Health & Environment Midterm

What is the main focus of Environmental Health?

Studying how environmental factors affect human health and preventing related hazards

How does Environmental Health differ from Environmental Science?

Environmental health focuses on human impacts, while environmental science studies ecosystems broadly

What are the 3 main exposure routes?

Inhalation, ingestion, and dermal/skin absorption

What is the goal of environmental health professionals?

To assess and control how human activities affect natural resources and create health hazards

What does anthropogenic hazard mean?

A hazard created by human activity

Why is the “dose makes the poison” important in toxicology?

It shows that toxicity depends on the amount of exposure

What are the 3 types of environmental hazards?

Chemical, biological, and physical

What is biomagnification?

Increase of contaminant concentration at each higher trophic level

What is bioaccumulation?

Buildup of a chemical in an organism’s issues over time

What is bioconcentration?

Accumulation of a chemical in an organism due to its fat solubility

What are the 5 stages of toxicokinetics?

Absorption, distribution, metabolism, storage, and excretion

What is the body burden?

Total amount of a toxic substance present in a body

What is epidemiology?

The study of disease distribution and determinants in populations

What is the difference between prevalence and incidence?

Prevalence is existing cases, incidence is new cases

Who is the father of epidemiology?

John Snow, linked cholera to contaminated water

What is an ecological study?

A study using group-level data to compare disease and exposure rates

What is the ecological fallacy?

When group-level associations are assumed true for individuals

What does relative risk measure?

Ratio of disease frequency in exposed vs non-exposed groups

What are the 4 steps of environmental risk assessment?

Release analysis, transport analysis, exposure analysis, and health effects analysis

What is hazard quotient?

Ratio of actual dose to reference dose for non-cancer risk

What is a stochastic effect?

Random effect where probability, not severity, depends on dose (ex. cancer)

What is a deterministic effect?

A dose-dependent effect with a threshold (ex. organ damage)

What is the precautionary principle?

Take preventive action before scientific proof of harm exists

How does environmental risk management differ from risk assessment?

Management controls or reduces risks; assessment quantifies them

What is the role of the International Agency for Research on Cancer (IARC)?

To evaluate evidence and classify carcinogens for humans

How many IARC carcinogen groups exist?

Four groups: Group 1, Group 2A, Group 2B, and Group 3

What kind of research evidence does IARC consider?

Human epidemiologic, animal, and mechanistic studies

What is the main focus of infectious disease in environmental health?

Diseases requiring environmental transmission

What is a zoonosis?

A disease transmitted from animals to humans

What is fecal-oral transmission?

Infection spread when fecal pathogens are ingested via contaminated food or water

What is vectorborne transmission?

Disease spread by a living carrier like a mosquito or tick

What types of pathogens cause infectious disease?

Worms, protozoa, bacteria, fungi, viruses, and prions

What is WASH?

Water, sanitation, and hygiene

How did water filtration affect typhoid fever?

It drastically reduced typhoid deaths in the US and Europe

What is Environmental Enteric Dysfunction (EED)?

Chronic gut inflammation from repeated fecal exposure causing malnutrition and stunting

What is the main cause of diarrheal disease in lower income countries?

Poor WASH infrastructure leading to fecal-oral transmission

What caused the arsenic crisis in Bangladesh?

Tube wells exposed people to arsenic-contaminated groundwater

What type of radiation is ionizing?

Radiation that knocks out electrons (ex. alpha, beta, gamma)

What is the greatest source of ionizing radiation exposure to humans?

Inhaled radon gas

What are non-ionizing radiation health effects?

Skin cancer, cataracts, immune suppression from UV exposure

What is aflatoxin?

A mold toxin causing liver cancer, with Hep B

What is ergotism?

Poisoning from ergot fungus on grains, called St. Anthony’s fire

What is ciguatera poisoning?

Fish-borne toxin illness from reef fish like snapper or barracuda

What are the 4 categories of natural disasters?

Hydrological, meteorological, geological, and biological

What are the 3 disposal routes for municipal solid waste?

Landfilling, incineration, and recycling

What is a major risk of landfills?

Methane emissions and leachate pollution

What is Air Pollution Control (APC) in waste-to-energy plants?

A system that removes acid gases, metals, and dioxins from flue gas

What are common byproducts of incineration?

Bottom ash and fly ash containing metals and toxins

What does a deposit-return scheme (DRS) do?

Adds a refund for returning bottles and cans to boost recycling

Which countries have more than 90% bottle return rates?

Denmark, Germany, and Norway

What industries commonly oppose deposit-return systems?

Beverage companies, retailers, and plastic manufacturers

What are the 3 stages of waste management systems?

Upstream (design/prevention), midstream (collection/sorting), downstream (treatment/disposal)

What are systemic factors in environmental health?

Broader social, economic, and political systems that shape exposure and health outcomes

Why is Western-style development not globally sustainable?

It relies on high resource use and pollution that cannot be maintained at a global scale

What is the difference between cross-sectional and cohort studies?

Cross-sectional studies assess exposure and disease at one time, cohort studies follow people over time to see who develops disease

What is a biomarker in epidemiology?

A measurable substance in the body that indicates exposure ot disease presence

What is an age-adjusted rate?

A disease rate standardized to a reference population to allow comparisons across age structures

What is a case series in descriptive epidemiology?

A report describing a group of cases with similar diseases or exposures

What does surveillance in epidemiology mean?

Ongoing collection and analysis of disease data to track trends and outbreaks

What is a reference dose (RfD)?

The estimated daily dose that is unlikely to cause harm during a lifetime

What is a cancer slope factor (CSF)?

A number describing the increase in cancer risk per unit of a chemical dose

What types of hazards generate the most public outrage?

New, involuntary, manmade, or uncontrollable risks

What is environmental justice?

Fair treatment and involvement of all people in environmental law and policy regardless of race or income

What is volatility?

Chemical’s tendency to turn into gas

What is solubility?

How easily a chemical dissolves in water

What is lipophilicity?

A chemical’s affinity for fats

What is persistence?

The time is takes for half a contaminant to degrade from the environment (half life)

What is the difference between acute and chronic exposure?

Acute is short-term and intense, chronic is over a long period

What is environmental monitoring?

Measuring contaminant levels in air, water, or soil to estimate exposure

What is environmental modeling?

Estimating exposures when direct measurements are unavailable

What is the difference between hazard and risk?

Hazard is the potential to cause harm, risk is the likelihood of harm occuring

What are contributors to emerging or reemerging infectious disease?

Urbanization, deforestation, climate change, weak infrastructure, and resistance to treatment

What is a reservoir?

Habitat where a pathogen lives

What is a mechanical vector?

A carrier that transmits pathogens passively like a fly or syringe

What is a host jump?

When a pathogen adapts to infect a new species

What are contaminants of emerging concern (CECs)?

New or unregulated chemicals

What type of radiation comes from uranium decay and is inhaled indoors?

Radon gas

What is the difference between alpha, beta, and gamma radiation?

Alpha is heavy particles, beta is electrons, gamma is high-energy waves

What unit measures radiation dose intensity?

The gray (Gy)

What unit measures radiation dose with biological effect?

The sievert (Sv)

What are the main health effects of ionizing radiation?

Cancer, cell death, and genetic damage

What is the main benefit of incineration (waste-to-energy)?

It reduces waste volume by up to 90% while generating energy

What is mechanical recycling?

Physically reprocessing materials

What is chemical recycling?

Breaking plastics into molecular components

What materials are infinitely recyclable?

Metals and glass

What is the exposure pathway?

Full chain from source to contact

What is the difference between morbidity and mortality?

Morbidity is illness within a population, mortality is death

How do descriptive and analytic epidemiology differ?

Descriptive studies describe disease patterns, analytic studies test exposure-outcome hypotheses

What limitation affects cross-sectional studies?

They cannot establish causality due to their snapshot nature

What is the hazard index (HI)?

Numerical value that represents the potential health risk from exposure to multiple chemicals

What is the human envelope?

The boundary that separates the body’s interior from the environment

What in the body are toxic substances often stored?

Bones, fat, and organs

What is biotransformation?

Metabolic conversion of a toxicant into a more or less harmful substance

What are spore-forming bacteria?

Bacteria that form dormant spores to survive harsh conditions

What is a decay chain in radioactivity?

A sequence of radioactive decays where the product of one decay is the parent of the next, leading to stable isotopes

What is the difference between venomous and poisonous?

Venomous refers to organisms that inject toxins through bites or stings, while poisonous describes those that are toxic when ingested or touched

What is leachate?

Liquid that drains or 'leaches' from a landfill, often containing hazardous substances

What is landfill-gas (LFG) recovery?

Capturing methane from decomposition to generate energy

What does the Copenhill facility in Copenhagen illustrate?

Modern waste-to-energy plant that converts waste into energy while providing public space

What is fate and transport?

How pollutants move through the environment and their eventual disposition in soil, water, or air