Pure science is used to solve a lot of different environmental problems. Infact, these days in high level education institutions, students are taught to apply their knowledge of pure sciences, such as chemistry, for environmental problem solving. But when the knowledge of pure sciences is used for practical and specialized purposes, they are called applied sciences. For example, biology can used to study the impact of active smokers on the environment, by examining the harm done to those who live with smokers using biological tests.