UNIT 6 POLLUTION REVIEW

2b. Explain how individual differences can cause problems in determining safe levels of chemicals in the environment.

1. Solubility 2. Persistence3. Bioaccumulation 4. Biomagnification 5. Chemical interactions

2e. What are antagonistic and synergistic interactions?

Chemical interactions is one of the 5 factors that affect harm. Antagonistic: reduces harmful effects. Ex.

Vitamins E and A. Synergistic: multiplies harmful effects. Ex.

When exposed to asbestos, someone who smokes has a 400x greater chance of getting lung cancer than a non-smoker (20x).

2f. In a lake environment, what animals would be most affected by biomagnification?

Biomagnification is another one of the 5 factors that affect harm. Large predatory fish Predatory birds

2g. What is the median lethal dose (LD 50) of a chemical?

LD 50: the amount received in one dose that kills 50% of the animals (usually rats and mice) in a test population within a 14 day period.

2h. How is the LD-50 determined? Animal Testing: develop data on the

response of test animals to various doses of a chemical to construct a dose-response curve. Expose a population of test animals to

measured doses in a controlled environment Using mathematical models, results from high-

dose exposures are extrapolated to low-dose levels.

Low-dose results on test organisms are extrapolated to humans to estimate LD50.

2i. What are some problems with epidemiological studies?

Epidemiological studies compare the health of people exposed to a particular chemical to the health of people not exposed. Too few people have been exposed to high

enough levels to determine the statistical significant differences.

Difficult to link to just one chemical – constant exposure to multiple ones.

Can’t be used to evaluate hazards from new technologies.

2j. Describe a non-linear dose-response curve.

No threshold: any dosage of a toxic chemical or ionizing radiation causes harm that increases with dosage.

2k. What is the difference between a non-threshold and threshold level dose-response curve. What is a more conservative estimate of chemical danger?

Threshold: a threshold dosage must be reached before any detectable harmful effects can occur.

3c. How can the precautionary principle be implemented when designing new chemicals?

"When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context the proponent of an activity, rather than the public, should bear the burden of proof. The process of applying the precautionary principle must be open, informed and democratic and must include potentially affected parties. It must also involve an examination of the full range of alternatives, including no action."

- Wingspread Statement on the Precautionary Principle, Jan. 1998

4a. Define and give an example of a nontransmissible disease.

Nontransmissible disease: caused by something other than a living organism and doesn’t spread from one person to another. Ex. Cardiovascular disorders, most cancers,

asthma, emphysema, malnutrition, diabetes.

4b. Define and give an example of a transmissible disease.

Transmissible disease: caused by a living organism (infectious agents such as bacteria, viruses, protozoa, or parasites) and can spread from one person to another. Ex. Hepatitis B, HIV/AIDS, Smallpox, Ebola,

cholera, tuberculosis, syphilis, malaria.

6a. Why are lichen especially affected by air pollution?

Symbiotic (mutually beneficial) relationship between a fungus and an alga

Do not possess roots Water and gas exchange occurs over the

entire lichen – good indicators of air quality.

8e. List the 6 outdoor pollutants that have national ambient air quality standards (NAAQS).

Carbon monoxide (CO) Nitrogen dioxide (NO2) Sulfur Dioxide (SO2) Suspended Particulate Matter (SPM) Ozone (O3) Lead

p. 438 – know their human sources and health effects

8f. How can US air pollution laws be improved?

Regulate CO2 emissions as well as other greenhouse gases Any chemical in high enough concentration

can become a pollutant Increased concentrations in the

troposphere by burning fossil fuels and clearing trees

Troposphere is warming

8g. What are the advantages and disadvantages of emissions trading?

Cap and trade: market approach to controlling air pollution Positives: cheap and efficient, anyone can

participate – environmental groups could purchase and not use

Negatives: buy their way out, creation of hot spots, cheating, doesn’t promote innovation or prevention

8h. How can sulfur emissions from coal-burning facilities be reduced?

Prevention is best Burn low-sulfur coal Remove sulfur from coal Convert coal to liquid or gas (coal gasification) Shift to less polluting fuels

Dispersion or Cleanup Disperse emissions above thermal inversion

layer with tall smokestacks Remove pollutants after combustion Tax each unit of pollution produced

8i. How are particulates removed from exhaust gas in power and industrial plants?

Ways to control particulates including SO2 Electrostatic Precipitator Baghouse Filter Cyclone Separator Wet ScrubberAll produce hazardous waste except for

cyclone separator. pg. 457

9e. How can scientists determine when a water body has been polluted?

Water Quality Index DO BOD pH Temperature Turbidity Nitrates Phosphates

10a. How is an oxygen sag curve related to stream pollution?

10b. What happened at the Cuyahoga River in Ohio? What changes happened shortly afterwards

Discharge of industrial wastes into the river and sewage systems resulted in the river catching fire and burning in 1959 and 1969

What do you think they did?

10d. How does cultural eutrophication occur? What are its effects? How can these effects be reduced?

When there is an accelerated input of plant nutrients (nitrates, phosphates and ammonium).

Results in a dramatic increase in DO due algal blooms, but as the algae dies and decomposition occurs, DO drops dramatically resulting in….

How do you think this could be prevented or reduced (Hint: think about the sources of plant nutrients)?

10e. What are the sources of chemicals that cause eutrophication?

Waste Phosphates in household detergents and

other cleaning agents Soil conservation and other land-use

controls to reduce run-off

10k. What are some strategies being used to preserve Chesapeake Bay?

Largest estuary Integrated coastal management: reduce

pollution inputs Reduce agricultural and urban runoff Banning phosphates detergents Upgrading sewage treatment plants Better monitoring of industrial discharges Replanting wetlands to filter nutrients and

other pollutants

10o. How can oil spills be cleaned up?

Mechanical methods Floating booms Skimmer boats Absorbent devices

Chemical methods Coagulating agents Dispersing agents Fire

Biological methods Bioremediation through bacteria

11d. What can water treatment plants not remove?

Pharmaceutical pollution

11e. How can sewage sludge be disposed of?

9% Compost – soil conditioners 36% Biosolids – fertilize farmland,

forests, golf courses, cemeteries, parkland, highway medians, and degraded land

55% Landfilled

11f. What are some of the problems with using sewage sludge as fertilizer?

Bacteria, toxic metals, and organic chemicals must be removed – expensive.

Use of outdated science to set standards for sludge use

11g. Describe a “living machine” ecological water treatment system.

12j. What is RCRA? What did it do?

Resource Conservation and Recovery Act Three requirements

Identify hazardous wastes and set standards for management

Permitting process for how waste is managed from companies that produce 100 kg/220 lbs

Use cradle-to-grave system to keep track of waste It doesn’t regulate…

Radioactive waste, household hazardous and toxic waste, mining waste, oil-and gas-drilling waste, liquid waste containing hydrocarbons, any waste from places that produce less than 100 kg/month

13c. Describe a resource exchange web. Why might businesses start using these as a model?

Wastes from one manufacturers become raw materials for another.

Figure 24-5

13f. What are the advantages and disadvantages of a materials-recovery facility vs. source separation?

MRF: mixed urban waste is separated by workers or machines for recovery and recycling. Figure 24-9

Source Separation: households and businesses separate recyclables

Pay-as-you-throw (PAUT)

14a. What is CERCLA? What did it accomplished?

Comprehensive Environmental Response, Compensation, and Liability Act also known as Superfund

Trust fund to achieve three goals: Identify abandoned hazardous waste sites Protect and clean up groundwater – keep

folks held accountable National Priorities List (NPL)