New Study: Smog Poses Greater Health Risk Because of Global Warming

More Bad Air Days for Southern, Eastern U.S. Cities
WASHINGTON, DC (September 13, 2007) -- People living in ten mid-sized metropolitan areas are expected to experience significantly more 'red alert' air pollution days in coming years due to increasing lung-damaging smog caused by higher temperatures from global warming.
The analysis[1] was prepared by researchers at Yale, Johns Hopkins and Columbia universities, in collaboration with researchers at State University of New York at Albany, and the University of Wisconsin-Madison and released today by the Natural Resources Defense Council (NRDC).
The study uses data from the 2007 journal Climatic Change, which looks at climate change, ambient ozone, and public health in U.S. cities. It was released today by NRDC and some of the nation's top medical experts.
"The air in many of our nation's cities is already unhealthy. Hotter weather means more bad air days for millions of Americans," said NRDC Climate Center’s Science Director Dan Lashof. "People with asthma are especially at risk, but everyone is adversely harmed by breathing unhealthy air. This research provides another compelling reason to establish enforceable limits on pollution."
The study, "Heat Advisory: How Global Warming Causes More Bad Air Days," projects that higher temperatures mean more smog for a given level of precursor emissions. Smog is formed when pollutants from cars, factories, and other sources mix with sunlight and heat.
On 'red alert' days -- everyone -- particularly children and people with asthma and other respiratory illnesses -- is advised to limit prolonged outdoor exertion. For people with asthma, smog pollution can increase sensitivity to allergens. The Environmental Protection Agency's blue ribbon panel of science advisers has concluded that the current ozone standard of 84 parts per billion (ppb) needs to be substantially reduced to between 60 and 70 ppb in order to protect public health.
"EPA should reduce the ozone standard to within the range recommended by its science advisers. A standard at the lower end of that range will save more lives. During warmer months high ozone levels already create breathing problems for children, elderly, and those with respiratory diseases," said Physicians for Social Responsibility's
Environment and Health Programs Dr. Director Kristen Welker-Hood. "We know that global warming will lead to higher temperatures, especially in urban areas, and as this study shows, we can expect more and more suffering related to unhealthy air the longer we wait to address global warming."
 In Washington, D.C., for instance, residents would see a 24 percent drop in clean air days per summer.  

The report looks at the following cities located in the eastern and southern half of the U.S.:

  • Asheville, NC
  • Cleveland, OH
  • Columbus, OH
  • Greenville, SC
  • Memphis, TN
  • Philadelphia, PA
  • Raleigh, NC
  • Virginia Beach, VA
  • Washington, DC
  • Wilmington, NC

These cities are highlighted because of their size, population and geographical differences. Federal policy makers representing these areas will be faced with critical decisions about reducing global warming emissions and it is important that they be made aware of the health implications of hotter temperatures.
Scientists say average temperatures will rise as much as 10 degrees F by the end of the century unless we start cutting global warming emissions.
Researchers project that, unless action is taken to curb global warming, by mid-century people living in a total of 50 cities in the eastern United States would see:

  •  A doubling of the number of unhealthy ‘red alert’ days
  • A 68 percent (5.5 day) increase in the average number of days exceeding the current 8-hour ozone standard established by the U.S. Environmental Protection Agency (EPA)
  • A 15 percent drop in the number of summer days with “good” air quality based on U.S. Environmental Protection Agency (EPA) criteria because of global warming
Scientists say the Earth is warming faster today than at any time in history. Globally, 11 of the last 12 years rank among the 12 warmest on record since 1850. Better technology in our cars, trucks and SUVs, and cleaner, more efficient energy choices like wind and solar power will help reduce carbon emissions that cause global warming as well as smog forming emissions like nitrogen oxide (NOx) gases, volatile organic compounds (VOCs), sulfur oxide (SOx) gas and particulates.

[1] Bell ML, R Goldberg, C Hogrefe, PL Kinney, K Knowlton, B Lynn, J Rosenthal, C Rosenzweig, JA Patz., 2007. Climate change, ambient ozone, and health in 50 US cities. Climatic Change 82:61-76.