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Cyanotoxins & Human Health. Alison Reeve Jiaxin Yu Marshall Ambros Rachel Beauregard Steve Hoffmann. Problem Statement. Cyanobacteria are capable of producing toxins and have been linked to human health concerns. Objectives.
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Cyanotoxins & HumanHealth Alison Reeve Jiaxin Yu Marshall Ambros Rachel Beauregard Steve Hoffmann
Problem Statement Cyanobacteria are capable of producing toxins and have been linked to human health concerns
Objectives • Study the behavior of cyanotoxins in the environment and the human body • Thoroughly investigate cyanotoxin's effects on human health in the Lake Champlain Basin. • Determine precautionary measures to prevent the toxins from further impacting human life and the environment.
Cyanobacteria History • They’ve been around for 2 billion years • Research on cyanobacteria toxicity began 19th century • Incidence of disease in 20th century caused by: • Population pressure • Global warming • Eutrophication of surface waters • Increased monitoring/awareness • Unknown factors? Charmichael 2001
Cyanotoxin Receptors DeMott 1991, EPA 2005 Humans Livestock Ducks Zooplankton (some indication) Fish? Shellfish?
Exposure • Eating contaminated food • Drinking contaminated water • Swimming or dermal exposure • Inhalation • ALS • Gastroenteritis, liver and kidney damage, death • Skin rashes • Irritation of eyes, nose, throat, skin, and respiratory tract
Cyanobacteria • Prokaryotic • Photosynthesizing • Important primary producer in aquatic ecosystems • Nuisance “blooms” in eutrophic environments • Some species produce toxins
Eutrophication • Phosphorus loading • Agricultural runoff • Stormwater runoff • Algae Blooms http://upload.wikimedia.org/wikipedia/commons/b/bb/DairyCattle.jpg http://www.belaireks.org/images/Planning%20_%20Zoning/Stormwater.jpg
Algae Blooms • Other Contributing Factors • Nitrogen concentrations • Water temperature • Light • Morphology of the impoundment • Effects on Ecosystem • Anoxia • Toxic Blooms
Toxic Cyanobacteria • 2,000 species: ~ 40 known to produce toxins • Anabaena spp. • Microcystis spp. • Planktothrix spp. • Nostoc spp. • Nodularia spumigena http://www.shigen.nig.ac.jp/algae/images/strainsimage/nies-0075.jpg www.igb-berlin.de/.../phycology/algae2.jpg www.icb.ufmg.br/big/lgar/img_t3.jpg http://www.soes.soton.ac.uk/staff/tt/nf/pics/nodusp6.jpg Microcystis aeruginosa Planktothrix rubescens Nodularia spumigena
Cyanotoxins Saxitoxin • Neurotoxins • Anatoxin-a • Anatoxin-as • Saxitoxin • β-Methylamino-L-alanine (BMAA) • Hepatotoxins • Microsystin-LR • Nodularin-R • Cytotoxins • Cylindrospermopsin • Gastrointestinal and dermatotoxins • Aplysiatoxin • Lyngbyatoxin a Anatoxin-as Anatoxin-a BMAA Microcystin LN Nodularin R Cylindrospermopsin • Aplysiatoxin
Neurotoxins • Anatoxin-a mimics acetylcholine • Anatoxin-as is structurally different from Anatoxin–a and is highly toxic • Saxitoxin is usually associated with red tides in marine ecosystems • Responsible for paralytic shelfish poisoning • Been detected in some freshwater species Anatoxin-a Acetylcholine
Hepatotoxins • Cyclic peptides • Cause liver damage • Long term exposure can lead to liver cancer
Past Cases • First known linked case found in Guam • Caruaru, Brazil, Summer 1996 • Dialysis center used water contaminated with microcystins • 23 patients died in first 2 weeks, 37 more within 5 weeks
Funari E, Testai E. Toxigenic cyanobacteria from marine, brackish and freshwaters. Chart. Critical Reviews in Toxicology, Feb2008; 38(2):98 Available from: Academic Search Premier, Ipswich, MA. Accessed March 20, 2010.
Funari E, Testai E. Toxigenic cyanobacteria from marine, brackish and freshwaters. Chart. Critical Reviews in Toxicology, Feb2008; 38(2): 101 Available from: Academic Search Premier, Ipswich, MA. Accessed March 20, 2010.
BMAAneurotoxin • Caused by over 30 species of cyanobacteria: • Ex. Microcystis, Anabaena, Nostoc, Planktothrix • Can cause motor neuron disease or death • Accumulates in brain tissue • Found in Guam and linked to ALS
Amyotrophic Lateral Sclerosis(ALS) • Neurodegenerative disease • About 2 per 100,000 people in US • Can be caused by the neurotoxin BMAA • Symptoms • Muscle weakness (including speech muscles) • Twitching and cramping of muscles • Trouble with speech • Shortness of breath, trouble swallowing • Death by suffocation
Parkinson’s Disease(PD) • Neurodegenerative Disease • Symptoms • Rigidity of muscles, slowing of movement • Muscle spasms or tremors • Loss of smell, blinking, smiling • Speech changes (soft, monotone, repetition) • Dementia in later stages
Alzheimer’s • 7th leading cause of death • Most common form of dementia • Destroys brain cells leading to memory loss, confusion, changes in personality, mood, behavior, problems with language
Primary Liver Cancer (PLC) • Most common form of liver cancer • About 90% of liver cancer patients have this form • Low 5-year survival rate • 1.6 million people are diagnosed every year
Water Treatment Techniques • Burlington water intake is located in deep water, forty feet below the surface. Cyanotoxins and cells accumulate in shallows and near water surface. • Must use several methods in conjunction to eliminate both cells and toxins • Coagulation/flocculation/sedimentation are good first steps, followed by: • filtration with membrane, sand or activated charcoal • Final treatment with UV light or ozone
Still Unknown • Why certain species of cyanobacteria produce toxins only sometimes • If chronic diseases are actually caused by cyanotoxins • What causes algal blooms • What factors besides shallow, stagnant water and phosphorus loading • How to effectively remove cyanotoxins from water
Exposure in Lake Champlain • Algal blooms in St. Albans Bay and Mississquoi Bay – not all toxic • Drinking water- only during major blooms • Ingestion or dermal contact • Swimming- dermal contact • Can lead to acute or chronic diseases, none reported thus far • Dog deaths from swimming • Only problem in summer
Algae via Remote Sensing • Can detect different types of blooms using aerial imagery • Each bloom has a different color • Color change from Southern to Northern lake due to blooms in the summer • Apparent on Google Maps
Lake Champlain’s Algae Problem • Not sure what causes toxicity • Algae blooms are caused by: • P/Nutrient/N cycles thrown off • Lack of/not enough BMP’s in place • Missisquoi Bridge • Turtle Habitat • Urban/Residential runoff • Transportation
Wetlands • Many wetlands have reached their holding capacities for nutrients • LCBP wetland preservation • Nutrients released when wetlands are destroyed • Could construct more in key areas, but it would only be a temporary fix
The Three Aspects • Prevention • Increase public and government awareness • Continuation of research and monitoring
Prevention To prevent cyanobacterial blooms To prevent human exposure to cyanotoxins
Cyanobacterial Bloom Prevention Prioritization Riparian Buffers Constructed Wetlands
Human Exposure Prevention Water treatment methods and technology Coagulation/Flocculation/filtration + UV light treatment Provisional guidelines (World Health Organization)
Public Awareness • Get Connected Clean Water Action • Be Informed • Demand Actions
Monitoring Areas with repetitive cyanobacterial blooms Areas with cyanotoxin exposure reports
Research • The behaviors and mechanisms of the cyanobacteria and toxins in both water and the human body. • To develop effective water treatment
Resources: DeMott, W.R. et al. (1991) Effects of Toxic Cyanobacteria and Purified Toxins on the Survival and Feeding of a Copepod and Three Species of Daphnia. Carmichael Limnology and Oceanography, 36, 7, 1346-1357. “International Symposium on Cyanobacterial Harmful Algal Blooms”. 2005 U.S. Environmental Protection Agency <http://www.epa.gov/cyano_habs_symposium/> Carmichael, WW. (2001) Health Effects of Toxin-Producing Cyanobacteria: “The CyanoHABs”. Human and Ecological Risk Assessment, 7, 5, 1393-1407. Parkinsons.org Alsa.org Alz.org LCBP.org