Carcinogenicity of some nitrobenzenes and other industrial chemicals

In rodent studies, drinking water exposure to ortho-phenylenediamine (tested as its dihydrochloride)2 increased the incidence of hepatocellular adenoma (HCA) in male and female rodents, of both HCA and hepatocellular carcinoma (HCC) combined in male mice, of HCC in female mice and male and female rats, of urinary bladder transitional cell papilloma and carcinoma in male rats, and of gall bladder papillary adenoma in male and female mice. Strong evidence suggested that ortho-phenylenediamine is genotoxic according to positive results in mammals, mammalian cells in vitro, plants, and prokaryotes. 2-Chloronitrobenzene is used to make colourants and various other chemicals; downstream uses include lumber preservatives, corrosion inhibitors, pigments, and agricultural chemicals. 4-Chloronitrobenzene is used in the production of agricultural chemicals, pharmaceuticals, paints, pigments, colourants, plastics, and paper, and in the treatment of textiles and leather. 2-Chloronitrobenzene and 4-chloronitrobenzene have been detected at low levels in edible fish. 2-Chloronitrobenzene and 4-chloronitrobenzene have been measured in workplace air in chemical factories, and urinary metabolites of 4-chloronitrobenzene have been detected in factory workers. Diets containing 2,4-dichloro-1-nitrobenzene7 increased the incidence of HCA, HCC, hepatoblastoma, and peritoneal haemangiosarcoma in male and female mice, of renal cell adenoma and carcinoma in male and female rats, and of preputial gland adenoma in male rats. 1,4-Dichloro-2-nitrobenzene increased the incidence of proximal tubule hyaline droplets and granular casts in male rats, and male and female rats fed 2,4-dichloro-1-nitrobenzene developed atypical hyperplasia and chronic progressive nephropathy.