Formaldehyde in the British chemical industry. An occupational cohort study.
This paper reports the mortality experience of a cohort of 7680 men who had first been employed before 1965 in one of six factories in the British chemical or plastics industry where formaldehyde had been manufactured or used. All the jobs undertaken by each man were classified, on the basis of subjective information, into four categories in terms of exposure to formaldehyde. More than 98% of the workforce were traced to the end of 1981. No deaths from nasal cancer were reported (1.07 expected), and no excess mortality was found for cancers at any of the sites previously reported to be possibly associated with formaldehyde. In one factory a significantly high mortality from lung cancer was found (standardised mortality ratio 124; 95% confidence limits 104, 148) when the mortality rates of England and Wales were used as a standard, but not when an adjustment was made based on the local area mortality. Within the factory the increased mortality was limited to men who had been exposed to "high" levels of formaldehyde. There were no trends of increasing mortality with duration of work or interval since first exposure. This result may be a chance finding or reflect the influence of smoking or some other factor. Although a carcinogenic action of formaldehyde seems less likely as an explanation it cannot be excluded. The statistical power of the study to detect various risks of nasal cancer is described.