On average, people in the United States spend more than 90 percent of their time indoors—in places like homes, schools, offices, gyms, and cars. These places are usually full of dust, which is more than just dirt. Household items like televisions, furniture, beauty products, cleaning products, and flooring materials shed chemicals that end up in the air and in the dust on our floors. These chemicals can enter our bodies from air and dust when we breathe, touch contaminated surfaces, and accidentally transfer them to our food or mouth with our dusty hands. And some of these chemicals can contribute to health problems.