Assessing Outdoor Air Near Schools
Mabel Holmes Middle School - Elizabeth, NJ
Results and Analysis of EPA’s monitoring
EPA selected this school for monitoring because it is located near a refining facility that converts crude oil into gasoline, diesel fuel, jet fuel, and heating oil, which are sources 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 acetaldehyde, acrolein, benzene, 1,3-butadiene, and nickel 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 | Measured levels of acetaldehyde, benzene, 1,3-butadiene, and nickel in the air are below the levels of significant concern suggested by previously available information. 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. |
| Key Pollutants Monitored | Acetaldehyde. Exposure to high levels can cause irritation of the eyes, skin and upper respiratory tract. |
| Next Steps | Because the acetaldehyde, benzene, 1,3-butadiene, and nickel levels are below levels of concern, EPA will not extend air toxics monitoring at Mabel Holmes Middle School. EPA remains concerned about emissions from stationary 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 New Jersey Department of Environmental Protection (NJDEP) will continue to oversee industrial facilities in the area through air permits and other programs. NJDEP will continue to collect air toxics monitoring information at a site closer to the source of interest in Elizabeth, NJ. |
Summary of Study Approach and Findings
Approach:
- A monitor collected air samples from August 23, 2009 through January 21, 2010 at the Mabel Holmes Middle School in Elizabeth, NJ.
- 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 acetaldehyde, acrolein, benzene, 1,3-butadiene, and nickel emissions.
Findings:
- Our analysis found that levels of acetaldehyde, benzene, 1,3-butadiene, and nickel in the air at the school are below levels of concern for long-term exposure.
- 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.
- The concentrations of acetaldehyde, benzene, 1,3-butadiene, and nickel measured at the school are lower than those suggested by the information that helped identify this school for monitoring.
- The analysis indicates that acetaldehyde, benzene, 1,3-butadiene, and nickel concentrations in the air near the school are influenced by nearby sources.
- The process to identify schools for monitoring relied on emissions estimates and other information. Ambient air monitoring at the school allowed measurement of what was actually in the air.
- Based on the analysis described here, EPA will not extend air toxics monitoring at this school. EPA’s ongoing research and national air toxics monitoring programs (e.g., the National Air Toxics Trends Stations) will continue to collect information on mobile source impacts on outdoor air nationally.
- 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 acetaldehyde, benzene, 1,3-butadiene, and nickel concentrations and information on acetaldehyde, benzene, 1,3-butadiene, and nickel
- Measured wind direction and wind speed at the school
- Information about nearby sources of acetaldehyde, benzene, 1,3-butadiene, and nickel emissions
Analysis of Measured Acetaldehyde Concentrations:
1. Calculate the average: We calculated the average of the acetaldehyde measurements (shown by the black diamond in the graph below). We compared this average to the long-term comparison levels (thick line on the graph below).
Result: The average acetaldehyde level for the samples collected was well below the long-term comparison levels.
2. Calculate a range: To account for varying air concentrations of acetaldehyde, we calculated a range around the average. We did this by estimating high and low values that the longer-term concentrations might reach using common statistical tools. We compared the highest point in the range (called the “upper bound”) to the long-term comparison levels.
Result: The high end of the range is lower than the comparison levels.
Analysis of Measured Benzene Concentrations:
1. Calculate the average: We calculated the average of the benzene measurements (shown by the black diamond in the graph below). We compared this average to the long-term comparison levels (thick line on the graph below).
Result: The average benzene level for the samples collected was below the long-term comparison levels.
2. Calculate a range: To account for varying air concentrations of benzene, we calculated a range around the average. We did this by estimating high and low values that the longer-term concentrations might reach using common statistical tools. We compared the highest point in the range (called the “upper bound”) to the long-term comparison levels.
Result: The high end of the range is lower than the comparison levels.
Analysis of Measured 1,3-Butadiene Concentrations:
1. Calculate the average: We calculated the average of the 1,3-butadiene measurements (shown by the black diamond in the graph below). We compared this average to the comparison levels (thick line on the graph below).
Result: The average 1,3-butadiene level for the samples collected was below the comparison levels.
2. Calculate a range: To account for varying air concentrations of 1,3-butadiene, we calculated a range around the average. We did this by estimating high and low values that the longer-term concentrations might reach using common statistical tools. We compared the highest point in the range (called the “upper bound”) to the comparison levels.
Result: The high end of the range is lower than the comparison levels.
Analysis of Measured Nickel Concentrations:
1. Calculate the average: We calculated the average of the nickel measurements (shown by the black diamond in the graph below). We compared this average to the long-term comparison levels (thick line on the graph below).
Result: The average nickel level for the samples collected was well below the comparison levels. The health concern is low.
2. Calculate a range: To account for varying air concentrations of nickel, we calculated a range around the average. We did this by estimating high and low values that the longer-term concentrations might reach using common statistical tools. We compared the highest point in the range (called the “upper bound”) to the long-term comparison levels.
Result: The high end of the range is lower than the comparison levels. The health concern is low.
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 of acetaldehyde, benzene, 1,3-butadiene, and nickel.
| What we looked at | What we found |
| We looked at whether the wind data taken on the days we took measurements of acetaldehyde, benzene, 1,3-butadiene, and nickel 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 of acetaldehyde, benzene, 1,3-butadiene, and nickel to be generally 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. | Although we lack long-term wind data at the monitoring site, the wind pattern at the NWS station during the sampling period is generally similar to the historical long-term wind flow pattern at that same NWS station. This suggests that on a regional scale, the 5‑month sampling period may be representative of year-round wind patterns. |
Analysis of Information on Nearby Sources of Acetaldehyde, Benzene, 1,3-Butadiene, and Nickel Emissions
| What we looked at | What we found |
| Whether we could determine if the sources were operating as usual during the sampling period | Recent emission levels of benzene, 1,3-butadiene and nickel from a nearby petroleum refinery are lower than those relied upon in previous modeling analysis. Information from the nearby source indicates that this facility was operating at a rate of 50-79% during the sampling period. |
The concentrations of acetaldehyde, benzene, 1,3-butadiene, and nickel measured at the school are lower than those suggested by the information that helped identify this school for monitoring. |
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| The New Jersey Department of Environmental Protection (NJDEP) will continue to oversee industrial facilities in the area through air permits and other programs. |
Additional Information
Technical Report for School: Assessing Outdoor Air Near Schools: Mabel Holmes Middle School (Elizabeth, NJ) (PDF) (40pp, 337k). The technical report is geared toward risk assessors, risk managers, and other regulatory agencies.
Background on School Monitoring Effort