"Determinants of health fall under several broad categories. Policies at the local, state, and federal level affect individual and population health. Increasing taxes on tobacco sales, for example, can improve population health by reducing the number of people using tobacco products. Some policies affect entire populations over extended periods of time while simultaneously helping to change individual behavior. For example, the 1966 Highway Safety Act and the National Traffic and Motor Vehicle Safety Act authorized the Federal Government to set and regulate standards for motor vehicles and highways. This led to an increase in safety standards for cars, including seat belts, which in turn reduced rates of injuries and deaths from motor vehicle accidents. Social determinants of health reflect the social factors and physical conditions of the environment in which people are born, live, learn, play, work, and age. Also known as social and physical determinants of health, they impact a wide range of health, functioning, and quality-of-life outcomes. Examples of social determinants include availability of resources to meet daily needs, such as educational and job opportunities, living wages, or healthful foods; social norms and attitudes, such as discrimination; exposure to crime, violence, and social disorder, such as the presence of trash; social support and social interactions; exposure to mass media and emerging technologies, such as the Internet or cell phones; socioeconomic conditions, such as concentrated poverty; quality schools; transportation options; public safety; and residential segregation. Examples of physical determinants include the natural environment, such as plants, weather, or climate change; the built environment, such as buildings or transportation; worksites, schools, and recreational settings; housing, homes, and neighborhoods; exposure to toxic substances and other physical hazards; physical barriers, especially for people with disabilities; and aesthetic elements, such as good lighting, trees, or benches. Poor health outcomes are often made worse by the interaction between individuals and their social and physical environment. For example, millions of people in the United States live in places that have unhealthy levels of ozone or other air pollutants. In counties where ozone pollution is high, there is often a higher prevalence of asthma in both adults and children compared with state and national averages. Poor air quality can worsen asthma symptoms, especially in children."