Presentation on theme: "Although this monitor is owned and operated by the State of Missouri, significant research was conducted with this technology for fence-line monitoring."— Presentation transcript:
Although this monitor is owned and operated by the State of Missouri, significant research was conducted with this technology for fence-line monitoring applications through an EPA Community Air Toxics Grant, Washington University, Cooper Environmental Services, and the State of Missouri. For information about this research you may contact the following individuals: Dan Bivins, US-EPA, (919) 541- 5244 John Cooper, Cooper Environmental Services, Portland, OR (503) 670-8127 Dr. Jay Turner, Washington University, St. Louis MO (email@example.com) Field operation and use of the Xact-620: William Wetherell, Jim Burnnert, MDNR (573 )526-3359 About this poster: Stephen Hall 573-526-3362 Got Lead? Comparison of a Near Real Time PM 10 Ambient Air Metals Monitor to a FEM Lead TSP Method Stephen Hall Missouri Department of Natural Resources Environmental Services Program Lead: a “Legacy” Pollutant Lead is an abundant natural resource in some areas of Missouri. Consequently, the use of this resource has created unique environmental and public health challenges for our state. Historic and current lead activities in Missouri: Mining - Milling - Smelting - Recycling Active Lead Smelting Large Lead Chat Piles The large lead chat pile in the background is located in an area known as the “Old Lead Belt” in Park Hills MO. A Lead TSP-Hi-Volume Sampler is in the foreground. Consequently “Every Day” is a Day of Lead Monitoring in Missouri Every Day TSP-Hi-Vol Samplers (alternating between two samplers) (For SIP) Every Third Day (For SIP & Special Projects) Every Six Day (For New NAAQS) And Now-Every Hour! Near Real time PM 10 Metals Monitor Measurement Principle: Non-Destructive X-ray Fluorescence Basic Features and Information: Sampling interval can be varied. 15min to 240min. Detection limits will vary depending on sampling time, filter loading and analysis time. Sample flow rate 16.7 Lpm PM 10 inlet. Up to 25 metals can be measured. (This monitor is “tuned” for As and Pb) What the Technology Can Show Us The instrument is useful for source profiling and understanding diurnal lead concentrations. Many other potential uses including near real time reporting of data to the public. The following example is a high lead concentration episode on December 23 rd and 24 th 2009. Could the Technology Be Used as a Near-Real-Time Surrogate for Pb-TSP? Although the Xact 620 24-Hr Pb-PM 10 averages are typically biased lower than the lead TSP method, the technology appears to provide a good relative indication of the magnitude of ambient air Pb concentrations when compared to the 24-hr time integrated TSP filter based samples. The technology is useful for reporting short term elevated lead concentrations in ambient air. More data and investigation are necessary to determine if the source profile is consistent over time and if site specific scaling factors or other statistical correction techniques could be applied reliably to produce a TSP surrogate. What Have We Learned? Diurnal concentrations of lead in ambient air vary with wind direction from the source. Preliminary Scaling Factors & Correlation Statistics Scaling Factors Additional Contact Information Lead TSP to lead PM 10 ratios are less consistent at lower concentrations. (possibly due to the ultra-coarse particulate component) Monthly Scaling Factors appear to meet the goals proposed for the use of Scaled Pb-PM 10 Data as a Surrogate for Pb-TSP (Federal Register /Vol. 73, No. 98 /Tuesday, May 20, 2008 / Proposed Rules, 29285). Although scaling factors for relating Pb- PM 10 to Pb- TSP were not promulgated in the final lead rule, they may yet find use for near-real-time public reporting applications. Doe Run Co. Primary lead Smelter, Herculaneum MO Herculaneum Main St. Air Monitoring Site Herculaneum Dunklin High School Air Monitoring Site St. Joe State Park 8,238-acre lead mine tailings site Donated to the State in 1976 2,000-acres of ORV trails on mine tailings. Active SPMS monitoring to measure Pb Ambient Air concentrations Sample Collected on tape -Tape advances -Sample analyzed by XRF while next sample is collected. Cooper Environmental Services Xact-620 24-Hr Pb-TSP 12.23 µg/m 3 24-Hr Integrated Xact-PM 10 : 8.40 µg/m 3 24-Hr Pb-TSP 4.81 µg/m 3 24-Hr Integrated Xact-PM 10 : 3.45 µg/m 3 Short term lead PM 10 concentrations can exceed the 24-hr integrated average for several hours at a time. X-ray tube and detector can be optimized for particular metals. (Consult manufacture for details) Xact-PM 10 data corrected with the average scaling factor generally yields a conservative TSP surrogate. Abstract: The State of Missouri purchased a near real time XRF metals monitor (Cooper Environmental Systems Xact 620) to support the goals of a community air toxics grant from EPA. At the end of the grant’s study period the XRF monitor was collocated at a TSP lead monitoring site near a stationary lead source for source profiling. This presentation reports the comparability of the continuous near- real time XRF metals data to an FEM TSP hi-volume method. Results indicate that the integrated 24-hr average of the XRF monitor measurements, although biased lower than the TSP 24hr samples, are well correlated in certain concentration ranges. The Pearson correlation coefficients for the paired data (Pb-TSP/near-real time Pb-PM 10 ) and resultant scaling factors are presented. The XRF monitor has benefits related to identifying the temporal changes in lead concentrations in the source area. The instrument identifies diurnal variation in elevated lead concentrations, which is not available using the traditional time integrated 24hr TSP sampling.
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