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Hotter and hotter summers would make it even more challenging to improve air quality. But Maryland is addressing climate change – and those strategies will also help to build on the gains already made in cleaning the air we breathe.
Although the last three summers have been scorchers, levels of air pollution are lower than in years past in Maryland thanks to such programs as the Maryland Healthy Air Act and the Clean Cars program.
This year, the temperature in Maryland topped 90 degrees on 43 days. On 29 of those days, the health standard for ground level ozone was exceeded. How much worse could it have been? In the hot summer of 1995, before many air pollution programs were in place, there were 51 days above 90 degrees – and 71 days when the ozone level topped the health standard now in place
There is growing evidence that climate change is increasing the likelihood of severe weather events, including prolonged heat waves. Maryland’s proposed Greenhouse Gas Reduction Plan includes more than 60 measures to address climate change, and many of them bring air quality benefits. These measures include strengthened standards on energy efficiency and conservation, supporting the use of electric vehicles through proper infrastructure and increased use of public transit.
Heat waves
In the last few years Maryland has had some of the hottest summers since the 1990s. The last three summers have been described as the hottest in the Washington area since records have been kept.
These hot temperatures play a role in the formation of ozone, a pollutant that is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) are heated by the sun. Nitrogen oxides are emitted when fossil fuels such as coal and gasoline are burned, while VOCs are released when fuels, paints, solvents and personal hygiene products are used.
Increased exposure to ground level ozone creates a greater potential for health impacts, particularly for children and sensitive populations such as the elderly and those with respiratory and heart conditions. Breathing ozone can trigger a variety of health problems, including chest pain, coughing and throat irritation and can worsen conditions such as asthma. Over the long term, repeated exposure to ozone can even scar lung tissue.
During the past three decades, Maryland has made significant progress in addressing this public health concern. Pollution control programs have reduced VOCs and NOx from various sources, including vehicles, smokestacks, industrial activity and incinerators. Maryland’s Healthy Air Act has reduced NOx emissions by almost 70 percent by placing stricter controls on power plants. More stringent standards have also been placed on vehicles through the Maryland Clean Cars Program, which allows Maryland to adopt California’s stricter vehicle emission standards. These new standards significantly reduce a number of emissions including VOCs, NOx and greenhouse gases (GHGs).
Air check
In order to measure levels of air pollution in the State, Maryland employs a network of stations to monitor our air. These monitors allow us to not only measure levels of ozone, but also learn about the impacts of weather patterns on pollutant transport from other states. The most recent addition to MDE's network is the Horn Point monitor on the Eastern Shore in Cambridge. This monitor provides a significant addition to our understanding of air quality in the State as a whole. Not long after the Horn Point monitor was installed this year it recorded the state's highest 8-hour level of ozone on one of the summer's hottest days. This reading was surprising, considering the lack of locally generated emissions, and it points to the importance of understanding how air pollution moves – both within and among states.
MDE meteorologist Laura Warren forecasts air quality, and this information is relayed to the public so that Marylanders can plan their activities to protect their health and take action to reduce emissions. These actions can include using public transit, carpooling or using battery-powered lawn mowers. Many of the actions that can help reduce ozone also reduce GHG emissions. That means that our individual efforts to improve air quality can also help reduce the emissions that lead to climate change — and, in the long run, reduce the heat waves that go hand-in-hand with unhealthy air.
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