While the EPA is correct that there is important new information in recent studies about the association between ambient fine PM and adverse health effects, the Agency has largely ignored the implications of this information. The results of epidemiological studies indicate clearly that the association between air pollution and adverse health effects is complex and that the health effects cannot be attributed to any single component of the generalized air pollution mixture.
We then get the translation of that argument into plainer English:
Yes, yes, and while it is clear that the firing squad killed the prisoner, it is shown that the wound pattern was complex and it is difficult to say that any single bullet was fully responsible for doing him in, therefore the barrage was essentially harmless.
The EPA needs to listen to the scientists regarding the need for tougher air quality standards and to ignore nonsensical arguments like the one above, against this regulation. Of course, being the Bush Administration, this isn't likely to happen when the EPA makes its decision this late summer or fall.