APES REVIEW
If 1 mg/kg of mass of a pesticide is the LD50 for rats in an experiment, what would be considered safe exposure for humans?
.001 mg/kg
Dysentery
Amoeba is one possibilty
Which of the following best describes the action of an endocrine disruptor?
An endocrine disruptor blocks the receptor protein binding site of a hormone so that the cell cannot receive a signal.
Which of the following best describes why persistent organic pollutants (POPs) are toxic to organisms?
B They do not break down easily and can accumulate in the fat tissue of an organism.
Plague
Bacterium
Lead
Batteries, paints
A biologist is studying a small food web in which phytoplankton are eaten by krill, krill are eaten by fish, and fish are eaten by seals. During their study of the ecosystem, the biologist discovers that PCBs are present in measurable levels in the water and wants to examine how PCBs could vary in different trophic levels. Which of the following best identifies a testable hypothesis for the study?
Biomagnification will cause the seals to have the highest amount of PCBs in their tissues.
Mercury
Burning coal
Superfund Act
CERCLA
Identify three common methods for disinfecting treated effluent
Chlorine, Ozone, UV light
Severe dehydration
Cholera Dysentery
Which of the following approaches would best decrease the impact of frequent flooding in a community that is subject to the hazard of flooding?
Construct wetland areas near the rivers and streams.
Persistent organic pollutants
DDT PCBs Dioxins PFOA PFOS
Which of the following best describes the source of persistent organic pollutants (POPs) that could accumulate in the tissues of a top predator?
DDT and other pesticides that are sprayed to control for mosquitoes
Which of the following best describes why DDT is classified as a persistent organic pollutant?
DDT is very stable, and as much as 50% of the original concentration can remain in the soil 15 years after the initial application.
Which of the following is the most likely impact of thermal pollution from power plants on a river ecosystem?
Decreased oxygen levels because warm water holds less dissolved gas than cold water does
Which of the following is an expected consequence of runoff and sewage in an aquatic environment?
Decreased oxygen production by seaweed on the seafloor from an increase in turbidity
Scientists are interested in studying the bioaccumulation of mercury in different species of dolphins exposed to the same concentration of mercury. The dolphins in the study will be of similar age and living in the same habitat. Which of the following best identifies a testable hypothesis for the study?
Different species of dolphins will have different levels of mercury in their fatty tissues depending on the species' ability to absorb and excrete mercury.
Which is part f the tertiary treatment of wastewater?
Disinfection
A scientist wants to study the effect of DDT in a fish-eating bird species. She measures a variety of variables in a population of birds over a period of ten years to determine how levels of DDT affect bird survival and reproduction. Which of the following identifies a scientific question she could ask to best evaluate the effect of DDT on the bird species?
Does the persistence of DDT lead to eggshell thinning or developmental deformities in the bird species?
Researchers suspect that sewage leaked into the Moose River. Rates for which of the following diseases should be used to determine whether the human population using the river as a source of drinking water was exposed to sewage?
Dysentery
Cadmium
E-waste, batteries
What is another name for treated waster that is discharged to a body of water?
Effluent
Which of the following strategies would best increase the total volume of municipal solid waste being recycled?
Enacting a single-stream recycling program and providing bins to residential homes
Which of the following pollutants would most likely be responsible for gender imbalance in a population of frogs in which all observed frogs are female?
Endocrine disruptors
Which of the following best describes the action of endocrine disruptors in organisms?
Endocrine disruptors mimic naturally occurring hormones in animals, leading to developmental disorders.
Which of the following water quality tests would best indicate if sewage from the wastewater treatment plant has contaminated the Moose River?
Fecal Coliform (measured at the sight below the facility)
Indicator species for potential pathogens in a body of water
Fecal Coliform Bacteria
Which of the following examples includes both a point and a nonpoint source of pollution?
Fertilizer from suburban lawns and wastewater from a water treatment plant
Which of the following best describes how a malfunctioning air compressor would affect the process of sewage treatment?
Fewer bacteria would be available to absorb dissolved organics in the tank.
Which of the following is associated with the primary treatment of sewage?
Grit Chamber
Endocrine disruptors directly affect which of the following in an organism?
Hormones
Mercury concentrations were measured in freshwater shrimp populations in two different ponds, one polluted with mercury and one unpolluted, with a similar food web in each pond. Which of the following best identifies the scientific question that would guide this investigation?
How much mercury accumulates in the tissues of freshwater shrimp living in a polluted pond?
Which of the following is the most likely consequence of runoff transporting chemicals that are endocrine disruptors to a pond?
Increased frequency of birth defects in fish populations in the pond
Which of the following would result in the largest reduction in volume of municipal solid waste disposed of in landfills?
Introduce composting programs for yard trimmings and food waste
Which of the following is an example of a point source of pollution?
Leaking septic tank
Which of the following strategies will best help to protect mangrove habitats?
Limiting coastal development and maintain a shoreline buffer zone
Significant increases in water temperature can drastically change dissolved oxygen (DO) levels in a lake. Why does the combined effect of these two environmental changes result in algal blooms?
Low dissolved oxygen leads to death for aerobic organisms, like fish, whose decomposition provides an overabundance of nutrients for the algae, resulting in the large blooms.
Acute respiratory distress
MERS SARS
Zoonotic Virus (by animal)
MERS SARS plague West Nile
Used as a gasoline additive to oxygenate fuel and prevent engine knock. Tank leaks contaminated groundwater and gave water an off-taste. Now replaced by ethanol.
MTBE
Destroys red blood cells & clogs up small vessels in organs
Malaria
Arsenic
Mining, smelting, groundwater
Which of the following is a point source pollutant that would likely affect the ecosystem health of a coral reef?
Oil released from the broken hull of a shipwrecked tanker
Which of the following is the best example of a point source pollutant?
Oil tanker spill
Used in transformers and capacitors due to its fire retardant and insulating properties; carcinogen
PCBs
A scientist is studying PCBs in tertiary consumers. She wants to determine if PCBs can be found in tertiary consumers even though these compounds were banned in the United States in the 1970s. Which of the following best identifies a testable hypothesis for the study?
PCBs are persistent organic compounds that are fat-soluble, so they should be found in the fatty tissues of tertiary consumers even though the compounds have been banned for decades.
Found in stain- and water-resistant fabrics, non-stick products, food packing materials, fire-resistant foams. No longer produced in US, but could be in imported items. Almost all people in America have these chemicals in their blood. Carcinogens; endocrine disruptors; developmental delays
PFOA, PFOS
Which of the following best explains why top predators can have up to 60 times as much of persistent organic pollutant (POP) as their prey and up to 600 times as much of the pollutant as producers?
POPs are not carbon-based compounds, so animal digestive systems lack enzymes capable of breaking them down. POPs biomagnify in the fatty tissues of animals but not in plants.
According to the World Health Organization, persistent organic pollutants (POPs) are found in nearly all tested organism tissues and environmental samples. Which characteristic of POPs accounts for their presence in living tissues and in environmental samples?
POPs are released in to the air, water, and land, which allows them to be transported and incorporated in multiple ways.
Which of the following best describes a way that persistent organic pollutants (POPs) cause harm in the environment?
Persistent organic pollutants are soluble in fat, so they accumulate in an organisms' fatty tissues.
Which of the following correctly identifies an example of an endocrine disruptor and the effect it might have on the human body?
Phthalates in cosmetics and shampoos reduce fertility.
Tracks hazardous waste from cradle to grave
RCRA
Which of the following is the most likely reason that a community with good sanitation could still have individuals who contract cholera?
Runoff from a nearby agricultural field pollutes a reservoir used for drinking water.
Which of the following would best be described as a point source of pollution from a farm?
Runoff from the waste lagoons of Concentrated Animal Feeding Operations, which enters local waterways after a flooding event
Scientists are interested in determining if selenium, from a nearby mine, magnifies in the tissues of fish living in a lake. Which of the following best describes a testable hypothesis for the study?
Selenium will be at a higher concentration in fish tissue than in the tissue of fish prey.
Which of the following statements best describes how the Clean Water Act legislation aims to protect wetlands from being lost?
The Clean Water Act requires wetlands to be constructed to mitigate the effect of newly drained wetlands.
Which of the following best describes why a population in an area that has poor sanitation can be particularly at risk for a cholera outbreak?
The bacterium that causes cholera is spread through ingestion of contaminated water or food.
When water used to cool power plants during normal plant operations is released into adjacent waterways, which of the following is most likely to occur as a result?
The dissolved oxygen in the adjacent waterways would decrease because used coolant water is warm and leads to thermal pollution.
A massive bluegill fish kill was observed in a lake near a power plant during the winter months. It was determined that the plant was releasing large amounts of hot water into the lake. Which of the following explains what likely caused the death of so many bluegills in the lake?
The influx of warmer water caused an unexpected increase in the metabolic rate of the bluegills, which led to increased physiological stress from limited resource availability.
A small lake, located downstream of a power plant, recently experienced a die-off of multiple aquatic species. Environmentalists had been monitoring the temperature of the lake for several months prior to the die-off and noticed a significant spike in the temperature of the lake immediately preceding the die-off event. Which of the following best explains why the die-off event occurred in the lake following the increased water temperature?
The warm water decreased the amount of dissolved oxygen in the water, which led to an increase in the respiration rate of the aquatic organisms.
The amount of toxin that causes the first symptoms to appear
Threshold dose
Caseation (destruction of organ tissues)
Tuberculosis
Which of the following is the most likely reason that V. cholerae can spread rapidly through a population?
V. cholerae is a microscopic bacterium that can survive in various aquatic environments for prolonged periods of time and can cause a delayed onset of visible symptoms.
MERS
Virus
Which of the following best describes how thermal pollution from power plants can affect aquatic ecosystems?
Warm water discharged into rivers and streams decreases the oxygen content of the water, which reduces the number of fish species.
Meningitis or encephalitis
West Nile Zika
Mosquito as disease vector
West Nile malaria Zika
Incineration is one solution to reduce the volume of municipal solid waste. Municipal solid waste can be used to produce energy at waste-to-energy plants. Which of the following materials would be best suited for incineration to reduce total volume, produce energy, and have minimal release of air pollutants?
Wood
Microcephaly of the fetus
Zika
RCRA
among other things, regulates landfills
What must be done to sludge before it can be sent to a landfill or used as fertilizer?
bacteria digest it to reduce volume and remove pathogens and then it is dewatered
Secondary Treatment:
biological removal, aeration & sedimentation, bacteria reduce BOD ,disinfection, removed solids collected as sludge
Heavy Metals
cadmium lead mercury arsenic
Goes on top of the landfill once it's closed out. Prevents rain from seeping in, controls odor, prevents animals from coming in contact with waste, contains hazardous gases, prevents debris from blowing away.
cap - layer of clay topped with a flexible liner and then soil
Attributed to lack of clean water
cholera dysentery
Tertiary Treatment:
depends - combination of physical, biological, or chemical, removal of nitrogen and/or phosphorus, optional, disinfection
What is the difference between a dump and a landfill?
dump - not regulated, no liner, left open, dig a hole in the ground, fill it with trash, maybe even burn it, now illegal thanks to RCRA landfill - regulated, clay underlayment with membrane liner on top, collection of leachate, daily cover, regulated by RCRA chat_bubble_outline close
CERCLA
enacted in response to the threats posed by hazardous waste sites such as Love Canal
SDWA
establishes MCLs for water delivered to consumers
Liquid that seeps out of a landfill as a result of rainwater percolating through it
leachate
The __________ the LD50, the more toxic the substance.
lower
Landfill gas is mostly _____ and carbon dioxide
methane
What does the fact that the chemicals in problem 7 are nonpolar have to do with bioaccumulation/biomagnification?
nonpolar substances dissolve well in other nonpolar substances (like body fat) so they accumulate in an organism once ingested if these substances were polar, they would dissolve well in water and might be eliminated in urine rather than build up in your body
If the US no longer uses DDT, explain how it could be found in birds here today.
persistent, so still present in environment from years ago (1/2 life in aquatic environment can be 150 years) transports easily (attached to dust, evaporates into air and mixes with precip, wind currents, water currents) chat_bubble_outline
Primary Treatment:
physical removal, screening & grit removal, removes paper, eggshells, suspended solids, removed solids collected as sludge
CWA
regulates discharges of pollutants into surface waters