EVR Chapter 10
Sea Surface Temp Graph: In which of the following years was the sea surface temperature more than 1ºC above the average temperature? Select all that apply.
1983,1987,1997
Sea Surface Temp Graph: In which of the following years did the incidence of cholera reach its lowest level?
1989
Toxicant used as a flame retardant and insulator; carcinogen and scars the lungs when inhaled
Abestos
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.
Most widely used herbicide in the United States; an endocrine disruptor
Atrazine
Widely used as a lining in metal food and drink cans and to make polycarbonate plastic, a hard, clear plastic found in water bottles and many other products. Mimics the female sex hormone estrogen
Bisphenol-A
________ is/are biodegradable and known to have (a) short persistence time(s).
Bt
Toxic Substances in the Environments Causes and Consequences
Causes: -commercial production of many chemicals -massive use of chemicals in food, agriculture, medicine, and industry Consequences: -contamination of soil, air, and water -increase in reproductive disorders -bioaccumulation and biomagnification of toxins in the food chain Solutions: -consumer choice of low-toxicity products -stricter regulations requiring that consumer products be thoroughly tested before being released to market
Insecticide used to kill mosquitoes; banned in the United States in 1973 due to its toxicity
DDT
One example of a(n) __________ would be the quantity of toxic substance that causes 50% of lab rats to show reduced appetite after exposure.
ED50
Of the following U.S. agencies, ________ is primarily responsible for addressing issues regarding mercury pollution.
EPA
The __________ is the quantity of a toxic substance needed to kill half of the study organisms.
LD50
Neurotoxin that magnifies within food webs; typically found in polluted bodies of water; it poisoned thousands of people when it was dumped into the waters off Japan; people who ate contaminated fish from the waters exhibited convulsions, slurred speech, loss of muscle control, and sudden fits of laughter; some people died
Mercury
Rachel Carson's book Silent Spring primarily focuses on the environmental problems associated with ________.
Pesticide toxicity
Types of environmental hazards:
Physical: -Suffering injury during an earthquake -exposure to UV light during everyday activities Chemical: -exposure to bisphenol A in drinking water -ingesting synthetic pesticides on food Biological: -suffering nutritional deficiencies from an intestinal parasite -contracting influenza and becoming ill Cultural: -inhalation of carcinogens when choosing to smoke cigarettes -exposure to excessive UV light when going to a tanning salon
________ are best defined as substances that cause birth defects.
Teratogens
Used as a sleeping pill for pregnant women; teratogen that now is banned
Thalidomide
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).
Sea Surface Temp Graph: Which of the following statements is supported by the data in the graph?
There is a positive correlation between sea surface temperature and the incidence of cholera.
Although it is not harmful, when compound D is inhaled, it activates the body's defenses in a small percentage of people, causing respiratory problems.
allergen
Which term describes a type of toxicant that overactivates the immune system?
allergen
Figures such as these ________.
are used by scientists in risk assessment
Mercury is not readily excreted; it is stored in mammalian body tissues. This is best described as ________.
bioaccumulation
Sea Surface Temp Graph: Is this statement supported or not supported by the data on the graph? As global warming causes sea surface temperatures to increase in the future, the incidence of cholera in Bangladesh will also increase.
cannot be determined from the graph
People in a city are exposed, over a long period of time, to high levels of compound F that has entered their water supply from a nearby landfill. Residents of the city experience elevated rates of stomach and intestinal cancers over the next 30 years.
carcinogen
Persistent exposure to compound C in workers in steel foundries causes higher incidence of throat and lung cancer later in life
carcinogen
Louis Guillette is most famous for his studies ________.
describing reproductive and developmental abnormalities in alligators Florida lakes
The amount of toxic substance to which an organism is exposed to it the __________.
dose
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
Sea Surface Temp Graph: What does the red graph line represent?
incidence of cholera
The Toxic Substances Control Act regulates ________.
industrial chemicals
Toxicant present in paint; damages the brain, liver, kidney, and stomach when ingested
lead
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
Chronic exposure to high levels of compound E in rabbits slows their reaction speeds, increasing their risk of being eaten by a predator
neurotoxin
Factory workers exposed to elevated levels of compound B experience uncontrollable twitching and problems coordinating their movements.
neurotoxin
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
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
The __________ is the adverse effects an organism experiences when exposed to a toxic substance.
response
Sea Surface Temp Graph: What does the left y-axis show?
sea surface temperature anomaly, in degrees Celsius
A human embryo exposed to compound G in the womb experiences an increased probability of being born with more than 10 fingers or toes
teratogen or endocrine disruptor
Exposure to compound A at critical points in development causes female fish to develop male-like characteristics, rendering them infertile.
teratogen or endocrine disruptor
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
Some toxic substances elicit effects only when they overwhelm the body's defenses above a(n) __________ dose.
threshold
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
