking millions of jobs.

Those claims are deeply suspect, however; they assume that tighter standards would force many manufacturing and energy plants to close, and a significant number of cars to be taken off the road. Yet smog limits shouldn't require such drastic steps. The European Union manages to limit smog to 60 parts per billion, and Canada to 63 parts per billion, and their economies have yet to crumble.

McCarthy defended her decision on the grounds that the science on ozone danger remains uncertain. But uncertainty calls for caution to avoid public harm -- an argument this administration has made persuasively to justify its aggressive greenhouse-gas limits. It should have applied the same standard to clean up lung-damaging smog.      

To contact the senior editor responsible for Bloomberg View’s editorials: David Shipley at davidshipley@bloomberg.net.