Cristina González-Maddux Institute for Tribal Environmental Professionals

1. Metal enrichment of PM2.5 from industrial activitiesThe roles of TRI and regional geochemistry in particulate composition studiesShiprock, NM Cristina González-Maddux Institute for Tribal Environmental Professionals Northern Arizona University

2. Overview • Background • Mining impacts on surficial composition • Other industrial influences and TRI queries • Dust and particulate matter • Human health concerns • Research • Project 1: Shiprock, New Mexico – fine particulate study, focus on enrichment factor • Project 2: Fry Canyon, Utah – mine waste bioaccessibility • Summary

3. Mining in the Four Corners states • Uranium reserves in the Four Corners:Northern Arizona, Marysvale, Paradox Basin, Sand Wash, Front Range, Tallahassee Creek, Marshall Pass, Grants Mineral Belt • Of ~4,000 mine site proxies in the USGS MAS/MILS database, ~3,000 are located in the Four Corners states Map source: Uranium Location Database Compilation. Technical Report EPA-402-R-05--009.

4. Mine site abandonment “The Navajo Abandoned Mine Lands Reclamation Program (NAMLRP) identified more than 1,032 abandoned uranium mine sites. As of 2005, 913 sites have been reclaimed (p. 224).” - US EPA TENORM Technical Report, Vol. 1 (2006)

5. Uranium mine waste • Overburden • Protore • Barren or waste rock • Drill cuttings • Waste treatment sludge

6. Sources of windblown dust Underground and surface mines: • Waste rock (overburden pile) • Protore piles • Ore stockpiles

7. Wind erosion of mine products and waste Tailings dam 1973 Heap-leach pile 2010, (abandoned in 1968)

8. Mine proximity to human communities • EPA calculations based on 2000 U.S. Census data and the Basins MAS/MILS database

9. Toxics release inventory • TRI chemical release reports were reviewed for metals emissions in order to establish potential local or regional industrial influences on enrichment • Fugitive and point source industrial air emissions were compiled for both San Juan County, New Mexico as well as for all surrounding counties: • Rio Arriba County, NM, Sandoval County, NM, McKinley County, NM, Montezuma County, CO, La Plata County, CO, Apache County, AZ, and San Juan County, UT.

10. Coarse dust v. particulate matter

11. Particulate and soil dust composition • Primarily soil dust constituents: Al, Si, S, K, Ca, Fe • Trace metals also present

12. Particle toxicity

13. Human exposure pathways • Deleterious metals associated with uranium mine waste • vanadium (V), copper (Cu), arsenic (As), uranium (U), • other trace elements and trace metals (Sb, Se, Pb, Cr, Zn) • Human exposure pathways • Ingestion • Inhalation • Dermal penetration

14. Chemical toxicity The health effects associated with oral or dermal exposure to natural and depleted uranium appear to be solely chemical in nature and not radiological, while those from inhalation exposure may also include a slight radiological component, especially if the exposure is protracted. - ATSDR toxicological profile for uranium, May 2011

15. Project 1: Shiprock, NM Composition of fine particulate matter (PM2.5) downwind of AUMs

16. Field location

17. Research goals • Collect samples of PM2.5 dust downwind of AUMs • Identify metals in PM2.5 • Compare observed and expected concentrations using enrichment factor [EF] analysis

18. Methods: sample collection • Collection • 10 samples collected over 3 months (2009 and 2010) • PM2.5 monitor (Met One) • Teflon filters (47mm) • 96 h/sample • 37 m3 of air sampled per filter (6.7 LPM) • Analysis • Gravimetric (± 0.1 ng) • XRF spectrometry – major soil elements (Chester LabNet) • ICP-MS – trace metals (ASU)

19. Air sampling location 6, 7 5 4 UMTRA site Climax Transfer Station 1 2 3 Methods: TRI survey for local industrial emissions 1. Four Corners Generating Station, APS – coal fired power plant; 2. BHP Navajo Coal Co. – coal mining operation; 3. BHP Navajo Coal Co. – coal mining operation; 4. San Juan Refining Co. (A.K.A. Western Refining SW) – petroleum refinery; 5. Coastal Chemical Co., L.L.C. – chemical manufacturer (incl. petrochemicals); 6. San Juan Coal Co., San Juan Mine – coal mining operation; 7. San Juan Generating Station, PNM – coal fired power plant.

20. Toxics Release Inventory results Industry key: EU = electric utilities, CM = coal mining, P = petroleum, SCG = Stone/Clay/Glass A Combined results for San Juan county, NM and all surrounding counties: Rio Arriba county, NM, Sandoval county, NM, McKinley county, NM, Apache county, AZ, San Juan county, UT, Montezuma county, CO and La Plata county, CO. B Includes pounds of toxins released for both elemental compounds and element.

21. Results: PM2.5 concentration • Average concentration 10 µg/m3 • U.S. EPA 24-h fine particulate standard 35 µg/m3

22. Results: Elemental composition • 6 soil elements were most abundant: Al, Si, S, K, Ca, Fe (range 0.1-1.0 µg/m3) • 24 trace metals were detected (0.1-14 ng/m3) • 11 trace elements were enriched in both major sampling periods (Winter 2009, 2010) Enrichment Factor analysis EF(X) = ([Xsample/Alsample] / [Xcrust/Alcrust])

23. Results: Enriched elements

24. Slightly enriched or not enriched

25. Shiprock Conclusions • San Juan County (NM) airshed is burdened by enriched concentrations of several deleterious and toxic metals • Federal particulate standards were not exceeded at any point during the study • Probable contribution to toxic metal enrichment from industrial sources • No data to definitively link AUM metals to fine particulate composition (additional research needed to evaluate)

26. Summary • Shiprock served as excellent study site • It is subject to regional air quality issues that may have human health implications based metal enrichment in fine particulate • Additional research is required to determine the true airshed burden from abandoned and active mine sites • Air dispersion modeling • Isotopic analysis • Currently investigating the role of mining interference factor