Parkinson’s Queensland Statement on Paraquat
Paraquat (paraquat dichloride) is a herbicide and a component of agricultural products that has been extensively used in Australia since the 1960s. It is a toxin, known to be harmful to humans through a large volume of scientific data published in a variety of papers and reports. Paraquat has been widely used across the world in agriculture and other settings for decades but is now banned in 91 countries. Some recent reports, including one published in 2024 highlight the health risks of paraquat. It can enter the body through skin absorption, inhalation or ingestion and it can damage many organs including the lungs, kidneys, heart, central nervous system, liver and spleen. In Australia there have been notable suicides by paraquat ingestion, with as little a teaspoon of concentrated paraquat enough to cause death. Long-term exposure has also been linked to adverse health outcomes including cancers, kidney and respiratory failure. In experimental animals paraquat administration can result in damage to the brain and symptoms similar to that observed in human Parkinson’s disease. Several studies, using different methodologies and in different countries and settings, have linked paraquat exposure to an increased risk of Parkinson’s disease. All this information, taken together has led many to call of paraquat to be banned.
An ABC report, broadcast on Landline on 1 September 2024 recently presented some of this information and subsequently several groups across Australia have been calling for the banning of paraquat in this country.
FAQs
What is paraquat? It is a toxin used as a herbicide in some agricultural products.
Is paraquat dangerous to human? There are many reports of the adverse health effects on paraquat poisoning, particularly if used inappropriately or without correct personal protective equipment. There is emerging evidence that long-term exposure may also have impacts on health and increase the risk for complex medical conditions.
Does paraquat cause Parkinson’s disease? No – not directly. Most people who develop Parkinson’s have never been exposed to paraquat and many people who have experienced significant exposure will never develop Parkinson’s. However, paraquat exposure likely increases the risk of developing Parkinson’s disease. Scientific consensus suggests that there may be a doubling of risk for substantial exposure. This means that eliminating these exposures would mean that less people would develop PD. In an Australian setting case-control studies have shown that exposure to environmental toxins like paraquat more than double the risk for PD (Todorovic et al 2015 ), that exposures in individuals with susceptible genetic backgrounds may be at even greater risk (Menegon 1998 ) and that the prevalence of PD may be higher than expected in regional and remote Australia, in areas that are often those with the highest use of agrochemicals like paraquat (Peters et al 2006, Mellick et al Ecosystems report part 2 ).
Anyone interested in finding out more can consult the websites and articles listed below:
Landline story can be found at After the Harvest: Concerns over links between a common herbicide and Parkinson’s disease – ABC News
Follow-up story with Farmers Federation attempt to silence story Australia’s peak farm lobby tries to silence members after ABC investigation exposes Parkinson’s link to controversial chemical – ABC News
Leah Utyasheva, Prabath Amarasinghe, Michael Eddleston et al. Paraquat at 63 – the story of a controversial herbicide and its regulations: It is time to put people and public health first when regulating paraquat., 23 May 2024, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-4402338/v1]
Paul, K. C. et al. (2024). Agricultural paraquat dichloride use and Parkinson’s disease in California’s Central Valley. International journal of epidemiology, 53(1), https://doi.org/10.1093/ije/dyae004
Shabrina, L. S., Armen Ahmad, & Fadrian Fadrian. (2023). Diagnosis and Management of Paraquat Intoxication. Bioscientia Medicina : Journal of Biomedicine and Translational Research, 7(8), 3478-3499. https://doi.org/10.37275/bsm.v7i8.848
Todorovic, M., Newman, J. R. B., Shan, J., Bentley, S., Wood, S. A., Silburn, P. A., & Mellick, G. D. (2015). Comprehensive Assessment of Genetic Sequence Variants in the Antioxidant ‘Master Regulator’ Nrf2 in Idiopathic Parkinson’s Disease. Plos One, 10(5). https://doi.org/10.1371/journal.pone.0128030
Menegon, A., Board, P., Blackburn, A., Mellick, G., & Le Couteur, D. (1998). Parkinson’s disease, pesticides, and glutathione transferase polymorphisms [Article]. Lancet, 352(9137), 1344-1346. https://doi.org/10.1016/s0140-6736(98)03453-9
Peters, C. M., Gartner, C. E., Silburn, P. A., & Mellick, G. D. (2006). Prevalence of Parkinson’s disease in metropolitan and rural Queensland: a general practice survey. J Clin Neurosci, 13(3), 343-348. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16540321
Peters, C. M., Gartner, C. E., Silburn, P. A., & Mellick, G. D. (2006). Prevalence of Parkinson’s disease in metropolitan and rural Queensland: a general practice survey. J Clin Neurosci, 13(3), 343-348. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16540321
Compiled by Professor George Mellick on behalf of Parkinson’s Queensland 20 September 2024.
