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Mitigation of Cyanotoxins. Richard Lorenz City of Westerville & The Ohio State University, Stone Laboratory. IAFP, 2016. Grand Lake St. Marys . OH. The Great Lakes. Lake Erie Microcystis Bloom. Detroit. Stone lab. Toledo. Cleveland. Mitigation of Cyanotoxins Topics.
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Mitigation of Cyanotoxins Richard Lorenz City of Westerville & The Ohio State University, Stone Laboratory IAFP, 2016 Grand Lake St. Marys. OH
Lake Erie Microcystis Bloom Detroit Stone lab Toledo Cleveland
Mitigation of CyanotoxinsTopics • Source Water Detection • Indicators and Monitoring • Analytical Methods for Cyanotoxins • Prevention & Treatment Options • Risks to Food
Source Water Detection • Visual Bloom • Not all blooms are Cyanobacteria • Not all Cyanobacteria blooms produce toxins • Not all blooms are visible or form scums BGA Bloom – No toxins Planktothrix Bloom - Toxins
SourceWater Detection • Satellite • Visible light – true color Spectral Analysis -Phycocyanin
Source Water Monitoring • Microscopic Examination • Grab or concentrated sample w plankton net • ID to Genus and enumeration • Automated FlowCam – particle imaging Anabaena Aphanizomenon Microcystis Cylindrosperomopsis Planktothrix
Source Water Monitoring -Bloom Indicators • Changing Water Quality Parameters • Increased pH, chlorophyll, phycocyanin, turbidity, conductivity, dissolved oxygen, temperature • Grab samples • Continuous data - remotely with probes on Sondes • http://habs.glos.us/map/
Source Water Monitoring • Relationship of Toxins to Taste and Odors • Toxins and T & O events can be related, but notlinked • Cyanobacteria can produce Geosmin and MIB • But so can other organisms - Actinomycetes • Not all Cyanobacteria blooms that produce T & O also produce toxins • Not all toxic blooms produce T & O compounds • T & O event warrants further investigation
Toxin Analytical Methods • Various Options Based on Objective • Screening & field methods • Quantitative/Qualitative lab methods • Standard Methods Evolving • Lack of Standards • 6 of 100+ Mircocystin Variants • Reporting Levels Close to Health Advisories
Sampling • Glass or PETG bottles • Sequestering agent for any oxidants • Refrigerate/Freeze • Preparation • Extracellular toxins • Filter • Intracellular toxins • Lyse: chemical, sonication, freeze thaw
Common Analytical Methods • Enzyme-linked Immunosorbent Assay (ELISA) • Test Strips/tubes • Plate kits • Liquid Chromatography-Ultraviolet (HPLC-UV) • Liquid Chromatography with tandem Mass spectrometery (LC-MS/MS) • Quantitative Polymerase Chain Reaction (qPCR)
Enzyme Linked Immunosorbent Assay (ELISA) Microcystin-ADDA Method • Measures Total Microcystins • Detects all variants based on ADDA group, highly selective • MC Variants not identified • Indirect measurement of antigen using an antibody
ELISA, continued • Suitable for complex samples – Tap & natural waters • No concentration step • Sold in Kits, no high end equipment/expertise • Certified by USEPA, Ohio • Relatively Inexpensive • Quantification based on MC-LR, can over/under report other variants
ELISA Microtiter Plate Kit • Generate Std. Curve • Plate reader, color is inversely proportional to MC conc. • Range 0.15-5 ppb, Reporting Level 0.3 ug/L • Quick ~4 hrs, operational needs • ~$500/kit (42 tests) • MC, Cylindrospermopsin, Anatoxin-a & Saxitoxin
ELISA Based Field Test strips • Screening qualitative test • 30 minutes • Source water chemical lysing adds 20 minutes • 0-5 & 0-10 ug/L range • Strips for Anatoxin-a, MC
ELISA Based Test Kit Tube • Screening Method, semi-quantitative • Lysing required for total MC • ~1 hour • $5-7/test (~$200/kit) • Generate std curve, Reporting Range<0.15-5 ug/L • Absorbance w photometer @ 450 nm • Results confirmed for regulatory use
Liquid Chromatography-Ultraviolet (HPLC-UV) • LC separates components • MC UV absorption at 238nm • Non-selective detector, co-eluting interferences • Less expensive than MS • Less sensitive than MS ~0.3 ug/L
Liquid Chromatography w Tandem Mass Spectrometry LC-MS/MS • Typically require solid phase extraction step • Only tap water • Sensitive to ~0.02 ppb • Variants can be ID, with standards • More expensive than ELISA, LC-UV • Highly skilled analysts • Standard Method USEPA 544 • Limited to 6 MC variants • Standard Method 545 • Anatoxin-a & Cylindrospermopsin
LC-MS/MS MMPB Method • MMPB – 2-methyl-3(methoxy)-4-phenylbutyic acid • Chemically cleaves ADDA group • Total MC, all variants • Natural and tap waters • No freeze thaw or lysing • Quick ~2 hours • Sensitive 0.05 ppb • No standards needed • Confirms ELISA results
Quantitative Polymerase Chain Reaction qPCR • Simultaneously quantifies Total Cyanobacteria along with Genes responsible for Toxin production • Total Cyanobacteria • Based on 16S rDNA gene - correlates with cell counts • Identifies Genes that produce • Microcystins/Nodularin • Cylindrospermopsin • Saxitotoxin • 2-3 hours limited availability • Specific - no gene = no toxin • Proven molecular diagnostic method, very sensitive, high sample throughput, costly equipment and reagents, can be inhibitors to PCR • http://www.phytoxigene.com/products/
Mircocystins Method Study – Ohio EPA • 16 MC variants found • Most common variants: MC-YR, MC-LR, MC-RR • 91% samples had MC-variants not detected by USEPA Method 544 (LC-MS/MS) • LC-MS/MS under reported total MC • LC-MS/MS MMPB agreed with ELISA results - total MC
Mitigation of Cyanotoxins in the Source Water Supply • Prevention • Nutrient control • external/internal loading • Water Column Mixing • Treatment of source water • Algaecide • Avoidance • Alternative source • Manipulating intake depth
Mitigation of Cyanotoxins in the Water Supply • Treatment Options • Cell removal – keep cells intact • Coagulation, flocculation, clarification, filtration, micro or ultra membrane filtration • Toxin Removal/Destruction • Reverse Osmosis • Oxidation • Ozone,Free Chlorine, Permanganate, UV very high dose with hydrogen peroxide • Adsorption • Activated Carbon: PAC or GAC
Effectiveness of Oxidants on Cyanotoxins *dependent on initial cyanotoxin concentration, pH, temperature, and presence of NOM Source: OAWWA/OEPA White Paper on Cyanotoxin Treatment
Mitigation of Cyanotoxins in the Water Supply, continued • Optimize • Current Treatment Processes • Chemical Feed Capacity • Stop any Recycling • Multiple Barriers • Source Water • Cell Remove Intact • Adsorption • Increase Oxidant Dose and Contact Time
Cyanotoxins Potential Impact On Foods • Fish and Shellfish • Organs & Mussel, exceed TDI 0.04 ug/kg/day • Not removed by cooking • Livestock Water, Forage and Feed • Cattle deaths • Crop Irrigation • Process Water • In Store Misting • Supplements
Microcystins in Crops From Irrigation • Spray • Found both toxins and algal cells on leafy crops • Cells remained after 10 days & were not removed by washing • Ground • Root uptake with translocation to shoots in seedlings • MC found: • Lettuce, tomatoes, carrots, rice, rape seed • Forage crops, clover • Varies with crop
Phytotoxic Effects of MircocystinsPhysiological & Morphological Impact • Reduced Seed Germination • Rice, rape seed, alfalfa, lentil, corn, wheat, pea • Reduced Seedling Growth • Potato, bean, cress, spinach, wheat, corn, rice, pea • Reduced Crop Quality and Yield • Inhibits regulatory enzymes (protein phosphatases) • Bioaccumlation
Mitigation of Cyanotoxins Summary • Monitor - Source Water for blooms • Not all visible • Water Quality indicators • Toxin screening • Can occur year round • Test • Analytical methods evolving • Ohio – ELISA MC- ADDA – Total MC • LC-MS/MS – Saxitoxins, Cylindrospermopsin, Anatoxin-a and individual MC variants • may under report Total MC • MMPB capture Total MC • qPCR • Treat - reduce/eliminate Toxins • Remove cells intact • Oxidize - Free Chlorine • Absorb – Activated Carbon • Case by case basis