Population Characteristics: Measures and Data
Which parts of demographic profiles can influence environmental public health, and why?The characteristics of a population can help determine the possible impact of health problems and the trends and patterns of disease over space and time. Age, sex, race/ethnicity and socioeconomic status can influence community health by operating at different points in people’s lifetimes.
These characteristics may be related to the number of new and existing cases of a particular disease. For example, in the U.S., the number of new cases of different types of cancer among racial groups varies greatly. White women have the highest number of new breast cancer, leukemia, and non-Hodgkin’s lymphoma cases; Black women have the highest number of new colon and pancreas cancer cases; Hispanic women have the highest number of new cervical cancer cases; and Asian/Pacific Islanders have the highest number of new stomach cancer cases. The recent publication CDC Health Disparities and Inequalities Report — United States, 2011 offers many examples of unequal rates of illness among different ethnic and racial groups.
The association between population characteristics and the environment can be difficult to measure. But 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 chance for exposure to several environmental conditions that can threaten their health because they are more likely to live near hazardous waste sites and in areas with high air pollution and poor housing conditions.
For example, low-income populations, minorities, and children living in inner cities have more emergency department visits, hospitalizations, and deaths resulting from asthma than the general population. In New York, people living within a half mile of toxic land sites were 66% more likely to be hospitalized for asthma and 13% more likely to be a member of a minority group than people outside the half mile radius.
A growing body of research evidence is pointing out that children are at higher risk from environmental exposures, especially to toxic chemicals. Children exposed to secondhand tobacco smoke are at a higher risk for acute lower respiratory infections, asthma, and middle ear infections. Knowing about distinct age groups in childhood can help understand the extent of poor health associated with socioeconomic circumstances (such as lack of access to health care). This is important because certain socioeconomic factors present during childhood point to poor physical health as adults.
Why are these particular population measures in use versus others?The population and birth numbers included in WTN are used for rate calculations that form other indicators for health effects elsewhere in this site. Population data used for calculating rates of hospitalization are slightly different from general population data: because hospitalization data contain only the ZIP-code of residence for the patient, CHS assigns county of residence based on where the majority of the population lives, in order that rate calculations match up numerators and denominators. Washington residents who are hospitalized in federal hospitals and out-of-state hospitals are not currently used to calculate hospitalization rates. (For more details, see Data Notes for health effect topics that are illustrated by hospitalization indicators.)
Some indicators, such as those for adverse birth outcomes, are showing trends in birth weights of babies. Because multiple births could make these calculations artificially low, there are two birth measures shown.
Finally, both birth and population measures can be stratified to examine how certain age groups that have specific health risks associated with them look as compared to exposures and health outcomes shown in WTN.
Which population health risks can be mitigated or avoided, and how?Some population health risks are well documented in research, including effects of mothers’ tobacco use on unborn children and environmental tobacco smoke on infants and children. Probabilities of developmental problems can be reduced by helping parents shift their behaviors during pregnancy and child-rearing. Likewise, knowing that certain cancer-causing contaminants occur at harmful levels in air and drinking water gives some choices to families about whether or not to modify their family’s activities to avoid exposure.
However, purchasing drinking water and moving are not realistic personal choices for many families. Discussing such issues with lawmakers and joining advocacy groups who can suggest policy changes are other avenues for reducing risk for large groups of people. Tracking population subgroup data over time may increase the capacity to ask research and policy questions that move toward avoiding exposures that put segments of the population at extra risk. Many specific suggestions are made in the Health of Washington State report (see link at right).