Envir 130 ch 14
21) Tyrone Hayes is well known for his studies of ________. A) gonadal abnormalities in frogs B) the dangers of DDT C) the neurological effects of pesticide poisoning D) reproductive and developmental abnormalities in alligators in Lake Apopka E) the dangers of secondhand smoke
Answer: A Section: 14.1 Bloom's Taxonomy: Knowledge/Comprehension
25) The European Union's experience with polybrominated diphenyl ethers (PBDEs) has shown that ________. A) if the toxin is removed from the environment, concentrations in human tissues fall B) economic factors have superceded health concerns C) these molecules can be rapidly metabolized by decomposers D) human metabolism of these compounds could solve the problem without legislation E) these molecules result in birth ratios of 9 males : 1 female
Answer: A Section: 14.1 Bloom's Taxonomy: Knowledge/Comprehension
27) A naturally occurring substance that is potentially toxic to people is ________. A) radon gas B) DDE C) bispnenol-A D) carbon dioxide E) Salmonella
Answer: A Section: 14.1 Bloom's Taxonomy: Knowledge/Comprehension
24) The effect of a toxicant on fetuses and young children ________. A) is greater because of their developmental immaturity, rapid growth, and smaller size B) is less than for adults because their metabolism is higher C) has not raised concern among environmental health professionals D) has been thoroughly evaluated for every chemical released into both indoor and outdoor environments E) is generally the same as for adults because all individuals generally have the same response to a toxicant
Answer: A Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
9) Bisphenol-A is ________. A) an estrogen mimic that is used in plastic manufacturing B) produced when fossil fuels are burned C) released from aerosol spray cans D) a currently used herbicide E) a banned insecticide
Answer: A Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
29) What are the properties of toxicants that are likely to build up in animals through bioaccumulation? A) They are nonbiodegradable and lipid-soluble. B) They are biodegradable and water soluble. C) They are gases that are readily carried by pesticide drift. D) They contain nitrogen and sulfur. E) They are carcinogenic and mutagenic.
Answer: A Section: 14.3 Bloom's Taxonomy: Knowledge/Comprehension
2) The LD50 indicates the ________. A) amount of toxicant it takes to kill half the population B) lowest dose that kills any member of the population C) lowest dose that kills 50 out of 1000 members of the population D) lowest dose required to cure half of the population E) lowest dose required to cure the entire population
Answer: A Section: 14.4 Bloom's Taxonomy: Application/Analysis
12) The Toxic Substances Control Act regulates ________. A) industrial chemicals B) drugs C) pesticides D) food additives E) cosmetics
Answer: A Section: 14.6 Bloom's Taxonomy: Knowledge/Comprehension
22) Infectious disease accounts for ________% of deaths globally. A) less than 1 B) almost 25 C) almost 40 D) almost 50 E) almost 70
Answer: B Section: 14.1 Bloom's Taxonomy: Knowledge/Comprehension
3) Based upon the specific health effects described in the scenario, mercury would be best classified as a ________. A) synergist B) neurotoxin C) carcinogen D) endocrine disruptor E) allergen
Answer: B Section: 14.2 Bloom's Taxonomy: Application/Analysis
1) Rachel Carson's book Silent Spring focuses primarily on the environmental problems associated with ________. A) aquifer depletion B) pesticide toxicity C) loss of biodiversity D) overpopulation E) deforestation
Answer: B Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
10) Transport of airborne toxicants, a specific problem in agricultural environments, is called pesticide ________. A) leaching B) drift C) run-off D) transposition E) globalization
Answer: B Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
28) According to a 2002 study by scientists at the National Water-Quality Assessment Program (NAWQA), ________ % of U.S. streams contain traces of wastewater contaminants. A) 100 B) 80 C) 50 D) 10 E) less than 1
Answer: B Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
3) ________ are substances that cause birth defects. A) Allergens B) Teratogens C) Carcinogens D) Neurotoxins E) Vectors
Answer: B Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
4) Carcinogens may be difficult to identify because ________. A) they are the least common toxicants B) there is a long lag time between exposure to the agent and disease C) they are rare in nature D) there is no way to measure the carcinogenic potential of a substance E) most are invisible
Answer: B Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
6) Substances that cause harm by affecting the immune system include ________. A) neurotoxins B) allergens C) teratogens D) hormones E) antibiotics
Answer: B Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
8) The worldwide drop in sperm counts among men has been attributed to ________. A) DDT B) endocrine disruptors C) teratogens D) radon E) allergens
Answer: B Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
5) PCB contamination ________. A) is the main focus of the book Silent Spring B) is a continuing problem because PCBs are nonbiodegradable and persist in the environment C) has never been documented outside the United States D) was the main environmental problem in Lake Apopka E) results from overapplication of pesticides
Answer: B Section: 14.3 Bloom's Taxonomy: Knowledge/Comprehension
26) Studies of endocrine disruptors have shown that they are closely associated with all of the following except ________. A) gonadal abnormalities B) lung cancer C) low birth rates D) male feminization E) thyroid hormone abnormalities
Answer: B Section: 14.4 Bloom's Taxonomy: Knowledge/Comprehension
1) Figures such as these ________. A) are used by epidemiologists in the assessment of a toxicant's effect B) are used by scientists in risk assessment C) are used to report the effects of a toxicant on wildlife populations D) represent typical dose-response curves for endocrine disruptors E) allow scientists to determine the exact quantity of a toxicant that will harm humans
Answer: B Section: 14.4, 14.5 Bloom's Taxonomy: Application/Analysis
2) Prior to 2005, no rules regulating mercury emissions from coal-fired power plants existed in the United States. This represents the ________. A) precautionary principle B) innocent-until-proven-guilty approach C) dose-response initiative D) case-study approach E) Ames approach
Answer: B Section: 14.6 Bloom's Taxonomy: Application/Analysis
1) Which of the following U.S. agencies is primarily responsible for addressing issues regarding mercury pollution? A) DOE B) EPA C) USDA D) BLM E) OSHA
Answer: B Section: 14.6 Bloom's Taxonomy: Knowledge/Comprehension
11) The ________ registers and regulates pesticides in the United States. A) FDA B) EPA C) USDA D) BLM E) PRA
Answer: B Section: 14.6 Bloom's Taxonomy: Knowledge/Comprehension
2) Briefly comment on the research to determine the toxicity of bisphenol-A (BPA). Also, explain why this topic represents a challenge to scientific integrity and credibility and the implications for national and international policies that depend on the research of this compound.
Answer: Bisphenol-A (BPA) has been implicated as a hormone (estrogen) mimic and disruptor in various species of mammals and in humans. Used in the manufacture of many plastic products, it is liable to leach out of the products, especially drinking bottles, and be ingested along with food, water, baby formula, etc. There is more than a 90% chance of the presence of BPA in any American's body. Research by Patricia Hunt at Case Western Reserve University and many others have shown that BPA is a potent hormone disruptor in mice. Recently, BPA has been implicated as a correlative factor in diabetes and cardiovascular disease. European studies have shown that BPA is also harming numerous wildlife species. It is disturbing that the majority of industry-funded and conducted research projects have concluded that BPA poses little or no risk, while peer-reviewed studies of those with no industry bias have come to opposite conclusions. In fact, as of 2007, more than 80% of more than 150 government-funded studies showed that test animals were harmed by low doses, but those funded by the industry showed no harm. This once again warns us to be sure to enquire about the funding sources of research where the profit motive is strong. As of 2010, six major U.S. plastics manufacturers have pledged to stop using PBA. In 2008, Canada became the first nation to declare BPA toxic. With conflicting information from industry and federally sponsored research, the EPA and FDA are in the process of trying to formulate policy for managing the risk from BPA. Section: 14.0, 14.2, and 14.5 Bloom's Taxonomy: Synthesis/Evaluation
30) Which of the following are indoor chemical hazards? A) PCBs B) DDT and DDE C) radon and asbestos D) petroleum and toxic waste tanks tank leaks E) wastewater toxicants
Answer: C Section: 14.1 Bloom's Taxonomy: Knowledge/Comprehension
2) ________ are substances that cause cancer. A) Allergens B) Teratogens C) Carcinogens D) Neurotoxins E) Vectors
Answer: C Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
5) Concentrations of methyl mercury are higher in large fish than in their prey and in the air. This is best described as ________. A) distillation B) toxification C) biomagnification D) bioaccumulation E) synergism
Answer: C Section: 14.3 Bloom's Taxonomy: Application/Analysis
14) Aquatic animals such as fish and frogs are especially good indicators of pollution because ________. A) they are easy to catch B) these organisms are the most abundant on earth C) most chemicals are water-soluble and thus can easily enter these organisms D) all chemical toxicants are found in water E) both kinds of animals are vertebrates, and the metabolism of these organisms is most like ours
Answer: C Section: 14.3 Bloom's Taxonomy: Knowledge/Comprehension
3) Assuming that the scales for graphs (a) and (b) are identical, which of the following statements is true? A) The toxicant shown in (b) has a lower LD50 compared to the toxicant shown in (a). B) The toxicant shown in (b) has a higher toxicity than the toxicant shown in (a). C) The toxicant shown in (b) has a lower toxicity than the toxicant shown in (a). D) Graphs (a) and (b) show results for the same toxicant, but graph (a) shows a higher dose than graph (b). E) Graphs (a) and (b) show results for the same toxicant, but graph (b) shows a higher dose than graph (a).
Answer: C Section: 14.4 Bloom's Taxonomy: Application/Analysis
7) The book Our Stolen Future was important because it ________. A) was the first book that discussed water pollution problems in Lake Apopka B) was the first book that discussed environmental problems with DDT C) focused on the impacts of endocrine-disrupting chemicals on humans D) was the first book to dispute claims in Rachel Carson's book Silent Spring E) is credited with starting the environmental movement in the United States
Answer: C Section: 14.4 Bloom's Taxonomy: Knowledge/Comprehension
18) The goal of the Stockholm Convention is to ________. A) reduce global warming B) reduce the ecological footprints of people around the world C) end the use and release of 12 POPs shown to be the most dangerous D) prevent the spread of the AIDS E) educate women about birth control
Answer: C Section: 14.6 Bloom's Taxonomy: Knowledge/Comprehension
4) Mercury is not readily excreted; it is stored in mammalian body tissues. This is best described as ________. A) distillation B) toxification C) biomagnification D) bioaccumulation E) synergism
Answer: D Section: 14.3 Bloom's Taxonomy: Application/Analysis
4) The flat line at the left in (b) probably represents ________. A) the fact that there is no physiological effect of the toxicant at low doses B) that no data were collected for the flatline area C) competing effects of some other substance whose effect wasn't measured D) the body's physiological processes coping with low doses of a toxicant E) the fact that no toxicant was introduced until the response line begins to rise
Answer: D Section: 14.4 Bloom's Taxonomy: Application/Analysis
19) The Yaqui Valley, Mexico, study showed that ________. A) wealth is correlated with intelligence B) infectious disease is more widespread in poor countries C) frogs were affected by water pollution D) developmental delays occurred in children exposed to pesticides E) organic agriculture can be successful with government support
Answer: D Section: 14.4 Bloom's Taxonomy: Knowledge/Comprehension
20) Louis Guillette is well known for his studies of ________. A) gonadal abnormalities in frogs B) the dangers of DDT C) the neurological effects of pesticide poisoning D) reproductive and developmental abnormalities in alligators in Lake Apopka E) the dangers of secondhand smoke
Answer: D Section: 14.4 Bloom's Taxonomy: Knowledge/Comprehension
23) Synergistic effects of toxicants ________. A) have effects of individual toxicants that tend to cancel one another out B) typically exhibit additive effects of the individual toxicants C) are not numerous in the natural environment D) are greater than the sum of the effects of the components E) always involve synthetic toxicants
Answer: D Section: 14.4 Bloom's Taxonomy: Knowledge/Comprehension
6) Debate over the use of DDT to control malaria is likely to continue. However, over the past several decades, much has been learned about how this insecticide works, and why its extensive use poses an environmental concern. Discuss three characteristics of this chemical that cause it to be problematic.
Answer: DDT is a synthetic chemical, developed in the mid-1940s as an insecticide to be used against malaria. This chemical has many of the critical characteristics which cause it to be particularly harmful to a wide array of warm-blooded organisms, including humans. Its persistence, transport in the environment, and uptake by many nontarget organisms contribute significantly to its environmental health concerns. DDT is not easily broken down in the environment, and even its by-products are toxic. DDT's environmental persistence is estimated to vary between 30 and 100 years. Because it is sprayed over wide areas, it easily gets into water supplies and affects aquatic food webs. Because it is taken up by insects and other small organisms found in lower trophic levels, its ability to bioaccumulate in higher organisms in the food chain is dependent on its fat-solubility characteristic. That is, DDT is able to be stored in the tissues of living organisms without breaking down, and this characteristic leads to its biomagnification in the food web. Organisms that feed on other organisms whose tissues have stored DDT are likely to store an even higher concentration. Some of the most well-documented environmental effects of DDT have been egg-shell thinning in birds of prey; however, cancer and developmental abnormalities have also been documented in amphibians and other higher vertebrates. Section: 14.2, 14.3, and 14.4 Bloom's Taxonomy: Application/Analysis
8) Explain how response to hazards can vary based upon individual differences and type of exposure. Give examples, where appropriate.
Answer: Different individuals may be more sensitive to hazards. Differences can be genetically based, can result from varying abilities of the body's organs to detoxify substances, or can be due to a person's overall condition. People in poor health are often more vulnerable to hazards. Sensitivity can also vary with sex, age, and weight. Fetuses, infants, and young children tend to be more sensitive to toxicants because of their small size and rapid growth. Acute exposure, which is high exposure for short time periods, differs from chronic exposure, which is lower exposure over long time periods. Acute exposures are easier to recognize because they often stem from discrete events such as accidental ingestion, oil or chemical spills, or a nuclear accident. Chronic exposure is more common and more difficult to detect and diagnose. Chronic exposure often affects organs gradually, as happens when smoking causes lung cancer or when alcohol abuse induces liver or kidney damage. Pesticide residues on food or low levels of arsenic in drinking water also pose chronic risk. Section: 14.2, 14.3 Bloom's Taxonomy: Application/Analysis
15) ________ is/are biodegradable and known to have (a) short persistence time(s). A) DDT B) DDE C) PCBs D) PBDEs E) Bt
Answer: E Section: 14.3 Bloom's Taxonomy: Knowledge/Comprehension
16) The bald eagle and peregrine falcon are ________. A) found only in Florida B) U.S. invasive species C) overhunted for their feathers D) extinct E) top consumers susceptible to eggshell damage caused by DDT
Answer: E Section: 14.3 Bloom's Taxonomy: Knowledge/Comprehension
13) FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act) ________. A) was enacted in the 1960s B) is enforced by the FDA C) was originally enacted to protect public health D) was originally enacted to protect the environment E) and its later amendments charge the EPA with registering new pesticides and regulating their sale, use, and labeling
Answer: E Section: 14.6 Bloom's Taxonomy: Knowledge/Comprehension
1) Explain what endocrine disruptors are, and give examples. Explain why endocrine disruptors are a problem for humans, and discuss why they have not been banned.
Answer: Endocrine disruptors are toxicants that interfere with the body's hormones. Examples include DDT and bisphenol-A. Endocrine disruptors are problems for humans because human reproduction, growth, and development can be affected by hormone mimics. They have not been banned because scientific evidence for the problems they cause has been slow in coming. Research documenting endocrine disruptor effects is controversial because it is relatively new. Research poses economic threats to chemical manufacturers as well. For instance, Tyrone Hayes's work has met with fierce criticism from scientists associated with atrazine's manufacturer which will lose money if its use is banned or restricted. Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
9) List the environmental factors and chemical properties that determine the rate of degradation of toxicants.
Answer: Environmental factors such as temperature, moisture, available oxygen, and sun exposure can affect the rate of degradation of toxicants. The chemistry of the toxicant would determine how it is degraded and to what extent these environmental factors affect its degradation. Atrazine is an example of a toxicant that has variable persistence, depending upon environmental conditions. Biodegradable toxicants are quickly broken down under conditions that favor the sustenance of the organisms degrading them. DDT, PCBs, and toxicants used in the manufacture of plastics, however, resist breakdown under most environmental conditions due to their chemical composition. Section: 14.2 Bloom's Taxonomy: Knowledge/Comprehension
11) Briefly explain dose-response analysis.
Answer: The dose-response analysis allows scientists to quantify the toxicity of a given substance by measuring how much effect a toxicant produces at different doses or how many animals are affected by different doses of the toxic agent. Dose is the amount of toxicant the test animal receives, and the response is the type or magnitude of negative effects the animal exhibits as a result. Section: 14.4 Bloom's Taxonomy: Knowledge/Comprehension
10) What does the field of environmental health encompass?
Answer: The field of environmental health assesses environmental factors that influence human health and quality of life. It seeks to prevent adverse effects on human health and on ecological systems essential to environmental quality and long-term human well-being. Acute (large dose, rapid onset of disease) symptoms are relatively easier to identify and to tie to a specific cause. It is much more difficult to trace the causes of chronic symptoms (low doses over a long period of exposure), which are found in the majority of environmental toxicants. Both epidemiological methods and case studies are significant lines of enquiry. Section: 14.1 Bloom's Taxonomy: Knowledge/Comprehension
7) Explain risk assessment and risk management. Discuss how risk management combines science and other social factors.
Answer: The first step in risk assessment determines whether a substance has toxic effects, by measuring dose-response effects of toxicant exposure. The second step assesses the likely exposure that an individual will have to the toxicant including frequency, concentration, and time of exposure. Risk management consists of decisions and strategies to minimize risk. Federal agencies charged with managing risk consider findings in light of economic, social, and political needs and values. Costs and benefits are addressed with regard to both scientific and nonscientific concerns. While economic benefits are generally known, easily quantified, and of a definite and stable amount, health risks are hard-to-measure probabilities that impact a small percentage of people that will suffer greatly. For example, if a pesticide is used, people may suffer, but if it is not used, people may not have enough to eat. Both costs must be considered before banning the pesticide. Section: 14.5 Bloom's Taxonomy: Application/Analysis
5) How is the precautionary principle used in environmental health? What is an alternative philosophical approach?
Answer: The precautionary principle states that substances, such as potential toxicants, are assumed to be harmful until shown to be harmless. This approach allows us to identify troublesome toxicants before they are released into the environment, but it may also significantly impede the pace of technological and economic advance. Thoroughly testing every existing substance for its effects is long, complicated, and expensive, so some may favor the innocent-until-proven-guilty approach. This approach assumes that substances are harmless until shown to be harmful. This approach may lead to putting substances into wide use that may later turn out to be dangerous. Section: 14.6 Bloom's Taxonomy: Application/Analysis
4) What are epidemiological studies, and what is their value? Are there any disadvantages to epidemiological studies?
Answer: They involve large-scale comparisons among groups of people, usually contrasting a group known to have been exposed to a toxicant with a group that has not. They allow for the risk of exposure to a toxicant to be determined. They are realistic, but a long time is required for the results of the studies to be determined. Furthermore, they do not address future effects of new products. Results of epidemiological studies must be interpreted cautiously because many factors affect health, and results do not determine cause and effect; they only measure statistical association. Section: 14.4 Bloom's Taxonomy: Application/Analysis
3) Explain and give an example of biomagnification.
Answer: When one organism ingests a toxicant, the toxicant may become concentrated within its tissues. When the higher level consumer feeds, it eats multiple organisms at the lower trophic level, consuming magnified quantities of toxin with each feeding. Thus, with every step up the food chain from primary producer to top predator, concentrations of toxicant increase. An example of biomagnification in nature is when birds of prey consume toxic amounts of DDT because they eat big fish which have eaten small fish which have eaten zooplankton which have eaten algae which have ingested small amounts of DDT from polluted water. Another example of biomagnification in nature is seen in polar bears of Svalbard Island in Arctic Norway. Polar bears fed on seals that have already experienced biomagnification of toxicants such as PCBs. Properties that biomagnified toxins have in common is being lipid-soluble and nonbiodegradable or slowly degradable. Section: 14.3 Bloom's Taxonomy: Application/Analysis
3) Toxicant potentially present in paint; damages the brain, liver, kidney, and stomach when ingested
D) lead Section: 14.1, 14.2, and 14.4 Bloom's Taxonomy: Knowledge/Comprehension
4) Toxicant used as a flame retardant and insulator; carcinogen and scars the lungs when inhaled
E) asbestos Section: 14.1, 14.2, and 14.4 Bloom's Taxonomy: Knowledge/Comprehension
2) Insecticide used to kill mosquitoes; banned in the United States in 1973 due to its toxicity
F) DDT Section: 14.1, 14.2, and 14.4 Bloom's Taxonomy: Knowledge/Comprehension
1) Most widely used herbicide in the United States; an endocrine disruptor
H) atrazine Section: 14.1, 14.2, and 14.4 Bloom's Taxonomy: Knowledge/Comprehension
5) Used as a sleeping pill for pregnant women; teratogen that now is banned
I) thalidomide Section: 14.1, 14.2, and 14.4 Bloom's Taxonomy: Knowledge/Comprehension
6) Neurotoxin that magnifies within food webs; typically found in polluted bodies of water; it poisoned thousands of people when it was dumped into a Japanese bay; people who ate contaminated fish from the waters exhibited convulsions, slurred speech, loss of muscle control, and sudden fits of laughter; some people died
K) mercury Section: 14.1, 14.2, and 14.4 Bloom's Taxonomy: Knowledge/Comprehension
