Assessing Outdoor Air Near Schools
Temple Elementary - Diboll, TX
- Understanding the Monitoring Data
- Initial Sampling
- Initial Analysis
- Additional Sampling
- Final Analysis
Results and Analysis of EPA’s monitoring
EPA selected this school for monitoring because it is located near a plywood manufacturing facility which is a source of air toxics emissions. Computer models were used to determine which air toxics may be present at elevated levels in the outdoor air near the school. These models showed that acrolein could be present in the air around the school and prompted EPA to test to see if the levels present may be of concern.
|Primary Findings||Results of a recent short-term laboratory study have raised questions about the consistency and reliability of monitoring results of acrolein. As a result, EPA will not use these acrolein data in evaluating the potential for health concerns from exposure to air toxics in outdoor air as part of the School Air Toxics Monitoring project. Levels of volatile organic compounds (other than acrolein) and associated longer-term concentration estimates are below levels of significant concern for short-term and long-term exposures.|
|Key Pollutants Monitored||Acrolein. Exposure to high levels can cause irritation of the eyes, nose, and throat.|
|Next Steps||EPA plans to conduct additional sampling for acrolein at this school in early 2011. EPA has identified several simple steps that we believe will significantly improve the accuracy of acrolein sampling and that will allow us to understand whether acrolein in the outdoor air may pose a health concern at a particular school.
EPA remains concerned about emissions from sources of air toxics and continues to work to reduce those emissions across the country, through national rules and by providing information and suggestions to assist with reductions in local areas.
The Texas Commission on Environmental Quality (TCEQ) will continue to oversee industrial facilities in the area through clean air regulatory programs.
Summary of Study Approach and Findings
- A monitor collected air samples from September 4, 2009 through March 8, 2010 at the Temple Elementary School in Diboll, TX.
- We posted individual air sample results on this website throughout the monitoring period to keep your community informed during the monitoring period.
- During the monitoring period, we evaluated the monitored concentrations to see if there was a concern from short-term exposures (e.g., several weeks).
- When the monitoring was complete, we analyzed the results to see if there was a concern from long-term exposures (over a lifetime).
- Also, when the monitoring was complete, we evaluated all the air samples from the on-site monitor. We also evaluated information on wind speed and wind direction from a weather monitor at the school, along with historical weather information and information about nearby sources of acrolein emissions.
- Results of a recent short-term laboratory study have raised questions about the consistency and reliability of monitoring results of acrolein. As a result, EPA will not use these acrolein data in evaluating the potential for health concerns from exposure to air toxics in outdoor air as part of the School Air Toxics monitoring project.
- Levels of volatile organic compounds (other than acrolein) and associated longer-term concentration estimates are below levels of significant concern for short-term and long-term exposures.
- Acrolein emissions from the key source have decreased from the 13 tons reported in 2002, which was what was modeled by the NATA 2002, to the most recent reports from the 2008 TRI of 8.5 tons per year.
- EPA has identified several simple steps that we believe will significantly improve the accuracy of acrolein sampling and that will allow us to understand whether acrolein in the outdoor air may pose a health concern at a particular school. EPA plans to conduct additional sampling for acrolein at this school in early 2011.
- Click here for additional information
How We Analyzed the Information We Collected at this School
The analysis considered whether the information collected at the school might raise concerns for the health of children or adults at the school. We looked at the following types of information:
- Measured concentrations and information on acrolein
- Measured wind direction and wind speed at the school
- Information about nearby sources of acrolein emissions
Analysis of Measured Acrolein Concentrations:
Result: Acrolein concentrations were not evaluated due to consistency and reliability issues in the sampling and analytical method.
Analysis of Measured Wind Direction and Wind Speed at the School
We took measurements of wind direction and speed every day during the sample period. We took special note of the wind speed and direction on the days we took measurements.
|What we looked at||What we found|
|We looked at whether the wind data taken on the days we took measurements of are similar or different from the wind patterns during the entire sampling period.||We found the wind patterns taken on the days we took measurements to be similar to those observed during the entire sampling period.|
|We looked at whether the wind pattern during the sampling period is reflective of regional wind pattern over the long term.||We lack long-term wind data at the monitoring site, and the wind patterns at the NWS station during the sampling period are not similar to the historical long-term wind flow pattern at that location. This suggests that, on a regional scale, the 5-month sampling period may not be representative of year-round wind patterns.|
Analysis of Information on Nearby Source ofAcroleinEmissions
|What we looked at||What we found|
|Whether we could determine if the source was operating as usual during the sampling period||Acrolein emissions from the source have decreased since the 2002 estimate of 13 tons per year used in modeling analyses for this area. The 2008 TRI emissions are approximately 8.5 tons per year.|
|The nearby source of acrolein has a Title V operating air permit issued by TCEQ that includes operating requirements.|
Technical Report for School: Assessing Outdoor Air Near Schools: Temple Elementary School (Diboll, TX) (PDF) (24pp, 187k). The technical report is geared toward risk assessors, risk managers, and other regulatory agencies.