For many of us summertime means spending more time outside, enjoying the longer days and milder nights. It’s a great time to be a kid and a kid at heart when the lightning bugs come out to play. The outdoor concert season is in full swing, and if you’re not into live music, there are always outdoor movie nights around here on the weekends.
At the same time, there’s an added danger in the summertime that not everyone notices, but perhaps more people should. During these warmer days with more sunlight and lighter breezes, our atmosphere tends to trap pollutants closer to the ground. For sensitive groups such as those with asthma, heart disease, the very young and the elderly, poor air quality is a serious issue. It may surprise you to learn that it’s something we can all help alleviate.
It may also surprise you to learn that ground-level ozone is not the only pollutant of concern. While ozone is definitely more prevalent in the summer, the Environmental Protection Agency actually has five other air pollutants they monitor with set standards in mind. These six common air pollutants are known as “criteria air pollutants,” and are ground-level ozone, particulate matter, carbon monoxide, lead, sulfur dioxide, and nitrogen dioxide.
All six can have negative health effects on people, especially those with lung and heart issues. Sulfur dioxide, nitrogen dioxide and ozone in high concentrations can also harm sensitive plants.
Where do criteria pollutants come from?
Ozone is produced by chemical reactions in the atmosphere that happen when sunlight interacts with NOx and volatile organic compounds (VOC). High in the atmosphere, ozone is actually a good thing because it blocks harmful UV-B rays, which play a role in the development of skin cancer. However, close to the ground, ozone can cause breathing problems.
Carbon monoxide (CO) is released when we burn things including the fuels used in cars, trucks, boats, etc. While high levels of CO do not tend to occur outside, when they do, they can be harmful to people with certain types of heart disease because carbon monoxide limits the amount of oxygen pumping through our blood to our hearts and brains. In very high amounts, it can be deadly, which is why it is such a dangerous problem indoors.
Particulate matter is one name for hundreds of different small solid particles and liquid droplets that make their way into our air. PM includes smoke, dust, pollen, and microscopic matter made up of organic compounds and metals.
Lead pollution is put into the atmosphere during the processing of ore and metals, the use of leaded fuel for aviation, manufacturing lead-acid batteries, etc. The use of unleaded gasoline has helped reduce the amount of lead in the air greatly, so not all regions have problems with lead pollution.
Sulfur dioxide and nitrogen dioxide are emitted into the air through the burning of fuels for transportation, utilities, etc. Both contribute to haze and visibility issues as well as acid rain. Both can cause breathing issues in sensitive groups.
Non-criteria pollutants exist, too.
One example of a pollutant that is not on the EPA’S air standards criteria list is mercury. In past years, in North Carolina, we’ve heard a great deal about mercury poisoning of our rivers and streams, which in turn poisoned our fish and could lead to high levels of mercury in people who eat those fish. Did you ever wonder how mercury got into the water?
Gaseous mercury is naturally released from “rock, soils, and surface waters, or emissions from volcanoes and from human activities.” It can travel a thousand miles through the air, combine with water and be deposited back to the earth with rain. Mercury is a natural part of our environment, but with fossil fuel burning and waste incineration, humans have added more mercury to the atmosphere and eventually to our water sources. In that way, it is now a pollutant and mercury poisoning is a serious health issue for those who have it.
Steps we can take to reduce air pollutants:
You might have noticed that burning fuels is a source of most of the above listed pollutants. Logically, the first thing we should consider in improving air quality is finding and developing cleaner fuel sources in such a way that people will want to use them. They need to be easily accessible and affordable, but that is as much as I will say since I am neither an engineer nor a policy maker.
Individually, we can consciously be more economical with our fuel, especially during the summer months – drive less and ride-share or walk and bike more. We can also do things that burn fuel during the morning or later in the evening when the sun is not directly overhead – mowing is the first thing that comes to my mind. Direct sunlight causes the chemical reaction with engine emissions that creates ground-level ozone. Personally, I am considering buying an electric lawn mower, which will greatly reduce those emissions from my own yard.
Solar and wind have received a great deal of press in recent years in North Carolina. We are a leading state for solar energy production, and solar panels for homes are gaining in popularity with improved technology and reductions in price. Wind farms are a bit more controversial than solar options, but they are also becoming more popular across the country. Both have great potential for reducing pollution.
You might have noticed that I have not mentioned carbon dioxide as a pollutant. Many people mistakenly think of it as such because of its link to global warming. Technically, it is not a pollutant. In fact, it’s a requirement for plant life and plant life is a requirement for human life. That being said, if too much CO2 in the atmosphere may cause negative effects in the long term and reducing it happens to be a byproduct of reducing the EPA’s criteria pollutants… well, that’s not such a bad thing, is it?