A comparison of the monetized impact of IQ decrements from mercury emissions.
OBJECTIVE
The U.S. Environmental Protection Agency (EPA) reports that the upper bound of benefits from removing mercury emissions by U.S. power plants after implementing its Clean Air Interstate Rule (CAIR) is $210 million per year. In contrast, Trasande et al. [Environ Health Perspect 113:590-596 (2005)] estimated that American power plants impose an economic cost of $1.3 billion due to mercury emissions. It is impossible to directly compare these two estimates for a number of reasons, but we are able to compare the assumptions used and how they affect the results.


METHODS
We use Trasande's linear model with a cord/maternal blood ratio of 1.7 and calculate health effects to children whose mothers had blood mercury levels >/= 4.84 microg/L.


RESULTS
We introduce the assumptions that the U.S. EPA used in its Clean Air Mercury Rule (CAMR) analysis and discuss the implications. Using this approach, it is possible to illustrate why the U.S. EPA assumptions produce a lower estimate.


CONCLUSIONS
The introduction of all the U.S. EPA assumptions, except for those related to discounting, decreases the estimated monetized impact of global anthropogenic mercury emissions in the Trasande model by 81%. These assumptions also decrease the estimated impact of U.S. sources (including power plants) by almost 97%. When discounting is included, the U.S. EPA assumptions decrease Trasande's monetized estimate of global impacts by 88% and the impact of U.S. power plants by 98%.
Griffiths
Charles
C
U.S. Environmental Protection Agency, Washington, DC 20004-2403, USA. griffiths.charles@epa.gov
McGartland
Al
A
Miller
Maggie
M
D000397:Air Pollution / Q000009:adverse effects / Q000191:economics*; D002648:Child; D003031:Coal; D004305:Dose-Response Relationship, Drug; D004777:Environment; D005260:Female; D006801:Humans; D007360:Intelligence / Q000187:drug effects*; D008628:Mercury / Q000191:economics / Q000633:toxicity*; D008962:Models, Theoretical; D011210:Power Plants; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D014481:United States; D014484:United States Environmental Protection Agency
D003031:Coal; D008628:Mercury