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Harmful Algal Blooms at Surface
Water ReservoirsStephanie A. Smith, Ph.D.
September 18, 2014
NY AWWA Tift Symposium
Liverpool, NY
HABs
• “Bloom” – overgrowth of algae, usually but not always visible
• “Algae”—often not true algae, but rather are cyanobacteria, a.k.a. “blue-green algae”
• “Harmful”—causing adverse ecological impacts and/or posing a potential threat to animal and human health
▫ Toxins are an obvious issue, but what about…
▫ Anoxic conditions that kill fish
▫ Deaths of pets, livestock
▫ Taste and odor issues in drinking water
▫ Sludge disposal—is it toxic?
▫ Economic damage at recreational lakes
Figure 3Paerl & Paul (2012) Water Research 46:1349-1363
3
Figure 4Paerl & Paul (2012) Water Research 46:1349-1363
4
Competitive advantages
• Growth at high temperature
• Buoyancy regulation
▫ Microcystis, Anabaena, Aphanizomenon, Planktothrix
• Nitrogen fixation
▫ Aphanizomenon, Nostoc, Cylindrospermopsin, Anabaena
• Toxin production?
5
It’s Obvious, right?
6
Or is it?
Photos courtesy of Steve Morton, NOAA
Or is it?
8
Suspected Planktothrix rubescens, but turned out to be EuglenaHeather Raymond, OH EPA, 2012
P. rubescens and M. aeruginosaHeather Raymond, OH EPA, 2012
Or is it?
9
Lyngbya, Julie Letterhos
http://www.epa.state.oh.us/portals/35/inland_lakes/PHOTO%20GALLERY%20OF%20OHIO%20HABs.pdf, Ohio EPA accessed February 2013
Cylindrospermopsis, Heather Raymond
Planktothrix, Linda Merchant-Masonbrink
HABs: The Toxins
• “Cyanotoxins”
• Hepatotoxins, neurotoxins, dermatoxins
• Acute or chronic
• One toxin can be made by multiple organisms
• One organism can make multiple toxins
• For any one toxin, there may be multiple structural types, or “congeners”
10
HABs: The toxins
11
microcystin nodularin
cylindrospermopsin
anatoxin
saxitoxin
Microcystin-LR
The Toxins
Toxin Organisms Target organ/system
Effects
Microcystin
Microcystis,Anabaena, Aphanizomenon, Anabaenopsis, Planktothrix
Liver
Abdominal pain, vomiting and diarrhea, liver inflammation, dermatitis, and more…
Anatoxin
Anabaena, Aphanizomenon, Cylindrospermopsis, Oscillatoria, Planktothrix
Nervous system
Neurotoxin; tingling, burning, numbness, drowsiness, slurred speech
Cylindrospermopsin
Cylindrospermopsis,Aphanizomenon, Umezakia, Lyngbya,Rhaphidiopsis, Anabaena
Liver See MC
Toxin potency
13
Cyanotoxin LD50(ug/kg)
Comparison LD50(ug/kg)
Saxitoxins 10 Ricin 22
Anatoxin-a 200 Cobra venom 185
Anatoxin-a(S) 20 Sarin 218
Microcystin-LR 50 Curare 500
Cylindrospermopsin 300/180 Strychnine 2500/980
Hudnell (2010), Toxicon 55:1024-1034
Intracellular or Extracellular?
Healthy cells making microcystin or anatoxin-a
Healthy cells making cylindrospermopsin
Dying cells release toxins of any type
What’s a TPO to do?
• Define your goals
▫ For your source
▫ For your raw water intake
▫ For treatment
• Develop an approach to meet those goals
• Develop a contingency plan
Phycocyanin, chlorophyll, turbidity, etc.
Monitor
Microscopy, to look for toxic vs. nontoxic taxa of algae
Identify
Measure for algal toxins using test strips or ELISA
Measure
Limit nutrients, algaecides, natural products
Manage
Monitoring Tools
• YOUR EYES!
• Turbidity
• Temperature
• pH
• Dissolved oxygen
• Filter backwash—is it green?
• Taste & Odor—in summer?
• Fluorescent pigments
Principles of Fluorescence
Chlorophyll
Plants and green algae have chlorophyll
Principles of Fluorescence
Chlorophyll
Phycocyanin
Cyanobacteria (blue green algae) have phycocyanin + chlorophyll
Fluorometers• Used in a wide range of
applications
▫ microbiology, medical, WQ, molecular research, etc.
• Portable or Submersible
• Automated data logging
Google image search “handheld fluorometer”
Google image search “submersible fluorometer”
YSI
Portable Fluorometers
• Measure, PC, Chl, or both
▫ Changes in pigment reflect changes in population
▫ Establish a baseline, and monitor for changes
▫ No magic cutoffs!
Identify: Microscopy
• Different types of microscopes with different features
▫ Classical compound light, inverted, phase contrast, fluorescence…
▫ These are bacteria…need 100-1000X!
• Wide range in price
• Significant skill
Identify: Microscopy
Oscillatoria
Lyngbya
Identify: Microscopy
• Again, define your goals:
▫ Do you need full identification and enumeration of all taxa present, OR
▫ Do you just need to know if you have potentially toxic organisms to help decide whether you should test for toxins, OR
▫ Are you using this as a monitoring tool, and you are regularly looking for shifts in the population, OR
▫ Some combination of the above?
Phycocyanin, chlorophyll, turbidity, etc.
Monitor
Microscopy, to look for toxic vs. nontoxic taxa of algae
Identify
Measure for algal toxins using test strips or ELISA
Measure
Limit nutrients, algaecides, natural products
Manage
Microcystin International Guidelines
Country Limit Note…
Australia 1.3 ppb total microcystins
Canada 1.5 ppb MC-LR MAC
Czech Republic, China, Italy, Japan, Korea
1 ppb MC-LR, WHO provisional guidance
New Zealand 1 ppb Addresses 5 other toxins
Brazil 1 ppb Presumed total MC; has CYN and SAX guidelines, too
Spain 1 ppb Total microcystins
United State of America ??? ???
Cyanotoxins are not regulated in the
U.S.• Safe Drinking Water Act requires USEPA to
publish list of unregulated potential contaminants
▫ Contaminant Candidate List (CCL) #3 has
Anatoxin-a
Microcystin LR
Cylindrospermopsin
Cyanotoxins are not regulated in the
U.S.• However…2014 ASDWA Survey, 34 states
responding
▫ 5 have advisory thresholds for MC, 2 for additional toxins
▫ 6 have programs and policies, 4 have draft policies, 8 are discussing drafting policies
• General consensus—the regulations will be coming…
Holy Toledo!
• ADDA-ELISA detected >2 ppb in finished water
• USEPA, OEPA confirmatory testing with ELISA + LC/MS
• Is the WHO guideline the way to go, and if so, what does it actually mean?
Toxin Analyses
NMR LC/MS
TLC
Bioassay
ELISA
High sensitivityLow sensitivity
Low specificity
High specificity
HPLC
PPIA
ELISAs
• For water, by far the most popular
• Considered a screening tool
• A handful of popular commercial kits
▫ Abraxis
▫ Beacon
▫ Modern Water
▫ Envirologix
▫ Enzo Life Sciences (Abraxis?)
ELISAs
• Some limitations
▫ Antibody binding to an analyte, so actually an indirect measurement
▫ Cross reactivity of those antibodies with other things (low specificity)
▫ What are the antibodies binding to?
Does ADDA add up?
nodularin
Does ADDA add up?
• WHO guidelines and others were not based on ADDA or total microcystins, they were based on MC-LR, and LR only…
• Does this matter? Are the microcystins all the same?
LD50 -- ToxicityToxin LD50 (µg/kg) Animal Route ReferenceMC-LR 43.0 Mouse i.p. Gupta et al., 2003
38 ± 9 Mouse i.v. Kondo et al., 199236 (reported as ng/g) Mouse i.p. Stoner et al., 19895000 Mouse Oral Fawell et al., 199950-158 Mouse i.p. Fawell et al., 1999>5000 Rat Oral Fawell et al., 1999122 Rat (fed) i.p. Miura et al., 199172 Rat
(fasted)i.p. Miura et al., 1991
73 Mouse i.p. Watanabe et al., 1988MC-YR 110.6 Mouse i.p. Gupta et al., 2003
91 ± 2 Mouse i.v. Kondo et al., 199268 Mouse i.p. Watanabe et al., 1988
MC-RR 235.4 Mouse i.p Gupta et al., 2003600 Mouse i.p. Watanabe et al., 1988111 (reported as ng/g)
Mouse i.p. Stoner et al., 1989
MC-LA 39 (reported as ng/g) Mouse i.p. Stoner et al., 1989MC-LY 91 (reported as ng/g) Mouse i.p. Stoner et al., 1989
Phycocyanin, chlorophyll, turbidity, etc.
Monitor
Microscopy, to look for toxic vs. nontoxic taxa of algae
Identify
Measure for algal toxins using test strips or ELISA
Measure
Limit nutrients, algaecides, natural products
Manage
#1 Goal at the Source: Prevention
• Know your watershed, not just your water
• Preventing growth:
▫ Limit nutrient inputs
▫ Good aeration and mixing
▫ Flowing/movement of water
▫ Do copper or other treatments before the bloom?
• Preventing intake:
▫ Intake valves at different depths
▫ Rotation of reservoirs/more than one source
Manage the Source
• Copper is still the most popular
• Peroxide-based
• Alum treatment of reservoirs
• Is the toxin intra- or extra- cellular?
Intracellular or Extracellular?
Healthy cells making microcystin or anatoxin-a
Healthy cells making cylindrospermopsin
Dying cells release toxins of any type
Intracellular toxin (Intact Cells) Removal
Treatment Yay or Nay?
Pretreatment oxidation Nay
Coag/Sediment/Filtration Yay
Membranes Assumed Yay
Flotation/DAF Yay
Oxidation processes Nay
Extracellular Toxin (waterborne) Removal
Treatment Yay or Nay?
Membranes Maybe…
Potassium PermanganateYay for MC and Ana, not sure on
CYN
Ozone Yay for all
Chlorine dioxide Nay for acceptable DW doses
Chloramines Nay
ChlorinationYay for MC if pH is below 8,
ineffective for Ana
UV Radiation Yay, but really high doses
GAC/PAC Yay
Chlorination
pH MC-LR CT values in (mg x min)/L
ppb 10⁰C 15⁰C 20⁰C 25⁰C
6 50 46.6 40.2 34.8 30.8
10 27.4 23.6 20.5 17.8
7 50 67.7 58.4 50.6 44.0
10 39.8 34.4 29.8 25.9
8 50 187.1 161.3 139.8 121.8
10 110.3 94.9 82.8 71.7
9 50 617.2 526.0 458.6 399.1
10 363.3 309.6 269.8 234.9
Acero et al 2005
Chlorination
• For MC: pH below 7
• Saxitoxin, higher pH is better
▫ At pH 9 CT of 15
• Cylindrospermopsin
▫ CT of 15 at pHs above 6
• Anatoxin-a is not degraded by chlorine
• However, byproducts may have some toxicity in the case of cylindrospermopsin
Nicholson et al 2003; Senogles et al 2000; Carlile et al 1994; Shaw et al 2001
Carbon
• Generally effective for the extracellular toxins
• Challenge is disposal/regeneration
• Mesoporous for MC and CYN, micro for ANA
Management
• Must have a plan for response—just like any contaminant or contingency plan
• Must have a plan for public outreach and communication
▫ Frazil ice example from OH—very savvy usage of social media
In Summary…
• There are tools for dealing with HABs: Monitor/Identify, Measure, and Manage
• From a drinking water perspective, being reactive, rather than proactively monitoring and managing, can have serious consequences
In Summary…
• There needs to be consensus and leadership regarding how we handle HABs
▫ How to monitor and measure
▫ How to regulate/mitigate the causes
▫ How to build the foundation of understanding
• The situation we are in now reflects the paucity of research funding in this area for the last 25 years
▫ Reactionary funding does not solve problems!
Thank You
• www.beaglebioproducts.com
• 614-682-6588