Содержание
- 2. Definition The term “environmental risk” is used widely: environmental risk is sometimes used as a synonym
- 3. By their nature, environmental risks are characterized by spatial propagation, time-lag occurrence, multiplier effects, accumulation, and
- 5. Environmental risk trade-offs It is estimated that in 2010 there were 219 million cases of infection,
- 7. Risk analysis Risk analysis allows us to estimate impacts on the environment and on human health
- 8. In general, a risk factor should meet the following conditions: Exposure to the risk factor precedes
- 9. Risk assessment is a system of analysis that includes four tasks: 1. Identification of a substance
- 10. Toxicants are usually identified when an associated adverse health effect is noticed. In most cases, the
- 11. The risk assessment process consists of four basic steps: Hazard identification—Defining the hazard and nature of
- 13. DOSE-RESPONSE EVALUATION Dose-response evaluation is required both in determining exposure scenarios for the pollutant in question
- 14. Possible dose-response curve Curve A illustrates a threshold response: There is no observed effect until a
- 15. Some characteristic features of the dose-response relationship are: Threshold. The existence of a threshold in health
- 16. Bioconcentration of DDT A study of the Lake Michigan ecosystem found the following bioconcentration of DDT:
- 17. Some characteristic features of the dose-response relationship are: 5. Exposure time and time vs. dosage. Most
- 18. POPULATION RESPONSES Individual responses to a particular pollutant may differ widely; dose-response relationships differ from one
- 19. Distribution of odor thresholds in a population
- 20. Individual responses and thresholds also depend on age, sex, and general state of physical and emotional
- 21. EXPOSURE AND LATENCY Characterization of some health risks can take a very long time There is
- 22. EXPRESSION OF RISK Risk is defined as the product of probability and consequence, and is expressed
- 23. EXPRESSION OF RISK An expression of risk incorporates both the probability and some measure of consequence.
- 24. The probability, or frequency of occurrence, of adverse health effects in a population is written as
- 25. Relative risk Relative risk is the ratio of the probabilities that an adverse effect will occur
- 26. Relative risk of death is also called the standard mortality ratio (SMR), which is written as
- 27. In this particular instance, the SMR is approximately 11/1 and is significantly greater than 1. Three
- 28. Risk may be expressed in several ways: Deaths per 100,000 persons. In 1985 in the United
- 30. Deaths per 1000 deaths. Using 1985 data again, there were 2,084,000 deaths in the United States
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