The harmful effects of smoking do not end with the smoker. More than 126 million nonsmok-
ing Americans, including children and adults, are regularly exposed to secondhand smoke.
Even brief exposure can be dangerous because nonsmokers inhale many of the same carcino-
gens and toxins in cigarette smoke as smokers. Secondhand smoke exposure causes serious
disease and death, including heart disease and lung cancer in nonsmoking adults and sudden
infant death syndrome, acute respiratory infections, ear problems, and more frequent and
severe asthma attacks in children.
Maps and Models
- Have students interpret the information shown on the map below.
Figure 26.3: Epidemiologists study how diseases spread. The above map shows where hu-
mans contracted West Nile Virus between 2000 and 2006.? )
- Have students interpret the data in the model below and make a testable prediction
based on the information presented in the model.
You use models for many purposes. A volcano model, is not the same as a volcano, but it
is useful for thinking about real volcanoes. We use street maps to represent where streets
are in relation to each other. A model of planets may show the relationship between the
positions of planets in space. Biologists use many different kinds of models to simulate real
events and processes. Models are often useful to explain observations and to make scientific
predictions.