PMRA’s response to SAC-PCP feedback on the National Water Monitoring Program for Pesticides

This page describes the Committee's feedback on the National Water Monitoring Program for Pesticides (NWMPP) and the PMRA's response.

Context

One of the objectives of the June 23, 2023 SAC-PCP meeting, which occurred virtually over Zoom, was to present and solicit SAC-PCP members' perspectives on the PMRA's National Water Monitoring Program for pesticides.

Meeting summary

The meeting summary from the June 23, 2023 SAC-PCP meeting can be found here: Science Advisory Committee on Pest Control Products: Meeting summary June 23, 2023 - Canada.ca.

Purpose

The presentation provided an overview of the PMRA's National Water Monitoring Program for pesticides and covered numerous topics on the subject, which included:

Goals of a national-scale water monitoring program;
Framework development;
Priority pesticides for water monitoring;
Sampling site selection;
Water monitoring pilot program; and,
Demonstration of the PMRA's new public dashboard for water monitoring results.

Summary of SAC-PCP feedback and the PMRA's response

Concentration of pesticides in water can change rapidly during and after a rainstorm. Could information on precipitation before/during the time of sampling be available in the water monitoring dashboard?

PMRA's response:

The weather conditions at the site around the time of samples are not linked to the PMRA's water monitoring dashboard. However, users can use the sampling dates and locations to obtain the historical weather data.
Non-target analysis (NTA) would allow the PMRA to perform retrospective analyses of the data collected. Will the framework consider this type of analysis?

PMRA's response:

Non-target analysis is mentioned as an analysis method for consideration by water monitoring programs; however, it is not described in great length.
One member expressed a concern about how the PMRA selected sites for the first year of the program. A concern was raised that the wetlands selected in Saskatchewan did not have crops around them in Saskatchewan, which may have resulted in the data looking better than if crops were located close to the wetlands. It would be useful for the PMRA to add a disclaimer to the water monitoring dashboard that explains that site selection for the pilot project did not follow the method as outlined in the framework.

PMRA's response:

PMRA was transparent on how the sites were selected for the pilot program and text is available on our webpages for the pilot program as well as the dashboard. To establish the pilot program in a short timeframe, we needed to rely fully on the experience and expertise of our sampling partners in the regions. We asked sampling partners to target agriculture regions and consider current or historical sampling locations especially those with previous pesticide detections. Due to resource constraints, some sites were selected closer to the sampling partners' offices.

Most of the Saskatchewan wetland sites selected in year 1 of the pilot program were located adjacent to or within agricultural fields. The factor that resulted in the data looking better than expected was the frequency of sampling more than the location of the sites. Due to some startup issues, sampling in these wetlands did not commence until July, which resulted in missing the critical time when pesticides may enter these wetlands. Limited sampling (one or two visits) was conducted in these wetlands before sampling was paused.

In Year 2, the sites for wetlands sampled in Saskatchewan changed. ECCC worked collaboratively with landowners and PMRA to select new wetland sites, which are located within or adjacent to agricultural fields. Sampling started in mid-May with samples collected weekly at six sites and twice monthly at five sites.
Following a discussion on prioritizing pesticides for consideration in monitoring programs, it was pointed out that some of the parameters within the ranking system discussed are positively or negatively correlated. It was suggested that if both parameters are used, it may remove some chemicals from the priority list. An example was given using Kow and Koc.

PMRA's response:

There are five primary fate endpoints that determine the potential for pesticide exposure in aquatic environments. These include the bioconcentration factor (BCF) or octanol-water partition coefficient (Kow), water solubility (mg/L), organic carbon partition coefficient (Koc), and half-life in soil (t1/2 or DT50). These commonly measured parameters can be used in fate ranking and scoring systems to help determine the potential for a pesticide to leave the soil compartment and enter water:
- Aerobic soil half-life as an estimate of persistence in the environment
- Bioconcentration factor (BCF) or octanol-water partition coefficient (Kow) as an estimate of the potential to be taken up by organisms
- Soil sorption coefficient (organic partition coefficient - Koc) as an estimate of the potential for a pesticide to leave the sites of application and move to surface or groundwater
- Water solubility as an estimate of the ability of a chemical to be transported by runoff
Although Koc and Kow generally have a predictable correlation, for certain compounds (e.g., ionogenic organic compounds) the same relationship between fate variables may not hold true (e.g., chemicals may partition to clay in the soil instead of organic carbon)^{Footnote 1}. Weighting water solubility, BCF or logKow, and Koc individually accounts for varying properties of pesticides with regards to leaching, bioavailability and bioaccumulation potential.
It was pointed out that the distance from the sampling site is important to consider as it is related to the concentration and therefore, the risk.

PMRA's response:

PMRA recognises that the distance between the application site and the sampling location can affect the concentration detected. This aspect is considered when evaluating environmental monitoring data. An important note is that agriculture / forestry and urban runoff is a non-point source input to the environment. For most water monitoring programs, the distance from the closest edge of field to the sampling location can be determined; however, pesticide use information for a particular field is often unknown. In addition, concentrations detected at a particular location is influenced by pesticide application upstream in the watershed. Therefore, it is difficult to determine if the concentration detected resulted from application to a particular field.
A SAC-PCP member suggested that there may be additional organizations in Alberta that may be interested in participating in the sampling process.

PMRA's response:

PMRA requested a list of these organizations, which has since been provided by the SAC-PCP member.
SAC-PCP suggested that it is important to establish a hypothesis-driven research program from the beginning. A clear vision will ensure the Water Monitoring Program well defines their experimental designs, variables, limits of the program, sample size, sample variability, etc. These need to be carefully considered prior to initiating such a large national endeavor.

PMRA's response:

It is important to note that the PMRA's pesticide water program is not a research program but rather a regulatory monitoring / surveillance program. Monitoring and surveillance programs do not typically have hypotheses.

To establish a strong monitoring program it is important to understand the goals and expected outcomes so that the program can be designed accordingly. PMRA has thoroughly engaged with the technical working group (TWG) to establish and answer these questions. The main goal of a long-term pesticide monitoring program is to generate high-quality data on concentrations of pesticides (and transformation products) in water across Canada to inform and strengthen pesticide risk assessments and regulatory decision making. The framework for pesticide monitoring programs outlines the goals to ensure the data will be usable for within the regulatory context.
SAC-PCP wanted to confirm that the detection limits for the pesticides are available as these are essential for interpretation of the data. There was also a request that they are listed on the water monitoring dashboard.

PMRA's response:

Both the method and sample detection limits are available on the Government of Canada Open Data portal for each sample result in the main data file: 'Water-Qual-Eau_PMRA-ARLA.csv'
With respect to scoring of pesticides for consideration in water monitoring programs, clarification is needed on how the scores were weighted. SAC-PCP advised that PMRA may need to explain why some pesticides are not being analyzed. It was also questioned if there is a mechanism to add pesticides to a priority list based on other concerns, such as public concern.

PMRA's response:

For the purpose of the tool developed to prioritize pesticides for consideration in water monitoring programs, it was decided to use a simple approach that would weigh the environmental fate and toxicity data equally and higher than use data as represented by the area of application, which is given half the weight of the other parameters. This is consistent with the CCME Water Quality Protocol for the Protection of Aquatic Life (CCME, 1991), which places the highest priority on the fate and toxicity parameters for guideline development.

When developing the scoring system for the ranking tool, the PMRA included data on both acute and chronic data for fish and invertebrates and a single most sensitive endpoint for the vascular plants and algae. Acute and chronic toxicology data are weighted equally to generate a total ecotoxicity score for each organism group.

PMRA recognizes that there will be a need to address why particular pesticides are not presented in a priority list. There may be various reasons why a monitoring program may want to add pesticides not identified as priority to an analytical list, and these will be explored.
SAC-PCP recognized the additional expense to analyze glyphosate as it requires a different analytical method. The cost to analyze glyphosate would be the same as a large suite of pesticides in a multi-residue LC method. SAC-PCP suggested that glyphosate-specific analysis in a subset of samples (e.g., 1 in 10 samples) would be sufficient. This would help ensure the public does not think that the PMRA did not include it or is concealing results.

PMRA's response:

PMRA appreciates SAC-PCPs validation on this point and this suggestion will be considered during the development and implementation of the long-term program.
SAC-PCP asked for clarification on data format.

PMRA's response:

The data is available on the Government of Canada Open Data portal in CSV format.
SAC-PCP requested clarification on how the new water monitoring data will be used in PMRA's Environmental Risk Assessments. Clarification was requested on why it is now an issue and what was done before.

PMRA's response:

For many years, the PMRA has routinely considered water monitoring data in pesticide risk assessments for human health and the environment, when relevant data are available. Historically, water monitoring data were typically not sufficiently robust for pesticide regulatory decision–making. However, these data were valuable and gave indications of areas for further investigation and evaluation.

For each risk assessment, the PMRA determines an estimated environmental concentration (EEC) as an estimate of human health and environmental exposure. These values are generated using computer modelling, which can include conservative assumptions. There is a desire for the PMRA to use pesticide concentrations detected in the environment under real-use conditions to inform risk management decisions, when appropriate.

Data generated through a long-term pesticide monitoring program will be considered along with all other data available for an active ingredient to further characterize (when needed) the exposure of aquatic organisms and humans to pesticides. The data from this program will be assessed and evaluated in the same way as all other available data to determine if it is relevant and robust for a particular assessment.

In addition, these data can assist the PMRA in the prioritization of pesticide re-evaluations and identify areas where further investigation is required.
SAC-PCP questioned: Why is this a Health Canada effort when environmental water monitoring responsibility is split among other federal Ministries such as ECCC and the provincial & territorial jurisdictions? Are we doubling our research efforts instead of complementing each other? It was identified that pairing data on pesticides and other water contaminants and variables would strengthen the outcome.

PMRA's response:

Over the past 20 years, the PMRA has been working with federal partners, provinces and territories to ensure that Canadian pesticide water monitoring data available is considered in pesticide regulatory decisions. This was typically achieved by requesting water monitoring data from FPT partners at the initiation of re-evaluations.

The goal of establishing a long-term collaborative national-scale water monitoring program for pesticides is not to replace existing programs, but rather to supplement and improve the robustness of Canadian pesticide water monitoring data.

The results of PMRA's survey of FPT partners indicated that many provincial and territorial governments do not have the capacity to frequently collect water samples to monitor for current-use pesticides in their water monitoring programs due to funding limitations.

Thus, the national-scale water monitoring program developed and led by Health Canada in collaboration with federal and provincial partners will complement existing programs and enhance the availability of relevant data for pesticide risk assessment and management.
The SAC-PCP requested clarification on how the Water Monitoring Program deals with pesticide mixtures. In addition, how other contaminants and important water variables will be included in the PMRA database. If one of the objectives of the Water Monitoring Program is generating data to help assess pesticide ecosystem risk, why silo-ing pesticides?

PMRA's response:

PMRA's mandate is to ensure that the pesticides used in Canada are efficacious and that risks to human health and the environment are acceptable.

PMRA recognizes that there are other important contaminants of concern; however, these fall outside the PMRA's mandate and may be covered or assessed by provincial / territorial governments or other federal departments.

Current internationally accepted methodologies for registering a pesticide for use consider individual pesticides. Given that, for this national-scale program, a large suite of pesticides is analyzed in each sample, multiple pesticides will be detected, which can support both individual pesticide risk assessments and assessment of cumulative risk from pesticide mixtures.

The PMRA has published a Science Policy Note (SPN2018-02) outlining its framework for assessing the cumulative human health effects of pesticides that have a common mechanism of toxicity. However, methodology for assessing cumulative environmental effects has not been established within the international pesticide regulatory community.

The consideration of multiple stressors in the environment in a risk assessment is beyond the mandate of the PMRA.
Clarification was sought on the types of water that is analyzed under this program.

PMRA's response:

For the pilot program, the water that is being sampled is primarily inland surface freshwater in agricultural landscapes. In addition, we have collected some groundwater samples from wells, and supply water for drinking water from treatment plants. A future long-term program will continue to examine these types of waters but also consider additional locations such as those in urban and forestry environments.
The SAC-PCP recognized HC's willingness to work toward the Target 7 of the COP's Biodiversity Framework for pesticide risk reduction. Clarification was requested on how the water monitoring program will help to reduce pesticide risk for the Target 7.

PMRA's response:

Health Canada is exploring how these data could contribute to meeting Target 7 goals. Prior to signing the Kunming-Montreal Global Biodiversity Framework (GBF), Canada did not have a comprehensive, baseline dataset on pesticide concentrations in water or other media. The PMRA's water monitoring program was conceptualized and the pilot program was started before the GBF Target 7 was developed and therefore was not designed with GBF Target 7 in mind. However, the long-term water monitoring program could support Canada's efforts towards GBF Target 7 by enhancing the availability of real-world data on concentrations of pesticides in Canada's waters. These data will support an understanding of overall risk from pesticides, identify any change in pesticide risks and inform next steps for protecting biodiversity in line with Target 7 and the GBF. Over time, there may be a need for adjustments in the water monitoring program to align with Canada's efforts to achieve GBF objectives, which may include additional sampling in targeted areas.
The SAC-PCP understood that given the title of the program, the main environmental media sampled would be water. However, given that lipophilic pesticides tend to concentrate in organisms and sediment, more environmental media could be considered.

PMRA's response:

Given the PMRA's regulatory needs, concentrations of pesticides in water are the main focus. It is true that lipophilic pesticides tend to concentrate in living organisms and in sediment; however, current pesticide risk assessment protocols do not examine concentrations in organisms and sediment. As risk assessment methodologies evolve, the levels of pesticides in organisms and sediments may become of interest to the PMRA.
The SAC-PCP asked if all 245 pesticides will be analyzed in all samples or will the list be variable based on province and sampling site given that not all pesticides are sold or and used across the country? It was pointed out that "non-detect" in areas where pesticides are not used could bias the public eye and would be a loss of public money to carry out unnecessary expensive chemical analyses.

PMRA's response:

Currently 190 current-use pesticides are analyzed in all water samples collected as part of the PMRA's program. One hundred and eighty-seven (187) chemicals (185 pesticides and 2 transformation products) are being analyzed by the Health Canada laboratory and the remainder are being analyzed by the University of Guelph laboratory. As the program evolves, the pesticides analyzed will be refined based on new or discontinued registrations.

The method used is multi-residue; therefore, it is the same cost to receive the information on one pesticide versus the entire list. Thus, there should not be a perceived "loss of money". In fact, it would be considerably more expensive to develop separate methods for different regions depending on the products used in that area.

The PMRA recognizes the challenge with non-detects in areas where pesticides are not used. In these cases, careful consideration of the regional use of pesticides is important for data interpretation.
How will the Water Monitoring Program tackle data acquisition to address the Cumulative Effects calculations newly established by Bill S5? Should water samples be sent to labs for specific cell line analyses (e.g., endocrine disrupting activities, AhR activation, etc.)?

PMRA's response:

CEPA and the Pest Control Products Act (PCPA) are complementary pieces of legislation that contribute to federal management of toxic substances to protect human health and the environment. The PCPA already requires the assessment of cumulative human health effects of pest control products with a common mechanism of toxicity. In addition, PMRA has consulted on a proposed amendment to the Pest Control Products Regulations to require the Minister to consider the cumulative environmental effects of pesticides that have a common mechanism of toxicity, where information and methodology are available. The amendment would also give the Minister explicit authority to require registrants and applicants to submit available information on cumulative environmental effects, for consideration in the PMRA's environmental risk assessments.

Currently, the water program does lend itself to data acquisition for cumulative effects assessment through the use of the multi-residue analytical process (i.e., the occurrence of multiple pesticides within a single sample is accounted for).

Specific cell line analyses are currently outside the scope and mandate of the water monitoring program.
SAC-PCP requested clarification on the ideal frequency of sampling while understanding seasonal differences. Typically, pesticides are applied in Spring and Summer; however, some pesticides can be used in the fall to protect or to dry a crop. In the winter, as water levels are reduced, pesticide concentrations can increase, and high concentrations of pesticides can be detected at snow melt.

PMRA's response:

The ideal frequency of sampling as it relates to seasonal differences is discussed in the draft framework. To ensure the data collected can be used in pesticide risk assessments, it is important to ensure the frequency and timing of sampling is appropriate for the type of risk to be assessed. Pesticide risk assessments generally consider both acute and chronic risk, therefore, more frequent sampling during pesticide use periods is more likely to capture peak concentrations and provide the temporal information required.

It is also acknowledged that important information can be gained from spatial rather than temporal frequency in a dataset. More sites across the area can provide a spatial picture of the pesticide concentrations. However, the data generated under a lower frequency sampling program at more sites may not be reliable for pesticide regulatory decisions.

There are various other considerations when establishing a sampling program, including meteorological events that can contribute to runoff events and cause pesticide movement to nearby watercourses. In addition, pesticide application timing can influence the likelihood of detecting a specific pesticide in a waterbody. The collection of samples during post-harvest and pre-seeding periods could inform pesticide persistence. Seasonality and changes in weather can influence the schedule of sample collection. As an example, pesticides that are not detected in the summer can be found in the winter. Therefore, some component of winter monitoring may be of interest, as feasible.

Different types of water bodies and sampling methods may require different sampling frequencies.
- Streams: Through the examination of years of data collected and analyzed for risk assessments, it has been demonstrated that collecting grab samples two to three times per week in flowing surface water during high pesticide movement periods is most likely to generate data suitable for risk assessment while meeting other provincial/territorial and community program objectives.
- Lakes: Less frequent monitoring may be required in some lakes, especially those with long residence times (i.e., the period of time a single parcel of water remains in a given waterbody). For very large lakes, such as the Laurentian Great Lakes, annual or less frequent monitoring at offshore stations can be used to track long-term (e.g., decadal scale) changes that cannot be detected at other locations due to higher variability. Timing of lake monitoring will need to take into account the timing of pesticide use in the surrounding watersheds, the time needed for waters to reach the lake, and the potential for dilution in the lake.
- Wetlands: Generally, sampling in wetlands once per week may be acceptable for risk-assessment purposes. However, an increased sampling frequency is recommended following times of pesticide application or during runoff events to capture peak concentrations. Conversely, sampling frequency may be reduced during extended dry periods.
- Groundwater: Groundwater monitoring programs tend to collect samples for chemical analyses less frequently compared to surface water programs due to the less transient nature of these systems. For shallow monitoring wells that are installed to monitor a potential pollution source (monitoring wells), quarterly sampling may be sufficient, though twice monthly frequency may be preferred. As for domestic wells with less frequent pumping rates, they could be sampled once or twice per year.
Who is paying for the Water Monitoring Program? What internal funding programs?

PMRA's response:

To further strengthen the transparency and sustainability of pesticide management in Canada, the Government of Canada announced on August 4, 2021 an investment of $50 million in the PMRA and Agriculture and Agri-Food Canada's pest management research, to be supported by Environment and Climate Change Canada from fiscal year 2021-22 to 2023-24. The work to develop the framework for a National-scale Water Monitoring Program for Pesticides, including the pilot water monitoring program, is being funded through this allocation.
What is your action plan when detected concentrations of pesticides exceed limits?

PMRA's response:

Exceedances signal that more analysis over time and at specific sites is required. Health Canada will continue to monitor exceedances over time to better understand the potential risk and to identify actions that may be needed to reduce any potential risks (e.g., initiation of a special review).
The SAC-PCP suggested that field apps that can capture pH, water & air temperature, rain, GPS, and other important field variables could help with systematic and consistent collection of these variables. Are such field apps being used at sample collection?

PMRA's response:

The PMRA agrees that the use of field apps connected to sampling devices, such as automated field probes and autosamplers are useful and can avoid human transcription errors. However, it is not possible to insist that all sampling partners use these apps. They may not have access to this technology as it is more expensive than non-automated field equipment. The framework discusses using these sorts of devices and apps, if possible, to reduce human transcription errors.

Many sampling partners are using automated field probes combined with other in field manual measurements to collect ancillary field data. The parameters collected using automated field probes, such as a YSI or HydroSondes, as well as similar data collected by non-automated systems, are available on the Government of Canada's Open Data portal for download.

Additional parameters, such as stream flow, crop type, general weather and field conditions, are also being collected at some locations, where possible. These additional parameters are not available in the public Open Data portal as this information is dependent on sampling partner resources and access to equipment; so, it is not standardized across the country at this time.
A member of SAC-PCP suggested that a sub-sample of water could be used to investigate biodiversity using environmental DNA which could contribute to the Biodiversity Framework.
PMRA's response:

This is an interesting research idea. ECCC is leading the National Biodiversity Strategy, which will be implemented in collaboration with provinces, territories and Indigenous representatives, with input from partners and stakeholders (Canada's 2030 National Biodiversity Strategy - Canada.ca). This type of research is currently outside the scope of the work the PMRA is undertaking for water monitoring. There are researchers in ECCC who are working in agricultural landscapes through the AAFC's Living Labs initiative and conducting this type of research on the biodiversity in aquatic habitats. In future years, the PMRA could look for linkages with ECCC to enhance knowledge of biodiversity in these landscapes.
SAC-PCP wanted to understand what type of metadata associated with the collected samples. It was stated that metadata is important for the interpretation and comparison of the pesticides' concentration data.

PMRA's response:

Indeed, metadata are very important for the contextualization of observed pesticide results. When this type of data is available for water monitoring datasets, it enhances their usefulness for pesticide risk assessments.

The framework for water monitoring programs for pesticides addresses this issue by providing guidance in terms of valuable information that could be collected, such as the following:
- The name of the waterbody and the location of the sampling site
- The type of water body as well as description such as size, stream order, or wetland class
- The GPS coordinates or masked information (for privacy considerations)
- General site observations or specific conditions at the time of sampling, and site photographs
- Environmental conditions, such as weather conditions (precipitation events, snowmelt), air temperature, water temperature, and streamflow (potentially the presence of nearby hydrometric stations)
- Runoff events
- Information on land use immediately adjacent to sampling sites; specific crops grown within the watershed
- Additional water quality data could also be collected (e.g., nutrients, conductivity, etc.).
Les concentrations correspondent-elles aux concentrations totales ou libres dans l'eau ? Les mesures de contaminants par 'grab sampling' ou par échantillonneurs passifs ne donnent pas exactement les mêmes informations non plus de ce point de vue.

PMRA's response:

The concentrations available on the dashboard and Government of Canada Open Data portal correspond to 'free' concentrations as samples are filtered prior to analysis.

In the program to date, all samples were collected by grab or ISCO autosampler. Passive samplers are a tool that is being explored; however, as you have correctly identified, the information provided by passive samplers is not the same as grab samplers. The PMRA needs to investigate this sampling method further to understand how results could be used in risk assessments or as a predictive tool for future targeted sampling.
A SAC-PCP member highlighted that the concepts of mixtures and cumulative risk assessment are not recognized as emerging priorities. Integrating the monitoring or pesticides with environmental contaminants that could have combined effects could be interesting. Is the system we're building flexible to transform to integrate more contaminants or data sources, and enable more complex statistical analysis?

PMRA's response:

The PMRA's pilot program was established to inform the development of a larger scale, national program. At the same time, PMRA has drafted, along with a large group of experts across the country, a framework to act as guidance for pesticide water monitoring programs across Canada. The goal of the framework is to ensure that data collected in pesticide water monitoring programs are comprehensive and consistent such that they can be used in risk assessments to inform pesticide risk management decisions.

Indeed, mixtures and cumulative environmental effects are known emerging priorities and multiple pesticides are currently detected in single samples in Canadian waters. A long-term program on pesticide monitoring can contribute to this picture. Confirming the presence of numerous pesticides at various sampling sites appears to be a first step in providing indications of their overall presence in some Canadian freshwaters. At this time, cumulative effects in environmental risk assessments are not considered due to lack of information and standard methodologies. PMRA is currently proposing changes to the Pest Control Products Regulations related to cumulative environmental effects, including an amendment that would require the Minister to consider the cumulative effects on the environment of pesticides that have a common mechanism of toxicity, where information and methodology are available. The international regulatory community is attempting to understand how cumulative environmental effects of pesticides can be considered within a regulatory paradigm that has been traditionally focussed on individual pesticides.

It should be noted that the cumulative exposure of pesticides with other contaminants is outside the mandate of the PMRA; however, we do believe that through the design of a long-term program there is flexibility to adjust to changing needs for the pesticide regulatory system.
A member of SAC-PCP asked for clarification related to the selection of priority pesticides so as to ensure pesticides that are short-lived in the environment are considered. In addition, the consideration of transformation products was also highlighted.

PMRA's response:

To clarify, all pesticides used outdoors in Canada are considered within the priority ranking tool, including those with short half-lives. The ranking tool scores and ranks the following parameters:
- Aerobic soil half-life as an estimate of persistence in soil
- Bioconcentration factor or octanol-water partition coefficient as an estimate of bioaccumulation
- Soil sorption coefficient as an estimate of mobility in soil
- Water solubility as an estimate of the ability of a chemical to move in run-off
- Ecotoxicity (both short-term and long-term toxicity) to aquatic organisms including fish, invertebrates, plants and algae
- National sales data of the pesticides, which provides an indication of the use of the pesticide in Canada.
If a particular pesticide has a short half-life but is highly toxic, highly mobile and used in large quantities in Canada, it is likely to be ranked higher than other pesticides.

This tool is designed to provide guidance for pesticide monitoring programs that wish to gather information and data that are relevant for the PMRA in its regulatory decision-making.

Ideally, if a pesticide is determined to be a priority, the transformation products identified in the pesticide's regulatory residue definitions for human health and environmental risk assessments should be analyzed. However, very few analytical methods exist for transformation products, and it can be cost-prohibitive to develop analytical methodologies to include all transformation products in a monitoring program. As such, it would be important to prioritize the addition of specific transformation products to ensure a balance between cost and risk assessment needs. Non-targeted analysis methods could perhaps prove useful as an initial scan of transformation products, and depending on the frequency of detection, targeted analyses of some of them could then be considered.

More information

For any inquiries, please reach out to the SAC-PCP Secretariat: pmra.sacpcp-ccspa.arla@hc-sc.gc.ca.

Footnotes

Footnote 1

Mackay, D., Shiu, W-Y., Ma, K-C. Illustrated Handbook of Physical-Chemical Properties and Environmental Fate for Organic Chemicals: Volume V – Pesticide Chemicals. Lewis Publishers. 1997.

Return to footnote 1 referrer

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Date modified:: 2024-04-23

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