BIOL 1005 1st Edition Lecture 24Outline of Last Lecture I. VideoOutline of Current Lecture I. SalinizationII. Saltwater IntrusionIII. Watershed ApproachesIV. Decision Making ProcessV. Risks and Benefits Both HaveVI. Uncertainty Does Not Eliminate RiskVII. Risk PerceptionVIII. GraphIX. Death Per Million Hours of ExposureX. Measuring RiskXI. Risk AssessmentXII. Measuring ToxicityXIII. Acute vs. Chronic EffectsXIV. Accepting RiskXV. Risk ManagementXVI. Cost-Benefit AnalysisXVII. Internal and External CostsXVIII. Market-Based InstrumentsXIX. MBIsXX. Tragedy of the CommonsCurrent LectureI. Salinization- As plants extract water from the ground, salt content of the ground increases.- Irrigation of arid farmland can make salinization more acute due to increased evaporation rates.II. Saltwater Intrusion- Saltwater goes into freshwater or groundwater suppliesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Watershed Approaches- In 1998, EPA switched regulatory approaches. Rather than issue standards on a site by site approach, the focus is now on watershed-level monitoring and protection.- States are required to identify waters not meeting water quality goals and develop total maximum daily loads (TMDL) for each pollutant and each listed water body.IV. Decision Making Process (Risk)-V. Risks and Benefits of Both- Probability – How likely is it?- Magnitude – How good or bad and how large a spatial and temporal area does it affect?- Uncertainty – What is the quality of information on which estimates of probability and magnitude are basedVI. Uncertainty Does Not Eliminate Risks- Uncertainty of risk results from imperfect knowledge of both probability and magnitude and may obscure both- BUT---- Unrecognized risks are still risks- Uncertain risks are still risks- Denied risks are still risks- More complex systems have more uncertainty of estimatesVII. Risk Perception- Voluntary or Involuntaryo Nuclear Power Plant or Smoking- New Technologies versus Familiaro Genetic engineering and waste generation versus cars- Personal Control versus lack of controlo Expert and Public - Factors influencing risk perception:- Rating risks based on agendas.- Most people have trouble with statistics.- Personal experiences can be misleading.- We have an exaggerated view of our abilities to control our fate.- News media sensationalizes rare events.- Irrational fears lead to overestimation of certain dangers.- Fear of the unknown.VIII. GraphIX. Deaths Per Million Hours of Exposure- Mountain Climbing 40,000- Cigarette Smoking 3,000- Swimming 2,560- Air Travel 500- Struck by Lightning 100- Living near nuclear power plant 0.5X. Measuring Risk- Probability versus PossibilityXI. Risk Assessment- Estimate of the probability of harm to human health or the environment- What degree of risk is acceptable???XII. Measuring Toxicity- Animal Testing- Most commonly used and widely accepted toxicity test is to expose a population of laboratory animals to measured doses of specific toxins.- Sensitivity differences pose a problem.- Dose Response Curves- LD50 - Dose at which 50% of the test population is sensitive.XIII. Acute vs. Chronic Effects- Acute Effects - Caused by a single exposure and result in an immediate health problem.- Chronic Effects - Long-lasting. Can be result of single large dose or repeated smaller doses.- Very difficult to assess specific health effects due to other factors.XIV. Accepting Risk- Most people will tolerate a higher probability of occurrence of an event if the harm caused by that event is low.- Harm of greater severity is acceptable only at low levels of frequency.- EPA generally assumes 1 in 1 million is acceptable risk for environmental hazards.XV. Risk Management- Which risks have priority?- How much risk is acceptable?- How much money to achieve that level?- What are the spending priorities?- How will the plan be enforced and monitored?- Politics of risk management frequently focus on adequacy of supporting scientificevidence.- Defining the extent of the problem helps determine the rest of the policy process.- Below a certain risk threshold, action may be unnecessary.XVI. Cost-Benefit Analysis- Social Cost and Social Benefit- Does everything have an economic value?- Are (can) all costs and all benefits be included in the analysis?- Costs to future generations?XVII. Internal and External Costs- Product-related expenses borne by someone other than the individuals using theresource.- Pollution-prevention costs incurred to prevent pollution can often be factored into life-cycle analysis.- Internal Costs - Expenses borne by those using a resource.- External Costs - Expenses borne by someone other than those using a resource.- Internalizing Costs - Ensuring those that reap the benefit of resource use also bear all external costs.- Pollution–prevention costs – sewage treatment- Pollution Costs- Expenditures to avoid pollution damage- Increased health cost- Loss of use cost- Environmental costXVIII. Market-Based Instruments - Incentive based instead of regulated conduct- “environmental protection at low cost”XIX. MBIs- Tradable emissions permits -trade or bank- Taxes and charges – fund cleanup- Deposit – refund programs – bottle deposit- Subsidies – reduce business or product costXX. Tragedy of the Commons- Garrett Hardin (1968) - Pasturelands in England provided free by King to anyone wishing to graze cattle.- Optimal individual strategy is to enlarge personal herd as much as possible.- Each successive herd increases in size.- Commons becomes