TABLE 1 Calculation of Environmental Load Index (ELI) for 1 kg of CO Released to the Air

Unit Effect

Nuisance

Morbidity

CO2 Effect

Oxidant Effects

Safeguard subject

Impact measure

Human health

CO concentration

Human health

CO concentration

All 5

CO2 equivalents

All 5

Ethylene equivalents

Fl, value

100a

100,000a

0.08887b

0.0005b

F2, persons affected

750,000,000c

750,000,000c

1

1

F3, frequency or intensity

O.1d

0.001d

3e

3e

F4, duration

0.01f

0.01f

1

1

F5, contribution to total effect

6 x 10-13g

6 x 10-13g

1

1

ELI contribution

0.000045

0.00045

0.266202

0.0015

ELI for 1 kg of CO released to the air

 

0.27

a Fl values for the first two unit effects reflect the assessment that the value of "moderate nuisance" is 102 ELU/person-year and that of "painful morbidity and/or severe suffering" is 105 ELU/person-year.

b Because CO has impacts similar to those of CO2 and ethylene, the ELIs for these two species are given in the last two columns of the F1 row. By definition, the ELI already aggregates the impact over all pertinent safeguard subjects.

c The F2 value is the scope of the effect; in this case, an estimated one-third of the global urban population (~2,280 million) is exposed to excessive CO concentrations 1 percent of the time.

d The F3 values represent World Health Organization estimates that 10 and 0.1 percent of those exposed to concentrations of CO above recommended levels are affected at the nuisance or morbidity level, respectively.

e The magnitude of the impact of CO is estimated at three times the impact of CO2 and ethylene, so the F3 term is 3. Other terms are set to 1, because these other effects have already been captured in the ELIs of the equivalent chemicals

f The F4 values represent estimates that critical levels of exposure to CO are experienced 1 percent of the time.

g The F5 values represent the incremental effect of 1 kg of CO released. Because global human- caused releases of CO are estimated at 1,600 million metric tons/yr, the incremental impact of 1 kg released is 6.25 x 10-13.

SOURCE: Steen and Ryding (1992).

higher price that some consumers would have been willing to pay (recall that demand curves slope downward). Finally, there is the critical question of how to establish these costs and prices when markets do not exist. Although litigators are prepared to place a value on wrongful death or pain and suffering during a civil suit, no markets exist for pain, clean air, or future well-being. Generally, most environmental attributes are external to markets; many of the classical examples of market externalities are based on environmental issues.

Where markets exist, EPS uses market prices to establish the costs of avoidance. Where market prices do not exist, EPS relies on two alternatives. If gov-



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