11/1/2017 Environmental Risk Assessments at the Pest Management Regulatory Agency Presented at uOttawa November 9 2017 Mélanie Whiteside Environmental Assessment Directorate Pest Management Regulatory Agency Health Canada Overview • PMRA • Environmental Assessments – Problem Formulation – Exposure – Toxicity – Risk – Mitigation • Questions 2 PMRA | Who are we? • Part of Health Canada • Employs over 350 scientists of various backgrounds – biologists, chemists, toxicologists, epidemiologists, plant pathologists, weed scientists, entomologists, soil specialists, etc. • Responsible for regulating pesticide use in Canada, under the authority of the Pest Control Products Act (PCPA) The mandate of the PMRA is to protect human health and the environment by minimizing risks associated with pesticides, while enabling access to effective products in a context of sustainable pest management. 3 1
11/1/2017 PMRA | What do we do? • Register new pesticides and new uses – Science-based evaluations, based on information provided by the applicant (hundreds of studies are required for agricultural uses!) • Monitor the use of registered pesticides – Verify that uses are compliant, and take appropriate action in situations of non-compliance – Receive and review incident reports • Re-evaluate registered pesticides to ensure they continue to meet current scientific standards – 15-year cycle – Considers recent assessment methods and all relevant information made available since the initial registration 4 PMRA | What is considered? A pesticide is registered when it is found to have value and its use does not pose unacceptable risks to the health of Canadians or to the environment. Human Health Health of workers, Value Environment consumers and residents Efficacy, social and Fate in the environment, effects on plants and economic benefits, sustainability animals Risk Management / Décision 5 Environmental Assessments | General Framework Problem formulation Exposure Toxicity Risk characterization Risk mitigation options 6 2
11/1/2017 Environmental Assessments | Problem Formulation The problem formulation defines the scope of the evaluation • in which environmental compartments the pesticide can be found after its application • which non-target organisms could be affected 7 Environmental Assessments | Problem Formulation During this phase of the assessment: • Understand the use – type of pesticide (herbicide, insecticide, fungicide, etc.) – site of application (agriculture, forest, aquatic, industrial, residential, materials, structures, buildings, pools, etc.) – application method (foliar spray, soil spray, soil incorporation, soil injection, tree injection, seed treatment, bait, etc.) – application rate and number of applications per season • Scan of the submitted data – the number of studies and type of data that are provided depends on the potential for environmental exposure 8 Environmental Assessments | Exposure The potential for exposure is a key concept which depends on several parameters, including • the properties of the pesticide • how the pesticide is used 9 3
11/1/2017 Environmental Assessments | Exposure Pesticide properties • solubility, vapour pressure, routes of transformation, etc. Use pattern • the site of application – environmental exposure is expected when pesticides are used outdoors (varying exposure levels depending on the use) – environmental exposure is generally minimal for indoor uses, although possible in certain cases (e.g. greenhouse effluent) • the amount applied – for a given pesticide use, exposure increases when more is applied (high application rate, several seasonal applications) • the application method – spot treatment vs. broadcast – drift 10 Environmental Assessments | Exposure Terrestrial environment: • A pesticide can enter the terrestrial environment following – a direct application to soil or foliage – deposition of spray drift on terrestrial habitats adjacent to the treatment area – leaching from treated material (such as treated seeds or treated wood) into the surrounding soil 11 Environmental Assessments | Exposure • Non-target terrestrial organisms can then be exposed to the pesticide – earthworms in the treated field – bees coming in contact with spray droplets during application or consuming pollen and nectar containing the pesticide – birds and small mammals feeding on plants (foliage, seed, fruit) or invertebrates containing the pesticide – non-target plants that serve as habitat (such as hedgerows and shelterbelts) 12 4
11/1/2017 Environmental Assessments | Exposure Aquatic environment: • A pesticide can enter the aquatic environment following – deposition of spray drift from a terrestrial application – runoff from the field – application to a water body or its shoreline – discharge of effluent – leaching from treated material (such as treated seeds or treated wood) into the surrounding water 13 Environmental Assessments | Exposure • Non-target aquatic organisms can then be exposed to the pesticide – fish, aquatic invertebrates, algae and aquatic plants – in the water column or in sediments 14 Environmental Assessments | Exposure Atmospheric environment: • The presence of a pesticide in air is primarily based on its inherent physical and chemical properties • The atmospheric environment includes – air in the vicinity of the site of application – long-range atmospheric transport and subsequent deposition to areas away from the application site 15 5
11/1/2017 Environmental Assessments | Exposure Information most commonly used to characterise environmental fate: • Physicochemical properties • Laboratory studies of transformation • Laboratory studies of mobility • Field dissipation studies 16 Environmental Assessments | Exposure Physicochemical properties • Can be indicative of certain aspects of the fate and behaviour of the pesticide in the environment • Aid in the interpretation of laboratory studies • Requested data: 17 Environmental Assessments | Exposure Laboratory studies of transformation • Provide information on the probable routes of dissipation in the environment, the rates of transformation (t ½ , DT 50 ) and transformation products • Requested data: 18 6
11/1/2017 Environmental Assessments | Exposure Laboratory studies of mobility • Provide information on the potential for a pesticide to migrate away from the site of application into other environmental compartments • Requested data: 19 Environmental Assessments | Exposure Field dissipation studies • Provide a better understanding of the persistence and movement of the pesticide under more realistic conditions • Substantiate the information provided in the laboratory studies • In terrestrial or aquatic environments • Should be representative of Canadian conditions For example, for terrestrial studies, the studied site can be in Canada or in another country, as long as in a relevant ecological region 20 Environmental Assessments | Exposure Leaching potential • The potential for leaching of a pesticide increases when – soluble in water – low volatility – low adsorption to soil organic matter – transforms slowly (long half-life) • Leaching can be observed in field studies (dissipation studies, lysimeter studies or prospective groundwater studies) • Concentrations of the pesticide in groundwater can be estimated with predictive models • Leaching can also be confirmed using monitoring data (sampling of groundwater) 21 7
11/1/2017 Environmental Assessments | Exposure Summary long-range transport volatilisation drift phototransformation hydrolysis biotransformation run-off adsorption-desorption leaching to groundwater hydrolysis phototransformation biotransformation adsorption-desorption 22 Environmental Assessments | Toxicity The toxicity data that are considered in our risk assessments encompass several non-target species, either terrestrial or aquatic • dose-response studies • mostly lab, but sometimes field • short-term (acute) EC 50 , LC 50 , LD 50 , LR 50 • long-term (chronic) NOEC, NOEL EC 50 : concentration at which an adverse effect is observed for 50% of the test population LC 50 : concentration at which mortality is observed for 50% of the test population LD 50 : dose at which mortality is observed for 50% of the test population LR 50 : application rate at which mortality is observed for 50% of the test population NOEC: no-effect concentration NOEL: no-effect level 23 Environmental Assessments | Toxicity Terrestrial invertebrates 24 8
11/1/2017 Environmental Assessments | Toxicity Terrestrial vertebrates 25 Environmental Assessments | Toxicity Terrestrial vascular plants 26 Environmental Assessments | Toxicity Freshwater species 27 9
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