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Pesticides and Metals in Selected Foods - April 1, 2018 to March 31, 2019

Food chemistry - Targeted surveys – Final report

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Summary

Targeted surveys provide information on potential food hazards and enhance the Canadian Food Inspection Agency's (CFIA's) routine monitoring programs. These surveys provide evidence regarding the safety of the food supply, identify potential emerging hazards, and contribute new information and data to food categories where it may be limited or non-existent. They are often used by the Agency to focus surveillance on potential areas of higher risk. Surveys can also help to identify trends and provide information about how industry complies with Canadian regulations.

Grain, nut/seed and vegetable-based products are staple foods consumed in CanadaFootnote 1,Footnote 2. These are products of agricultural commodities and may contain pesticide residues introduced from the environment or if the crops were treated with pesticides in the field, during transport and/or during storage to prevent damage from insects, moulds or other pests. These products may also contain levels of metals from environmental sources. Though metals such as arsenic, cadmium, lead and mercury are not permitted to be added to foods, and manufacturers are responsible for measures aimed at reducing accidental introduction of these elements in foods (e.g., from lead solder in steel equipment), their presence is expected in foods, at very low levels, primarily as a result of their natural presence in the environment.

The main objectives of this targeted survey were to generate additional baseline surveillance data on the level of pesticide residues and metal levels in selected grain, nut/seed and vegetable-based foods available on the Canadian market and to compare the detection rates of pesticides in this targeted survey to those recorded in previous surveys.

A total of 3348 samples of grain, nut/seed and vegetable-based products were collected and tested for pesticides and metals. Residues of 5 different pesticides were detected in 1327 (40%) of the samples. The overall compliance rate for pesticides in products tested was 99.3%. Most of the non-compliant results (20 of 22) were associated with pesticide residues exceeding the general MRL of 0.1 ppm (mg/kg), while 2 non-compliant results contained pesticide residues in violation of a specific established MRL for flaxseed. Health Canada (HC) determined that the levels of pesticides observed in the current survey are not expected to pose a concern to human health, therefore there were no recalls resulting from this survey. The CFIA conducted appropriate follow up activities to improve compliance which included further testing of similar products in subsequent years.

Of the 3348 samples collected, 3153 were analysed for a suite of 20 metals. Only the data for metals of highest concern to human health at low levels of exposure are presented in this report, most notably: arsenic, cadmium, lead, and mercury. Lead and cadmium had the lowest and the highest overall detection rate, respectively. Potato products and ready-to-eat (RTE) meals were associated with the lowest detection rate and the lowest observed levels of the metals, while botanical powders were often found to contain the highest detected levels of these metals. There are no regulations in Canada for metal levels in the products tested. All data generated were forwarded to HC for human risk assessment and determined to pose no concern to human health.

What are targeted surveys

Targeted surveys are used by the CFIA to focus its surveillance activities on areas of highest health risk. The information gained from these surveys provides support for the allocation and prioritization of the Agency's activities to areas of greater concern. Originally started as a project under the Food Safety Action Plan (FSAP), targeted surveys have been embedded in our regular surveillance activities since 2013. Targeted surveys are a valuable tool for generating information on certain hazards in foods, identifying and characterizing new and emerging hazards, informing trend analysis, prompting and refining health risk assessments, highlighting potential contamination issues, as well as assessing and promoting compliance with Canadian regulations.

Food safety is a shared responsibility. We work with federal, provincial, territorial and municipal governments and provide regulatory oversight of the food industry to promote safe handling of foods throughout the food production chain. The food industry and retail sectors in Canada are responsible for the food they produce and sell, while individual consumers are responsible for the safe handling of the food they have in their possession.

Why did we conduct this survey

Chemical hazards in foods can come from a variety of sources. Pesticides may be present as contaminants in the environment or they may be deliberately used by farmers to protect food and crops from pests. Different pest pressures and climatic conditions in food export countries may result in the potential use of pesticides that are not approved for use in Canada, or result in pesticide residues in products that do not meet established Canadian maximum residue limits (MRLs) to be legally sold in CanadaFootnote 3. Inappropriate use of pesticides may pose a health risk to consumers, with the risk dependant on the type of pesticide, its concentration, the effects on the human body, and the length of exposure to the pesticide by the consumer.

Metals are naturally-occurring elements that may be present in very low amounts in rock, water, soil, or air. Therefore, finding these substances in food products is not unexpected as trace levels generally reflect normal accumulation from the environment. They may be present in finished foods due to their presence in the ingredients used to manufacture those foods, and/or may be unintentionally incorporated along the food production chain.

There are a number of metals that may be of concern to human health at certain levels of exposure. Most notably, arsenic, cadmium, lead, and mercury have been shown to have effects on human health, even at low levels of exposure. The results of only these metals of highest concern are presented in this report.

Grain, nut/seed and vegetable-based foods are products of agricultural commodities and may contain pesticide residues introduced from the environment or if the crops were treated with pesticides in the field, during transport and/or during storage to prevent damage from insects, moulds or other pests. The objective of this targeted survey was to obtain additional baseline data on the levels of pesticides, arsenic, cadmium, lead and mercury in these types of products available on the Canadian market, and to compare the detection rate of pesticides in foods with previous targeted surveys.

What did we sample

A variety of domestic and imported grain, nut/seed and vegetable-based foods available on the Canadian market were sampled between April 1, 2018 and March 21, 2019. Samples of products were collected from local/regional retail locations located in 6 major cities across Canada. These cities encompassed 4 Canadian geographical areas: Atlantic (Halifax), Quebec (Montreal), Ontario (Toronto, Ottawa) and the West (Vancouver, and Calgary). The number of samples collected from these cities was in proportion to the relative population of the respective areas. The shelf life, storage conditions, and the cost of the food on the open market were not considered in this survey.

Table 1. Distribution of samples based on product type and origin
Product type Number of domestic samples Number of imported samples Number of samples of unspecified Table Note a origin Total number of samples
Botanical powders 29 135 32 196
Grain products 250 494 241 985
Nut/seed products 215 178 102 495
Potato products 189 387 303 879
RTE meals 282 385 126 793
Grand total 965 1579 804 3348

How were samples analyzed and assessed

Samples were analyzed by an ISO/IEC 17025 accredited food testing laboratory under contract with the Government of Canada. See Appendix A for a list of the pesticides included in the multi-residue pesticide method. Glyphosate and its metabolite AMPA were also tested for in this survey using separate methodology. Samples were also subjected to a multi-metal method that analyzes for 20 metals. Only the data for metals of highest concern to human health at low levels of exposure, most notably: arsenic, cadmium, lead, and mercury, are presented in this report. The results are based on the food products as sold and not necessarily as they would be consumed.

Pesticide MRLs are established by the Pest Management Regulatory Agency (PMRA) of HC and appear in their MRL databaseFootnote 3. Pesticide MRLs apply to the specified raw agricultural commodity as well as to any processed food product that contains the commodity unless otherwise specified. According to section B.15.002 (1) of the Food and Drug Regulations (FDR), in the absence of a specific MRL, residues of a pesticide or other agricultural chemical must not exceed the general MRL of 0.1 ppm.

Contaminants and other adulterating substances in foods have regulatory maximum levels that are established by HC. In the absence of a specific maximum level, they assess the levels of arsenic, cadmium, mercury and lead on a case-by-case basis using the most current scientific data available.

What were the survey results

Pesticides

A total of 3348 samples of domestic and imported grain, nut/seed and vegetable-based foods were tested for over 480 pesticides in this targeted survey. Pesticide residues were not detected in 2021 (60%) samples. In the remaining 1327 samples, residues of up to 5 different pesticides were detected in a single sample. A summary of the pesticide results by each product type can be seen in Table 2.

When evaluated by commodity, the percentage of samples with pesticide residues detected ranged from 26% in potato products to 55% in grain products. Glyphosate was the most frequently detected pesticide in most product types. In potato products, diquat had the highest detection rate. The overall compliance rate for pesticides in the products tested was 99.3%. Compliance was assessed against the MRLs which were in place when the survey was carried out. There were 22 non-compliant results associated with 2 grain products, 12 botanical powders and 8 seed products. All of the non-compliant samples contained a single non-compliant pesticide residue and in most cases the non-compliance was associated with pesticide residues exceeding the general MRL of 0.1 ppm. Only 2 non-compliant results contained pesticide residues in violation of a specific established MRL for flaxseed. The average amount of residue detected in the non-compliant samples exceeding the general MRL was 0.22 ppm.

HC determined the levels of pesticides in observed in the current survey were not expected to pose a concern to human health, therefore there were no recalls resulting from this survey. The CFIA conducted appropriate follow up activities to improve compliance.

Table 2. Results of pesticide testing in selected foods
Product type Number of samples Number (percentage) of samples with detected pesticide residue(s) Number (percentage) of non-compliant samples
Botanical powders 196 68 (34%) 12 (6%)
Grain products 985 546 (55%) 2 (0.2%)
Nut/seed products 495 193 (39%) 8 (1.6%)
Potato products 879 225 (26%) 0 (0)
RTE meals 793 295 (37%) 0 (0)
Grand total 3348 1327 (40%) 22 (0.7%)

Metals
Of the 3348 samples collected, 3153 were tested to see the levels of trace elements present. Only the results of the metals of highest human health concern (arsenic, cadmium, lead and mercury) are presented in this report. Most of the survey samples (77%) contained one or more of these four metals, while only 11% of the samples contained traces of more than 2 metals.

Table 3. Detected levels of metals in selected foods
Product type Number of samples % pos for arsenic Average level (range) of arsenic (ppm) %pos for cadmium Average level (range) of cadmium (ppm) %pos for lead Average level (range) of lead (ppm) %pos for mercury Average level (range) of mercury (ppm)
Botanical powders 187 68 0.180 (<LOD-5.03) 85 0.204 (<LOD-1.19) 73 0.330 (<LOD-3.42) 53 0.0020 (<LOD-0.031)
Potato products 817 2 0.046 (<LOD-0.090) 87 0.076 (<LOD-0.353) 0 0.023 (<LOD-0.035) 7 0.0008 (<LOD-0.006)
RTE meals 740 6 0.094 (<LOD-0.507) 33 0.015 (<LOD-0.075) 2 0.034 (<LOD-0.134) 8 0.0012 (<LOD-0.016)
Grain products 939 29 0.172 (<LOD-1.09) 73 0.034 (<LOD-0.174) 9 0.046 (<LOD-0.308) 28 0.0016 (<LOD-0.010)
Nut/seed products 470 19 0.069 (<LOD-0.387) 72 0.089 (<LOD-1.06) 9 0.030 (<LOD-0.15) 17 0.0009 (<LOD-0.005)
Grand total 3153 17 0.148 (<LOD-5.03) 68 0.070 (<LOD-1.19) 9 0.180 (<LOD-3.42) 18 0.0015 (<LOD-0.031)

<LOD = Below the limit of detection (0.0005 - 0.02 ppm, depending on the laboratory and the analyte)
Note: Average values were calculated using only results for samples with quantifiable metal levels

Table 3 illustrates the level of these metals found in the products tested. Lead and cadmium had the lowest and the highest overall detection rate, respectively. Potato products and RTE meals were associated with the lowest detection rate and the lowest observed levels of the metals, while botanical powders were often found to contain the highest detected levels of these metals. Not unexpectedly, the highest levels of arsenic were found in rice productsFootnote 4. High cadmium levels were frequently associated with products containing commodities that are known to accumulate relatively high concentrations of cadmium from soilFootnote 5, specifically potatoes, flaxseed and sunflower seeds. There are no regulations in Canada for the levels of these metals in the products tested. HC determined that none of the products posed a health risk to consumers.

What do the survey results mean

In comparison to previous survey years, the detection rates for pesticides in all commodity types collected were consistent (Table 4)Footnote 6,Footnote 7,Footnote 8,Footnote 9,Footnote 10,Footnote 11. A slight increase in the detection and non-compliance rates for products since the 2015 to 2016 survey can be attributed to an increase in the method sensitivity and a larger number of analytes being tested for. Some differences observed may also be due to the sample size and the specific type of product tested.

Table 4 includes pesticide results in raw potatoes observed in 2010 to 2011, as limited data was available on pesticide levels in potato products. The rate of detection in raw potatoes was much higher than that in potato products observed in this survey. This was expected; it has been documented that the residue levels of chlopropham are significantly lower in potato products compared to the raw commodityFootnote 12. This pesticide was found in 38% of raw potatoes tested in 2010 to 2011 survey but it was not detected in processed potato products tested in this survey. Other pesticide residues were also less frequently detected in the processed products.

Table 4. Pesticide testing results in grain, nut/seed and vegetable-based products from various survey years
Product type CFIA survey year Number of samples Number (percentage) of samples with detected pesticide residue(s) Table Note b Number (percentage) of non-compliant samples
Grain products (Barley)
Grain products (Barley)
Grain products (Barley)		 2018 to 2019
2015 to 2016
2013 to 2014		 195
68
15		 105 (54%)
54 (79%) Table Note c
1 (0.7%)		 0
0
0
Grain products (Bran)
Grain products (Bran)		 2018 to 2019
2017 to 2018		 62
170		 36 (58%)
111 (65%)		 0
5 (3%)
Grain products (Crackers)
Grain products (Crackers)		 2018 to 2019
2017 to 2018		 199
75		 168 (84%)
63 (84%)		 0
0
Grain products (Pasta)
Grain products (Pasta)		 2018 to 2019
2017 to 2018		 300
245		 205 (68%)
196 (80%)		 0
0
Grain products (Rice products)
Grain products (Rice products)
Grain products (Rice products)
Grain products (Rice products)
Grain products (Rice products)
Grain products (Rice products)
Grain products (Rice products)		 2018 to 2019
2017 to 2018
2015 to 2016
2014 to 2015
2013 to 2014
2012 to 2013
2011 to 2012		 229
449
108
23
50
93
84		 32 (14%)
77 (17%)
19 (18%) Table Note c
3 (13%)
12 (24%)
8 (9%)
10 (12%)		 2 (0.9%)
9 (2%)
0
0
0
0
0
Nut/seed products
Seed products
Seed products		 2018 to 2019
2014 to 2015
2013 to 2014		 495
33
26		 193 (39%)
5 (15%)
3 (12%)		 8 (1.6%)
0
0
Potato products
Potatoes		 2018 to 2019
2010 to 2011		 879
259		 225 (26%)
237 (92%)		 0
2 (0.8%)
RTE meals
RTE meals
RTE meals		 2018 to 2019
2016 to 2017
2014 to 2015		 793
2000
46		 295 (37%)
1062 (53%)
18 (39%)		 0
2 (0.1%)
0

In this survey, the reported average levels of metals for RTE meals and grain products are higher and the detection rates are lower compared to those previously found in similar product typesFootnote 6,Footnote 7,Footnote 8. This is mostly due to differences in the limits of detection (LODs). If the LODs are considered when the values are compared, the results are in close agreement.

Appendix A: List of analytes (483) included in the PESTICIDE-GCLC multi-residue pesticide program used by the accredited laboratory in this survey

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