Risk of lymphatic or haematopoietic cancer mortality with occupational exposure to animals or the public.
BACKGROUND
Occupational exposure to animals or the public could result in exposure to infectious agents, which may play a role in the aetiology of lymphohaematopoietic (LH) cancers.


OBJECTIVE
To conduct a population based, case-control study of death certificate data from 1984 to 1998 in 24 US states in order to evaluate the risk of mortality from LH neoplasms associated with occupational exposure to animals or the public.


METHODS
Cases were selected as those with an underlying cause of death of non-Hodgkin's lymphoma (NHL, n = 72,589), Hodgkin's disease (HD, n = 5479), multiple myeloma (n = 35,857), or leukaemia (n = 68,598); 912 615 controls were randomly selected from all remaining deaths, frequency matched on age, sex, race, and geographic region.


RESULTS
Occupational exposure to animals was associated with modest increased risks of mortality from all four LH cancers; these associations varied by region. Occupational exposure to the public was associated with only negligible increased risk with LH cancer outcomes. Occupations involving animal exposure were predominantly agricultural, and the risks associated with employment in the livestock industry exceeded the corresponding risks associated with the crop industry for all outcomes except HD.


CONCLUSIONS
Increased risks of NHL, HD, multiple myeloma, and leukaemia were associated with occupations that involved animal exposure. Regional differences in risk imply that the risks may be associated with exposure to specific livestock or farming practices. However, these associations may be confounded by other farming related exposures, such as pesticides. Because the use of death certificates to classify occupation may result in misclassification during aetiologically relevant time periods, these hypotheses should be further explored in studies with detailed information on lifetime occupation.
Svec
M A
MA
Department of Epidemiology, University of Washington, Seattle, Washington, USA.
Ward
M H
MH
Dosemeci
M
M
Checkoway
H
H
De Roos
A J
AJ
D000382:Agricultural Workers' Diseases / Q000209:etiology* / Q000382:microbiology; D000818:Animals; D016022:Case-Control Studies; D003141:Communicable Diseases / Q000150:complications / Q000635:transmission*; D003644:Death Certificates; D018562:Disease Transmission, Infectious; D019337:Hematologic Neoplasms / Q000209:etiology* / Q000382:microbiology; D006801:Humans; D007938:Leukemia / Q000209:etiology / Q000382:microbiology; D008223:Lymphoma / Q000209:etiology / Q000382:microbiology; D009784:Occupational Diseases / Q000209:etiology* / Q000382:microbiology; D016273:Occupational Exposure; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D015047:Zoonoses