BIO 120 Exam 2

Which of the following statements correctly describes how factors related to the individual influence how she or he responds to toxins in the environment? (Select all that apply.)

-Age affects susceptibility to toxins, as chemicals that might be relatively harmless to adults may be dangerous to young children. -Immunological status affects susceptibility to toxins. A healthy individual may be insensitive to doses of toxins dangerous to someone who is ill.

Rank the following by the probability of dying from the event in your lifetime in the United States, with the highest chance at the top of the list.

-cancer -falls -drowning -poisonous snake, spider -botulism

What is the current worldwide 5-year survival rate of children?

95%

The danger of a chemical (its toxicity) is determined by the ______. (Select all that apply.)

A. route of entry B. dose C. timing of the exposure E. sensitivity of the organism

Allergens

Activate responses in the immune system

Developing radiation sickness after exposure to radiation

Acute effect

Exposure to radiation during an x-ray for a broken foot

Acute exposure

Choose the correct statement below concerning the relationship between allergens and antigens.

All antigens are allergens, but not all allergens are antigens.

Increasingly sensitive instruments can detect chemicals at very low doses. What does this mean for the toxicity of these chemicals?

Although we can detect a substance, the level may be too low to cause harm.

Neurotoxins

Attack nerve cells or the nervous system

Chemicals that interrupt the normal endocrine hormone functions of the body are called endocrine hormone disrupters. Select all the well-known endocrine hormone disrupters from the list below.

BPA PCBs DDT

Because it is so widely used, glyphosate, which is better know as , is a persistent organic pollutant (POP) of particular concern.

Blank 1: Roundup

Epidemics that affect animals and wildlife are referred to as diseases.

Blank 1: ecological

People often base decisions regarding risk-taking on their and familiarity rather than facts.

Blank 1: emotions

Exposure to a toxic substance can effect the , (the system that regulates gene function), rather than the gene itself; effects can be passed through multiple generations.

Blank 1: epigenome

The idea of the is that chemical compounds can regulate their activity by stimulating or inhibiting gene expression.

Blank 1: epigenome

Chloropyriifos is a POP of concern; it is a(n) used in agriculture, traps, greenhouses, and golf courses.

Blank 1: insecticide

POPs, or , organic pollutants, are those that do not easily degrade; this makes them useful but also allows them to accumulate and reach toxic concentrations in many environments.

Blank 1: persistent

The poor ventilation in some buildings can lead to headaches, allergies, and fatigue associated with building .

Blank 1: sick Blank 2: syndrome

The 400-fold increase in cancer rates for people who are asbestos workers and smoke is an example of .

Blank 1: synergism or synergy

Carcinogens

Cause cancer (uncontrolled cell growth resulting in tumors)

Developing lung cancer after exposure to radiation

Chronic effect

Exposure to background radiation, like from radon gas

Chronic exposure

Which of the following statements about chronic and acute exposure and effects are correct? (Select all that apply.)

Chronic exposure involves continuous or repeated contact with a toxic substance over a long period of time (months or years). Acute exposure involves a single contact with a toxic chemical. It may last a few seconds or a few hours.

Which of the following aspects of toxicology are necessary to understand and must be considered in setting environmental health policy? (Choose all that apply.)

Chronic versus acute exposure Dose-response curve Risk assessment and characterization

Why did the 2014 outbreak of Ebola in West Africa spread so rapidly? (Choose all that apply.)

Communities affected were suspicious of foreign help. It occurred in poor, war-torn countries.

Mutagens

Damage or alter genetic material

What currently is the most commonly used method of testing the toxicity of a chemical?

Exposing a group of lab animals under controlled conditions

Which of the following statements about the potency (strength) of toxic substances is true?

For some toxic substances, a millionth of a gram (an amount invisible to the naked eye) can be lethal.

Suppose that statistically you had a roughly 1 in 100 chance of dying in a motor vehicle accident. What is a reasonable conclusion you could draw from this?

I can tolerate the risk if I choose to.

Which of the following groups of people is most likely to have an increased exposure to toxic chemicals because of their job responsibilities?

Industrial workers

Which of the following statements about global health trends are true? (Select all that apply.)

Infectious diseases such as diarrhea are on the decline globally. Chronic conditions such as cardiovascular disease and diabetes are increasing and spreading to poorer populations.

What infectious disease is a particular worry for public health officials because it comes from viruses that mutate rapidly and move from animals to humans?

Influenza

Which of the following correctly describe the toxicity testing of chemicals on animals? (Select all that apply.)

It is expensive and time-consuming. It is very commonly used.

How pervasive are depression and suicide in woman worldwide?

It is prevalent in both developing and developed regions.

How likely are you to be exposed to air pollution indoors as opposed to outdoors?

Just as likely

Which of the following statements best describes the effects of low doses of toxins?

Low doses of toxins can have variable effects and can cause either more or less serious health problems than high doses.

The dose-response curve showing LD50, as provided here, describes which of the following ideas? (Select all that apply.)

Members of a population vary in sensitivity to a toxin. Most organisms tolerate some exposure to a toxin but ultimately the dose gets large enough to kill them. LD50 is the dose of the toxin that is lethal to half the population.

Which aspect of antibiotic resistance development in microbes is depicted in this image?

Random genetic mutations create antibiotic-resistant individuals that survive and multiply to develop into an antibiotic-resistant colony.

What factors are included in the World Health Organization's (WHO) definition of health? (Select all that apply.)

Social well-being Physical well-being Mental well-being

Why is influenza a particular worry for public health officials? (Select all that apply).

The influenza virus can move from wild and domestic animals to humans and recombine genes rapidly making the disease very difficult to control. The influenza viruses evolve rapidly which makes it hard to develop fail safe vaccines to prevent the disease.

How do East Asian and Pacific countries compare to the United States in terms of child mortality rate?

The rates are the same.

Probability is a key consideration in risk acceptance. A heavy cigarette smoker has a 1 in 4 chance of dying from lung cancer during his lifetime, while an avid hiker has a 1 in 700,000 chance of dying from a venomous snake bite during his lifetime. Based on this information, which of the following are reasonable conclusions? (Select all that apply.)

The risk of snake bites associated with hiking is known and most likely will not worry most people enough for them to give up hiking. Cigarettes are 175,000 times more likely to kill you than snakes.

Select the statement that best describes the difference between antagonistic and additive reactions in determining toxicity.

The toxicity of a chemical is decreased by an antagonistic reaction, whereas it is increased by an additive reaction.

Dog bites and snake bites

These have risks between 1-in-230,000 to 1-in-700,000.

Car accidents and firearms

These have risks of 1-in-100.

Heart disease and cancer

These have risks of 1-in-2.

Water-soluble types

These substances move widely in the environment and also have ready access to body cells as their solvent is ubiquitous.

Oil-soluble

These substances need a carrier molecule to move through the environment, but once they are inside cells they likely accumulate and persist.

Which of the following applies to ecological diseases?

They affect wildlife populations, such as bats and frogs.

Dog bite

This has a risk of 1 in 230,000.

Falling space debris

This has a risk of 1 in 5 million.

Which of the following statements are true about toxins? (Select all that apply.)

Toxins react with cellular components to disrupt metabolic functions or cellular processes. Extremely small amounts of some toxins can cause damage.

Solubility is important in determining how a substance travels and is absorbed. Which type(s) of chemicals travel through the environment most easily?

Water-soluble

You and your parents may disagree about the risk associated with your exposure to tobacco or alcohol. What is the most likely reason for the disagreement?

We perceive risk differently, depending on control, interests, or context.

By definition, persistent organic pollutants (POPs) are compounds that ______. (Select all that apply.)

accumulate in the environment do not degrade readily are found in nearly every geographic location on earth

The idea of the epigenome is that chemical compounds can regulate their activity by ________. (Select all that apply.)

altering genetic expressions in ways that can be passed on to offspring stimulating or inhibiting gene expression

Additive reactions are those in which the toxicity of two or more chemicals add together for a greater effect. Alternatively, ______ reactions interfere with or stimulate the breakdown of other chemicals.

antagonistic

Some allergens work indirectly to cause an immune response. Those allergens that work directly to cause an immune response are called ______.

antigens

The term disease refers to ______.

any abnormal change in body conditions that impairs normal functions

Cells absorb and store a variety of molecules through the process of . It is essential to accumulate nutrients, but can result in the storage of harmful chemicals.

bioaccumilation

Toxic exposure in a pregnant rat ______.

can affect the pregnant rat, her offspring, and further generations

Recent evidence shows that the epigenome can be important in understanding long-term effects of toxic substances because ______.

changes in proteins and molecules that regulate gene function can pass effects of exposure to future generations

The emerging discipline that attempts to understand how our environmental changes threaten our own health as well as that of the natural communities on which we depend for ecological services is called medicine.

conservation

A given poison will produce ______ reactions in different species.

different

An attempt to quantify the burden caused by disease is known as the ______.

disability-adjusted life years (DALYs)

Pathogens are ______.

disease-causing organisms

What infectious disease caused by a virus and carried by other mammals and transmittable to humans emerged in an outbreak in West Africa in 2014?

ebola

Personal risk perception is most strongly affected by ______ in the majority of people.

emotions

Substances that have a synergistic relationship with each other ______.

enhance each other's effects

Conservation medicine attempts to understand how ______.

environmental changes threaten our own health as well as the health of the natural communities on which we depend

The saying, "The dose makes the poison," is reminding us that ______.

every material can be poisonous under some conditions

True or false: Species react to a given poison in the same way.

false

The World Health Organization (WHO) defines as a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity.

health

The nonlinear effects of dose and health hazards are called ______.

hormesis

Antibiotic resistance, in which infectious bacteria are not controlled by antibiotic drugs, is a growing concern for _____.

hospitals and schools feedlots

Toxicology involves many different lines of study including ______. (Choose all that apply.)

how diet might affect an organism how a substance might enter an organism the movement of chemicals through an ecosystem

The assessment of toxins is done in many different ways. Two specific types are retrospective and prospective studies. The major difference is retrospective studies identify people that have been exposed to a possible toxin in the past and prospective studies ______.

identify a group of people and follow their exposure to possible toxins moving forward

Disease refers to ______.

impairment of body functions

For optimal human health, it is best if our skin and bodies remain ______.

in a complex but harmonious balance with nonhuman life-forms

WHO projections are that psychiatric and neurological conditions will ______ in the future.

increase

What characteristics define an emergent disease?

it has not been previously known or has been absent for at least 20 years

The term LD50 refers to the ______.

lethal dose for half of the population

Our ability to create instruments that detect increasingly lower doses of a substance ______.

makes the substance no less toxic than it previously was

The leading reasons for non-rational risk perception include ______. (Select all that apply.)

misunderstanding probabilities about harm from a hazard political or economic interest related to the hazard personal ignorance about the hazard irrational fears

Trends in obesity-related illnesses such as heart disease and diabetes show that such diseases are ______.

no longer just for the wealthy, as they are now becoming common in the developing world

Hormesis are the ______.

nonlinear health effects from the linear increase in dose

The human body can be considered an ecosystem because ______.

of the approximately 100 trillion cells that make up the human body, only about 10% are actually human

The Black Death, the 1918 influenza, and the H1N1 flu virus caused widespread infections on a worldwide basis; we call these ______.

pandemics

Another term for toxin is ______.

poison

Sick building syndrome describes the headaches, allergies, and chronic fatigue some people experience because of the ______.

poor indoor ventilation of the chemicals released from objects in buildings and the buildings themselves

Risk, in environmental science, can be defined as the ______.

probability of harm multiplied by the probability of exposure

In toxicology, a ______ study uses people who have already been exposed to a toxin and a ______ study uses people who may in the future be exposed to a toxin.

retrospective; prospective

In environmental studies, is defined as the probability of harm multiplied by the probability of exposure.

risk

The disability-adjusted life years (DALYs) are a measurement of ______.

the burden (or total cost) of disease

If a pregnant rat is exposed to a toxic substance, her offspring will suffer the effects because ______.

the expression of their genes may change

The dose, route of entry, timing of exposure, and sensitivity of the organism all play a role in determining ______.

toxicity

A person who studies might investigate how a drug or radiation enters the body and then what effects the external factor has on an organism.

toxicology

Allergens are substances that affect us by ______.

triggering a response in our immune systems

True or false: Every material can be poisonous under some conditions.

true

True or false: Indoor air can be more polluted than outdoor air.

true

Toxic substances ______ in their potency (strength).

vary widely