<human>:  What technology exists to monitor air pollution?
<bot>: The most common technology used to monitor air pollution is air quality monitoring systems. These systems measure air pollutants such as particulate matter (PM), nitrogen oxides (NOx), sulfur dioxide (SO2), ozone (O3), carbon monoxide (CO), and volatile organic compounds (VOCs). The data collected by these systems can be used to track and monitor changes in air quality in a given area, which helps to assess the potential health risks associated with air pollution.