To clean up pollution, the federal and local governments implemented numerous plans including the constant monitoring and reporting of environmental conditions, such as <answer>ozone and nitrogen oxides</answer>. When the levels of these two pollutants reached critical levels, contingency actions were implemented which included closing factories, changing school hours, and extending the A day without a car program to two days of the week. The government also instituted industrial technology improvements, a strict biannual vehicle emission inspection and the reformulation of gasoline and diesel fuels. The introduction of Metrobús bus rapid transit and the Ecobici bike-sharing were among efforts to encourage alternate, greener forms of transportation.
What pollutants does the city closely monitor?
ozone and nitrogen oxides