Population characteristics can help predict the possible end results of health problems and your risk for certain diseases. They can also show how diseases can develop and change over time and from one place to another.

Population characteristics include

• sex,
• age,
• race and ethnicity, and
• socioeconomic factors, such as how much money and what kind of job you have.

Although some research shows that population characteristics and the environment are related, it is difficult to measure the relationship. Some research shows that these factors do affect a person's exposure to environmental hazards. Racial minorities and low-income populations may have a greater risk for exposure to several environmental conditions that can threaten their health. The greater risk is because those populations are more likely to live near hazardous waste sites, in areas with high air pollution levels, and in poor housing conditions.

For example, low-income populations, minorities, and children living in inner cities have more emergency department visits, hospital stays, and deaths caused by asthma than the population as a whole. In New York, people living within a half mile of toxic land sites were 66% more likely to be admitted to the hospital for asthma, 30% more likely to be poor, and 13% more likely to be a member of a minority group than people living more than a half mile from the site.

Children exposed to secondhand smoke are at a higher risk for asthma, lung infections like pneumonia or bronchitis, and middle ear infections. Children living below or near the poverty level are more likely to be exposed to secondhand smoke than children living in higher income households. Some studies suggest that crowded housing and lower parental education levels also may be related to a child's exposure to secondhand smoke.