Malathion and parathion are both examples of synthetic, broad spectrum, organophosphate insecticides and acaricides.1,2 They work by forming a covalent bond with acetylcholinesterase (AChE) enzyme, affecting the nervous system of insects and resulting in death.3
What is the difference?
Malathion
Malathion exists in liquid form only.4
It is used to control mosquitos and fruit-fly populations, insects on agricultural crops and vegetable gardens, as well as pet fleas and headlice.4,5
Parathion
Parathion is available in a range of different formulations, such as dusts, ULV liquids and wettable powders.2 It is used on crops such as fruit and vegetables, wheat, nuts, and cotton.1,6 It has been banned for use in the EU or US, so it is unlikely that you will be exposed to it.7
Environmental and Human Safety Classifications
Parathion has been classified as a Group 2B carcinogen by the International Agency for Research on Cancer (IARC), meaning it has the ‘possibility’ of causing cancer in humans.8 On the other hand, Malathion has been classified as group 2A, meaning it is ‘probably’ carcinogenic to humans.8
When used, insecticides can travel through the food chain and impact our ecosystems. This has caused negative environmental, biodiversity, and health effects.3
Both malathion and parathion have a high ecotoxicity, as they can cause moderate to high toxicity to birds, bees, freshwater fish and aquatic invertebrates, crustaceans, as well as sediment dwelling organisms.1
How could you get exposed?
There are a range of ways you might be exposed to parathion or malathion. Click below to see relevant case studies.
References
- Lewis K .A., Tzilivakis J., Warner D .J., Green A. An International Database for Pesticide Risk Assessments and Management. Human and Ecological Risk Assessment: an International Journal. 2016 Mar 31; 22(4):1050–64. [Cited: 28th October 2024]. Available from: https://sitem.herts.ac.uk/aeru/ppdb/en/Reports/506.htm#none
- U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Agency for Toxic Substances and Disease Registry. Toxicological Profile for Parathion [Internet]. Atlanta, Georgia : ATSDR; 2017 Jan [Cited: 1st November 2024]. Available from: https://www.atsdr.cdc.gov/toxprofiles/tp205.pdf
- Araújo M.F., Castanheira E.M.S., Sousa S.F. The Buzz on Insecticides: A Review of Uses, Molecular Structures, Targets, Adverse Effects, and Alternatives. Molecules [Internet]. 2023 Apr 21; 28(8):3641. [Cited: 28th October 2024]. Available from: https://www.mdpi.com/1420-3049/28/8/3641
- U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service Agency for Toxic Substances and Disease Registry. Toxicological Profile for Malathion [Internet]. ATSDR; 2003 [Cited: 1st November 2024]. Available from: https://www.atsdr.cdc.gov/ToxProfiles/tp154.pdf
- United States Environmental Protection Agency. Malathion [Internet]. [Cited: 1st November 2024]. Available from: https://www.epa.gov/mosquitocontrol/malathion
- U.S. Environmental Protection Agency. Parathion [Internet]. U.S. Environmental Protection Agency; 2000 Jan [Cited: 27th October 2024]. Available from: https://www.epa.gov/sites/default/files/2016-09/documents/parathion.pdf
- Pohanish R.P.P. In: Sittig’s Handbook of Pesticides and Agricultural Chemicals (Second Edition) [Internet]. William Andrew Publishing; 2015. p. 634–8. [Cited: 17th November 2024]. Available from: https://www.sciencedirect.com/science/article/pii/B9781455731480000169
- Iarc Working Group On The Evaluation Of Carcinogenic Risks To Humans, International Agency For Research On Cancer. IARC Monographs on the Evaluation of Carcinogenic Risks to humans. Volume 112, Some Organophosphate Insecticides and herbicides. [Internet]. Vol. 112. 150 cours Albert Thomas, 69372 Lyon Cedex 08, France: International Agency for Research on Cancer; 2017 [Cited: 12th November 2024]. Available from: https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Some-Organophosphate-Insecticides-And-Herbicides-2017