County Eases Recent Air Pollution Guidelines

Just two months after adopting new, stiffer toxic emission guidelines for new installations of plant and equipment, the Allegheny County Health Department voted to relax one of the new guidelines. Rather than measuring pollutant levels at the company’s property line, as called for in the November approved guidelines, the new relaxed requirement will be to measure the pollutant level at the nearest habitable structure.

Last August when the guidelines were proposals and made available to the public, the Allegheny Institute produced an analysis of the guidelines in which we challenged the type of measure of toxicity being proposed and all also strongly questioned the use of the company "fence-line" as the appropriate place to measure the pollutant. For one thing, the gauge of carcinogenic effect being employed is the Maximum Individual Carcinogenic Risk (MICR). The MICR-a creature of the EPA-is defined as the estimated risk of contracting cancer for an individual exposed to the pollutant 24 hours per day, 7 days per week, and 52 weeks per year for 70 years. The risk setting is placed at one predicted case of pollutant caused cancer in 100,000 persons so exposed.

Obviously, the MICR is a questionable measure since there has never been, nor is there likely to ever be, a study lasting 70 years that keeps a person continuously exposed to a specific toxic emission level. In other words, the MICR is a projection and depends on assumptions about mechanisms and extrapolations of effects over a very long time based on controlled experiments for much shorter duration. Indeed, subjecting individuals to deliberate exposure to toxic emissions for periods of time in order to assess carcinogenic effects is a violation of accepted protocols for human testing. In the absence of direct tests, scientists are forced to use epidemiological studies in an effort to assess the carcinogenic effects of a toxic substance. Such studies are extraordinarily difficult to refine to a level that statement t with high degrees of confidence can be reached, especially when the risk factor is being set so stringent as one cancer in 100,000 exposed individuals-over a period of continuous exposure lasting 70 years.

However, beyond the inherent difficulties in using the MICR, having the measure taken at plant boundary line is seriously over the top. What if the nearest domicile is 200 yards away? The likelihood of the toxic emission being nearly as concentrated as at the boundary is highly improbable, the more so depending on strength of prevailing air flows.

In short, the Health Board made the right decision regarding where to measure the pollution. Now they need to revisit the MICR and satisfy themselves that the standard is of value.

Finally, it should be borne in mind that the new guidelines apply only to new or rehab installations. What if the new equipment is less polluting than the old but does not meet the new guidelines? The impact might well be to have the firm continue using the old equipment rather than investing in new, cleaner equipment. Where is the logic in creating such a scenario?