Mortality in Iowa farmers and farm laborers, 1971-1978.

Death certificate analyses of white California males aged 20 through 64 dying from 1959 through 1961 indicated unusually high mortality rates in farm laborers from respiratory diseases and accidents. To determine whether this mortality pattern is pervasive among agriculturally employed workers, similar analyses in Iowa from 1971 through 1978 were completed. Only mortality from work-related accidents was found to be excessive; respiratory disease deaths were no more frequent than among the general population. The reason for high respiratory disease mortality in California remains unknown. The two worker populations differ with respect to ethnic background, socioeconomic status, mobility and accessibility of medical care. Worker exposures to agricultural chemicals and to dust are substantial in both regions, but are qualitatively different. One or more of these factors could account for the different rates of respiratory disease mortality.