Agricultural Health Study

We are no longer enrolling new participants, but rather following up with those already enrolled.

Your continued involvement will help future generations of farmers lead healthier lives. In addition, your participation ensures that the study results best reflect the experience of all farm families.

Research suggests that while agricultural workers may be healthier than the general population, they may experience higher rates of leukemia, myeloma, non-Hodgkin's lymphoma, and cancers of the lip, stomach, skin, brain, and prostate than people in more urban areas. Other conditions like asthma or neurological diseases may be related to agricultural exposures. The study focuses on agricultural factors that may affect these and other health outcomes, but more importantly seeks to identify factors that promote good health. Although the study enrolled farmers who obtained a license to apply restricted-use pesticides, farmers may have other exposures that affect their health. For example, they may have regular contact with animals or grain dusts that have been linked to asthma in susceptible individuals.

Commercial pesticides applicators and farmers handle many of the same chemicals although the methods of application and the frequency of exposure may differ. The AHS was designed to study the relationship between chemical exposures and health. Just as farmers may reduce exposure to chemicals that lead to disease by employing good work practices, commercial pesticide applicators also have opportunities to reduce their exposure to potentially harmful agents.

Study members are contacted periodically to provide updated information on their health and farm or pesticide application activities or to participate in special studies. Updating information on exposures and health is an important feature of long-term health studies. Participation is voluntary, but we hope that study members will recognize the importance of the information learned and be willing to continue to assist us in this important research effort.

Your ongoing participation, regardless of whether you are currently involved with farming, is important to the success of the Agricultural Health Study. Many of the health conditions of interest may occur many years after exposure to pesticides or other farm agents. It is important that we keep in touch with participants regardless of whether they are still farming. We especially need to include retired farmers and commercial applicators and those who stopped working for other reasons. If we only studied those who are still working, we might underestimate any long-term health risks associated with agricultural exposures. We recognize that retired farmers or those who are sick may not be up to completing long questionnaires. Questionnaires for those who are no longer farming are shorter because we will not need to collect information on work practices, and a proxy questionnaire is available for individuals needing someone to assist with their completion.

Privacy laws prohibit release of personal information that could be used to identify participants in research projects such as this. To protect privacy to the "full extent of the law," your name is separated from the information you provide, and an I.D. number was substituted at the field stations in Iowa and North Carolina. Your name and other personal identifying information are stored in locked files and secure servers at the coordinating center. Researchers generally have access only to portions of the data that have been coded in such a way that they cannot tell the identity (name, address, etc.) of participants. Access to the actual hand-completed questionnaires is restricted to key staff members who have signed privacy agreements which bind them to protect the privacy of study subjects. When we publicize results from the study, we only report summary information, never names of study members.

Results of research using AHS data are published in the scientific literature and information on these publications is provided on the AHS website. Study updates that are mailed directly to participants and shared with others in the agricultural community, such as county extension services, summarize key findings and provide updates on ongoing study activities.

We are trying to determine why some people who are exposed to certain toxins develop diseases, while others exposed to the same toxins do not. Genetics may explain some of this. We are using genetic information from cheek cells collected in the mouth rinse samples, combined with exposure information from questionnaires, to get a more complete picture of how exposures are associated with risk of developing specific health conditions. We are also using mouth rinse samples to investigate the bacteria that live inside the mouth (the oral microbiome) and determine their association with disease risk.

Participants will not be informed of individual results from tests done using the buccal cells. The tests we will conduct are for research purposes only. For most of these tests, we will not know how to interpret individual results in terms of risks or benefits. We will provide you with summary findings through periodic communications about research activities of the Agricultural Health Study.

Although you won't receive any direct benefits, the study may uncover factors that cause and prevent diseases among farmers and their families. Thus you will be helping all farmers and their families. Knowledge gained from this study can be used by the agricultural community to develop procedures for safer working conditions. Results from this study will also help us understand the risks associated with pesticides and other factors in the general population.

We are inviting the adult children of AHS participants to enroll in a new study focused on how growing up on a farm may impact health in early adulthood and beyond. We will ask this group to answer online surveys about childhood activities and their health.