Algae Blooms: A public health perspective

Algal Blooms: A public health perspective

Muskoka Stewardship Conference May 2017 Karen Kivilahti Program Coordinator, Safe Water

Overview • • • •

Health effects and exposure pathways Precautions Public health role Challenges

Blue-Green Algae (BGA) • • •

30%-50% of blooms produce cyanotoxins Assume toxins are present Do not use water for infant formula

BGA Toxins

Cyanobacteria (BGA) Cell rupture Cyanotoxins

Hepatotoxins (e.g. Microcystins) Most Common

Neurotoxins (e.g. Anatoxins)

Dermatoxins (e.g. Aplsiatoxins)

Routes of Exposure Inhalation

Direct body contact

Ingestion

Potential Health Effects Human health risks depend on the type and concentration of the toxin as well as the route and duration of exposure.

Cyanotoxin Hepatotoxins

Symptoms Vomiting, diarrhea, fever, abdominal cramps and potential liver damage

Neurotoxins

Muscle weakness, paralysis and breathing problems

Dermatoxins

Itchy, irritated skin and eyes

Exposure Pathways at the House/Cottage

Ingestion Ingestion

Ingestion/Inhalation/Skin

Inhalation Skin

Exposure Pathways at the Lake

Ingestion/Inhalation Ingestion/Inhalation/Skin

Ingestion/Inhalation/Skin Ingestion/Skin

Inhalation/Skin

Precautions to Take • Avoid using the water for drinking, preparing infant formula, food/drink, brushing teeth, bathing/showering

• Do not swim where a bloom is visible • Do not allow pets to drink or swim • Avoid watering your lawn or gardens with surface water • Avoid eating fish caught from the lake

Surface Water & Drinking Water Systems Municipal Systems

Small and Private Systems

• Monitor based on observations

• Monitor based on observations • Residential treatment systems may

and testing

• Effective and complex treatment • Monitoring finished water quality • Low risk

not be reliable

• Boiling water can increase toxin concentrations

• Increased risk

Public Health • Issues drinking water and swimming advisories • Identifies potential risks associated with recreational use • Determines potential risks for small drinking water systems • Communicates health-related issues and public notices • Monitors laboratory test results • Rescinds and updates advisories and public notices

Phased Approach

• Surveillance • Visual assessment • Screening/testing conducted by MOECC • Ongoing until terminated

• Intervention • Public notification (e.g. swim advisory, social media, door-to-door)

• Termination • Based on both visual observations and laboratory testing

Surveillance 1.Visual assessment and rapid field test 2.Public notification, if required 3.Algal identification 4.Screen for total microcystin 5.Confirm microcystin-LR (+ other toxins) Abraxis for Recreational Water,

Visual Assessment

• Acting on visual signs is more protective than relying on testing alone

• Visual signs of a bloom may include: • Presence of a scum or mat (e.g. spilled paint) • Reduced water transparency; and/or • Water may appear green or bluish-green

Intervention Door-to-door notification

Risk Communication

• Critical during and after an event • Effective communication of precautions that limit exposure • Challenges: • How to best notify the public and affected residents • Is it a known problem or is it new to the lake • The number of rental versus permanent residents • Toxin levels and the location of the bloom may vary • Toxins have been detected even when bloom is not visible

Acknowledgements • Health Canada • Ministry of the Environment and Climate Change • Ministry of Health and Long-Term Care • World Health Organization • United States Environmental Protection Agency • Sudbury and District Health Unit • Halton Region • Connecticut Department of Public Health and Fuss O’Neill

Contact Information Karen Kivilahti Program Coordinator – Safe Water 705-721-7520 Karen.Kivilahti@smdhu.org