Assessment of PCB Air Risks
at Bloomington-ICS Water Treatment Plant

June 6, 2002

From:
J. Milton Clark
Health and Science Advisor
US EPA-Region 5

The air concentrations of PCB outside and inside the facility collected in April 2002 do not present significant risks to nearby residents or workers. Air concentrations and risks are noted below.

There are no residential areas near the northeast or outside the plant to the North. A reasonable maximum daily exposure would be about 2 hours per day in these locations. To assess worst case risks to nearby residents, it was assumed that a person would be exposed for 24 hours per day. It should be recognized that actual risks to residents will be considerably lower because (1) persons are unlikely to be home 24 hours per day, seven days per week (2) PCB measurements were taken at the fence line and residents are located further away and (3) indoor PCB air levels in the residences will be lower than those outside. It will be assumed that the outside person exposed person will be a 14 year old (50 kg weight) with a daily respiration rate of 15 m3/day, while indoor the person would have a respiration rate of 20 m3/day and weigh 70 kg. A cancer potency factor of 0.7 (mg/kg-bw-day)-1 has been applied and using a reference dose of 2.0F-5mg/kg-bw-day.

Nearby residents or persons visiting the facility, including women, would have no significant cancer or non-cancer health risks, indicating that the plant is not causing a health concern. In addition, workers wearing personal monitors had PCB air levels all under the NIOSH criteria of one ug PCB/m3.

There has been some discussion that the facility or other PCB treatment is increasing health risks to persons. Clearly this is not the case. Background air levels in Bloomington from the April sampling, yield cancer risks less than one in a million and have no significant non-cancer risks to persons. Therefore, there are no long-term health concerns with PCB treatment or disposal. The removal of high level PCB containing wastes from the community, containment of lower levels of PCBs in landfills, and treatment of waste streams will continue to lead to a reduction of overall PCB air levels.