PBH Study Guide for Exam #2: Modules 6, 7, and 8

Comprehensive vocabulary flashcards covering Modules 6, 7, and 8, including vector biology and control, toxicology and exposure pathways, and occupational health, safety hierarchies, and history.

Mechanical vector

Carries a pathogen on its body without the pathogen developing or reproducing inside the vector.

Biological vector

The pathogen lives, develops, or reproduces inside the vector before being transmitted to another host.

Zoonotic disease

A disease naturally transmitted from animals to humans, sometimes through a vector.

Anthroponotic disease

A disease whose main reservoir is humans and that is transmitted between humans, sometimes through a vector.

Intrinsic incubation period

The time between a person becoming infected and developing symptoms.

Extrinsic incubation period

The time between a vector taking in a pathogen and the pathogen becoming developed enough to be transmitted by the vector.

Dengue

A viral disease primarily transmitted by Aedes mosquitoes that often causes high fever, severe headache, pain behind the eyes, and muscle or joint pain; severe cases can cause bleeding, shock, and organ damage across four main virus types.

Zika

A viral disease primarily transmitted by Aedes mosquitoes and sexually; often causes mild illness or no symptoms, but infection during pregnancy can cause serious birth defects including congenital Zika syndrome.

Aedes aegypti

The main mosquito vector for dengue and Zika viruses, characterized by a black body with distinctive white markings that breeds in standing water, including containers, buckets, tires, and flowerpots.

Physical source reduction (vector control)

A mosquito control strategy focused on removing breeding sites by emptying standing water, cleaning gutters, covering water-storage containers, and discarding old tires.

Biological source reduction/control

Using living organisms or biological agents—such as Bti (Bacillus thuringienisis israelensis), larva-eating fish, or Wolbachia-based mosquito-control programs—to reduce mosquito populations.

Borrelia Burgodorferi

The bacterial agent that causes Lyme disease.

Black legged tick

The vector that transmits Lyme disease when it attaches and feeds, allowing bacteria to pass into a host.

Exposure pathway

Describes how a harmful substance travels from its source to a person and how that person comes into contact with it.

Source of contamination

The origin point of a hazardous substance in an exposure pathway, such as lead pipes.

Environmental transport and fate

How contamination moves or changes in the environment, such as lead dissolving into water.

Exposure point

The specific place where a person comes into contact with a contaminant, such as a kitchen faucet.

Exposure route

How a contaminant enters the human body, such as ingestion by swallowing contaminated water.

Receptor population

The group of people who are exposed or potentially exposed to a contaminant, such as residents drinking tap water.

Linear dose-response

A dose-response relationship in which the response changes proportionally with dose, with risk increasing steadily as dose increases.

Nonlinear dose-response

A dose-response relationship where the response does not change proportionally with dose; a small dose increase may have little effect, followed by a larger change.

Threshold dose-response

A relationship where there is no measurable harmful effect below a certain dose, producing effects only after sufficient exposure.

No-threshold dose-response

A relationship where any additional exposure may increase risk, even at low doses; commonly used to model radiation-related cancer risk.

Hormesis

A dose-response phenomenon where low doses produce a different, sometimes opposite response from high doses, such as stimulatory effects at low doses and harmful effects at high doses.

Bioaccumulation

A process where a contaminant builds up inside a single organism over time because it enters faster than the organism can eliminate it.

Biomagnification

A process where a contaminant becomes more concentrated at higher levels of a food chain.

Toxin

A poisonous substance that can harm or disrupt the normal functioning of an organism, such as Botulinum toxin interfering with nerve function.

Carcinogen

An agent that can cause or increase the risk of cancer, such as asbestos being associated with lung cancer mesothelioma.

Half-life

The time required for half of the amount of a substance to be eliminated or for its concentration to decrease by half under specified conditions.

Acute exposure

A single exposure or exposures occurring over a short period.

Subacute exposure

Repeated exposure over days or a few weeks.

Subchronic exposure

Repeated exposure over a substantial portion of a person's life, typically lasting weeks to months in toxicology studies.

Chronic exposure

Repeated or continuous exposure over a long period, often months to years.

Elimination (hazard control)

A control strategy that removes a hazard completely, such as removing a broken machine or removing workers from dusty mining areas.

Substitution (hazard control)

A control strategy that replaces dangerous materials or processes with safer alternatives.

Engineering controls

Changes made to equipment or the workplace to isolate workers from hazards or reduce them, such as installing machine guards, ventilation systems, or water sprays.

Administrative controls

Measures such as safety rules, worker training, procedures, and adjusted work schedules used to reduce exposure to hazards.

Personal protective equipment (PPE)

Safety gear—such as gloves, helmets, goggles, respirators, and protective clothing—worn to protect workers from hazards.

Triangle Shirtwaist Factory Fire

A workplace disaster on March 25, 1911, in New York City where 146 workers died due to locked doors, overcrowding, and inadequate fire safety, sparking public outrage and major labor reforms.

Frances Perkins

Workplace safety advocate who witnessed the aftermath of the Triangle Fire, helped develop New Deal programs, helped create the Social Security Act of 1935, and became the first female U.S. Secretary of Labor in 1933.

Max Blanck and Isaac Harris

The owners of the Triangle Shirtwaist Factory at the time of the 1911 fire.

Rose Schneiderman

A labor organizer who advocated for workers' rights and stronger safety protections following the Triangle Shirtwaist Factory Fire.

Al Smith

A New York state legislator who helped investigate factory conditions and promote labor reforms following the Triangle Fire.

Robert F. Wagner

A New York state senator who helped lead investigations and push for labor legislation after the Triangle Shirtwaist Factory Fire.

Primary prevention (occupational disease)

Interventions that prevent disease before it occurs, such as replacing a toxic chemical with a safer alternative.

Secondary prevention (occupational disease)

Interventions aimed at detecting disease early through screening or monitoring, such as testing workers regularly for early signs of lead exposure.

Tertiary prevention (occupational disease)

Interventions that reduce complications and help workers manage an existing disease, such as providing treatment and rehabilitation for occupational lung disease.