Nitraterelated

Nitrate-related refers to topics connected with nitrates (NO3−) and related species such as nitrite (NO2−) across chemistry, environment, agriculture, health, and industry. Nitrates are inorganic anions common in soil and water, arising from natural nitrogen cycling and from human activities.

Chemistry and forms: Nitrate is the most oxidized form of nitrogen found in natural waters and soils, with nitrogen in the +5 oxidation state. It forms salts with cations such as sodium, potassium, and ammonium, and can participate in redox processes, being reduced to nitrite or ammonium under certain conditions.

Sources: Natural sources include mineral weathering and atmospheric deposition. Anthropogenic sources include agricultural fertilizers, animal manure, sewage, food processing, and fossil fuel combustion.

Environmental impacts: Elevated nitrate levels can contaminate groundwater and surface water, contributing to eutrophication and algal blooms. This can reduce dissolved oxygen and harm aquatic ecosystems. In drinking water, high nitrate intake raises concerns for human health, particularly for infants, where nitrite formation can affect oxygen transport.

Health considerations: Nitrate itself has limited acute toxicity, but can convert to nitrite in the gut, with potential methemoglobinemia risk in infants. Nitrite can form N-nitroso compounds under certain conditions, which are studied for carcinogenic potential.

Measurement and regulation: Nitrate is measured as nitrate or nitrate-nitrogen using methods such as ion chromatography or colorimetric assays. Drinking-water standards vary, but many jurisdictions impose a maximum contaminant level around 10 mg/L as nitrate-nitrogen.

Management: Mitigation strategies include responsible fertilizer management, buffer zones to reduce runoff, and appropriate water treatment for affected supplies.