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Air Monitoring Results
The Missouri Department of Natural Resources Environmental Services Program recently performed SUMMA canister sampling over a 60-day period at a location near BP Amoco's property in Sugar Creek. Samples were taken over a 24-hour period every 3 days from February 3 through April 7. The procedures for the air sampling were described in the July issue of Sweet Talk.
Twenty valid samples were collected. The samples were analyzed for 65 pollutants and 16 different compounds were found. This sampling was done to determine if there are health issues related to the outdoor air levels of pollutants at the monitoring location, but not to determine if any particular sources were related to the pollutant levels. The study was given to the Agency for Toxic Substances and Disease Registry (ATSDR) to perform a Health Consultation.
ATSDR reports that all detected chemicals were below health-based comparison values for non-cancer effects. Benzene concentrations ranging from non-detect (ND) to 1.3 parts per billion (ppb), 1,1-dichloroethene from ND to 0.88 ppb, methylene chloride from ND to 1.8 ppb, and tetrahydrofuran from ND to 4.9 ppb exceeded their respective health-based comparison values for cancer effects. Exceeding a health-based comparison value does not necessarily suggest the existence of a public health hazard. Comparison values are used only to identify those site-specific contaminants warranting further document review.
Based on studies reviewed by ATSDR no animal or human studies have shown adverse health effects due to chronic exposures to benzene levels of 1,000 ppb or less. Studies on workers exposed to levels of methylene chloride at levels up to 475,000 ppb have shown no excess cancer. 1,1-dichloroethelene and tetrahydrofuran were detected in only 1 of 20 valid samples. These two chemicals have not been detected during other ambient air sampling events. Therefore, there is no reason to believe the residents have a chronic exposure to either compound. ATSDR concludes that exposure to ambient air in the Norledge area where the sampling was done would not be expected to result in adverse health effects. There is no recommendation by ATSDR for further outdoor air monitoring.
During the Amoco Focus Group meeting on June 26, a question was asked about how the air monitoring site was chosen. The monitoring site was chosen near residences and as close as possible to the locations where most of the odors have occurred. Considerations for choosing the monitoring site included concerns with clearances from obstacles that would prevent good air flow and reaching agreement with the property owner for installing and having access to the monitoring equipment on a regular basis. Additionally, regulators cannot take regulatory action for sampling on the property of facilities that are the source of pollutants. Taking all of these things into account meant that only certain locations were appropriate and available.
To get a copy of the Sugar Creek Air Monitoring Report or ask questions, contact
Terry Rowles; Missouri Department of Natural Resources; Air Pollution Control Program P.O. Box 176; Jefferson City, MO 65102-0176; phone 1-800-361-4827 or 573-751-4817; fax: 573-751-2706.
To get a copy of the June 25, 2001 Health Consultation report by ATSDR or ask questions, contact Denise Jordan-Izaguirre at (913) 551-1310.
