Is nitrogen dioxide a pollutant
Across the ocean in Los Angeles, California, residents here often notice that the Los Angeles skyline is often shrouded in a reddish-brown haze that blurs the view, revealing visible air pollution in the area that makes it difficult to see for miles in any direction.
One component of this smog is nitrogen dioxide (NO2), an irritating air pollutant that irritates the respiratory tract and can trigger asthma or other illnesses. Scientists scanned the skies over dozens of U.S. cities and made a startling discovery about the haze that hangs over Los Angeles: air quality improvements in the Los Angeles area have come to a virtual standstill because of the abundance of nitrogen oxide pollutants here.
Nitrogen oxides, a combination of nitric oxide (NO) and nitrogen dioxide (NO2), are produced by motor vehicles and industrial machinery such as power plants, boilers, turbines, and cement kilns. When NOx molecules mix with volatile organic compounds (VOCs) from vehicles and a wide range of household and commercial products and are exposed to sunlight, they form pollutants such as ozone. In cities like Los Angeles, Memphis, and Washington, D.C., NOx lifetimes declined from 2006 to about 2010. Then it began to pick up again, especially in Los Angeles, once considered one of the most polluted areas in the U.S. for nitrogen dioxide and other pollutants.
A team of scientists used data from ground-based instruments and monitoring instruments aboard the European Space Agency’s Sentinel-5P satellite to map the amount of nitrogen dioxide in California’s air down to the neighborhood level. The team also quantified concentrations near different types of properties within those neighborhoods. The dark orange areas in this map show where nitrogen dioxide concentrations were highest in 2018 and 2019. Nitrogen dioxide concentrations are significantly higher in urban population centers such as Los Angeles, San Jose, and San Francisco.
Corridors with high NO2 concentrations can also be seen along major arterials in California: State Route 99, Highway 5, and Highway 101. Cars and trucks are a major source of nitrogen dioxide, a byproduct of fossil fuel combustion, so it is not surprising that air pollutant levels are high near roadways.
Researchers have also found high levels of nitrogen dioxide near infrastructure in Los Angeles-researchers have noted high levels of nitrogen dioxide near some food processing plants and high-rise apartments. Some researchers believe that some of the nitrogen dioxide in the air near high-rise apartments comes from the high density of vehicular activity here, but for food processing plants and other food-processing facilities, fossil-fuel-burning equipment, such as space heaters, water heaters, natural gas furnaces, and ovens, may also be a nitrogen dioxide producer and pose a hazard to denser populations in the area.
In fact, nitrogen dioxide is a common atmospheric pollutant in many countries and regions around the world, except in the U.S. In addition to posing a hazard to human health, nitrogen dioxide can lead to environmental problems such as acid rain, photochemical smog, and the greenhouse effect, so accurately determining the concentration of nitrogen dioxide in the ambient air is important for environmental protection and health monitoring.
Nitrogen dioxide sensors FS01901 is a fuel cell type electrochemical gas sensor, the working electrode and the opposite electrode on the reduction reaction and the release of charge to form a current, the size of the resulting current and the concentration of nitrogen dioxide is proportional to the Faraday’s law, through the size of the test current can be determined by the concentration of nitrogen dioxide high and low.
