More Articles . Nitrogen, is a naturally occurring element essential for growth and reproduction in both plants and animals. Nitrogen is found in amino acids that make up proteins, in nucleic acids that comprise hereditary material and life's blueprint for all cells, and in several other organic and inorganic compounds. Volatile organic nitrogen compounds are released to the atmosphere when plants decay. Dry deposition, or air pollution, contributes large amounts of nitrogen to watersheds .
Coastal fogs are another source of nitrogen.
Where the watershed covers a much larger area than does the estuary, atmospheric deposition onto the land surface rather than the estuary itself is more important. Pollution of the air we breathe is related to many factors. Climate, humidity, concentration of air pollutants in heavily industrial and densely populated areas, thermal inversion, stagnant air masses, seasonal and perennial airborne pollens, dust, moulds, spores and ozone are a few contributors to the problems we face in the air. Allergies are pollutants typically caused by naturally occurring airborne particles. For example, pollens in the spring and fall from grasses, weeds, trees and flowers.