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Preliminary Assessment of Cyanotoxin Occurrence in Lakes and Reservoirs in the United States

Preliminary Assessment of Cyanotoxin Occurrence in Lakes and Reservoirs in the United States. Keith A. Loftin, Jennifer L. Graham, Michael T. Meyer, Andrew C. Ziegler, Julie E. Dietze U.S. Geological Survey S usan Holdsworth , Ellen Tarquinio U.S. Environmental Protection Agency.

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Preliminary Assessment of Cyanotoxin Occurrence in Lakes and Reservoirs in the United States

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  1. Preliminary Assessment of Cyanotoxin Occurrence in Lakes and Reservoirs in the United States Keith A. Loftin, Jennifer L. Graham, Michael T. Meyer, Andrew C. Ziegler, Julie E. Dietze U.S. Geological Survey Susan Holdsworth, Ellen Tarquinio U.S. Environmental Protection Agency

  2. Acknowledgements USEPA Office of Wetlands, Oceans and Watersheds (National Lake Assessment Website: http://www.epa.gov/owow/lakes/lakessurvey/) USGS Toxic Substance Hydrology Program (http://toxics.usgs.gov/regional/emc/) Disclaimer: Any use of trade, product, or firm names in this presentation is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  3. Outline • Concerns and Guidelines • Introduction to Cyanotoxins and Cyanobacteria • USGS cyanotoxin sampling protocol: • http://pubs.usgs.gov/sir/2008/5038 • C. Previous Occurrence in Midwest 1999-2006 • D. Toxin Studies • 1. 2007 EPA National Lake Assessment (2007 US EPA NLA) • 2. 2006 USGS Midwestern US Cyanotoxin Reconnaissance of • Cyanobacterial Blooms (2006 USGS MCR) • E. Take Home Message Lakeline, 26(2), Summer 2006.

  4. Concerns and Guidelines Binder Lake, IA August 2006 • Known Acute effects and chronic effects • - hepatotoxins • - neurotoxins • - dermatotoxins • - carcinogens • EPA Contaminant Candidate List 3 • Anatoxin-a • Cylindrospermopsin • Microcystin-LR • WHO guidelines – Microcystin-LR • Drinking water – 1.0 ppb • Recreational water • Low Risk - < 10 ppb • Moderate Risk - 10-20 ppb • High Risk - > 20 ppb

  5. = reported incident = news report Newsworthy Cyanotoxin Events in the U.S. At Least 35 U.S. States With Reportsof Cyanotoxin Associated Poisonings Cyanobacteria Made the News in at Least 21 U.S. States During 2006 East Okoboji Lake, IA June 2000 After Graham, 2006

  6. Photic Zone Sampling vs. Bloom Sampling Cyanotoxin transport: Intracellular: Wind Hydraulic Bouyancy Regulation Extracellular: Hydraulic (Dissolved-Phase) Particulate-Bound Sampling protocol critical to ability to interpret data! Higher concentrations of cyanobacteria and toxins more likely in wind blown accumulations near shore. Cheney Reservoir, KS, June 2003 Upper Gar, IA August 2006

  7. Dissolved-Phase Toxin (Extracellular) Particulate Toxin – meaning depends on whether cells are lysed. = + Environmental Distribution of Cyanotoxins“The Quick Version” Total Toxin Total Toxin = Extracellular Toxin + Intracellular Toxin + Particulate Toxin

  8. Microcystins were Commonly Found in the Midwest by ELISA (1999 – 2006) • Integrated photic zone • samples. • 78% (n = 359) of lakes had • at least one detectable • occurrence of toxins. • Total concentrations • ranged from: • < 0.10 to 52 ppb. Mozingo Lake, MO October 2001 After Graham and others 2004 and 2006

  9. Randomly selected lakes for 2007 EPA National Lake Assessment - Photic Zone Sampling (http://www.epa.gov/owow/lakes/lakessurvey/) Total lakes: n=1150 for Microcystins • Total microcystin • samples collected in • photic zone in deepest • part of lake. • All samples were • analyzed by ELISA. • 2 % of samples will • be analyzed by • LC/MS/MS for • confirmation. Image from EPA 841-F-06-002

  10. 2007 EPA NLA – Photic Zone Sampling Microcystins Were Found Throughout the United States Especially in the Upper Midwest. % Overall Detections (with Reference Lakes and Resampled Lakes): 32 % (401/1238)

  11. 2006 USGS Midwestern US Cyanotoxin Reconnaissance – Targeted Cyanobacterial Blooms and Accumulations • Cyanobacterial blooms and accumulations in 23 midwestern • lakes (KS, MO, IA, MN) were targeted over a 1 week period in • August 2006. • Measurements included: water chemistry, cyanotoxin analysis by • ELISAs and LC/MS/MS (dissolved and total), taste-and-odor • compounds (SPME-GC/MS), chlorophyll a (fluorescence), and • phytoplankton ID.

  12. 2006 USGS Midwest US Cyanotoxin Reconnaissance During August 2006 all lakes (n=23) had detectable microcystins when ELISA and LC/MS/MS are combined, 30% had detectable Anatoxin-a, and 9% had detectable Nodularin-R. ELISA (MRL = 0.10 ppb, 0.02 ppb, 0.04 ppb) LC/MS/MS (MRL = 0.010 ppb) 1. ELISA detections of Cylindrospermopsin were not reproduced by LC/MS/MS 2. ELISA detections for Saxitoxins could not be confirmed at this time. Still working to include these compounds in our LC/MS/MS method.

  13. 2006 USGS Midwest Recon Microcystins Were the Dominant Class of Cyanotoxins (ELISA - 23 lakes) Upper Pine Lake, IA August 2006 Rock Creek Lake, IA August 2006

  14. 2006 USGS MCR – Blooms and AccumulationsMicrocystins –LR and –RR were the Most Abundant Congeners and Microcystin–RR had the Highest Concentrations. % Detects 30% 52% 39% 91% 39% 61% 78% 65% 9% No detections above 0.010 ppb for Cylindrospermopsin, Deoxycylindrospermopsin, and Lyngbyatoxin-A.

  15. 2006 USGS MCR Cyanotoxin Mixtures Were Commonly Found in Midwest Lakes and Reservoirs in 2006 by LC/MS/MS with Up to 9 Toxins Measured in One Sample.

  16. Comparison of ELISA Results for Microcystins Photic Zone Sampling vs. Blooms and Accumulations Higher Detection Frequencies and Higher Concentrations were Observed in Blooms and Accumulations than in Photic Zone Sampling. • Study objectives dictate sample collection procedures (i.e. photic zone vs blooms and accumulations, etc.).

  17. Take Home Message… • Cyanotoxins are present at levels that may be of concern for human health and ecological impact in some cases. Specifically, microcystins are found nationwide and are frequently encountered in the Midwest. • Anatoxin-a occurred in 30% of the 2006 USGS Midwest Recon at levels up to 9.5 ppb. • Predictably, higher detection frequencies and higher concentrations of toxins can be encountered in cyanobacterial blooms and accumulations versus photic • zone sampling. • In the 2007 EPA study (photic zone sampling), 9 (0.7 %) lakes exceeded WHO recreational guidelines (20 ppb) and 143 (12 %) lakes exceeded WHO drinking water guidelines (1.0 ppb) for microcystins. • In the 2006 USGS Midwest Recon (Bloom and Accumulation sampling), 4 (17 %) lakes exceeded WHO recreational guidelines (20 ppb) and 18 (78 %) lakes exceeded WHO drinking water guidelines (1.0 ppb) for microcystins. Microcystin-LR, one of the most toxic microcystin congeners, was detected most frequently (91 %). • LC/MS/MS results indicate that toxin mixtures may be fairly common.

  18. Keith Loftinkloftin@usgs.gov(785) 832-3543 Jennifer Grahamjlgraham@usgs.gov (785) 832-3511 Additional Information Available on the Web: Cyanobacteria- http://ks.water.usgs.gov/Kansas/studies/qw/cyanobacteria USGS cyanotoxin sampling protocol: http://pubs.usgs.gov/sir/2008/5038

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