Malathion

also see children, kidney, organophosphates

Two Common-Use Organophosphate Pesticides in Drinking Water Put Nearly Everyone at Cancer Risk    (Beyond Pesticides, July 28, 2022) A report published in Chemosphere finds organophosphate (OP) insecticides readily contaminate drinking water resources, threatening human, animal, and ecological health. OPs have a wide range of biological uses—from insecticides to flame retardants—that make these chemicals ubiquitous, significantly contributing to ecosystem contamination.    The study finds water resource sites with a lower pH (more acidic) and near agricultural areas tend to contain higher concentrations of OP residues. Moreover, the concentration of OPs in water resources differ during the seasons, with spring and winter concentrations much higher than summer or fall. Regarding carcinogenicity, malathion has a high cancer risk in all scenarios with concentrations above U.S. Environmental Protection Agency (EPA) accepted limit of 1.0E-6, while diazinon has a high cancer risk in all scenarios, but low age population (e.g., children)     SNAP Comment: There are still 13 malathion and  5 diazinon formulations still registered with the PMRA on 26 August 2022

Common Insecticide Malathion Linked to Chronic Kidney Disease (Beyond Pesticides, October 19, 2021) 'Exposure to the insecticide malathion increases risk of developing chronic kidney disease (CKD), according to a study recently published in the International Journal of Environmental Research and Public Health.... Risk was not significantly increased by exposure to the other pesticides studied'.(2,4-D, chlorpyrifos, and 3-PBA, the major metabolite for most synthetic pyrethroid insecticides).   'Despite strong links between malathion and a range of different cancers, EPA deigned the chemical as having “suggestive evidence of carcinogenicity,” not the stronger “likely carcinogen” designation initially proposed by EPA staff.' SNAP Comment: As of 19 October 2021, there are 13 malathion products registered in Canada, 5 of those for domestic use (use by consumers, all for outdoor use only)

Liver and Kidney Damage Tied to Exposure to the Organophosphate Insecticide Malathion   (Beyond Pesticides, November 9, 2018) 'A Tunisian study (published in January 2018) on the effects in pre-pubertal mice of exposure to malathion — an organophosphate pesticide first registered for use in the U.S. in 1956 — demonstrates significant distortion of liver and kidney biochemistry and function in the animals. Deleterious effects include compromise of feeding ability, metabolism performance, neurologic deficits, reduction of overall body weight, and simultaneous increases in the weights of livers and kidneys, with structural anomalies and lesions in those organ.' The article also refers to other recent studies that found deleterious effects of malahion. 'Information from the (EPA) risk assessment was disturbing enough that the EPA took the uncharacteristic step; that information included evidence of histopathological lesions of the nasal cavity and larynx from exposures below the “dose” that typically causes the inactivation of acetylcholinesterase'    SNAP COMMENT:  In 2005, I attended a pesticide session when the SK government was working on the Green Strategy. I was immediately and repeatedly attacked by the Syngenta representative but won every argument. The last one of the day was about malathion. I pointed out that the US EPA had requested studies on the respiratory toxicity of malathion but had apparently not yet received any. The EPA's concern came from the even more widespread spraying of malathion for mosquito control after the West Nile virus scare. He was sure I was out to lunch and promised he would find the info and let me know. No need to say, I never heard from him. The fact is that the standard tests to determine toxicity (dose at which 1/2 of the animals die) for pesticide registration are dermal (skin) exposure and oral (eating the pesticide in food), On toxicity charts, these are the 2 measurements you will find. I have never seen a chart reporting how toxic a pesticide is when breathed in, although it is the most common form of exposure. It appears the US EPA now has received some data allowing them to publish a warning about respiratory exposure.