11/1/2017 Overview PMRA Environmental Risk Assessments at the - PDF document

11/1/2017 Overview • PMRA Environmental Risk Assessments at the • Environmental Assessments Pest Management Regulatory Agency – Problem Formulation – Exposure Presented at uOttawa – Toxicity November 9 2017 – Risk – Mitigation Mélanie Whiteside • Questions Environmental Assessment Directorate Pest Management Regulatory Agency Health Canada 2 PMRA | Who are we? PMRA | What do we do? • Part of Health Canada • Register new pesticides and new uses – Science-based evaluations, based on information provided by the applicant • Employs over 350 scientists of various backgrounds (hundreds of studies are required for agricultural uses!) – biologists, chemists, toxicologists, epidemiologists, plant pathologists, weed scientists, entomologists, soil specialists, etc. • Monitor the use of registered pesticides – Verify that uses are compliant, and take appropriate action in situations of • Responsible for regulating pesticide use in Canada, under the authority of non-compliance the Pest Control Products Act (PCPA) – Receive and review incident reports The mandate of the PMRA is to protect human health and the • Re-evaluate registered pesticides to ensure they continue to meet current environment by minimizing risks associated with pesticides, scientific standards while enabling access to effective products in a context of – 15-year cycle sustainable pest management. – Considers recent assessment methods and all relevant information made available since the initial registration 3 4 PMRA | What is considered? Environmental Assessments | General Framework A pesticide is registered when it is found to have value and its use does not pose unacceptable risks to the health of Problem formulation Canadians or to the environment. Human Health Exposure Toxicity Health of workers, Value Environment consumers and residents Efficacy, social and Fate in the environment, economic benefits, effects on plants and Risk characterization sustainability animals Risk mitigation options Risk Management / Décision 5 6 1

11/1/2017 Environmental Assessments | Problem Formulation Environmental Assessments | Problem Formulation During this phase of the assessment: The problem formulation defines the scope of the evaluation • Understand the use • in which environmental – type of pesticide (herbicide, insecticide, fungicide, etc.) compartments the pesticide can be – site of application (agriculture, forest, aquatic, industrial, residential, found after its application materials, structures, buildings, pools, etc.) • which non-target organisms could – application method (foliar spray, soil spray, soil incorporation, soil injection, be affected 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 7 8 Environmental Assessments | Exposure Environmental Assessments | Exposure Pesticide properties The potential for exposure is a • solubility, vapour pressure, routes of transformation, etc. key concept which depends on several parameters, including Use pattern • the properties of the pesticide • the site of application • how the pesticide is used – 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 9 10 Environmental Assessments | Exposure Environmental Assessments | Exposure • Non-target terrestrial organisms Terrestrial environment: can then be exposed to the • A pesticide can enter the pesticide terrestrial environment following – earthworms in the treated field – a direct application to soil or – bees coming in contact with foliage spray droplets during application or consuming pollen and nectar – deposition of spray drift on containing the pesticide terrestrial habitats adjacent to the treatment area – birds and small mammals feeding on plants (foliage, seed, – leaching from treated material fruit) or invertebrates containing (such as treated seeds or treated wood) into the the pesticide surrounding soil – non-target plants that serve as habitat (such as hedgerows and shelterbelts) 11 12 2

11/1/2017 Environmental Assessments | Exposure Environmental Assessments | Exposure • Non-target aquatic organisms Aquatic environment: can then be exposed to the • A pesticide can enter the pesticide aquatic environment following – fish, aquatic invertebrates, – deposition of spray drift from a algae and aquatic plants terrestrial application – in the water column or in – runoff from the field sediments – 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 14 Environmental Assessments | Exposure Environmental Assessments | Exposure Information most commonly used to characterise environmental fate: Atmospheric environment: • Physicochemical properties • The presence of a pesticide in air is primarily based on its inherent • Laboratory studies of transformation physical and chemical properties • Laboratory studies of mobility • The atmospheric environment • Field dissipation studies 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 16 Environmental Assessments | Exposure Environmental Assessments | Exposure Physicochemical properties Laboratory studies of transformation • Can be indicative of certain aspects of the fate and behaviour of the • Provide information on the probable routes of dissipation in the pesticide in the environment environment, the rates of transformation (t ½ , DT 50 ) and transformation products • Aid in the interpretation of laboratory studies • Requested data: • Requested data: 17 18 3

11/1/2017 Environmental Assessments | Exposure Environmental Assessments | Exposure Laboratory studies of mobility Field dissipation studies • Provide information on the potential for a pesticide to migrate away from • Provide a better understanding of the persistence and movement of the the site of application into other environmental compartments pesticide under more realistic conditions • Requested data: • 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 19 20 Environmental Assessments | Exposure Environmental Assessments | Exposure Leaching potential Summary • The potential for leaching of a pesticide increases when long-range transport – soluble in water – low volatility volatilisation – low adsorption to soil organic matter drift – transforms slowly (long half-life) • Leaching can be observed in field studies (dissipation studies, lysimeter studies or prospective groundwater studies) phototransformation hydrolysis • Concentrations of the pesticide in groundwater can be estimated with biotransformation run-off adsorption-desorption predictive models leaching to groundwater hydrolysis • Leaching can also be confirmed using monitoring data (sampling of phototransformation biotransformation groundwater) adsorption-desorption 21 22 Environmental Assessments | Toxicity Environmental Assessments | Toxicity Terrestrial invertebrates 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 24 4