MIDTERM1

Question 1

Epidemiology

Answer 1

is the study and analysis of the distribution, patterns and determinants of health and
disease. It is a cornerstone of public health, and shapes policy decisions by identifying risk factors for disease and targets for preventive healthcare.

Question 2

Environmental Risk

Answer 2

arises from environmental hazards or environmental issues…..aims to assess the effects of stressors, often chemicals, on the local
environment

Question 3

Hazard

Answer 3

Something that has the potential to harm you.

Question 4

Risk

Answer 4

likelihood of a hazard causing harm.

Question 5

Natural Environment

Answer 5

Consists of those parts of the earth – living or non-living – that are not a product of human activity. This includes living organisms, ecosystems, climate, weather, minerals, soil, air,
and water. The implication, of course, is that humans are not part of the natural system, which is clearly wrong; but it is reasonable to distinguish natural from man-made change

Question 6

Built Environment

Answer 6

Consists of everything constructed by humans,
including buildings, towns, cities, roads,
infrastructure, water and energy supply systems, and perhaps even cultivated forests, urban parks, botanic gardens, and reservoirs.

Question 7

The Three P’s

Answer 7

Pollution, Population, Poverty

Question 8

Epidemiologic transition

Answer 8

Shift in the pattern of morbidity and mortality
– Before shift: causes primarily related to infectious and
communicable diseases
– After shift: causes associated with chronic, degenerative
diseases

Question 9

hazardous agents

Answer 9

Account for many of the forms of environmentally associated
morbidity and mortality
* Examples
– Microbes
– Toxic chemicals and metals
– Pesticides
– Ionizing radiation

Question 10

Prevalence

Answer 10

Number of existing cases of or deaths
from a disease or health condition in a
population at some designated time
Point prevalence =
Number of persons ill / Total number in the group
at a point in time

Question 11

Incidence

Answer 11

Occurrence of new disease or mortality
within a defined period of observation
(e.g., a week, month, year, or other time
period) in a specified population………….
Incidence rate = Number of new cases over a time period / Average population at risk during the same time period x multiplier (e.g., 100,000)

Question 12

Cross-sectional study

Answer 12

Different groups compared at the same time

Question 13

Case Fatality Rate (CFR)

Answer 13

CFR(%) =
Number of deaths due to disease “X” /
Number of cases of disease “X”
x 100 during a time period

Question 14

Longitudinal study

Answer 14

same group compared over time.

Question 15

Odds Ratio (OR)

Answer 15

Measure of association between exposure and
outcome— Used in case-control studies

Question 16

What Is the Epidemiologic Triangle?

Answer 16

Used to describe causality of infectious diseases
* Provides framework for organizing the causality
of other types of environmental problems

Question 17

Environment in the “Triangle

Answer 17

Domain in which disease-causing agents
may exist, survive, or originate
* Consists of “All that which is external to
the individual human host.”

Question 18

Host in the “Triangle”

Answer 18

“person or other living animal, including
birds and arthropods, that affords
subsistence or lodgment to an
INFECTIOUS AGENT under natural
conditions”

Question 19

Agent in the “Triangle”

Answer 19

“factor (e.g., a microorganism, chemical substance, form of radiation, mechanical, behavioral, social agent or process) whose presence, excessive presence, or (in deficiency diseases) relative absence is essential for the occurrence of a disease”

Question 20

Limitations of Epidemiologic Studies

Answer 20

• Long latency periods
• Low incidence and prevalence
• Difficulties in exposure assessment
• Nonspecific effects

Question 21

What Is Environmental Epidemiology?

Answer 21

• Study of diseases and health conditions
  (occurring in the population) linked to
  environmental factors
• Exposures usually involuntary

Question 22

Carcinogen

Answer 22

• Chemical (or substance) that causes or is
  suspected of causing cancer, a disease associated
  with unregulated proliferation of cells in the body

Question 23

Latency

Answer 23

• Time period between initial exposure and
  a measurable response
• Can range from a few seconds (in the case of acutely toxic agents) to several
  decades for agents that may be
  carcinogenic

Question 24

Biomagnification

Answer 24

(Toxic Pathways) (Bioaccumulation)
– the accumulation or increase in concentration of a
substance in living tissue as it moves through the food
chain.
– e.g. Cadmium, mercury are biomagnified

Question 25

Bioaccumulation

Answer 25

Toxins that bioaccumulate in the tissues of one organisms may be transferred to other organisms as predators consume
prey. * With each step up the food chain, concentrations of the toxin can be magnified
* This is called Biomagnification
▪ Heavy metals
▪ Chlorinated hydrocarbons

Question 26

Persistent Organic Pollutants (POPs)

Answer 26

• Persistence of the chemical
  – How long it can remain in the environment. – Chemicals have half lives
• (POPs) are extremely
  dangerous due to their ability to be biomagnified.
  – For example, phthalates found in polyvinyl chloride plastic & some deodorants & cosmetics have been shown to be toxic to lab animals
• Nearly everyone in the U.S. has phthalates in their tissues because these chemicals are highly persistent

Question 27

types of hazards

Answer 27

-Chemical hazards— from harmful chemicals in
air, water, soil, food, and human-made
products.
* Natural hazards– such as fire, earthquakes,
volcanic eruptions, floods, and storms.
* Cultural hazards– such as unsafe working
conditions, unsafe highways, criminal assault,
and poverty.
* Lifestyle choices– such as smoking, making
poor food choices, drinking too much alcohol,
and having unsafe sex.

Question 28

pathogen

Answer 28

an organism that can
cause disease in another organism.
– Bacteria.
– Viruses.
– Parasites.
– Protozoa.
– Fungi.

Question 29

Risk Assessment

Answer 29

Provides a qualitative or quantitative estimation
of the likelihood of adverse effects that may
result from exposure to specified health hazards
or from the absence of beneficial influences
* Hazard identification
* Dose–response assessment
* Exposure assessment
* Risk characterization

Question 30

Exposure Assessment

Answer 30

Procedure that “identifies populations exposed
to the toxicant, describes their composition and
size, and examines the roots, magnitudes,
frequencies, and durations of such exposures”
* One of the weakest aspects of risk assessment
* Takes into account the following:
– Where the exposure occurs
– How much exposure occurs
– How a toxic substance is absorbed by the body

Question 31

Zoonosis

Answer 31

An infection or infectious disease
transmissible under natural conditions
from vertebrate animals to humans”
Methods for Transmission of Zoonoses
* Contact with the skin
* Bite or scratch of an animal
* Direct inhalation or ingestion
* Bite of an arthropod vector

Question 32

Vector

Answer 32

An insect or any living carrier that transports an
infectious agent from an infected individual or its
wastes to a susceptible individual or its food or
immediate surroundings”
* Various species of rodents
– Rats and mice
* Arthropods
– Mosquitoes
– Ticks
– Sand flies
– Biting midges

Question 33

DDT (dichloro-diphenyl-trichloroethane)

Answer 33

It was initially used with great effect to combat malaria, typhus, and the other insect-borne human diseases among both military and civilian populations

Question 34

Exposure Source

Answer 34

origin of environmental contamination ex. Industrial releases, consumer product chemicals, combustion byproducts(car pollutants)

Question 35

Exposure Route

Answer 35

Contact, ingestion, inhalation ex food, dust, drinking water,

Question 36

Exposure pathway

Answer 36

Exposure Pathway Categories.
Element 1: Contamination Sources.
Element 2: Environmental Fate and Transport.
Element 3: Exposure Points.
Element 4: Exposure Routes.
Element 5: Potentially Exposed Populations.

Question 37

Risk assessments

Answer 37

Risk assessment is the process
of using statistical methods to
estimate how much harm a
particular hazard can cause to
human health or to the
environment.
- It helps us to establish priorities
for avoiding or managing risks.
- It involves deciding whether or
how to reduce a particular risk
to a certain degree
ex. cooking an egg lowers the risk of food poisoning

Question 38

Dose-Response Assessment

Answer 38

Estimates how much of the chemical it would take to cause varying degree of health effects that could lead to illness. What is the relationship between dose and incidence of the adverse effect in humans?————–How the proportion of responding individuals in a population or the severity of the toxic response within an
individual increases with dose is investigated.

Question 39

Hazard Identification

Answer 39

Identifies any potential health problems that a chemical can cause. Does the agent cause an
adverse effect?

Question 40

Exposure Assessment

Answer 40

Determines the amount, duration, and pattern of exposure to the chemical

Question 41

Risk Characterization

Answer 41

Assesses the risk for the chemical to cause illness in the general population. What is the
estimated incidence of the effect in a given population?

Question 42

NOAEL

Answer 42

NOAEL: no-observed-adverse-effect-level ….. is defined as the highest dose where the effects observed in the treated group do NOT imply an adverse effect to the subject.

Question 43

LOAEL

Answer 43

LOAEL: lowest-observed-adverse-effect-level…. Lowest dose at which there WAS an observed toxic or adverse effect.

Question 44

DNEL

Answer 44

DNEL: Derived No-Effect Level

Question 45

EDI

Answer 45

Estimated daily intake (mg/kg/day)