Occupational use was associated with an increased risk of prostate cancer in a Canadian case-control study8 and in the AHS, which reported a significant trend for aggressive cancers after adjustment for other pesticides.9 In mice, malathion increased hepatocellular adenoma or carcinoma (combined).10 In rats, it increased thyroid carcinoma in males, hepatocellular adenoma or carcinoma (combined) in females, and mammary gland adenocarcinoma after subcutaneous injection in females.4 Malathion is rapidly absorbed and distributed. Red meat and processed meat Monograph Working Group Members A Blair (USA)--Meeting Chair; L Fritschi (Australia); J McLaughlin; C M Sergi (Canada); G M Calaf (Chile); F Le Curieux (Finland); I Baldi (France); F Forastiere (Italy); H Kromhout (Netherlands); A 't Mannetje (New Zealand); T Rodriguez unable to attend (Nicaragua); P Egeghy unable to attend, G D Jahnke; C W Jameson; M T Martin; M K Ross; I Rusyn; L Zeise (USA) Invited Specialists C Portier (Switzerland) Representatives M E Gouze, for the French Agency for Food, Environment and Occupational Health and Safety (France); J Rowland, for the US Environmental Protection Agency (USA) Observers M K Boye Jensen, for Cheminova (Denmark); B Fervers, for the Léon Bérard Centre (France); E Giroux, for University Jean-Moulin Lyon 3 (France); T Sorahan, for Monsanto Company (USA); C Strupp, for the European Crop Protection Association (Belgium); P Sutton, for the University of California, San Francisco (USA) IARC/WHO Secretariat L Benbrahim-Tallaa; R Carel; F El Ghissassi; Sonia El-Zaemey; Y Grosse; N Guha; K Z Guyton; C Le Cornet; M Leon; D Loomis; H Mattock; C Scoccianti; A Shapiro; K Straif; J Zavadil For the Preamble to the IARC Monographs see http://monographs.iarc.fr/ENG/Preamble/index.php For declarations of interests see http://monographs.iarc.fr/ENG/Meetings/vol112-participants.pdf We declare no competing interests.