Agriculture Health Study
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|ClinicalTrials.gov Identifier: NCT00352924|
Recruitment Status : Active, not recruiting
First Posted : July 17, 2006
Last Update Posted : May 18, 2018
The "Agricultural Health Study" (AHS) is a collaborative effort between the National Cancer Institute and the National Institute of Environmental Health Sciences. The U.S. Environmental Protection Agency and the National Institute for Occupational Safety and Health are providing support for a limited exposure assessment effort.
Initial data collection on a prospective cohort of 89,658 study subjects has been completed as of December 1997. Participants completed questionnaires that included items on pesticides used, other agricultural exposures, and work practices that modify exposure as well as on other activities that may affect either exposure or disease risks (e.g., diet, exercise, alcohol consumption, medical conditions, family history of cancer, other occupations and smoking history). Phase II of the study (1998-2003) updated information on occupational exposures, diet, work practices and medical history by means of a computer assisted telephone interview. We also collected buccal cells on sample of 34,000 study participants to assess the effect of inheritable polymorphisms and the interaction of environment and genomic predisposition.
The stimulus for this prospective investigation comes from the growing evidence that, despite a low mortality overall, farmers experience an excess of several cancers. These excesses have been observed in retrospective epidemiological studies among agricultural workers in several countries. Excess cancers are observed for the lymphatic and hematopoietic system, connective tissue, skin, brain, prostate, stomach and lips. Several of these tumors (brain, NHL, multiple myeloma, and prostate) are also increasing in the general population in many of these countries. This suggests a common set of exposures may explain the high rates in farmers and rising rates in the general population.
Farmers, their families, and other pest control workers may have contact with a variety of potentially hazardous substances including pesticides, solvents, fuels and oils, engine exhaust, dust and zoonotic viruses and other microbes. Our cohort study includes all registered pesticide applicators in Iowa and North Carolina and the spouse of applicators who are farmers. The health effects of pesticide use are the primary focus of the study. The influence of other farm exposures are also being evaluated.
The focus of the phase II follow-up period (2004-2008) is to update exposure information and health histories by means of a computer assisted interview and also following the cohort to determine disease incidence and mortality. The cohort is being followed through the cancer registries within Iowa and North Carolina, the Social Security Administration database, state vital statistics offices, National Death Index, and various in-state databases, such as the listing of registered pesticide applicators. Individuals who enrolled into the study but who are no longer at the address given during enrollment (based on subsequent attempts at follow up) have been submitted and will continue to be submitted (through NIOSH) in the standard format to the IRS under their Project 057 Taxpayer Address Request Program. Identifying data provided to the IRS include only SSN and the first four letters of last name of cohort member. IRS provides in return the most current address in IRS records if a match (SSN + all four letter of last name) is found. The purpose of this effort is to identify members of the cohort who have moved out of state, to enable adjustment of person-years for incidence and mortality calculations. Persons who have moved out of state can be followed for vital status and cause of death, but not for cancer incidence.
Continuation of the protocol will provide a valuable epidemiologic resource to help prevent cancers in the future by identifying risk factors in the rural/agricultural environment. Because more cases of important cancer outcomes occur in this cohort every year, potential cancer causes can be evaluated with increased statistical power. Larger number of cases also allows for statistical control of confounding factors, making more meaningful conclusions about cancer risk, and, for some relatively infrequent cancers, such as the lyphomas and leukemias, greater follow-up time is necessary to make any meaningful observations.
|Condition or disease|
|Prostate Cancer Pesticide Exposure Lymphoma Multiple Myeloma|
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|Study Type :||Observational|
|Actual Enrollment :||89655 participants|
|Official Title:||The Main Agricultural Health Study - A Prospective Study of Cancer and Other Diseases Among Men and Women in Agriculture|
|Study Start Date :||April 30, 1993|
- Cancer incidence in pesticide applicators [ Time Frame: Was annual; now semi annually (cancer linkages) ]Identify and quantify cancer risks among men and women, whites,and minorities associated with specific direct pesticide exposuresand exposures to other agricultural agents.
- Non-cancer disease incidence in pesticide applicators [ Time Frame: Follow-up was every 5 years (to date); now to be every 3-5 years (CMS linkage) ]Evaluate non-cancer health risks associated with exposure to pesticides and other potential agricultural exposures, e.g.,neurotoxicity, reproductive hazards, asthma and other respiratorydiseases or symptoms, immunological toxicity, kidney disease, birth outcomes, and growth and development among offspring.
- Disease in spouses and children of farmers [ Time Frame: Cancer as annual; now semi annual; other diseases, about 3-5 years ]Evaluate the disease risks among spouses and children of farmers thatmay arise from indirect contact with agricultural chemicals (e.g., ambient air drifts, pesticide residues on rugs, furniture, and other items, transferring chemicals) and nonoccupational exposures (e.g.,applications to pets, in homes, and on gardens).
- measurement of pesticide and other agricultural exposures [ Time Frame: Follow-up was every 5 years (to date) ]Assess agricultural exposures using periodic interviews andenvironmental and biological monitoring
- Agricultural exposures and biomarkers of exposure, biologicaleffect, and biomarkers of pre-clinical disease and genetic susceptibilityfactors [ Time Frame: Follow-up was every 5 years (to date); now to be every 3-5 years (CMS linkage) ]Study the relationship between agricultural exposures, theoccurrence of biomarkers of exposure, biological effect, andbiomarkers of pre-clinical disease and genetic susceptibility factorsrelevant to carcinogenesis.
- Disease risk and dietary exposures [ Time Frame: Baseline and first follow-up only ]Identify and quantify cancer and other disease risks associated withdietary exposures and cooking practices and chemicals resultingfrom the cooking process.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00352924
|United States, Iowa|
|University of Iowa|
|Iowa City, Iowa, United States, 52242|
|United States, North Carolina|
|Research Triangle Institute|
|Research Triangle Park, North Carolina, United States, 27709|
|Principal Investigator:||Laura Beane-Freeman||National Cancer Institute (NCI)|