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Blue Green algae: an overview Monique D’Amour Safe Environments Programme (Longueuil, Québec) and Michèle Giddings Water Quality & Microbiology Division (Ottawa, Ontario) Health Canada
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Federal-Provincial Roles and Responsibilities for Drinking Water Federal (Health Canada) 4 advice 4 research 4 risk assessment/management with provinces 4 drinking water quality on Federal lands Federal (Health Canada) 4 advice 4 research 4 risk assessment/management with provinces 4 drinking water quality on Federal lands Provincial/Territorial 4 provision of safe DW 4 source water protection 4 water treatment 4 monitoring & surveys 4 research Responsibilities divided among levels of government
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Federal-Provincial-Territorial Committee on Drinking Water ã Representatives from each province, territory, and the federal government 30+ year working collaboration30+ year working collaboration Meets twice yearlyMeets twice yearly ã Establishes the Guidelines for Canadian Drinking Water Quality ã Health Canada’s Water Quality and Health Bureau is the Technical Secretariat to the Committee ã Representatives from each province, territory, and the federal government 30+ year working collaboration30+ year working collaboration Meets twice yearlyMeets twice yearly ã Establishes the Guidelines for Canadian Drinking Water Quality ã Health Canada’s Water Quality and Health Bureau is the Technical Secretariat to the Committee
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Identification Assessment Assessment Evaluation Evaluation costscosts benefitsbenefits consultationconsultationIdentification Assessment Assessment Evaluation Evaluation costscosts benefitsbenefits consultationconsultation Drinking Water Guideline Development Process
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Cyanobactieria in Canada ã Identification of a problem ã Assessment was required ã Identification of a problem ã Assessment was required
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Cyanobacterial Toxins in Canada: The History, Part I ã 1990-1992-1993: M-LR identified in Alberta lakes, detected in Shoal Lake, Winnipeg’s drinking water source, and in the city’s distribution system ã Manitoba requests an ‘Emergency Health Advisory’ (EHA) from Health Canada in 1994 4 EHA of 0.5 µg/L derived for M-LR in DW 4 EHAs are developed for specific situations; they do not have the rigorous review/consultation of full guidelines ã 1990-1992-1993: M-LR identified in Alberta lakes, detected in Shoal Lake, Winnipeg’s drinking water source, and in the city’s distribution system ã Manitoba requests an ‘Emergency Health Advisory’ (EHA) from Health Canada in 1994 4 EHA of 0.5 µg/L derived for M-LR in DW 4 EHAs are developed for specific situations; they do not have the rigorous review/consultation of full guidelines
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Cyanobacterial Toxins in Canada: The History, Part II ã M-LR added to the priority list for evaluation 4 Canadian surveys to date indicate Microcystin-LR is the most common hepatotoxin present in water supplies ã M-LR added to the priority list for evaluation 4 Canadian surveys to date indicate Microcystin-LR is the most common hepatotoxin present in water supplies
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Blooms of Cyanobacteria in Canada ã Blooms occur in all provinces (Prairies, Québec etc) T end to occur repeatedly in same supply T end to occur repeatedly in same supply 4 small shallow, slow-moving bodies of water common to prairies generally affected ã Blooms occur in all provinces (Prairies, Québec etc) T end to occur repeatedly in same supply T end to occur repeatedly in same supply 4 small shallow, slow-moving bodies of water common to prairies generally affected
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BloomBloom
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Cyanobacteria: General Description ã Cyanobacteria (blue-green algea) ã May produce neurotoxins, hepatotoxins ã Skin irritants, other toxins ã Surface water supplies (Hepatotoxins/neurotoxins) ã Hepatotoxins more widespread ã Cyanobacteria (blue-green algea) ã May produce neurotoxins, hepatotoxins ã Skin irritants, other toxins ã Surface water supplies (Hepatotoxins/neurotoxins) ã Hepatotoxins more widespread
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Microcystin -LR Microcystin L-R: hepatotoxins Produced by Microcystis aeruginosa (an others blue-greens algal species) Monocyclic heptapeptides (L–amino acids; L=Leucine; R=arginine) Microcystin L-R: hepatotoxins Produced by Microcystis aeruginosa (an others blue-greens algal species) Monocyclic heptapeptides (L–amino acids; L=Leucine; R=arginine)
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Microcystin-LR Structure
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Sources of Human Exposure ã Consumption of drinking water ã Recreational use of lakes and rivers 4 oral, dermal ã Showers 4 inhalation, dermal ã Algal food tablets 4 oral ã Consumption of drinking water ã Recreational use of lakes and rivers 4 oral, dermal ã Showers 4 inhalation, dermal ã Algal food tablets 4 oral
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ã Animals Primarily hepatotoxin Kidney damageKidney damage Lung damageLung damage Tumour promotorTumour promotor ã Humans Stomach cramps, vomiting, diarrhea, fever, headache, painful muscles & jointsStomach cramps, vomiting, diarrhea, fever, headache, painful muscles & joints Acute gastroenteritisAcute gastroenteritis Liver damageLiver damage M-LR Effects on Animals & Humans
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ã Microcystin administered by gavage to mice at levels of 0, 40, 200 and 1000 µg/kg bw/day for 13 weeks 40 µg/kg bw : no definite effect 40 µg/kg bw : no definite effect 200 µg/kg bw : slight liver changes in some animals 200 µg/kg bw : slight liver changes in some animals 1000 µg/kg bw : liver changes in all animals ã No-Observed-Adverse-Effect Level (NOAEL) set at 40 µg/kg bw/day Critical Effects
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TDI = 0.040 mg/kg bw/day 1000 = 0.00004 mg/kg bw M-LR Guideline Derivation Where –x10 for intraspecies variation –x10 for interspecies variation –x10 for less than lifetime study MAC = 0.00004 mg/kg/day x 70 kg x 0.80 1.5 L/day = 0.0015 mg/L (1.5 µg/L)
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Factors Affecting Bloom Formation & Toxin Production / Persistence ã Bloom Formation Inorganic nutrientsInorganic nutrients Water temperatureWater temperature pH level: 6-9pH level: 6-9 DaylightDaylight TurbidityTurbidity TurbulenceTurbulence Water flowWater flow ã Toxin production Environmental factorsEnvironmental factors 4 Temperature, light, nitrogen levels, carbon dioxide and/or pH Genetic differencesGenetic differences Metabolic processesMetabolic processes ã Toxin release ã Persistence Stable in waterStable in water Resistance to pH extremesResistance to pH extremes Heat resistantHeat resistant
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ã Reservoir management 4 Nutrient deprivation practices ã Algal cell removal 4 Coagulation, clarification, filtration, disinfection 4 Must not damage cells ã Toxin removal 4 Oxidation (ozonation); other methods such as UV, chloramination & hydrogen peroxide not as effective 4 Activated carbon (wood-based products best) 4 Slow sand filtration-biodegradation Microcystins – Water Management
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Flow chart: Management Water supply
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To obtain information onDW http://www.hc-sc.gc.ca/hecs- sesc/water/index.htm Find more information To obtain the supporting document on M-LR http://www.hc-sc.gc.ca/hecs-sesc/water/ pdf/microcys.pdf
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Acknowledgements Acknowledgements Michèle Giddings for providing technical supports, advices and specific expertise on Microcystine L-R and Drinking Water Guidelines
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