Swedish agricultural workers. A group with a decreased risk of cancer.

A Cancer-Environment Registry was established in Sweden in 1978. A study of the register revealed that for persons engaged in agricultural work, the risk for most types of cancer was lower than the respective national averages. For cancer of the trachea, bronchus, lung and pleura, the ratio of observed to expected numbers of cases is 0.39 (observed 934, expected 2375). The difference is statistically significant. For laryngeal cancer the ratio is 0.38 (observed 94, expected 248), which likewise is significant. Primary cancer of the liver and tongue also show less than expected frequency. The risk of cancer of the lip, however, is greater by a factor of almost 2 than the national average, which is consistent with results from other studies.