Workplace exposure to pesticides (herbicides and insecticides) is linked to a 60-70% heightened risk of the most common form of motor neuron disease-amyotrophic lateral sclerosis, or ALS for short, finds a synthesis of the available evidence, published online in Occupational & Environmental Medicine. This showed that compared with no exposure, any workplace exposure to pesticides was associated with a 60% heightened risk of ALS, based on the pooled data from 6 studies. And based on the results of 3 studies, any exposure to high levels of pesticides was associated with a near tripling in risk compared with no pesticide exposure, whereas any exposure to lower levels was associated with a doubling in risk. Compared with no exposure, exposure to herbicides was associated with a 70% heightened risk of developing the disease; exposure to either insecticides or fungicides was associated with a 60% heightened risk. But no increased risk was apparent in women who had been exposed to pesticides compared with those who hadn’t been.