At Significantly Higher Risk 
• Smokers, especially of cigarettes. 
• Beauticians, leather workers, machinists and metal workers, printers, rubber and textile workers, truckers and
  those exposed to industrial dyes.
• Abusers of certain pain medications. 
• People taking alkylating agent chemotherapy drugs, such as cyclophosphamide , or who have had radiotherapy
  to the bladder.