International Agency for Research on Cancer (IARC) - Summaries & Evaluations


VOL.: 25 (1981) (p. 49)

5. Summary of Data Reported and Evaluation

5.1 Summary of data

Information on the occurrence of cancer in lumber and sawmill workers is limited, and there are no cohort or detailed case-control studies involving sizeable numbers of cases in these specific occupations. The available epidemiological data are primarily from surveys of statements of occupation on death certificates.

The possibility that an increased risk of nasal tumours may exist for lumber or sawmill workers was suggested by British occupational mortality statistics, and in two case-control series using death certificate data in the US. A study in Australia found a higher frequency of lumber and sawmill employees among patients with adenocarcinomas than among patients with other nasal cancers. Each of these studies was based on small numbers of cases (five or less) with lumber-sawmill jobs; in none were detailed occupational histories obtained and in none was employment classification verified, so that the possibility of employment in the furniture-making industry at some time could not be excluded.

Lung cancer mortality was found to be low among lumber and sawmill workers in statistics from the US and England & Wales. Similar results were found in a study of lumber and sawmill workers who were members of an American carpenters' union. A death certificate review showed a three-fold excess of lung cancer among lumber, sawmill and forestry employees in rural, but not urban, areas of coastal Georgia in the US. None of these surveys took smoking habits into consideration.

A nearly three-fold increased risk of Hodgkin's disease was found among lumber and sawmill workers in a case-control comparison of statements of occupation on death certificates from upstate New York. No overall increased risk of Hodgkin's disease among persons occupationally exposed to 'wood and trees' was reported in a case-control study in Israel; however, an increased risk for the mixed-cellularity type of Hodgkin's disease was reported for afforestation and lumber workers. Another review of death certificates for patients with Hodgkin's disease in the US showed a 40% excess risk for all woodworkers, including lumber-sawmill workers. A 20% elevated risk for all lymphoproliferative and haematopoetic cancers combined was reported for lumber and sawmill workers who were members of the US carpenters' union. The mortality statistics for Washington state do not show elevated mortality ratios for Hodgkin's disease among sawyers or among miscellaneous woodworkers (including sawmill workers). In none of the above studies were more than 15 cases of Hodgkin's disease found among persons with lumber-sawmill jobs.

A suggestion of an increase in incidence of stomach cancer arises from the general trend of elevated mortality ratios for sawyers, lumbermen, loggers and related woodworking trades in the state and national occupational mortality series. The increases were in the order of 10-50%.

Increased risks of about six-fold of both histiocytic lymphomas and soft-tissue sarcomas associated with exposures to chlorophenols have been reported in Sweden. Although data relating risks to occupation were unavailable, most use of chlorophenols is in the sawmill industry.

The confusion between the two occupational groups - lumber and sawmill workers - might be a reason for the discrepancies among the epidemiological findings for different cancers in different countries at different times.

Definition of the occupational groups in the future should take into account that lumber and sawmill occupations are quite different from the point of view of exposure to dust and to chemicals. The description of the industrial processes given in the text shows that some of the chemicals used are those for which there is sufficient evidence of carcinogenicity in humans and/or in experimental animals (see Appendix 4, in this volume). Some of these chemicals are no longer used; however, some are still in use.

5.2 Evaluation

The epidemiological data are not sufficient to make a definite assessment of the carcinogenic risks of employment in the lumber and sawmill industries. Some studies suggest that the incidences of nasal cancers and Hodgkin's disease may be increased. It is not known whether some nasal cancer patients described as working in lumber and sawmill industries may have worked in furniture manufacturing. The hypothesized link to Hodgkin's disease is not adequately supported. Soft-tissue sarcomas and histiocytic lymphomas have been reported following exposures to chlorophenols; although the risk to sawmill and lumber workers was not quantified directly, the use pattern of chlorophenols suggests that sawmill workers in this study were at increased risk for both of these malignancies. Stomach cancer is slightly elevated among these occupational groups in six mortality series; however, this might be related to nonoccupational factors.

Subsequent evaluation: Suppl. 7 (1987)

Last updated: 8 April 1998

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