Which pollutant are you more likely to encounter in dangerous concentrations indoors rather than outdoors?

You are more likely to encounter elevated concentrations of carbon monoxide indoors, particularly from sources like gas appliances, heating systems, or vehicle exhaust in attached garages. Unlike outdoor environments, where carbon monoxide disperses quickly, indoor spaces can trap this toxic gas, leading to dangerous levels that pose serious health risks. Proper ventilation and regular maintenance of appliances are crucial to mitigate this hazard.