Explain how ecologic analysis is used to study the health effects of air pollution. Provide examples of uncontrolled factors that may affect ecologic study results.

Environmental Epidemiology Assessment
Kindly answer the under listed question and support it with current references.
1) Define the following terms:
a) Environmental epidemiology:
b) Natural experiment:
c) Descriptive epidemiology:
d) Odds ratio:
e) Relative risk:
2) Explain the work of John Snow using the methodology of the natural experiment.
3) List the reasons why epidemiology is important to research studies of environmental health. What are some of the important limitations of the epidemiologic approach with respect to the study of environmental health problems?
4) Explain how ecologic analysis is used to study the health effects of air pollution. Provide examples of uncontrolled factors that may affect ecologic study results.
5) Describe the importance of the contributions of Sir Percival Pott to environmental health, particularly in the field of cancer prevention
6) Describe Hill’s criteria for disease causality.
7) Explain the epidemiologic triangle and how it can be applied to environmental health.
8) Explain the difference between descriptive and analytic epidemiology. Provide examples of how both types of study design are utilized in the field of environmental health.
Kindly use this textbook to answer the above question and support it with referencesEssentials of Environmental HealthFriis, R. H. (2012). Essentials of environmental health (2nd ed.). Sudbury, MA: Jones & Bartlett Learning. ISBN-13: 9780763778903