A flight attendant for United Airlines has sued the airline for exposing flight crews to pesticides on planes serving Australia and New Zealand. The attendant, Susan Matthews, says she developed a full-body rash after contact with the pesticides. The spraying — which has been banned in the U.S. — occurs about once every eight weeks to keep nonnative insects from hitching rides and potentially wreaking havoc on agriculture abroad. A spokesperson for the Association of Flight Attendants said the spraying is normally done in vacant cabins, but United has been known to spray immediately before, and even during, flights. The suit seeks damages and a court order directing United to stop the spraying or find a safer way to do it.