Researchers at FDA analyzed Import Refusal Reports for food shipments refused entry into U.S. commerce between 1998 and 2004. Adulteration violations were examined closely, particularly those linked to pathogen contamination. The top trouble makers interms of improper sanitation were: 1. Vegetables and vegetable products (21% of total violations). 2. Fishery and seafood products (20 %); and 3. Fruits and fruit products (12 percent).