Pyrethroids — just because we can use them at home doesn’t mean that they’re harmless

This briefing by the Canadian Association of Physicians for the Environment examines the health and environmental risks of pyrethroids, a dominant class of synthetic insecticides used in domestic, veterinary, and agricultural settings. It highlights their role as neurotoxins and endocrine disruptors, specifically noting risks to children's neurodevelopment and human fertility, while calling for stricter regulation and the adoption of non-chemical alternatives.

• Pyrethroids are synthetic neurotoxins that dominate the global insecticide market with a 17% share and an estimated value of $7 billion. They function by maintaining sodium channels in an open position, which causes repetitive nervous influx and symptoms such as tremors and involuntary movements in animals.
• Human exposure occurs primarily through contaminated food and water, though workers face higher risks via inhalation and skin contact. In Québec, pyrethroids have been detected in surface waters of agricultural regions and in aquifers, though they are not among the 31 pesticides required for testing in large municipalities' drinking water.
• Children are particularly vulnerable to pyrethroids due to their developing bodies, higher proportional intake of food and air, and hand-to-mouth behaviors. Research indicates associations between pyrethroid exposure and neurodevelopmental issues, including a study where children with high exposure to the additive piperonyl butoxide scored 3.9 points lower on a mental development index scale.
• Chronic exposure to pyrethroids may impair human fertility by acting as endocrine disruptors. They can decrease testosterone levels, interfere with luteinizing hormone, and alter thyroid function, potentially leading to decreased sperm count, sperm mobility, and DNA damage.
• Pyrethroids pose significant risks to non-target species; they are toxic or highly toxic to fish and are suspected of contributing to the global decline of bee populations. Their toxicity to fish can be increased by 140-170% when combined with organophosphorus compounds.
• The document identifies a regulatory gap in Canada and the USA, noting that pyrethroids are not required to undergo mandatory advanced neurotoxicity testing during registration despite their known mode of action as neuron disruptors.

APA

Canadian Association of Physicians for the Environment (n.d.). Pyrethroids — just because we can use them at home doesn’t mean that they’re harmless. https://cape.ca/wp-content/uploads/2018/03/1.Backgrounder-–-Pyrethroids-just-because-we-can-use-them-at-home-doesn’t-mean-they’re-harmless.pdf#new_tab

Chicago

Canadian Association of Physicians for the Environment. Pyrethroids — just because we can use them at home doesn’t mean that they’re harmless. n.d. https://cape.ca/wp-content/uploads/2018/03/1.Backgrounder-–-Pyrethroids-just-because-we-can-use-them-at-home-doesn’t-mean-they’re-harmless.pdf#new_tab.

Wikipedia

{{cite report |author=Canadian Association of Physicians for the Environment |title=Pyrethroids — just because we can use them at home doesn’t mean that they’re harmless |url=https://cape.ca/wp-content/uploads/2018/03/1.Backgrounder-–-Pyrethroids-just-because-we-can-use-them-at-home-doesn’t-mean-they’re-harmless.pdf#new_tab |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{canadianassociationofphysiciansfortheenvironmentndpyrethroids, author = {{Canadian Association of Physicians for the Environment}}, title = {{Pyrethroids — just because we can use them at home doesn’t mean that they’re harmless}}, institution = {Canadian Association of Physicians for the Environment}, url = {https://cape.ca/wp-content/uploads/2018/03/1.Backgrounder-–-Pyrethroids-just-because-we-can-use-them-at-home-doesn’t-mean-they’re-harmless.pdf#new_tab}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }