By Judy Sheahan
July 18, 2011

Elizabeth (NJ) Mayor J. Christian Bollwage, Chair of the Conference of Mayors Brownfields Task Force, testified July 14 before the House Subcommittee on Investigations and Oversight, Committee on Science, Space, and Technology. Bollwage spoke on the issue of using the Environmental Protection Agency’s (EPA) Integrated Risk Information System (IRIS) as a risk assessment tool and its impact on brownfields redevelopment.

EPA, using IRIS, sent to the Office of Management and Budget (OMB) a new Proposed Interim Guidance on Dioxin in Soils at CERCLA (Superfund) and RCRA (solid waste) sites. In the Guidance, EPA recommends lowering the dioxin soil concentrations from one part per billion to 76 or even 3.7 parts per trillion. Typical background levels of dioxin in urban soils is already at 19.6 parts per trillion.

The Conference of Mayors has weighed in this debate with both EPA and OMB saying that if this guidance is adopted, it would have a “chilling” effect on not only brownfields redevelopment but all urban and suburban development.

“The IRIS system is a mix of scientific measurement, expert guesswork, and is surrounded by a high level of uncertainty about what might happen in humans if they are exposed to chemical substances.” Bollwage said, “In the end it is a tool.”

“I have learned through the experience of governing a city that when you use a tool to guide decision-making, you want the right tool applied to the right problem and you want to use that tool the right way,” Bollwage said.

EPA’s exposure assumptions are predominantly determined by worst-case exposure scenarios. Actual studies on dioxin in human blood suggest there are no differences in dioxin levels in people who lived on contaminated soils and those who don’t. In fact, people get 95 percent of their dioxin from the food they eat, not from exposure to soil. In addition, there is no documented case of a person who has died because of dioxin.

The mayor made the following recommendations:

• The EPA should continue to improve IRIS and the information base on toxicity and exposure assessment.

• The exposure assessment assumptions should be evaluated by the National Academies of Science to determine if more realistic assumptions are appropriate. For example, it would be helpful to have actual measurements or a “most likely case scenario” in addition to a “worst case scenario.”

• IRIS should be a tool to advise decisions, not mandate them.

“Mayors need the best tools available to help us make sound decisions,” Bollwage said. “Our goals for our cities are to protect the public health and the environment while encouraging economic vitality. We need tools that are based in reality and common sense.”