Day 20: Nitrates
Although the health effects of nitrates on humans are limited, their environmental effects are considerable. When discharged into streams, rivers and lakes (usually via runoff from agricultural land), nitrates promote bacterial growth which consumes oxygen in water (a condition known as hypoxia) that kills off aquatic life.
Nitrates in drinking water have been tied to blue-baby syndrome, a condition that develops when nitrates metabolize and interact with hemoglobin, creating methaemoglobin, which binds to oxygen and does not release, and can cause cyonisis. The EPA maximum guideline for Nitrates is 10 parts per million in drinking water.
Few compounds have had as varied an impact as nitrates did in the 20th century: their industrial synthesis made it possible to feed most of the world, while simultaneously making it possible to produce explosives and munitions on an industrial scale.
In an effort to make ammonia from atmospheric nitrogen at the beginning of the 20th century, german chemist Fritz Haber discovered a process for extracting them from the air, producing ammonium nitrate. It was improved upon by Carl Bosch in 1913, who while leading a research team at BASF developed the first industrial scale application of the process. This method for producing nitrates allowed Germany to produce gunpowder, and played a central role in their production of weapons in WWI.
The ability to produce nitrates on an industrial scale led to the creation of inorganic fertilizers in the aftermath of the war, which enabled unprecedented production and availability of fertilizer to farmers across the world, serving as a catalyst for what became the “Green Revolution.”
Nitrate-based fertilizers remain the backbone of most agricultural activities on earth, however synthetic fertilizers have in recent years been tied to increasing environmental degradation of aquatic and marine life. By depleting oxygen levels in water, excessive nutrients create aquatic “dead zones” – areas cannot sustain life, and are slowly taken over by plumes of blue-green algae. The dramatic increase in dead zones across the world now contributes to $400 billion loss to the global economy every year, and is generating demand for nutrient reduction programs across the world.