Final answer:
The six substances regulated by the National Air Quality Standards are carbon monoxide, ground-level ozone, nitrogen dioxide, sulfur dioxide, lead, and particulate matter.
Step-by-step explanation:
The six substances that are regulated by the National Air Quality Standards are:
- Carbon Monoxide (CO): emitted from combustion processes, mainly from mobile sources
- Ground-level ozone (O3): formed by the interaction of sunlight, heat, NOx, and VOCs
- Nitrogen dioxide (NO2): a major contributor to smog and acid rain
- Sulfur dioxide (SO2): emitted from fossil fuel combustion and industrial processes
- Lead (Pb): historically from fuels in motor vehicles, now mainly from ore and metal processing
- Particulate matter (PM): solid particles and liquid droplets suspended in the air
The six pollutants regulated by the National Ambient Air Quality Standards (NAAQS) are ground-level ozone, particulate matter (PM10 and PM2.5), carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead. These standards, established by the Environmental Protection Agency (EPA), aim to protect public health and the environment by setting limits on the allowable concentrations of these pollutants in the air.
Monitoring and controlling these substances help mitigate adverse effects on respiratory health, cardiovascular systems, and overall air quality, ensuring a safer and healthier living environment for communities across the United States.