Amines/adverse effects; Carcinogens/adverse effects; Neoplasms/chemically induced; 2-Naphthylamine/adverse effects; Acetyltransferases/genetics; Acetyltransferases/metabolism; Air Pollutants/adverse effects; Benzidines/adverse effects; Benzophenoneidum/adverse effects; Case-Control Studies; Cohort Studies; Coloring Agents/adverse effects; Developed Countries/statistics & numerical data; Developing Countries/statistics & numerical data; Disinfectants/adverse effects; Ecology; Environmental Exposure; Female; Genotype; Humans; Hydrocarbons, Aromatic/adverse effects; Male; Methylenebis(chloroaniline)/adverse effects; Neoplasms/epidemiology; Nitrogen Mustard Compounds/adverse effects; Occupational Exposure; Plants, Toxic; Polycyclic Compounds/adverse effects; Risk Factors; Rosaniline Dyes/adverse effects; Sex Characteristics; Smoke/adverse effects; Smoking/adverse effects; Smoking/epidemiology; Nicotiana/adverse effects; Urinary Bladder Neoplasms/chemically induced; Urinary Bladder Neoplasms/epidemiology