title: Mortality and cancer incidence among alachlor manufacturing workers 1968-99.
abstract: BACKGROUND
  Alachlor is the active ingredient in pre-emergent herbicide formulations that have been used widely on corn, soybeans, and other crops. It has been found to cause nasal, stomach, and thyroid tumours in rodent feeding studies at levels that are much higher than likely human exposures.
  
  
  OBJECTIVE
  To evaluate mortality rates from 1968 to 1999 and cancer incidence rates from 1969 to 1999 for alachlor manufacturing workers at a plant in Muscatine, Iowa.
  
  
  METHODS
  Worker mortality and cancer incidence rates were compared to corresponding rates for the Iowa state general population. Analyses addressed potential intensity and duration of exposure.
  
  
  RESULTS
  For workers with any period of high alachlor exposure, mortality from all causes combined was lower than expected (42 observed deaths, SMR 64, 95% CI 46 to 86) and cancer mortality was slightly lower than expected (13 observed deaths, SMR 79, 95% CI 42 to 136). Cancer incidence for workers with potential high exposure was similar to that for Iowa residents, both overall (29 observed cases, SIR 123, 95% CI 82 to 177) and for workers exposed for five or more years and with at least 15 years since first exposure (eight observed cases, SIR 113, 95% CI 49 to 224). There were no cases of nasal, stomach, or thyroid cancer.
  
  
  CONCLUSIONS
  There were no cancers of the types found in toxicology studies and no discernible relation between cancer incidence for any site and years of alachlor exposure or time since first exposure. Despite the small size of this population, the findings are important because these workers had chronic exposure potential during extended manufacturing campaigns, while use in agriculture is typically limited to a few days or weeks each year.
authors.affiliation: Monsanto Company, 800 North Lindbergh Blvd, St Louis, MO 63167, USA. john.f.acquavella@monsanto.com
authors.forename: J F
authors.initials: JF
authors.lastname: Acquavella
authors.forename: E
authors.initials: E
authors.lastname: Delzell
authors.forename: H
authors.initials: H
authors.lastname: Cheng
authors.forename: C F
authors.initials: CF
authors.lastname: Lynch
authors.forename: G
authors.initials: G
authors.lastname: Johnson
mesh_terms: D000081:Acetamides / Q000506:poisoning*; D000328:Adult; D002617:Chemical Industry; D015331:Cohort Studies; D004784:Environmental Monitoring / Q000379:methods; D062665:Epidemiological Monitoring; D005260:Female; D006540:Herbicides / Q000506:poisoning*; D006801:Humans; D015994:Incidence; D007484:Iowa / Q000453:epidemiology; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000139:chemically induced / Q000453:epidemiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000401:mortality; D009784:Occupational Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000401:mortality; D016273:Occupational Exposure / Q000009:adverse effects; D017678:Sex Distribution
chemical_list: D000081:Acetamides; D006540:Herbicides; C000188:alachlor