Since many exposures come during those field applications, the risks - to farmworkers and to nearby residents who can be affected if the chemicals drift - can occur much more frequently. "You are working in one field, and the tractor passes in the next field spraying," says Epifanio, 58, a veteran Mexican farmworker who asked that his full name not be used, out of fear for his job. "The wind brings it to you. It happens to somebody around here every single day."