Cancer mortality among workers in the Tuscan tanning industry ADELE

The mortality of2926 male workers at the tanneries in the "leather area" ofTuscany was examined from 1950 to 1983 comparing it with the national mortality. Cancer mortality was of particular concern because ofthe many chemicals known to be definite or suspected carcinogens used in the tanning cycle, in particular chromate pigments, benzidine based dyes, formaldehyde, and organic solvents. There was no excess of deaths for cancers of all sites but slight increases in deaths from cancer of the lung (SMR = 131, CI 95% = 88-182), bladder (SMR = 150, CI 95% = 48349), kidney (SMR = 323, CI 95% = 86-827), pancreas (SMR = 146, CI 95% = 39-373), and leukaemias (SMR = 164, CI 95% = 53-382) occurred. Two cases of soft tissue sarcomas were observed versus 0 09 expected (SMR = 2178, CI 95% = 250-8023). Chemical substances known to be carcinogenic for man and animals have been used in the tanning industry for many years.'3 It has not been clearly established if workers handling these materials are at an increased risk of developing cancer. Several studies have shown an increased risk of tumours of nasal cavity sinuses,' bladder,7-" pharynx, lung,'2"3 and of the haemopoietic and lymphopoietic systems8 among leather workers but few studies have dealt specifically with tannery workers. In a large case-control study on cancer of the bladder conducted in Boston, showing an increased risk for leather workers in general, an increased risk associated with tanning operations was not significant.7 No evidence of an increased risk of developing cancer was suggested by a cohort mortality study conducted in England.'4 Similar negative results were reported by Stern in a large cohort mortality study concerning people engaged in two chrome tanneries in the United States.'5 Others have reported an excess of malignant tumours of the intestine'6 and of cancer of the stomach and pancreas'7; in addition, an excess risk of cancer of the lung'3 and of the kidney'8 has been suggested. In Tuscany (Italy) leather production is a major industry and tanneries are concentrated in an area named the "leather area" in the provinces of Florence and Pisa. Accepted 9 January 1989 We have conducted a cohort mortality study in this area; of particular concern were cancers of the lung and urinary tract because chromates known to be carcinogenic for the lung and benzidine based dyes for the bladder were used. Materials and methods The leather area covers six municipalities in Florence and Pisa. There were 90 152 inhabitants in 1981. The tanning industry developed in the 1950s and is now the main industry in the area. In 1980 there were about 850 firms with about 7300 employees according to a local census. Most of the tanneries are small, often installed in old, unsuitable buildings, with no means ofenvironmental control and little automation. In recent years there has been some improvement of existing premises and the construction of new factories. Tanning is carried out in this area with natural or synthetic tannins or chrome salts; some factories combine the two methods. There is a much greater use of dyes, pigments, and solvents in the factories using the chrome process; in the traditional tanning of leather dyes are seldom used. In 1981-2 an environmental survey was conducted in a sample of 83 firms.'9 More than 2900 different products were listed, of which about 1000 were dyes. The use of some known or suspected carcinogens was noted, including benzidine based dyes, orthodianisidine based dyes, orthotolidine based dyes used for colouring in drums, hexavalent chrome salts used as pigment in finishing 384 group.bmj.com on June 18, 2017 Published by http://oem.bmj.com/ Downloaded from