This article calls for greater attention towards the environmental factors that influence ALS. This isof critical importance because we need to identify modifiable disease risks to lower incidence and develop treatments to improve patient outcomes. We must define the ALS exposome, the cumulative measure of life-long exposures, and how they relate to ALS onset and progression. This requires quantifying all environmental exposures, from the earliest stages prior to disease onset and throughout ALS development. Among the possible environmental ALS risks, our group recently reported that pesticides increase ALS risk and that higher concentrations of persistent organic pollutants are associated with a poorer ALS survival.