1.22 Field Study
enter a river in runoff rainwater that picks up pollutants as it runs over the ground. This type of pollution enters the
river everywhere. This is called nonpoint-source pollution.
Q:Assume that the river is polluted only by nonpoint-source pollution. Describe how the samples of river water
would compare in terms of the pollutants they contain.
A:All of the samples would contain about the same amount and types of pollutants.
Q:How might point-source pollution be identified?
A:Just one sample might be polluted. This would be the sample taken at, or just downstream from, the single source
of pollution.
Summary
- In a field study, a scientist gathers evidence in the real world instead of in a lab.
- Field studies are needed to investigate the environment. An example of a field study is collecting samples of
river water to test for evidence of pollution.
Vocabulary
- field study: Investigation of a problem in a real-world setting.
Explore More
The mileage sticker pictured below states how many miles this car can go on 1 gallon of gas. The sticker shows
the mileage for city driving and for highway driving. Unless you read the fine print at the bottom of the sticker,
you would expect to get these mileages if you buy the car. However, these mileages were measured under ideal
conditions in a lab, not as cars are actually driven in the real world. Gathering evidence to estimate average mileages
in the real world would require a field study.
- How do you think a scientist could gather evidence on the gas mileage of a car as it is actually driven in the
real world? - Do you think drivers should expect to get lower or higher mileages than the values given on the sticker? Why?