Some welfare recipients would have to pass drug tests before they could get their checks, under a bill that has passed in the Mississippi Senate and is headed to Governor Bryant. It would not apply to all welfare recipients, but to those whose answers on their applications for assistance indicate possible drug use. People who don’t pass would undergo treatment and pass future tests in order to keep their benefits. Critics say the tests will waste money without uncovering much drug use, which they say is not pervasive among welfare recipients. A judge rejected a similar law in Florida.