ENV 122 CH8 Environmental Health and Toxicology
Environmental health policies need to address ______________ because we may be destroying cycles that support human life if we don't protect different types of organisms.
ecosystems
Because the chemical industry thinks they are uncalled for, and toxicologists argue that there are problems with the necessary tests, the regulation of _______________disrupters has been difficult to enact.
endocrine
Antigens are ______.
foreign materials that stimulate the production of specific antibodies
Morbidity refers to ___________, whereas mortality refers to_________ . (Use only one word per blank.)
illness, death
What persistent pollutant formerly was used in paint and gasoline and is linked to numerous health concerns such as cancer, reproductive problems, mental issues, behavior problems, and deformities?
lead
All toxic substances are hazardous, but all hazardous substances are not toxic. This is because, unlike toxic substances, hazardous materials ______.
must be handled carefully in large doses, but they can be rendered relatively innocuous by dilution, neutralization, or other physical treatment do not damage or kill living organisms by reacting with cellular components to disrupt metabolic functions
POPs, or _______ __________ __________ , are dangerous because they don't degrade quickly and cells readily take them up.
persistent organic pollutants
Risk assessment is the ______.
process of estimating the threat a particular hazard poses to human health
Which of these is not a consideration of toxicology?
Eradication of diseases such as polio or smallpox
Which of the following are true about the effects of exposure to carcinogens?
Exposure to carcinogens can result in invasive, out-of-control cell growth that can cause malignant tumors, The U.S. EPA estimates that 200 million Americans live in areas where cancer risk from environmental carcinogens is ten times higher than normal.
True or false: Mortality refers to being ill, whereas morbidity refers to dying from a disease.
False
True or false: Ecological diseases refer to infectious diseases that strictly affect wildlife or cause damage to habitats.
False because Ecological diseases can affect domestic animals and can move from both wildlife and domestic animals to humans.
Why are animals still used to test toxicity of substances?
Tests on living animals are more reliable than other tests.
Of the many factors that determine whether a particular chemical will prove to be dangerous, which of the following are based on the nature of the chemical agent itself?
The chemical agent is water-soluble. The chemical agent is not biodegradable and thus is persistent in the environment.
Match the term with its correct definition. Toxic substance - Hazardous substance
These substances damage or kill living organisms because they react with cellular components to disrupt metabolic functions. They are often harmful even in extremely dilute concentrations. These substances damage or kill living organisms because they react with cellular components to disrupt metabolic functions. They are often harmful even in extremely dilute concentrations. - These substances are dangerous because they are flammable, explosive, acidic, caustic, irritants, or sensitizers. Many of these materials can be rendered relatively innocuous by dilution, neutralization, or other physical treatment. These substances are dangerous because they are flammable, explosive, acidic, caustic, irritants, or sensitizers. Many of these materials can be rendered relatively innocuous by dilution, neutralization, or other physical treatment
Which of the following applies to ecological diseases?
They affect wildlife populations, such as bats and frogs.
Which of the statements below accurately captures the relationship between toxicity and potency?
Though categorizing toxins based on potency is useful, it is complicated by differences in individual and species reactions to particular chemicals.
The study of toxicology ______.
draws from many disciplines, including biology, biochemistry, pharmacology, among others
Why is diet a consideration in health?
Diet-related obesity can lead to illnesses such as diabetes and cardiovascular disease. Vegetables, whole grains, and other healthy foods can boost our ability to tolerate toxins.
Match the examples to chronic or acute effects and exposures. Exposure to radiation during an x-ray for a broken foot - Developing radiation sickness after exposure to radiation - Exposure to background radiation, like from radon gas - Developing lung cancer after exposure to radiation -
Acute exposure Acute effect Chronic exposure Chronic effect
Which of the following statements about chronic and acute exposure and effects are correct?
Acute exposure involves a single contact with a toxic chemical. It may last a few seconds or a few hours. Chronic exposure involves continuous or repeated contact with a toxic substance over a long period of time (months or years).
Which of these sentences properly describes the difference between bioaccumulation and biomagnification?
Biomagnification occurs because of bioaccumulation.
Chemicals are generally divided into oil-soluble and water-soluble types. Match each type of substance to its characteristic. Water-soluble types - Oil-soluble types
Choice, These substances move widely in the environment and also have ready access to body cells as their solvent is ubiquitous. These substances move widely in the environment and also have ready access to body cells as their solvent is ubiquitous. - Choice, These substances need a carrier molecule to move through the environment, but once they are inside cells they likely accumulate and persist. These substances need a carrier molecule to move through the environment, but once they are inside cells they likely accumulate and persist.
Each factor listed below plays a role in determining environmental toxicity. Match each of the following factors to how it influences whether a particular chemical will prove to be dangerous. Factor related to the toxic agent - Factor related to the exposure - Factor related to the organism
Composition and reactivity of the chemical - Dose and frequency of contact with the chemical - Immunological status at the time of exposure to the chemical
The science involved in determining whether endocrine disrupters are harmful shows how establishing public policy is difficult. Which of the following statements correctly identify reasons why the debate currently surrounds regulating endocrine disrupters?
Data on which chemicals are endocrine disrupters are not definitive. The chemical industry disputes the need for testing, and industry-funded scientists point to contradictions and uncertainties in published studies.
Which of the following statements are true about how people apply probability in determining how much risk to accept and when to avoid exposure to certain risks?
For most people, a 1 in 100,000 chance of dying from some risk factor is often a threshold for changing what they do. Most people will tolerate a higher probability of occurrence of an event if the harm caused by that event is low.
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.
What can be concluded about policy decisions addressing hazardous and toxic nutrients based on the U.S. Environmental Protection Agency's assessment of relative risks to human welfare?
Our focus on reducing pollution to protect human health has neglected risks to natural ecological systems that may be of greater ultimate importance. Policy decisions about toxins must address how such materials affect not just humans but also organisms that define and maintain our environment.
In assessing the danger of toxic substances, which of these statements are true?
Our increasing ability to detect traces of a substance sometimes means that though we can detect it, the level may be too low to cause harm. The dose makes the poison.
Which of the following statements are reasonable conclusions that can be drawn from a recent headline that announced the discovery of 23 pesticides in 16 food samples?
Pesticide residues are not necessarily harmful, for a substance produces a harmful effect only if it reaches within the body in a high enough dose. The mere presence of a toxin is insignificant without considering how much is there, where it is located, how accessible it is, and who is exposed.
What is a probability calculation and how is it used in risk assessment?
Probability is a calculation of the statistical danger of a risk, and this information can help us decide which risks to tolerate and which to avoid.
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.
Match the dietary consideration to its positive influence on a particular health condition. Reduce the amount of salt and animal fat in your diet. - Include pectins, vitamins (like A, C, and E), and cruciferous vegetables (like cabbage and broccoli) in your diet. - Eat fewer calories and exercise more. - Stop drinking alcohol during pregnancy.
Reduces cardiovascular disease - Reduces cancer risk - Reduces obesity-related illnesses - Reduces risk of fetal alcohol syndrome
True or false: The World Health Organization (WHO) estimates that though 90 percent of all disease burden occurs in developing nations only about 10 percent of health care dollars are spent there.
True because According to Doctors Without Borders, the 10/90 gap is very real for less than one-tenth of all health care dollars are spent on the poor who have the heaviest burden of disease.
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
Public policies regarding toxicity are based on the results of ______, and scientists still have the most confidence in this method.
animal testing
Some allergens act directly as ______, and the immune system recognizes them as foreign, stimulating the production of specific antibodies.
antigens
As shown in the figure, every organism in the Lake Michigan food chain has some DDT in their body tissues at concentrations higher than in the environment due to _____________, whereas the reason that gulls, who are tertiary consumers, have about 240 times the concentration of compounds as compared to the small insects sharing the same environment is due to _________
bioaccumulation biomagnification
Substances that cause invasive, out-of-control cell growth resulting in tumors are called ______.
carcinogens
Lead was banned from gasoline and paint in the 1970s and health problems associated with its exposure have dropped significantly since then. However, a huge health scare in Flint, Michigan, occurred in 2016 when children were exposed to lead through ______.
contaminated drinking water
Debates in establishing environmental health policy include whether to ______.
demand protection from every potentially harmful contaminant or accept some exposure as our bodies can repair some damage establish acceptable toxin levels at the highest amount that does not cause measurable effects or as low as technically feasible
The heaviest burden of illness is borne by ______.
developing countries where many people cannot afford adequate health care or to live in a healthy environment
In 1973, the FDA required that cancer-causing compounds must not be present in meat at concentrations that would cause a cancer risk greater than 1 in a million lifetimes. This decision of the FDA was based on ______.
risk assessment
Microbes acquire resistance to antibiotics through different processes that include random mutations and __________ reproduction.
sexual
Persistent organic pollutants (POPs) are a concern because being ______.
stable, they do not degrade easily and have become extremely widespread in the environment
Fetal alcohol syndrome is a pattern of mental and physical defects that can develop in a fetus when a mother drinks alcohol during pregnancy. This specifically makes alcohol a ______.
teratogen
Chemicals or other factors that specifically cause abnormalities during embryonic growth and development are called___________.
teratogens
Setting environmental health policy is challenging because ______.
we are exposed to many sources of harm, and it is difficult to separate the effects of different hazards in order to evaluate their risks accurately
