DAVIS, CALIFORNIA — A new study finds that fertilized soils could be responsible for up to 40 percent of California's nitrogen oxides emissions.
California has the poorest air quality in the U.S., according to a 2017 American Lung Association report, according to Mother Jones.
Scientists from University of California, Davis published their findings in the journal Science Advances and found the state may be overlooking fertilizers as a major contributor to air pollution.
According to the study, California's Air Resources Board currently estimates nitrogen oxides emissions at four percent from fertilizer.

The team compared nitrogen oxides emissions over the Central Valley with fertilizer application rates, and discovered fertilized soils could be contributing up to 40 percent of the state's nitrogen oxides emissions.
Hundreds of thousands of tons of nitrogen fertilizer are used on crops in the Central Valley each year.

Excess fertilizer not used by crops is released into the atmosphere as nitrogen oxides and can create layers of smog that blanket towns and cities.
Smog can lead to health complications like asthma and acute bronchitis, as well as cause missed school and work days.