Presentation to: CAPE Webinar SeriesJune 16, 2020Kathleen Cooper, Senior Researcher, CELADr. Meg Sears, Chair, Prevent Cancer Now

Pesticides Indoors: Differences in Risk,

Regulation, and Necessary Precautions

1

• Legal aid clinic; poverty law mandate

• Legal representation; public legal education; law reform (over 30 years addressing pesticide law and policy)

• Among our priorities: • Human health effects of

toxic substances, esp. among vulnerable populations

2

About CELA and PCN

• National civil society group including scientists

• Primary cancer prevention is the cure

• Many factors contribute to cancer

• We apply scientific rigour to identify least-toxic options to minimize hazardous exposures

Pesticides used indoors – why it matters

Most time is spent indoors (80% – 90%) Direct exposure, may be higher than other pesticide sources Regulatory differences and limitations

Persistence is greater indoors Some health endpoints not assessed Indoor “environment” poorly characterized **Low income factors unaddressed – older housing, crowding, cleaning

challenges, etc. → higher use of pesticides**

Context: Multiple pesticide exposures and multiple chemical exposures (PBDEs, BPA, PFOs/PFAs, metals, etc.).

Nobody wants fleas, ants, cockroaches, bed bugs, mice, etc. Choices exist for lower risk and/or non-chemical alternatives

3

Pyrethrins and Pyrethroids

Most pesticides used indoors are in this class Replaced more toxic organophosphates (OPs) and carbamates Neurotoxic to insects; lower acute mammalian neurotoxicity

because mammals break down the pesticide quickly Widely used in agriculture, medical and veterinary products Pyrethrins (from chrysanthemums) degrade quickly in sunlight Pyrethroids → greater stability, persistence and toxicity Emerging evidence of endocrine toxicity at low exposure levels Routinely produced as mixtures with

1. synergists that slow insect enzymes to break down pesticide2. other pyrethroids, or other neurotoxic insecticides

Semi-volatile organic chemicals linger in dust and on surfaces, along with other toxins (e.g., lead, mould, outdoors pollution)

4

PESTICIDE MIXTURES

Pyrethrins and Pyrethroids SynergistsCo-formulantinsecticides

Co-formulated Pesticide Active

Ingredients

Allethrin

Cyfluthrin

Beta-cyfluthrin

D-Phenothrin

Imiprothrin

Lambda-

cyhalothrin

Mom

fluorothrin

Permethrin

Prallethrin

Pyrethrins

Tetramethrin

MGK264

PBO

Methoprene

Imidacloprid

Pyriproxifen

Allethrin (various isomers)

✔ ✔ ✔ ✔ ✔

Cyfluthrin ✔ ✔

Beta-cyfluthrin ✔

D-Phenothrin ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔

Imiprothrin ✔ ✔

Lambda-cyhalothrin NO CO-FORMULANTS

Momfluorothrin ✔ ✔

Permethrin ✔ ✔ ✔ ✔

Prallethrin ✔ ✔ ✔

Pyrethrins ✔ ✔ ✔ ✔

Tetramethrin ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔

Octylbicyclo HepteneDicarboximide(MGK264)

✔ ✔ ✔ ✔ ✔ ✔

Piperonyl Butoxide(PBO)

✔ ✔ ✔ ✔ ✔ ✔ ✔

Methoprene ✔ ✔

Imidacloprid ✔

Pyriproxyfen ✔ ✔

5

Progression of pesticide persistence [and toxicity]

Original organic pyrethrum low human toxicity, breaks down quickly in the environment

Successive pyrethroids include atoms and groups that may make them more persistent and/or toxic

6

Progression of pesticide toxicity

Reactive alkyne (triple-bond C) and N-containing ring

Prallethrin

Imiprothrin

7

Progression of pesticide persistence [and toxicity]

8

Halogens: chlorine (Cl) and fluorine (F)Permethrin

Cyfluthrin

Lambda-cyhalothrin

Potential health effects of pyrethroid containing insecticides

Known effects• Symptoms: numbness, itching/burning, nausea, dizziness,

headache, cough, allergic reaction, twitching and writhing• Interfere with nerve fibre signal transmission (alter

sodium channels in cell membranes) • Synergist piperonyl butoxide slows pesticide breakdown in

humans as well as insects• Mixtures with other types of insecticides more toxicEvidence building on longer term effects• Affect behaviour – Canadian, US, French, Korean and other

studies, correlate child behaviour with urinary metabolites • Earlier puberty in boys and later puberty in girls• Liver cancer, child brain tumours• Impacts on hormone systems (endocrine disruption) related

to child development and cancer 9

Law, Regulation, Guidance

Pest Control Products Act and Regulations Assessment of risk (hazard x exposure) and value

(efficacy) of product Risks to humans, environment (therein, persistence and

environmental fate) Residues in food, feed, and environment And a lot more… Therein: “Environment“ = outdoors only Legal requirement to set residue limits only for

agricultural use

10

Toxicity evaluation → the same for all pesticides Pyrethroids - focus is on acute neurotoxic hazard;

not (yet) considering chronic neurotoxicity, endocrine toxicity, cancer

Part of hazard assessment → persistence & dissipation

Persistent substances – often more toxic and more chemically stable/active (e.g., POPs)

Outdoors – processes of chemical breakdown (wind, sun, rain, microbial action)

Indoors – quasi-persistence/continuous presence; e.g., indoor surfaces, carpets, dust

Hazard Assessment

11

Examples of differences in persistenceOutdoors vs indoors Chlorpyrifos - pesticide now banned for indoor use: Env’l dissipation outdoors – a few days, up to 4 years

depending on outdoor env’l factors indoor residence time of nearly 7 years

Permethrin – pesticide commonly used indoors: Env’l dissipation outdoors – a few days up to several

months depending on outdoor env’l factors indoor residence time of nearly 4 years

Persistence indoors: parallels to POPs outdoors

12

Exposure Assessment Outdoors - analytical, laboratory and field studies of

environmental chemistry, fate, residues measuring: breakdown products, metabolites, impurities, tracking of env’l

pathways (in soil, sediment, water, air, biota) crop residue trials, crop residue decline studies, effects of processing of food or feed, etc.

All of above under different circumstances (variations in location, crop type, etc.)

Maximum residue limits for food and animal feed Addressed across very large # of guidance documents

Indoors – how much pesticide is used Exposure assessment guidance from USEPA

13

USEPA Standard Operating Procedures (SOPs) for Residential Pesticide Exposure Assessment

By 2012, ~ 20-year development: Some recognition of indoor differences but concludes:

Can estimate exposure from transferable residues right after use

Direction regarding “durations of exposure” Short-term (up to 30 days), intermediate-term (1-6 months) and

long-term (> 6 months)

Assumptions throughout: Pesticide exposure on day of application will be the same for entire

exposure duration period; measure it as such

Dust? - too hard to measure, likely irrelevant since rest of analysis is “conservative and protective”

No consideration of low income circumstances

14

Models and Biomonitoring Data(to test results of SOP modelling)

Complex exposure models (USEPA) Combine sources (diet, residential, etc.), pathways (inhalation,

dermal, etc.) and exposure factors (dermal absorption, hand-to-mouth transfer, etc.)

Compare results to biomonitoring data ( >99% detection of pyrethroid metabolites in Canadians)

Various model results align with biomonitoring results But, model results are compared to older biomonitoring data (and

none for very young children) Use of pyrethrins and pyrethroids has steadily increased across

time of biomonitoring Models also do not account for low-income differences

15

Canadian PMRA Exposure AssessmentUSEPA SOPs are de facto guidance

For indoor uses (Domestic and Commercial products used in residential settings): Demonstrate access to Residential Exposure Joint Venture -

REJV (proprietary data on use) Don’t account for dust Don’t account for low income circumstancesMost pyrethrins and pyrethroids now subject to re-evaluation/recently re-evaluated Exposure assessments are “conservative” using day-of-

application levels across exposure durationsCancellations or restrictions on indoor usesE.g., Cancellations on some halogenated pyrethroids (for

domestic products) 16

Changes resulting from re-evaluationLargely achieved via label changes

Bringing consistency to labels: E.g., broad definition of “residential”

“Commercial” products: New use restrictions (e.g., no fogging, hand-held mist

sprayers/blowers, broadcast or space spraying) Greater PPE Longer re-entry times; leaving literature for clients

“Domestic” products: Crack and crevice applications only Don’t spray over your head; ventilate well Remove “repeat treatment as necessary” Added precautions about kids, pets, food contact

Changes affect 100s of products

17

Incidents, non-compliance among PCOs Registrants must report pesticide incidents Incident reports influence PMRA enforcement of compliance

E.g., was large # of rodenticide poisonings → use restrictions, tamperproof/inaccessible bait (incident #s dropped)

Pest Control Operators (PCOs): High rates of non-compliance; priority for inspections since

2013. E.g.,: Not following labels – uses not listed; incorrect application

sites or rates (e.g., products limited to crack and crevice sprayed more broadly)

Use/possession of unregistered pesticides/expired products Inadequate use of PPE Non-compliant advertising

18

Conservative assumptions about exposure – adequate? Day-of-application levels assumed over entire timeframe of exposure

assessment. Seems unlikely to address risk Pesticides persist indoors much longer than durations chosen Increased restrictions following re-evaluations → hoped-for

conservatism likely insufficient Additional risks Not addressing all health endpoints – e.g., endocrine toxicity Unaddressed risk of overexposure for those on low income Heavy reliance on individuals or PCOs following labels

Lack of awareness that labels are the law Label instructions flow directly from the risk assessment If exceed allowed use, also exceed risk thresholds

19

Conclusions Regulatory evaluation of pesticides used indoors

Much depends on labels Addressing immediate but not long-term

exposure Label changes poorly communicated

Need clear alerts, esp. on Commercial products → when and how allowed uses changed

Often disallowing “space spraying” but can be very unclear what that means

Ingredients and instructions in tiny font Need clear, easier to read/see instructions;

pictograms; URLs for on-line instructions in multiple languages

20

Conclusions cont’dRegulatory evaluation of pesticides used indoors

Given regulatory shortcomings - prudent to choose lowest risk and/or non-chemical alternatives

Recall: Crucial link between label instructions and underlying

risk assessment → ALWAYS FOLLOW THE LABEL “Domestic” products contain the same “Commercial”

chemicals used by PCOs (just at lower concentrations)Reading labels: PCP# and Active Ingredient(s)

Are there multiple Active Ingredients? Read instructions, toxicity information, and

precautions (Deep dive: PMRA Label Search https://pr-rp.hc-

sc.gc.ca/ls-re/index-eng.php)Learn about the pests (to seek prevention) and about non-pesticide options

E.g., extreme cold, or extreme heat or steam for bed bugs

Good example: https://ruralroutespestcontrol.com/our-process

21

Making informed choicesChoosing lower risk alternatives

Making informed choicesKnow the pest; seek prevention

What do pests need? Make your space inhospitable

Food

Shelter

Safety

Clean. Store in glass/plastic.

Fill cracks, cover mattresses

Repel, trap, kill

22

They “built a better mouse trap”

Reading labels; making informed choiceslow risk, common chemicals

LABEL

Common chemicals are relatively benign

BUTNot risk-free (allergies, dust)

Recall: Law requires efficacy (they have to work)

23

Label changes after re-evaluation“spraying” increases risks

24

Two-year delay for label change (unless immediate risk) “60 Day Residual Control of Cockroaches” -

Pressurized Contact and Residual SprayClaims: Kills Ants, Bedbugs, Cockroaches, Earwigs, Spiders, Sowbugs, Silverfish, Dog & Cat Fleas, Brown Dog Ticks, House Flies“This product has a special valve that sprays in all directions even upside down for hard to reach areas.” “Hold container approximately 30 cm from surface being sprayed and spray until thoroughly wet but not until run-off. Thorough applications produce a coating which will vaporize into cracks and crevices for insect control. If reinfestation occurs, repeat application as necessary. Unpainted or unsealed concrete surfaces may require repeated application after two weeks if necessary. Provide adequate ventilation after indoor use. KEEP PETS AND CHILDREN AWAY FROM SURFACE UNTIL DRY. Do not use as a space spray.”

Re-evaluation: no broadcast application; localized spot spraying - unadjoining spots. Cracks and crevices, not on surfaces.

Example Fact Sheet – Bed Bugs and Pesticides – Information for Tenants in Ontario

Addressing bed bugs needs coordinated strategy: eliminating bug habitat and preparing for pest control Who applies the pest control? Making informed choices about Domestic or Commercial

pesticide productsCollaboration between tenant and landlord is essential Law as last resort https://cela.ca/bed-bugs-and-pesticides-information-for-tenants-in-ontario/

2525

Reading labels; making informed choicesAnticipate and apply label changes

26

Pesticide Active Ingredient Why make this choice? Precautions

Least toxic alternatives (also recall the non-pesticide options of extreme cold or extreme heat)Silicon dioxide(label may say “present as diatomaceous earth”)

• Non-toxic chemical made from tiny dried-up sea creatures.

• Very fine powder that cuts open the bug, causing it to dry out and die.

• Repeat treatments are often needed.

• Fine powder can be a strong irritant to lungs. • Label will warn against breathing dust.

Pyrethrins • Purified from chrysanthemum plant extract• No re-evaluation done yet by federal government

Pesticides to choose if least toxic alternatives don’t workPermethrin Federal government re-evaluation (will be updated label

instructions but not required until August of 2021):• cancel fogging or spraying; limited spot spraying and for

cracks and crevices

• May be in both Domestic or Commercial products

• Despite current label instructions, avoid fogging or spraying now.

• Ask PCO to avoid fogging/spraying.

Pesticides to try and avoidTetramethrin Federal government review, in effect February 2020:

• cancelled indoor broadcast (floors, carpets) and room perimeter (baseboards) treatments due to cancer risk

• removed “repeat as necessary” from label

• May be in both Domestic or Commercial products

• Avoid use of older products containing tetramethrin

• Watch for and avoid products containing tetramethrin in combinations with other pesticides

Beta-cyfluthrin • Allowed uses don’t include fogging or spraying but is used on mattresses.

• Found only in Commercial products. • Ask that PCO use this pesticide only as a last

resort.

Cyfluthrin Federal government re-evaluation decision:• limit domestic uses to spot spraying• disallow all uses other than low pressure spray into

cracks and crevices

• Avoid products containing cyfluthrin• Ask that products with this pesticide not be

used by PCOs.

Lambda-cyhalothrin Federal government re-evaluation is recommending:• cancel all indoor residential uses

• Found only in Commercial products. • Ask that products containing this pesticide not

be used by PCOs.

Options for pesticide products allowed for use against bedbugs

Precaution and Prevention Policy advocacy to address underlying causes

Preventative policy Pest control policy in co-ops, apartments, condos,

workplaces (IPM, visual inspections, low risk products, etc.)

Housing providers and safe housing advocates Maintenance responsibilities of landlords (and

tenants) More educational resources

Reform of pesticide regulation (social justice), including increased enforcement

Poverty reduction Affordable housinghttps://chfcanada.coop/submission-to-ontarios-poverty-reduction-strategy/http://www.basicincomecanada.org/

27

www.rentsafe.ca

Équiterre (client for research conducted in 2018) and MakeWay, formerly Tides Canada

Jennifer Kuhl, Canadian Association of Physicians for the Environment

Kathleen Cooper, Senior Researcherkcooper@cela.caMeg Sears, Chair, Prevent Cancer Nowmeg@preventcancernow.ca

Note: any images of specific products in this presentation do not constitute product endorsement

28

Thanks to:

29

Contact Us; Stay Informed

https://cela.ca/

CELA Bulletin sign-up: https://cela.ca/sign-up-stay-informed-cela-bulletin/

http://www.preventcancernow.ca/

http://www.preventcancernow.ca/join-pcn-and-stay-informed/

• Brander, Susanne M., Molly K. Gabler, Nicholas L. Fowler, Richard E. Connon, and Daniel Schlenk. “Pyrethroid Pesticides as Endocrine Disruptors: Molecular Mechanisms in Vertebrates with a Focus on Fishes.” Environmental Science & Technology 50, no. 17 (September 6, 2016): 8977–92. https://doi.org/10.1021/acs.est.6b02253.

• Davies, T. G. E., L. M. Field, P. N. R. Usherwood, and M. S. Williamson. “DDT, Pyrethrins, Pyrethroids and Insect Sodium Channels.” IUBMB Life 59, no. 3 (2007): 151–62. https://doi.org/10.1080/15216540701352042.

• Hwang, Moonyoung, Youngmee Lee, Kyungho Choi, and Choonghee Park. “Urinary 3-Phenoxybenzoic Acid Levels and the Association with Thyroid Hormones in Adults: Korean National Environmental Health Survey 2012–2014.” Science of The Total Environment 696 (December 15, 2019): 133920. https://doi.org/10.1016/j.scitotenv.2019.133920.

• Lu, Chensheng, Dana B. Barr, Melanie A. Pearson, Lance A. Walker, and Roberto Bravo. 2009. “The Attribution of Urban and Suburban Children’s Exposure to Synthetic Pyrethroid Insecticides: A Longitudinal Assessment.” Journal of Exposure Science and Environmental Epidemiology; 19 (1):69–78. https://doi.org/http://dx.doi.org.myaccess.library.utoronto.ca/10.1038/jes.2008.49.

• Lu, Chensheng, Gary Adamkiewicz, Kathleen R. Attfield, Michaela Kapp, John D Spengler, Lin Tao, and Shao Hua Xie. 2013. “Household Pesticide Contamination from Indoor Pest Control Applications in Urban Low-Income Public Housing Dwellings: A Community-Based Participatory Research.” Environmental Science & Technology 47 (4): 2018–25. doi:10.1021/es303912n .

• Nakagawa, Lia Emi, Alan Roberto Costa, Ricardo Polatto, Cristiane Mazarin do Nascimento, and Solange Papini. 2017. “Pyrethroid Concentrations and Persistence Following Indoor Application: Pyrethroid Persistence Indoors.” Environmental Toxicology and Chemistry, June. https://doi.org/10.1002/etc.3860.

• Oulhote, Youssef, and Maryse F. Bouchard. “Urinary Metabolites of Organophosphate and Pyrethroid Pesticides and Behavioral Problems in Canadian Children.” Environmental Health Perspectives, October 22, 2013. https://doi.org/10.1289/ehp.1306667.

• Pest Management Regulatory Agency, Health Canada – Reports and Publications (numerous) https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management.html

• Roberts JW, Wallace LA, Camann DE, Dickey P, Gilbert SG, Lewis RG, et al. Monitoring and Reducing Exposure of Infants to Pollutants in House Dust. In: Whitacre DM, editor. Reviews of Environmental Contamination and Toxicology Vol 201 [Internet]. Boston, MA: Springer US; 2009 [cited 2016 Sep 13]. p. 1–39. Available from: http://link.springer.com/10.1007/978-1-4419-0032-6_1

Selected References (1)

30

• Roberts, J. R., C. J. Karr, and Council on Environmental Health. 2012. “Pesticide Exposure in Children.” Pediatrics 130 (6): e1765–88. doi:10.1542/peds.2012-2758.

• Rudel, Ruthann A., David E. Camann, John D. Spengler, Leo R. Korn, and Julia G. Brody. 2003. “Phthalates, Alkylphenols, Pesticides, Polybrominated Diphenyl Ethers, and Other Endocrine-Disrupting Compounds in Indoor Air and Dust.” Environmental Science & Technology 37 (20):4543–53. https://doi.org/10.1021/es0264596.

• Saillenfait, Anne-Marie, Dieynaba Ndiaye, and Jean-Philippe Sabaté. “The Estrogenic and Androgenic Potential of Pyrethroids in Vitro. Review.” Toxicology in Vitro 34 (August 2016): 321–32. https://doi.org/10.1016/j.tiv.2016.02.020.

• US Environmental Protection Agency Office of Pesticide Programs, Standard Operating Procedures for Residential Pesticide Exposure Assessment. October, 2012. 582 pp.

• Viel, Jean-François, Charline Warembourg, Gaïd Le Maner-Idrissi, Agnès Lacroix, Gwendolina Limon, Florence Rouget, Christine Monfort, Gaël Durand, Sylvaine Cordier, and Cécile Chevrier. “Pyrethroid Insecticide Exposure and Cognitive Developmental Disabilities in Children: The PELAGIE Mother–Child Cohort.” Environment International 82 (September 1, 2015): 69–75. https://doi.org/10.1016/j.envint.2015.05.009.

• Viel, Jean-François, Florence Rouget, Charline Warembourg, Christine Monfort, Gwendolina Limon, SylvaineCordier, and Cécile Chevrier. “Behavioural Disorders in 6-Year-Old Children and Pyrethroid Insecticide Exposure: The PELAGIE Mother–Child Cohort.” Occupational and Environmental Medicine 74, no. 4 (April 1, 2017): 275–81. https://doi.org/10.1136/oemed-2016-104035.

• Weschler, Charles J., and William W. Nazaroff. 2008. “Semivolatile Organic Compounds in Indoor Environments.” Atmospheric Environment 42 (40):9018–40. https://doi.org/10.1016/j.atmosenv.2008.09.052.

• World Health Organization, and International Agency for Research on Cancer (IARC). “Report of the Advisory Group to Recommend Priorities for IARC Monographs during 2015–2019,” April 2014. https://monographs.iarc.fr/wp-content/uploads/2018/06/14-002.pdf.

• Ye, Xiaoqing, Wuye Pan, Yuehao Zhao, Shilin Zhao, Yimin Zhu, Weiping Liu, and Jing Liu. “Association of Pyrethroids Exposure with Onset of Puberty in Chinese Girls.” Environmental Pollution 227 (August 1, 2017): 606–12. https://doi.org/10.1016/j.envpol.2017.04.035.

Selected References (2)

31