NASA just issued some interesting maps that show improvements in air quality in the United States over the last ten years. New Jersey has made great progress with air quality since the 1970s. Our air meets all of the federal health-based air quality standards (for example, carbon monoxide, lead, SO2, particulates), except for one: ground-level ozone (commonly known as “smog”). We are in “ozone season”, the time of year when ground-level ozone concentrations are the highest (May 1 through October 1).
To learn more about ozone, I interviewed some of the Department’s air quality experts. My first interview was with Charlie Pietarinen, Chief of the Bureau of Air Monitoring. We talked about some of the basics of ozone.
JH: Charlie, in plain terms, what is ozone and where does it come from?
CP: The oxygen in the air we breathe is composed of molecules made up of 2 oxygen atoms joined together, but when three oxygen atoms join together we get ozone – a completely different substance. Ozone is not directly released to the air in any quantity, but is created when sunlight and heat cause other air pollutants to react with one another. The most significant contributors to ozone are oxides of nitrogen (NOx) and volatile organic compounds (VOCs). NOx is a product of the combustion of fossil fuels like gasoline, natural gas, coal and oil. VOCs are emitted like a vapor – the most common sources are gasoline and solvents.
JH: New Jersey doesn’t meet the ozone standard – in Clean Air lingo that is called “nonattainment”. How bad is it?
CP: New Jersey has made good progress toward attaining the ozone standard, but more needs to be done. The current ozone standard is 75 parts per billion (an 8-hour average). Attainment of the ozone standard is based on a statistic calculated from three years of monitoring data, not just the highest value recorded as one might think. This statistic is called the “design value”. For the most recent three year period, the highest design value recorded in New Jersey was 84 parts per billion, and 11 of our 16 air monitoring stations had design values above the standard of 75 parts per billion. While this makes ozone our most persistent and wide spread air pollution problem, we have done really well at reducing ozone over the years. At the end of 2003 the maximum design value recorded was 109 parts per billion and all of our sites were above the standard. Compare these numbers to design values at the end of 1988 when the maximum was 132 parts per billion. That means that our ozone levels have decreased by over 36% since their peak and by more than 23% in the last ten years. Those are impressive numbers.
JH: And why is ozone a concern in New Jersey?
CP: Ground-level ozone is a concern for us for three reasons: health, environment and economics.
In the upper atmosphere, ozone is a good thing. That’s the “ozone layer” – it reduces our risk of getting skin cancer or developing cataracts and protects the ability of crops and other plants to produce oxygen by absorbing ultraviolet light. In the lower atmosphere, however, ozone is an air pollutant that is harmful to humans. When we inhale air with high concentrations of ozone it can irritate the lining of the respiratory tract and cause coughing, wheezing, burning in the chest, and shortness of breath. People with asthma and other respiratory health problems are very sensitive to ozone. And studies show that prolonged exposure can cause permanent lung damage.
Ozone can also damage plant life, especially the leaves and needles of certain species. Damage from ozone can limit the ability of plants to take up oxygen, thus limiting growth. In severe cases it can kill plants. Crop damage due to ozone can have a significant adverse economic impact on farmers. Because ozone is so reactive, it can also damage many commonly used materials. Rubber, for example, is especially vulnerable to ozone and the life of your tires can be significantly shortened by ozone damage.
Finally, because New Jersey does not yet meet the ozone standard, the federal Clean Air Act requires new sources of NOx (for example, power plants) and VOCs (for example, gasoline refineries) to offset their NOx and VOC emissions by buying emissions “credits” that are sold by other facilities. Emissions offsets can be expensive to obtain, and that can be an added burden on new businesses or our existing businesses that want to expand. And, even though some of our upwind neighbors contribute to our ozone problem, they do not have to comply with the “offset” requirements that we do if the state meets the ozone standard. Thus, a company that wants to build a factory in the Northeast might find upwind states more attractive because they would not have to buy offsets in order to build a new plant.
The Department is working with other states and the federal government to remedy these inequities and ensure that all states do their part to reduce levels of ozone throughout the northeast, but it is a tough problem.
JH: What is your role in helping New Jersey with its ozone problem?
CP: My office measures air quality in the state to see if we are meeting the ozone standard, determine if our regulations are reducing ozone concentrations, and measure our progress in improving air quality. We also provide data to the public on current levels of ozone so they can take appropriate actions if the levels are high, and participate in a national system for automatically sending out alerts when ozone levels become unhealthy.
JH: My last question: Tell me three things I can do today that would reduce my own contribution to our ozone levels.
CP: Number 1: drive less during ozone season. About 50% of our ozone problem is due to mobile sources – cars and trucks. If you can car pool, use public transportation, ride a bike or walk instead of driving, you are making a big difference in reducing emissions of ozone-forming pollutants. If you have to use your car, combine trips were possible to reduce the overall distance that you drive, and purchase the most fuel efficient vehicle for your needs. Small engines like those used in lawn equipment are also a problem, so use them less if possible and try to avoid using them on days when ozone levels are forecast to be high. A third tip would be to keep all of the internal combustion engines you use well-tuned. This includes your car, lawn equipment, boat engines, and ATVs. Remember, anything that burns gas contributes to the ozone problem. In fact, even the storing of gasoline can contribute to the problem, so use cans that minimize evaporation and spills if possible.
Next month I will interview Sharon Davis to talk about why solving New Jersey’s ozone problem is a challenge that reaches across state lines.