EVR HW 10 (Exam 3)

Which of the following has contributed to longer life spans in the United States? On average, it appears that over the past 25 years, improved air quality in the United States has resulted in __________ in the lifespan of the average individual. Based strictly on increases in air pollution over the past few decades, where would we expect to see the greatest decrease in life spans? We would expect to see a decrease in life span in __________. Which of the following describes the greatest health risk posed by air pollution? Air pollutants __________.

All of the listed responses are correct. an increase of about five months Beijing, China damage blood vessels in human lungs

Why are scientists interested in the effects of environmental hazards on wildlife?

Animals can serve as an early warning to the damage of environmental toxins.

________ is/are biodegradable and known to have (a) short persistence time(s).

Bt

Of the following U.S. agencies, ________ is primarily responsible for addressing issues regarding mercury pollution.

EPA

For the graph you created in Step 3, what type of dose-response curve is this? At what concentration does this contaminant have its smallest toxic effect? Assume the toxic effect observed is decreased egg production in females. Given this information and the shape of the curve, what type of toxin is this likely to be? Assume you know that people drinking the groundwater would be exposed to concentrations of this contaminant less than 0.05 microgram per Kg. Which of the following statements represents the best judgment of the risks of this exposure? For the graph you created in Step 4, what type of dose-response curve is this? The dose at which 50% of a population exhibits a toxic response is called the TD50. What is the TD50 for this food preservative? What would you recommend as a maximum safe exposure level for this food preservative? Assume the curve in Step 5 is from a drug trial evaluating the effectiveness of a new medicine. What dose produces the desired effect in 95% of the population? Assume this curve is from a study evaluating mortality in an indicator species from exposure to an herbicide. What is the LD50? Assume this curve represents the portion of test animals developing tumors from exposure to groundwater contaminant. What dose causes cancer in 1% of the population?

J-curve 0.05 microgram per Kg an endocrine disruptor Twenty percent or more of individuals can be expected to experience toxic effects at this level of exposure. S-curve with threshold 8 gm/Kg 0.01 gm/Kg, because this is well below the lowest dose that results in measurable toxic effects 1.2 mg/Kg 0.04 mg/Kg 0.0034 mg/Kg

Assume that the scales for graphs (a) and (b) are identical. Compare the graphs. Which of the following statements is true?

The toxicant shown in (b) has a lower toxicity than the toxicant shown in (a).

You live in a community with lead pipes, but the water always tests free of lead. Which of the following is your water provider most likely doing? After much investigation, is discovered to be a drinking water contaminant. Which of the following federal agencies is responsible for regulation? Which of the following contaminants appears poised to be next to be fully regulated? Which of the following is most likely to have high nitrates in its water supply? You live in a city and the drinking water is tested for lead. After analysis, 8% of the homes tested had lead levels above 15 ppb. Is your city required to notify you?

Treating the water with a chemical. Environmental Protection Agency perchlorate A community surrounded by agriculture. No

Which term describes a type of toxicant that overactivates the immune system?

allergen

Use the figure above to answer the following question. Figures such as these ________.

are used by scientist in risk assessments

Mercury is not readily excreted; it is stored in mammalian body tissues. This is best described as ________.

bioaccumulation

How is the population of killer whales in the Puget Sound changing? The killer whale population is __________. The problems with the Puget Sound killer whale population have taught us to __________. The health problems of Puget Sound killer whales include __________. Based on the health problems of Puget Sound killer whales, we would expect to find __________.

declining in animals of all ages be very careful when adding new chemical compounds to natural environments symptoms similar to AIDS high levels of polychlorinated biphenyls in salmon in the Puget Sound

Louis Guillette is most famous for his studies ________.

describing reproductive and developmental abnormalities in alligators Florida lakes

Transport of airborne toxicants, a specific problem in agricultural environments, is called pesticide ________.

drift

The goal of the Stockholm Convention is to ________.

end the use and release of 12 POPs shown to be the most dangerous

The graph in (c) is one type that may occur when a test animal is exposed to a(n) ________.

endocrine disruptor

The book Our Stolen Future was important because it ________.

focused on the impacts of endocrine-disrupting chemicals on humans

What value of LD50 indicates low toxicity?

high

The Toxic Substances Control Act regulates ________.

industrial chemicals

Warren Porter compares the costs and benefits of current industry testing practices. Which of the following statements does he include as a benefit of the current approach? Porter describes some limitations of the current "innocent until proven guilty" approach. Identify the statement below that represents a limitation. In comparison to Porter, Marian Stanley suggests that current screening processes are adequate. Based on her essay, what might Stanley say about Porter's criticisms of the current approach? Although the authors disagree on the effectiveness of our current "innocent until proven guilty" approach, they do agree on one impact of requiring more comprehensive toxicity testing. On which of the following impacts would both authors agree? If you were on a legislative panel to review the Toxic Substances Control Act (TSCA) and wished to include new requirements based on the Precautionary Principle, which of the following policies would you include?

leads to greater economic activity Linear dose response does not necessarily measure hormonal and immune responses. Initial chemical screening triggers higher-level testing if there are any adverse effects. Additional testing is time-consuming and difficult and may be technically impossible. Require low physiological dose testing.

Studies of endocrine disruptors have shown that they are closely associated with all of the following except ________.

lung cancer

Aquatic animals such as fish and frogs are especially good indicators of water pollution because ________.

most chemicals are water soluble so they enter these organisms through drinking or skin absorption

Managing environmental risks requires assessing the relative danger or risks and planning appropriately. As mortal creatures, we assess risks to our health and well-being on a regular basis. For example, of the following potential causes of human death (data from 2012), which posed the greatest danger to human life?

motor vehicle accident

Infectious disease accounts for ________% of deaths globally.

nearly 25

Properties of toxicants likely to build up in animals through bioaccumulation are ________.

non-biodegradable, lipid-soluble

Synergistic effects of toxicants that are mixed together ________.

often are multiplicative (the mixed toxicants may multiply each other's effects)

Toxicants that interrupt essential biochemical processes in organisms by blocking one or steps in important biochemical reactions are known as ________.

pathway inhibitors

Rachel Carson's book Silent Spring primarily focuses on the environmental problems associated with ________.

pesticide toxicity

Living on a fault line that is prone to earthquakes is an example of a __________ hazard.

physical

Risk is determined using the statistical description called __________, which helps us to determine the likelihood of a certain event occurring.

probability

What does the left y-axis show? What does the red graph line represent? In which of the following years did the incidence of cholera reach its lowest level? In which of the following years was the sea surface temperature more than 1ºC above the average temperature? Which of the following statements is supported by the data in the graph? As global warming causes sea surface temperatures to increase in the future, the incidence of cholera in Bangladesh will also increase.

sea surface temperature anomaly, in degrees Celsius incidence of cholera 1989 1983, 1987, 1997 There is a positive correlation between sea surface temperature and the incidence of cholera. cannot be determined from the graph

Nicotine and alcohol have been shown to be harmful to a fetus in the womb in that they can lead to birth defects. Nicotine and alcohol are, therefore, potential __________.

teratogens

________ are best defined as substances that cause birth defects.

teratogens

The bald eagle, osprey, and peregrine falcon all are ________.

top consumers susceptible to eggshell damage caused by DDT

An organism, such as a mosquito, that transmits a disease-causing organism to a host is called a ________.

vector