By Daily Mail (U.S.) | Created at 2026-08-05 03:45:15 | Updated at 2026-08-05 18:16:06
19 hours ago
Exposure to pesticides sprayed on fruits, vegetables and other plants could increase the risk of devastating Amyotrophic Lateral Sclerosis (ALS) by up to 70 percent, a study has found.
Those who work with the chemicals, such as farmers, are dramatically more likely to develop the condition.
ALS, also known as Lou Gehrig's disease and which affects around 35,000 Americans, causes nerve cells that control movement to deteriorate.
This leads to a host of life-ruining symptoms like muscle weakness, loss of mobility, speech difficulties and changes to thinking and behaviour – robbing victims of their independence.
Just 20 percent of ALS patients live for longer than five years. And in many cases, the prognosis is as little as two years.
The cause of the disorder is not yet fully known, but scientists - from the Robert Sauvé Institute For Research in Quebec, have identified an interesting theory.
The team reviewed almost 800 studies but used 11 for their analysis, and involved data from more than 2,000 people with ALS.
They found that those who had been exposed to pesticides at work were around 60 percent more likely to develop ALS than those who had never been exposed.
Farmers and workers exposed to pesticides could be at a 70 percent higher risk of developing ALS
But those exposed mostly to herbicides - or weedkiller - had a 70 percent increased risk.
Pesticides are chemicals used to protect crops by killing or controlling weeds, insects and fungi.
The main types are herbicides, as well as insecticides and fungicides.
Even lower levels of exposure to pesticides of any kind were associated with around double the risk.
Interestingly, when researchers analysed men and women separately, they discovered the worrying link only applied to men.
Commenting on the findings in the journal Occupational and Environmental Medicine, the experts urged officials to introduce 'interventions aimed at reducing exposure during occupational pesticide use.'
The World Health Organisation has branded pesticides 'intrinsically toxic' and deemed them 'among the leading causes of death by self-poisoning'.
Many pesticides banned in other countries are still permitted for use in the US.
Chris Johnson on the field during a Tennessee Titans game in 2013. The star was diagnosed with ALS in 2025 at the age of 39 years
Eric Dane, best known for his role as Dr Mark Sloan on Grey's Anatomy, attends a premiere in June 2025. He was diagnosed with ALS in 2024 at age 51. He died in February this year, aged 53, from respiratory failure, which can be triggered by the condition
Among them is paraquat, a weedkiller outlawed across Europe and in more than 70 countries, which dozens of studies have linked to Parkinson's disease, a progressive neurological condition that slowly strips sufferers of movement, speech and independence.
Used to kill weeds and grasses on farms, it remains legal to use in the US. Vermont became the first state to move to ban its use this year.
Chlordane, a pesticide used to kill termites, was linked to ALS in separate studies. It was banned in the US in 1988 over health fears.
The study came amid high profile cases of ALS being diagnosed in the US.
NFL Legend Chris Johnson revealed his diagnosis at age 40 years last month in a heartbreaking interview, where he was only able to communicate through an eye-controlled computer.
Eric Dane, best known for his role as Dr Mark Sloan on Grey's Anatomy, died from ALS earlier this year at age 53, two years after he was diagnosed with the condition.
The illness can strike seemingly healthy adults in the prime of their lives, leaving experts scrambling to understand the cause.
While inherited genetic mutations account for around one in ten cases, the cause of the vast majority remains a mystery.
Increasingly, researchers have pointed to environmental factors such as pesticide exposure, pollution and diet.
Experts not involved in the new study have commented on its findings, urging caution. One intriguing theory has also suggested a mushroom that grows in northern states could be to blame for some cases.
Dr Johnathan Cooper-Knock, clinical lecturer at the University of Sheffield's School of Medicine and Population Health, said: 'The strength of this research is the use of data from eleven different studies and more than 2000 ALS patients; the findings are interesting and should lead to further work.
'However, this is a retrospective analysis which uses indirect measurements of pesticide exposure and it is therefore almost impossible to know whether the effect seen is mediated by the pesticide exposure or some unseen factor which may be correlated with pesticide exposure.'
