Air pollution occurs when pollutants from sources like cars, factories, power plants, and heating systems are released into the air. Some common air pollutants are carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO₂), nitrogen oxides (NOₓ), and particulate matter (PM). These pollutants don’t just affect air quality. They can also negatively impact water quality in lakes, rivers, and wetlands.
When pollutants are carried by the winds through the atmosphere, they don’t remain up in the air forever. Some pollutants mix with water vapor and react to form acidic compounds, which then fall to the ground as rain, snow, or dust, in a process called acidic deposition, commonly known as “acid rain.” The main ingredients of acid rain are SO2 and NOX, reacting with water in the air to form sulfuric and nitric acids, which can travel long distances before falling to the ground and into waterbodies. It’s important to know that acid rain and other highly acidic solutions may seem similar. However, acid rain is not nearly as caustic as some acids, with acidity levels closer to those of household vinegar or orange juice, whose acidity is measured through pH.
Pollutants from other states and countries can be transported long distances and acidify waterbodies in unpopulated or remote regions through acid rain. Many aquatic organisms can survive only when the pH remains near neutral. If water bodies become too acidic (low pH), over the long term, eggs may not hatch, and some organisms may die, paving the way for further problems. Some aquatic plants and animals are particularly sensitive to these changes and can disappear entirely from waterbodies, endangering fragile ecosystems.
Acidic water can also cause the release of chemicals, such as aluminum, from soil into water bodies and lakes. At high concentrations, aluminum is toxic to fish and can damage their gills, making respiration more difficult.
In addition to acid rain, mercury, a toxic air pollutant, is emitted into the air from some industrial processes. Once mercury settles into water, bacteria can change it into a highly toxic form, methylmercury, which can bioaccumulate, meaning its concentration increases at each level of the food chain - from small insects to small fish, and to larger animals that eat fish, who have the largest amount of toxin within their tissues. Because of this, many NYS waterbodies have fish consumption advisories to protect human health.
Laws such as the Clean Air Act have greatly reduced emissions and led to vast improvements statewide from the 1970’s up to the present day. However, even after full remediation of pollutants from waterbodies, it can still take many years for ecosystems to recover fully.
Understanding how air pollutants move from their source, into the sky, and then fall as rain is important. It shows that protecting water quality isn’t just about what goes directly into rivers and lakes. It raises awareness of the importance of maintaining clean air and reminds us that the benefits go beyond just breathing it. With improvements in technology, such as catalytic converters in vehicle exhaust, and by reducing our reliance on coal and other fossil fuels to generate energy, NYS has seen much less acid rain. By reducing emissions of pollutants such as SO2, NOX, and mercury, you can help reduce airborne emissions and help the aquatic environments of NYS become healthier for fish, plants, and people.
