A retrospective cohort mortality study of workers exposed to formaldehyde in the garment industry

Abstract

In order to assess the possible human carcinogenicity of formaldehyde we conducted a retrospective cohort mortality study of workers exposed for at least three months to formaldehyde in three garment facilities which produced permanent press garments. A total of 11,030 workers contributing 188,025 person-years were included in the study. Vital status was successfully ascertained through 1982 for over 96% of the cohort. The average (TWA) formaldehyde exposure at the three plants monitored in 1981 and 1984 by NIOSH was 0.15 ppm but past exposures may have been substantially higher. In general, mortality from nonmalignant causes was less than expected. A statistically significant excess in mortality from cancers of the buccal cavity (SMR = 343) and connective tissue (SMR = 364) was observed. Statistically nonsignificant excesses in mortality were observed for cancers of the trachea, bronchus and lung (SMR = 114), pharynx (SMR = 112), bladder (SMR = 145), leukemia and aleukemia (SMR = 113), and other lymphopoietic neoplasms (SMR = 170). Mortality from cancers of the trachea, bronchus and lung was inversely related to duration of exposure and latency. In contrast, mortality from cancers of the buccal cavity, leukemias, and other lymphopoietic neoplasms increased with duration of formaldehyde exposure and/or latency. These neoplasms also were found to be highest among workers first exposed during a time period of high potential formaldehyde exposures in this industry (1955-1962). However, it should be recognized that these findings are based on relatively small numbers and that confounding by other factors may still exist. The results from this investigation, although far from conclusive, do provide evidence of a possible relationship between formaldehyde exposure and the development of upper respiratory cancers (buccal), leukemias, and other lymphopoietic neoplasms in humans.

Epidemiologic evidence on the relationship between formaldehyde exposure and cancer.

“…The plants studied by Won g (36) and Fayerweather et al (40) also included some workers that were studied by Blair et al (25). Two plants were included in both studies by Sta yner (33,34). In the summation of the observed and expected numbers, howe ver, results from the earlier study by Sta yner (33) and the studies by Marsh (35), Fayerweath er et al (40), Wong (36), and Liebling et al (37) were not included because they were generally covered in the lat er study by Stayner et al (34) or in the study by Blair et al (25) .…”

“…Other casereferent studies in the United States (60) and Nordic countries (61) found no association between formaldehyde exposure and nasal cancer, but they were not specifically designed to assess risks from this chemical. Several cohort studies of industrial workers or professional workers have also failed to detect excesses of nasal cancer (23,25,34) although the power of the studies was small.…”

“…Contradictory results regarding nasopharyngeal cancer were obtained in other studies. No excesses occurred in most studies of professionals and no deaths from cancer of the nasopharynx were reported in the study of chemical workers in Great Britain (23) or in the investigation of garment workers in the United States (34). In these investigations, however, the expected numbers were small.…”

“…In the studies of multiple plants in the United States (24,25,28,29,33,34) and Great Britain (23,68) excess mortality from lung cancer was not observed in all the plants. Among garment workers (34) in the United States, deficits were observed at two plants, whereas one had an excess.…”

“…showed higher risks with shorter latency (34,43,50). Risk of lung cancer by level or duration of expo sure to formaldehyde is shown in table 8.…”