If you are reading this then you recently took a breath, and you will soon be taking another. Like most other complex organisms, we require oxygen from the air in order for our cells to carry out metabolism, release energy, and thus keep us alive. It’s not an exaggeration to say the air we breathe is vitally important to our very survival, and that the cleanliness or quality of that air is something we should be concerned with. Clean air that is free of impurities is made up chiefly of the gaseous element nitrogen (~78%), along with oxygen (~21%), argon (~1%) and trace quantities of carbon dioxide. National parks strive to maintain natural environments that are as unaffected by pollution as possible, and that includes protecting the air that is used by the plants, animals, and visitors within the parks. However, air is by definition very diffuse, and when it is negatively impacted by activities in one area, air currents soon spread those negative effects more broadly, including into parks. How do we know whether the air within national parks is clean and healthy or not? Some of the larger parks in the system actually test and monitor the air within their boundaries and have a very good idea about the quality (good or bad) of the air right where they are. Most parks though, including Fort Matanzas, rely on monitoring that is done elsewhere. The National Park Service (NPS) participates in several national, multi-agency air quality monitoring networks. (Including, for example, work done by the Environmental Protection Agency.) Air quality estimates for Fort Matanzas are produced by interpolating data from whichever monitoring sites are located closest to the park. There are four main air quality parameters that are measured locally and that are applicable to Fort Matanzas: Visibility/haze, ozone, nitrogen, and sulfur. On a sunny day unaffected by rain, fog, and other natural weather systems, it seems obvious that one should be able to see clearly for a far distance. But this doesn’t happen when there are particulates suspended in the air, because these tend to scatter and absorb light, resulting in hazy viewing conditions. Some particulates are natural, like sea spray along the coast. Other particulates result from anthropogenic (human-generated) activities like industry, vehicle exhaust, and clearing of land. If these non-natural particles are fine enough, not only do they reduce visibility, but if they’re inhaled they can cause respiratory irritation, allergic reactions, and reduced lung function. Ozone is a molecule of oxygen containing three oxygen atoms, rather than the two that make up the molecule we need to breathe. When ozone is formed in the upper atmosphere by sunlight it is beneficial because it is effective in blocking incoming ultraviolet radiation, which is harmful to people’s health when unfiltered by the ozone layer. But ozone formed closer to ground level is primarily generated as a by-product of fossil fuel combustion, and it is a hazard to animals and plants. Like particulates, it can irritate the respiratory systems of animals (including humans) when they breathe it in. Plant cells also respire through small openings in their leaves called stomata. When ozone enters the plant it damages leaf tissue and can affect the overall growth rate and survival of the plant. Some plant species are naturally more sensitive to ozone than others, including eastern red cedars and slash pines, both of which grow at Fort Matanzas.Finally, when nitrogen and sulfur oxides are produced by the combustion of fossil fuels, they mix with air and water vapor to form molecules of nitrate, ammonium, and sulfate. It is these molecules which dissolve in precipitation and fall back to earth as acid rain. Too much of this tainted precipitation collecting in one area can acidify the soil or water it encounters beyond normal levels. This can lead to altered soil and water chemistry which may negatively affect the plants and animals living in these systems. Because the area of the country in which Fort Matanzas is located is developing, it is not immune to the negative effects of that development, including air pollution. As of 2018 (the latest year for which the NPS has certified data) the air quality of the park (and the surrounding region, for that matter) was rated as “fair”. While the condition of the park’s air is not likely to improve drastically anytime soon, we can all do our part to hasten the day when the condition is upgraded to “good”. By supporting renewable energy sources, buying energy efficient products, lessening our reliance on automobiles, and following the three “R’s” of reducing the amount of things we purchase, re-using what we can, and recycling as much as possible, someday we’ll be breathing a little easier.
