. External triggers are typically meteorological instruments such as tipping bucket rain gauges or wind direction sensors. Regular maintenance is essential for any air quality... problems, learning deficits and lowered IQ. With the establishment of the Clean Air Act, the EPA was required to set National Ambient Air Quality Standards (NAAQS) for lead... of 80 such state-run are multi-pollutant, trace level sites with meteorological instrumentation that are intended to evaluate ambient air quality attainment. They also provide...