Autumn Quarter 2012
Study Guide for the Midterm Examination

In preparing for the mid-term examination you should have read all of the assigned chapters in the textbook and the required supplementary readings.  You should also review all of the course handouts posted to the course web site or handed out in class.  The exam will be compiled from these materials, plus information presented in the class lectures.  In particular, you should concentrate your study on the major principles and concepts identified for each of the following program areas.

Format:

The midterm exam will consist of approximately 40 objective questions (multiple choice) and one or two short essay questions that will be designed to test your ability to integrate and synthesize the material presented in the lectures and the readings.

Introduction

• Know the definition of environmental health.
• Be able to name the three factors (agent, host, environment) involved in any environmentally linked disease or injury and give examples of each.
• Be able to describe the three population hazards that have impacted human populations since the beginning of time.

Ecology

• Know the definition of ecocology and be able to explain how this sciece relates to the practice of environmental health.
• Be able to explain the concepts of ecosystems, ecological niches, and limiting factors.
• Being able to explain the concept of the “tragedy of commons” and its relation to Public Health.

Population & The Limits to Growth

• Understand and be able to discuss world population growth using the concept of population doubling time and the implications of the worst case projection (i.e., the limits to growth)
  
• Be able to explain what was the Club of Rome and its importance?
• Be able to discuss the five key trends that were analyzed in the "Limits to Growth" computer model (Population growth, Industrial Output, Resources Consumption, Food Production and Pollution).
  
• Be able to discuss population growth and how various population growth models (e.g. LTG) might predict different health outcomes on a global scale.
  
• Explain how choices we make in both our personal lives and as members of society have both positive and negative effects on the environment, and in turn on our health; and be able to give more than one specific example.
  

Epidemiology

• Know the definition of Epidemiology
• Understand what is meant by the terms prevalence and incidence of disease.
• Be able to explain what spatial distribution and temporal distribution are.
• Be able to identify what an agent, host, and environment are and how they are related.
• Explain the importance of stratification by age, race, sex or other factors in analysis of epidemiologic data.
• Know the three types of disease-causing agents (biological, chemical & physical) with examples.
• Know the three most important modes of transmission (for environmental health) of infectious agents and be able to provide examples.

Toxicology

• Know the definition of toxicology.
  
• Know and be able to explain the dose-response relationship and interpret dose-response curves
• Give examples of several health effects associated with exposure to specific chemical agents in the environment (e.g., asbestos, smoking, lead, arsenic, etc.)
  
• What are the four types of toxicology information used to determine environmental health risks to humans? (Human [Epidemiological] data, animal models, in vitro assays and structural activity models).
  
• Be able to discuss the ways a chemical agent is processed by the body, including concepts of biological half-life, chemical interactions and ADME (Absorption, Distribution, Metabolism and Excretion).
  
• Be able to identify several factors that influence an individual's susceptibility.
• Know what is an LD50 -- what it can and can not tell you.
  
• Be able to define the terms Threshhold, LOAEL, NOAEL.
• Be able to discuss the concepts of acute and chronic exposures, e.g., using fetal alcohol syndrome or other toxic effects as an example.

Risk Assessment

• Understand what is risk? (Risk = Hazard x Exposure)
• Understand the concepts of risk assessment, risk management and risk communication and be able to explain how these are used in the practice of environmental health.
• Explain how one might compare risks.
• Know and be able to explain the major types of methods used in hazard identification (pros vs. cons of each).
• Explain the difference between a threshold vs. non-threshold response.
• Describe two types of dose response curves (threshold vs. non-threshold).
• Know what an rfd (reference dose) is, how it is calculated and in what porgrams it is used.
• Know the process of cost-benefit analysis.
• Understand how public perception of risk plays a role.
  

Disease Transmission & Control

• Describe the major routes of transmission of pathogenic organisms of importance to Environmental Health.
• Explain how choices we make in both our personal lives and as members of society have both positive and negative effects on the environment, and in turn on our health. Be able to give more than one specific example.
• List several examples of infectious diseases transmitted through the environment, including at least one that is considered an emerging (or re-emerging) disease.
• Be able to identify several examples of environmental disease not caused by microorganisms, and describe how humans are exposed to the causative agent.
• Know basic prevention and control strategies and their effectiveness
• Be able to describe the four general engineering control strategies used to mitigate environmental health hazards and be able to present an example for each.
  

Water, Water Use and Drinking Water

• Be able to describe the issues surrounding global water availability and use
• Be able to describe the hydrologic cycle; and explain why is it important to the practice of environmental health.
• Know water availability and sources for drinking water
• Be able to identify the major waterborne diseases of the U.S., and be able to describe the causes of such waterborne disease outbreaks
• Be able to apply the "engineering control strategies" to particular situations in order to reduce the risk of waterborne disease outbreaks (isolation, shielding, treatment, substitution)
• Be able to list the steps involved in drinking water treatment for both surface and groundwater systems, and describe the purpose of each step in the process.

Wastewater -- Process, Treatment and Disposal

• Be able to describe a typical gravity On-site Sewage system (OSS) and how they work
• Be able to describe how municipal sewage is treated; including Primary, Secondary and Tertiary Wastewater treatment processes
• Be able to describe the problem(s) with combined sewer overflows
  

Food Protection

• Explain why most foods are considered perishable and the factors that lead to food spoilage.
• Describe the general trend of reported incidence of foodborne illness in the United States and the problems inherent with the reporting the true incidence of these diseases.
• •Explain the difference between an outbreak and a case.
• Know the major types of food pathogens and their incubation time.
• Describe the population groups at high risk of serious complications from foodborne illness.
• Explain the difference between infections and intoxications and be able to provide examples of each.
• Describe the four major causes of foodborne illness and be able to give examples of how each can be prevented.
• Explain the time/temperature relationship in food preparation and service and explain the importance of this concept to environmental health.
• Be able to describe how one could use the four engineering strategies to protect exposed populations from foodborne illness.

Sample Questions

1. In the definition of epidemiology presented in class, the study of the determinants of a disease in a community involves the investigation of:
A. person, place and time.
B. agent, host and environment.
C. the infectivity, pathogenicity and virulence of the agent.
D. the signs and symptoms of the disease.
E. all of the above.

2. What is the definition of ecology?
A. study of the effects of environmental factors on the health of human populations
B. the study of abundance and distribution of species, and their relationship to the environment
C. the science of the common factors in every environment
D. the study of global temperature fluctuations
E. study of the effects of human populations on the environment

3. Considering the adverse and positive effects of a compound exemplifies which of the following Risk Assesment approaches?
A. Expressed preference
B. Cost-benefit analysis
C. Revealed preference
D. Natural standards
E. None of the above

4.  The following is an example of an environmental cancer risk:
A.  smoking
B.  dietary factors
C.  air pollution
D.  bezene
E.  all of the above

5.  Public perception is most likely to overestimate a risk if the risk has which of the following characteristics?
A. The risk is voluntary
B. The risk is associated with a common event
C. The risk has an reversible health outcome
D. The risk is associated with a catastrophic event
E.  The risk is associated with smoking

6. When the proportion of a population with a disease is measured at a specific time, the resultant measure is called the:
A. Prevalence Rate
B. Incidence Rate
C. Dose-response curve
D. Stratification diorama
E. Confounding Factor

7. Development of cities brought:
A. Spread of pathogens
B. Problems with wastewater treatment and disposal
C. Finding and maintaining good water supplies
D. Trade
E.  All of the Above

8.  A zoonotic disease is best described as:
A. An arthropod which carries a pathogen to a new host
B. Disease transmitted from vertebrate animals to humans through various routes
C. Disease transmitted by a vector
D.  Any usual fatal or epidemic disease
E.  Asthma

9. Each of the following pathways is included in the carbon cycle except:
A. respiration.
B. decay of organic matter.
C. weathering of limestone deposits.
D. combustion of organic fuels.
E. All of these are included in the carbon cycle.

10. Which of the following hazards has been an environmental health concern since the appearance of Homo sapiens as a species?
A. Industrial Chemical Toxins
B. Over-nutrition
C. Contagious Disease
D. Vector-borne Disease
E. Untreated Wastewater