public health 203 exam 1

Healthy People 2020

Healthy People 2020

Provides "science-based 10-year national
objectives for improving the health of all
Americans

pollution

Release of harmful materials into the environment

poverty

Linked to overpopulation and is a determinant of adverse
health outcomes.
..1.2 billion people live on $1.25 a day

Factors that lead to urbanization

Industrialization
• Food availability
• Employment opportunities
• Lifestyle considerations
• Escape from political conflict

population dynamics

The study of short‐ and long‐term changes in the number of individuals for a given population, as affected by birth, death, immigration, and emigration.

fertility rate

the average number of children a woman of childbearing years would have in her lifetime, if she had children at the current rate for her country

demographic transition

change in a population from high birth and death rates to low birth and death rates

Epidemiologic Transition

describes a shift in the pattern of morbidity and mortality

environmental epidemiology

The study of diseases and health conditions (occurring in the population) that are linked to environmental factors.

Sir Percival Pott

A London surgeon thought to be the first individual to describe an environmental cause of cancer.
Chimney sweeps had high incidence of scrotal cancer due to contact with soot.

John Snow

Mapped the occurrence of cholera in London

choices when designing a study

Role of investigator
- Observation vs. experimental
• Purpose of study
- Descriptive vs. analytical
• Hypothesized effect
- Harmful or beneficial
• Unit of analysis
- Individual vs. community

descriptive studies

Depiction of the occurrence of disease in
populations according to classification by
person, place, and time variables

analytic studies

- Examines causal (etiologic) hypotheses
regarding the association between exposures
and health conditions.

Prevalence

Prevalence is a measure of disease
frequency and refers to existing cases of
disease or deaths.

point prevalence

refers to all cases of a
disease that exist at a particular point in
time relative to a specific population from
which the cases are derived.

Incidence

The occurrence of new disease or mortality
within a defined period of observation (e.g.,
week, month, year, or other time period) in
a specific population.

case fatality rate

percentage of population that dies from a specific disease

Crosss-Sectional Studies

Exposure and disease outcomes are
determined at the same time

ecologic study

a study in which the units of analysis are populations or groups of people rather than individuals

Case-control study

A type of epidemiologic study where a group of individuals with the diseases, referred to as cases, are compared to individuals without the disease, referred to as controls

cohort study

A type of epidemiologic study where a group of exposed individuals (individuals who have been exposed to the potential risk factor) and a group of non-exposed individuals are followed over time to determine the incidence of disease

odds ratio

Comparison of the odds of disease in
the exposed population with odds of
disease in the unexposed population

relative risk

The ratio of the incidence rate of a disease
or health outcome in an exposed group to
the incidence rate of the disease or
condition in a non-exposed group.

epidemiologic triangle

agent, host, environment

Causality

the relationship between cause and effect

Sir Austin Bradford Hill

British medical statistician
• Developed criteria to determine the causal
link between a specific factor and a disease

Bias

"Deviation of results or inferences from the
truth, or processes leading to such
deviation. Any trend in the collection,
analysis, interpretation, publication, or
review of data that can lead to conclusions
that are systematically different from the
truth."

selection bias

in an experiment, unintended differences between the participants in different groups

heathy worker effect

A source of bias that results from the fact
that employed populations tend to be
healthier than the general population.

recall bias

Cases may remember the exposure more
clearly than controls
• Information gathered from controls may not be
reliable

Confounding

occurs when two variables are associated in such a way that their effects on a response variable cannot be distinguished from each other

Hyponatremia

deficient sodium in the blood

Toxicology

study of poisonous substances and their effects upon body parts

Paracelsus (1493-1541)

Paracelsus was one of the founders of
modern toxicology

Matieu Orfila

authored a number of significant works, among them Trait des poisons (1813), which work described various types of poisons and their bodily effects, a development that contributed to the foundations of forensic toxicology

toxicologist

specialist in the study of poisons

environmental toxicology

examines how
environmental exposures to chemical
pollutants may present risks to biological
organisms, particularly animals, birds,
and fish.

poison

...any agent capable of producing a
deleterious response in a biological system

Toxicity

Refers to "the degree to which
something is poisonous" and denotes the amount
of a substance that can produce a deleterious
effect.

Toxicants

Toxic substances that are man-made or result from human (anthropogenic) activity.

Toxins

Usually refers to a toxic substance made
by living organisms including reptiles, insects,
plants and microorganisms.

dose

The amount of substance given at one time.
units: - Per unit weight (mg/kg)
- Per unit volume inhaled (ppm, mg/m3)

ways of describing a dose

Exposure dose
• Absorbed dose
• Administered dose
• Total dose
• External dose
• Internal dose
• Biologically effective dose

Lethal Dose (LD50)

dose at which 50% of test animals die

dose-response relationship

the characteristics of exposure to a chemical and the spectrum of effects caused by the chemical.

dose-response curve

A type of graph used to describe the effect of exposure to a chemical or toxic substance upon an organism such as an experimental animal.

threshold

Refers to the lowest dose at which a particular response may occur

Absoprtion

Once ingested, a toxicant must be absorbed into the body

distribution

Once absorbed, the toxic agent is (often) distributed throughout the body and/or different tissues

Metabolism

- Chemical and physical changes by your body that can increase or decrease toxicity

excretion

Process by which metabolic wastes are eliminated from the body

acute exposure

usually a single exposure for less than 24 hours

subacute exposure

exposure for one month or less

subchronic exposure

exposure for one to three months

chronic exposure

exposure for more than three months

half-life

The time required for a chemical in the body to decrease to 1/2 of its value at the beginning of the observational interval

Synergism

indicates that the combined effect of exposures to two or more chemicals is greater than the sum of their individual effects

Potentiation

happens when one chemical that is not toxic causes another chemical to become more toxic

antagonism

happens when two chemicals administered together interfere with each other's actions or one interferes with the action of the other

Latency

The time period between initial exposure and a measurable response.

Carcinogen

A cancer-causing substance

Thalimodide

Widely marketed in western Europe as a sedative • Prescribed to pregnant women in 1950s & 1960s to treat morning sickness • More than 10,000 children born with severe birth defects

NOAEL

no observed adverse effect level
The highest dose administered for which no harmful effects are observed • Used to establish reference dose

IRIS

Integrated Risk Information System • Database of reference doses and toxicity information • Grouped by chemical, target system

risk assessment

the process of measuring risk
provides a qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards.

exposure assessment

Identifies populations exposed to the toxicant • Describes their composition and size • Examines the roots, magnitudes, frequencies, and durations exposures

risk characterization

...estimates of the number of excess unwarranted health events expected at different time intervals at each level of exposure

Risk Management

Follows risk characterization
Seeks to control exposures to toxic chemicals in the environment.
Directed towards specific actions
Examples: - Banning of hazardous materials - Food safety - Recalls - Exposure standards

risk communication

Working with credible sources
Working with the media
Working with stakeholders

Process of Risk Assessment

1. Hazard identification
2. Dose-response assessment
3. Exposure assessment
4. Risk characterization

hazard

Inherent capability of an agent or a situation to have an adverse effect

Hazard Identification

examines the evidence that associates exposure to an agent with its toxicity and produces a qualitative judgment about the strength of that evidence

dose-response assessment

the measurement of the relationship between the amount of exposure and the occurrence of the unwanted health effects

exposure assessment

the procedure that identifies populations exposed to the toxicant, describes their composition and size, and examines the roots, magnitudes, frequencies, and durations of such exposures

risk characterization

Develops "...estimates of the number of excess unwarranted health events expected at different time intervals at each level of exposure."

environmental policy

A statement by an organization of its intentions and principles in relation to its overall environmental performance.
Environmental policy provides a framework for action and for the setting of its environmental objectives and targets.

Legislative Branch

Makes laws

Executive Branch

Enforces laws

Judicial Branch

Interprets the laws

the precautionary principle

preventive, anticipatory measures . . . [should] be taken when an activity raises threats of harm to the environment, wildlife, or human health, even if some cause-andeffect relationships are not fully established.

polluter pays principle

means that the polluter should bear the expenses of carrying out the pollution prevention and control measures . . . to ensure that the environment is in an acceptable state

relationship of risk assessment to policy process

Risk assessment is closely aligned with the policy process through the balancing of economic and other costs with health and societal benefits that may accrue through specific policy alternatives

environmental justice

Movement that represents the convergence of civil rights and environmentalism •
The concept of environmental justice denotes the equal treatment of all people in society irrespective of their racial background, country of origin, and socioeconomic status.
No group of people should bear disproportionate burden

Common E.J. issues

• Permitted air pollution facilities
• Brownfield/Superfund designation
• Landfill siting Hazardous materials siting • Public infrastructure
. Indirect EJ: Lack of minority representation in decision making

Difficult balance

In Houston, TX, 8 of 9 landfills are in neighborhoods of high minority percentages
In NC, census blocks with >50% minorities are 2.8x more likely to have landfills than blocks with <10% minorities Evidence is clear that minorities are disproportionately affected; siting is usually driven by economics.

EJ and Social Equality

Minorities tend to have disproportionate health burdens, lower SES
This encourages living in communities with lower SES standards
Which is where the facilities are located
Which have deleterious effects on health of those who live there

food deserts

urban and rural low-income areas with limited access to affordable and nutritious foods

World Health Organization (WHO)

a global institution dedicated to the improvement of human health by monitoring and assessing health trends and providing medical advice to countries

Environmental Protection Agency

• EPA develops and enforces regulations that implement environmental laws enacted by Congress.
• Responsible for protecting human health and safeguarding the natural environment

National Institute for Occupational Safety and Health (NIOSH)

• NIOSH is the federal agency responsible for conducting research and making recommendations for the prevention of workrelated injury and illness.
• Created in The Occupational Safety and Health Act of 1970 along with the Occupational Safety and Health Administration (OSHA).
Part of the Centers for Disease Control and Prevention (CDC)

National Environmental Policy Act (NEPA)

• One of the first laws ever written that establishes the broad national framework for protecting our environment.
• NEPA's basic policy is to assure that all branches of government give proper consideration to the environment prior to undertaking any major federal action that significantly affects the environment.
• Federal activities require EIA

Clean Air Act of 1970

A comprehensive Federal law that regulates air emissions from area, stationary, and mobile sources.
• Authorizes the EPA to establish National Ambient Air Quality Standards (NAAQS) to protect public health and the environment.
• NAAQS for six criteria pollutants
- Particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxide, ozone, lead

Clean Water Act

Started out as the Federal Water Pollution Control Act Amendments of 1972 and has been amended many times.
• This act set up the structure for regulating discharges of pollutants into U.S. waters.
• Includes construction of sewage plants, water quality criteria for surface waters, and pollution control programs for industrial plants.

Safe Drinking Water Act (1974)

Establishes drinking water standards for tap water safety, and requires rules for groundwater protection from underground injection; amended in 1986 and 1996. The 1996 amendments added a fund to pay for water system upgrades, revised standard: setting requirements, required new standards for common contaminants, and included public "right to know" requirements to inform consumers about their tap water.

Toxic Substances Control Act (1976)

EPA tracks the 100k industrial chemicals currently produced or imported into the U.S.
• EPA repeatedly screens these chemicals and can require reporting or testing of those that may pose an environmental or human-health hazard.
• EPA can ban the manufacture and import of those chemicals that pose an unreasonable risk.

Resource Conservation and Recovery Act (RCRA)

• EPA controls hazardous waste from the "cradle-tograve." This includes the generation, transportation, treatment, storage, and disposal of hazardous waste.
• Addresses environmental problems from underground storage tanks containing petroleum and other hazardous substances.
• RCRA focuses only on active and future facilities and does not address abandoned or historical sites.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)

• Provides a Federal "Superfund" to clean up uncontrolled or abandoned hazardous-waste sites as well as accidents, spills, and other emergency releases of pollutants and contaminants into the environment.
• EPA has power to seek out potentially responsible parties for any release and assure their cooperation in the cleanup.

Zoonosis

An infectious disease that is transmissible from animals to humans.

Vector

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