True or false: Indoor air pollution is often higher than it is outdoors.

Indoor air pollution is often higher than outdoor air pollution due to various factors present in enclosed spaces. Common indoor pollutants include volatile organic compounds (VOCs) emitted by paints, cleaning products, and building materials, as well as other substances like mold, tobacco smoke, and particulate matter from cooking or heating appliances. These contaminants can accumulate more easily indoors where ventilation is limited, leading to higher concentrations.

In many cases, people spend the majority of their time indoors, which can expose them to these pollutants significantly more than if they were outdoors. Additionally, indoor air can be trapped and recirculated, allowing pollutants to build up over time. Outdoor air pollution, albeit prevalent, often disperses more freely in open environments, reducing the concentration of harmful substances compared to the confined spaces of homes or offices. This combination of factors contributes to the reality that indoor air quality can be worse than outdoor air quality overall.