California is the only state that keeps such detailed data on where pesticides are applied. It also is the place that grows 9 out of every 10 strawberries Americans eat. Complicating things further, strawberries are grown near where people work and live and where children go to school. Fumigants, such as chloropicrin, methyl bromide and 1,3-Dichloropropene, are some of the most heavily used pesticides in the state. They are gases, prone to drifting away from the field. An analysis of more than 20 million records of pesticide applications showed a surprising trend. The heaviest pesticide use was not in the Central Valley of California (the heart of the state's agriculture), but in Monterey and Ventura counties — the strawberry capitals. This informed the rest of our reporting and led us to focus on the strawberry industry.