Pyrethroid insecticides are widely used in Quebec to control insect pests in market garden crops. Lambda-cyhalothrin is such an insecticide and is extensively used; however, there is very little data on this pyrethroid’s biological behaviour in the human body.

Farmworkers may be exposed to pyrethroids, such as lambda-cyhalothrin, during application in fields or due to their presence in a treated area, shortly after the application. According to several studies carried out in agricultural settings, respiratory exposure may occur during spraying, when protective equipment is not properly used. Exposure due to skin contact with treated crops or contaminated equipment has also been reported. 

A new study funded by the IRSST addresses the lack of knowledge about the toxicokinetics of biomarkers of exposure to lambda-cyhalothrin. 

This study fills the gap in knowledge of the toxicokinetics of the biomarkers of exposure to lambda-cyhalothrin in humans, promoting a better interpretation of biomonitoring data and a better assessment of the risks associated with workers’ exposure to this pesticide. It enabled the research team to develop a toxicokinetic model to establish the essential determinants of the biological behaviour of lambda-cyhalothrin and its metabolites. 

This new toxicokinetic knowledge and the modelling done in this research can be used directly to interpret biological monitoring data on exposure in workers exposed to lambda-cyhalothrin or other pyrethroids. Moreover, this research also allowed the team to derive a biological reference value that can be used in biomonitoring as a benchmark to assess the risks associated with exposure to lambda-cyhalothrin in workers. 

Agriculture is an industry that employs a large number of Quebec workers. According to the 2016 census by the Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec, this sector comprised approximately 28,150 farms and 54,500 workers. In agriculture, pesticides are used regularly during the spring and summer to limit the damage caused by insects, fungi and weeds, but their use represents a risk factor for workers’ health.