Document 052DZvGw50mBJbZpEOZv5xpd

02/13/2003 THO 10:45 FAX 312 896 1899 UIC LHS CHICAGO @005 Vi,l. 25 sr, 1936).* A conlortions are being JSTRY manufacture and lop tumors of the and absorption of .ted in the bladder, y 'workers and we rstand the reasons, range and mode of er in workmen eniermediates in the > and his associates* nt&neoua incidence er in males than in gjater in chemical ie^Ptanufonturers, y, the noxious sub* nine and magenta, induction period is dependent upon the he fact that it is the idual susceptibility istrial tumors to be beus or Dtastutf J population in general population of bladder in generul 0 years induction tine cause Feb. 1955 OCCUPATIONAL CANCER 129 more or less malignant than spontaneous ones. This is a killing disease, only 20 per cent of all cases having survived more than 10 years from the first recognition of the disease. Tn 1935, certain alterations in plant and technic were made and these have reduced the risk just significantly, but another 243 cases (over and above the 262 traced cases in a population of 4622 men) may be expected among British workers engaged in the manufacture of chemicals during the next few years. In 1945 and 1950, more drastic plant alterations were made and we can expect these to bear fruit in about 1965. Meanwhile, we need to be ever vigilant in recognizing as occupational tumors any that may occur in other industries in'which die dyestuff intermediates are in use. Case and Hosker (1954)* have recently demonstrated an occupational bladder-tumor risk in the rubber industry in England and Wales. Attention was drawn to this by tbe finding of a high incidence of bladder tumors in the hospital records of a County Borough which is an important center of the rubber industry. It is probable that the risk was introduced into tbe industry in 1928, when a certain antioxidant began to be used. The latter was known to have caused bladder tumors among the men in tbe chemical industry who manufactured it, and it contained about 2.5 per cent al Tree naphthylainine, both alpha and beta isomers. The treatment of the rubber "mix" containing the antioxidant volatilized quantities of naphthylamiucs. It needed a most laborious and careful search of records of many kinds to establish this risk on a sound statistical basis and it is satisfactory to report that the manufacturers of the antioxidant im mediately ceased its manufacture and the users discontinued its use and de stroyed old stockB. Of great interest to tho experimental worker is the search for the reasons for the localization of the tuxnore in the urinary tract, or perhaps the wider concep tion of localization along the routes of excretion would be preferable. If 2naphthylamlne is administered by feeding to dogs, all the animals will eventually develop turnons of the bladder, though the number and location will vary in individuals (Hueper and Wolfe, 1937 ;'* Bonser and her co-workers, 1951'). If 2-naphthylamine isfed to mice, hepatomas or benign cholangiomas will occur. If fed to rats or rabbits, occasional benign papillomas ofthe bladder will be seen. If benzidine is fed to dogs, bladder tumors occur after many years (Spitz, per sonal communication), but if injected into rats, hepatomas and acoustic gland tumors will be found (Spitz, Maguigan and Dobriner, 1950) if injected into mice, hepatomas only will occur (Bonser and her associates, unpublished obser vation) (Tabic 3). Such localization of tumors suggests that 3 important factors must be at work: (a) species variations in biologic response; (b) excretion of the original chemical or its metabolites along a specific pathway; and (c) concentra tion of these substances in certain sites. A study1 of the metabolism of 2-naphthylamine in various species showed that a conversion of the amine to 2-amino-l-naphtkol conjugates occurred and that the capacity to form tumors was roughly proportional to the concentration of these substances in the urine. In the dog, the ratio of urinary to serum content of