4-04 APES REVIII
AP Exam Review -
III
Chapters 16, 17, 19 & 20 -Hazmaterials/Toxicology/Waste
Toxicity- a measure of the adverse effects of chemicals is dependent on dose, duration and the response of the organism exposed. Effects can be acute or chronic depending on the agent and sensitivity. Responses are measure as LD50 or LC 50 the amount that in one dose kills 50% of the exposed populations (14days). In addition threshold effect indicates at what level the agent causes an effect on the organism. Dose response curves are either with or whithout a threshold.
Chemicals,
biohazards and radiation have been shown to cause hazards to health.
Hazards
are often classified as-
Carcinogens-
cancer causing
Mutagens-
cause mutations
Teratogens- cause birth defects
Results
when somatic or germ cells are effected.
Toxicants
can exhibit synergistic responses or antagonistic responses.
A
serious problem with toxicants e.g. pesticides is the ability to bioaccumulate in the food chain. Two associated factors are the half-life of
the chemical and its classification as broad spectrum or narrow spectrum (e.g.
pesticides)
Systems
effected are immune, nervous and endocrine systems .
Risks
are assessed using RISK ANALYSIS-= EPA policy
Identify
the hazard ( risk assessment), rank the risk
(comparative risk analysis), reducing or eliminating risk through (risk
management) and communicating the risk potential to the public (risk
communication).
We are a high waste society- 1.5% of all waste is municipal (household).
Hazardous
waste legally is discarded waste that contains toxic chemicals, solvents,
explosive or corrosive.
Goal-
1. reduce waste
2. reuse
3. recycle
4. treat or incinerate
5. use landfills- see text for design and use
Hazardous
Wastes- lead, dioxins
Concern
over hazardous wastes has caused a response by the government(legislation vs Agency) Two major
pieces of legislation are RCRA-Resource conservation and recovery act—identify
and set standards for management via storage, disposal.
CERCLA-
Comprehensive Environmental Response, Compensation and Liability Act or
“Superfund” Special
fund (taxes) to identify and clean up abandoned sites e.g.
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Figures and Tables- Fig 16-3, 16-6, 16-7, 16-13, 16-4, 17-6, 17-8,
17-9,17-10, 17-7, 20-1, 20-5, 20-7, 20-11, 20-15, 19-1, 19-2, 19-3, 19-5, Table 16-2, 17-1, |
Chapters 23 & 24
--Environmental Economics/Public Policy/Sustainability-
Economics in the
Environmentally
there are problems-
e.g. increasing
the price won’t change the fact that a resource is finite. In pollution control there is the realization
that infinite funds can’t be spent to clean up
pollution. Hence, COST BENEFIT ANALYSIS
concept has been employed to get the optimum decrease in pollution.
Externalities-
are difficult to place a value or price on e.g., the intangibles e.g. what is
the value of clean air or the actual cost of a disposable container
when collection, landfill costs are factored in.
Public
Policy- the
groups involved are:
Government- Executive,
Legislative, Courts, Government agencies (ex: EPA or USFS)
Public-
voters
Special
Interest Groups- both pro and con on environmental issues with their respective
political action committees (PAC’s)
Environmental
groups- often
provide independent monitoring or the watchdog approach, can be influential in
mounting legal challenges e.g. Sierra
Club sues over a violation of the endangered species act or wilderness act..
Sustainability-
Problem-
overpopulationà resource depletionà pollution and environmental degradation
Lack
of adequate resource planning, enforcement of environmental laws/regulations,
reliance on “free market” systems
Solutions- Employ sustainable
management, active approach ( recycle, conservation) shift to renewable energy
and low waste economies, reduce populations.
“Saving the planet is not a spectator
sport.” Lester Brown, WorldWatch Institute
Text and Figures-Fig 23-10, 24-6, Table 23-3, 24-2 |