Mortality patterns among workers exposed to acrylamide: Updated follow up

Objective: The objective of this study was to update the mortality experience of a cohort of workers with and without potential exposure to acrylamide (AMD) at three U.S. plants (n = 8508) and one plant in The Netherlands (n = 344). Methods: We computed standardized mortality ratios (SMRs) using national and local rates and modeled internal cohort rates to assess site-specific cancer risks by demographic and work history factors and several exposure indicators for AMD. Results: For the 1925-2002 study period, we observed both deficit and excess overall mortality risks among the U.S. cohort for cancer sites implicated in experimental animal studies: brain and other central nervous system (SMR = 0.67, confidence interval [CI] = 0.40-1.05), thyroid gland (SMR = 1.38, CI = 0.28-4.02), testis and other male genital organs (SMR = 0.64, CI = 0.08-2.30); and for sites selected in earlier exploratory analyses of this cohort: respiratory system cancer (RSC) (SMR = 1.17, CI = 1.06-1.27), esophagus (SMR = 1.20, CI = 0.86-1.63), rectum (SMR = 1.25, CI = 0.84-1.78), pancreas (SMR = 0.94, CI = 0.70-1.22), and kidney (SMR = 1.01, CI = 0.66-1.46). Except for RSC, attributed earlier to muriatic acid exposure, none of the mortality excesses was statistically significant. In the Dutch cohort, we observed deficits in deaths for all sites of a priori interest. An updated analysis of our previous exploratory findings for pancreatic cancer in the U.S. cohort revealed much less evidence of a possible exposure-response relationship with AMD. Conclusion: AMD exposure at the levels present in our study sites was not associated with elevated cancer mortality risks.