Nitrogen oxides, known collectively as NOx, are a dangerous group of chemical pollutants most commonly connected to combustion engines used in cars. NOx from car exhaust—especially diesel cars—has been linked to respiratory diseases, cancer, birth defects, and premature death.
Right now, governments focus most of their NOx-reducing efforts on regulating cars and trucks, because that’s assumed to be the most significant source. Power plants also produce NOx emissions, and are also regulated. But there may be another huge source of NOx emissions that has, to date, been almost completely ignored: farmland.
In a study published on Jan. 31, 2018 in the journal Science Advances, Director Houlton and his group of researchers from the University of California-Davis found that California—home to one of the most productive agricultural regions in the world—could have 20% to 51% more NOx pollution than previously thought. That would mean NOx pollution from farmland could amount to up to 40% of the total NOx pollution in California.