In order to grow and survive, living things need nutrients. Rising levels of nutrient concentration however, impacts the use of water that it is specified for. Nutrient pollution is “a form of water pollution and refers to contamination by excessive base-level concentrations, act as fertilizers, causing excessive growth of algae.” Nutrients come from many different places. They can appear naturally as a result of rock weathering and from the ocean, from mixing water currents.
Some water bodies are naturally high in nutrients like bedrock that may have a surplus of phosphorus. But for those water bodies a dangerous cyanobacteria, blue-green algae, produces toxins that can be deadly to animals and people. Toxin produced by the cyanobacteria can harm the “nervous system, cause stomach and intestinal illness and kidney disease, trigger allergic responses and damage the liver.”
Nitrogen is an essential nutrient used by all living things. Over the past century the increase in population has increased the demand for food and energy. Meeting these requirements has increased the amount of nitrogen in the environment. Nitrate, the most common form of nitrogen, is directly toxic to humans. Infants who drink water with high nitrate levels can develop a life-threatening blood disorder called blue baby syndrome. High nitrate levels in water can also affect thyroid function in adults and increase risk of thyroid cancer. Excess nitrogen is a common drinking water contaminant in agricultural areas. Nitrogen pollution in the air from burning fossil fuels contribute to many respiratory problems for children, the elderly, people with lung ailments and marine life.
Nitrogen pollution has a number of consequences in coastal marine ecosystems. Among some of the consequences is, changing the type and species of plants that make the organic matter. Food generates nitrogen in the environment as a product of both food production and food consumption. Food production leaves a legacy of nitrogen in the regions where it is produced. It is estimated that 10 times the amount of nitrogen is used during the food production process than is ultimately consumed by humans as protein. Much of this additional nitrogen is applied as fertilizer that can run off into groundwater, rivers and coastal waters. The production of animal protein adds substantial quantities of nitrogen to the environment in the form of nitrogen-rich manure that decreases water quality in agricultural areas. Once food is consumed, it can contribute to pollution through the production and discharge of sewage; “ humans do not utilize all of the nitrogen contained in food.” The remaining nitrogen is lost as waste to septic systems or wastewater treatment plants. Since most septic systems and treatment plants do not effectively remove nitrogen from the waste, nitrogen flows into rivers and coastal waters where it contributes to water quality problems. Once reactive nitrogen enters a watershed in food, or fertilizer, some of it is retained within the landscape, some of it returns to the atmosphere, and some of it flows downstream to coastal estuaries. The contribution of nitrogen to coastal waters from “atmospheric deposition includes nitrogen that is deposited directly to the estuary as well as nitrogen deposited on the watershed that ultimately is transported downstream to the estuary.” Coastal ecosystems are naturally very rich in plant and animal life. However, since the richness of saltwater ecosystems is naturally limited by the availability of nitrogen, excess nitrogen can lead to a condition of over-enrichment. The over-enrichment of estuaries promotes the excessive growth of algae. This algae can cause dead zones in areas of marine life, where all living things die out.
Ways to reduce excess nitrogen could include, looking to reduce wastewater nitrogen instances. One solution could be to add a biological nitrogen removal (BNR) at wastewater plants. BNR is a “process used for nitrogen and phosphorus removal from wastewater before it is discharged into surface or groundwater.” The BNR process would filter out any excess nitrogen and phosphorus that could potentially harm humans and wildlife.
Nitrogen pollution is increasing and contributes to many of our environmental issues. As a single nitrogen molecule goes through the environment, it adds to air quality decline, the adding of acids to soil and surface waters, and over-enrichment of coastal waters. Solving the nitrogen problem will require a “multi-pronged approach.” Adding nitrogen control technology to treatment plants would significantly reduce nitrogen pollution in river runoffs and the ocean. Efforts to make policies should include fiefforts to reduce airborne nitrogen emissions from vehicles and electric utilities and increased investment in improved wastewater treatment to address nitrogen pollution.