Brain and Central Nervous System
Peripheral Nervous System
Immune System/
Blood
Bone Marrow
Respiratory
System
Lungs
Immune System
Lymphatic System
Spleen
Stomach
Connective
Tissues
Male
Reproductive
System
Kidney
Female
Reproductive
System
Prostate
Cancers for Further Study
Other Chronic Conditions for Further Study
Brain
Connective tissues (soft tissue sarcoma)
Immune system and blood:
Leukemia (bone marrow)
Multiple myeloma (bone marrow)
Hodgkin’s disease (lymphatic tissue)
Non-Hodgkin’s lymphoma (lymphatic tissue)
Lip and skin
Prostate
Stomach
Immune system: Altered function, Hypersensitivity (contact dermatitis, asthma) Autoimmune
diseases (rheumatoid arthritis, lupus)
Kidney disease
Nervous system: Neurobehavioral effects,
Parkinson’s disease
Reproductive effects (male and female):
Infertility, Unsuccessful pregnancy
Respiratory system: Reduced lung function,
Asthma, Toxic dust syndromes
Previous Studies Suggest Agricultural Exposures and Health
Problems Are Linked
Study Timeline
The scientists meet annually with
advisors to discuss progress and plans.
The National Advisory Panel is made
up of scientists, Cooperative Extension representatives, and farmers;
meetings are open to the public. Similar state advisory committees meet in
North Carolina and Iowa.
A Summary of the First 12 Years of a Long-term Study of Iowa and North Carolina Pesticide Applicators and Farm Families
For More Information
Visit www.aghealth.org
References:
Alavanja, M.C.R., D.P. Sandler, S.B. McMaster, S.H. Zahm,
C.J. McDonnell, C.F. Lynch, M. Pennybacker, N. Rothman, M. Dosemeci, A.E. Bond, and A. Blair. The Agricultural Health Study. Environmental Health Perspectives.
104:362-9 (1996).
Prepared by:
Julia F. Storm, W. Gregory Cope, and Wayne G. Buhler of
North Carolina Cooperative Extension at North Carolina
State University and Katherine McGinnis of the Eastern
Area Health Education Center at East Carolina University.
Edited by:
Dee Shore
Graphic Design by:
Greg Miller, Brenda Bunch, Sandy Smith, and Dana C. Babbs
1993-1997
1998-2003
2004-2008
2009-2013
Recruit and survey
participants
Test pesticide exposure
estimates; Collect
genetic sample
Assess disease rates and
risk factors
Evaluate disease
mechanisms
Participants Reflect North Carolina and Iowa Agriculture
By comparing agricultural census data, scientists have found that the study
participants and their farms are typical of farms and farmers in North Carolina
and Iowa:
• Iowa’s farmers grow mainly corn and soybeans and raise hogs.
• North Carolina farmers grow corn and soybeans as well as tobacco,
peanuts, cotton, and such vegetable crops as cucumbers, tomatoes
and watermelon. They also raise beef, poultry, and hogs.
• Iowa farms are larger on average than North Carolina farms.
• Farmers in both states are predominantly white men.
• African-Americans make up a small minority of North Carolina farmers.
The Study has also learned that:
• More than one-half of the farmers’ spouses report being active in farm work.
• The Iowa commercial applicators were younger on average (39 years) at
enrollment than the farmer pesticide applicators (47 years). Commercial
applicators report more varied pesticide application tasks than Iowa farmers.
• About 3% of pesticide applicators in the study are women.
Illustrated by:
Brenda Bunch and Grace Jenkins
Photos courtesy of:
United States Department of Agriculture’s Natural Resources
Conservation Service and the Department of CALS Communication Services in North Carolina State University’s College
of Agriculture and Life Sciences.
Reviewed by:
Agricultural Health Study Executive Committee:
Michael Alavanja, Aaron Blair, Joy Herrington, Cynthia Hines,
Jane Hoppin, Charles Knott, Charles Lynch, Dale Sandler,
Kent Thomas
Extension Educators:
Amy Brown, Roger Crickenberger, Jerry DeWitt, Bill Ellers,
Mark Shour, Suzanne Snedeker, Fred Whitford
Others:
Dennis Schwab, Iowa farmer; John Acquavella, Monsanto
Company; Ernest Hodgson, NC State University
Published by:
North Carolina Cooperative Extension Service
September 2004
100,000 copies of this document were printed at a cost of $14,760,
or $0.15 per copy.
Distributed in furtherance of the Acts of Congress of May 8 and June 30,
1914. Employment and program opportunities are offered to all people
regardless of race, color, national origin, sex, age, or disability. North Carolina State University, North Carolina A & T State University, U.S. Department
of Agriculture, and local governments cooperating.
AG-Med-24
This publication series is an education project of the Southern Coastal Agromedicine Center of the North Carolina
Agromedicine Institute and was funded by a grant from
the National Institute for Occupational Safety and Health.
SOUTHERN
COASTAL
AGROMEDICINE
CENTER
F
armers and their family members are generally thought to be very
healthy—after all, farming and farm life are physically demanding, and
food is plentiful. Scientific research supports this belief to a certain extent:
as a group, farmers live longer and have lower death rates from heart disease
and lung cancer than the general population. On the other hand, farmers have
a higher risk of injury, respiratory problems and skin conditions. Some studies
have also shown that farmers have a higher risk of certain types of cancer.
To answer questions about the agricultural community’s health, scientists from
several federal health agencies began the Agricultural Health Study in 1993.
This large, long-term study examines how lifestyle habits, genetic factors, and
agricultural exposures at work and in
the environment contribute to the risk
The Agricultural Health
of disease. Scientists from the National
Cancer Institute, the National Institute of
Study seeks to identify factors
Environmental
Health Sciences, and the
that promote health.
United States Environmental Protection
Agency are conducting the Agricultural
Health Study. They are collaborating with scientists at the National Institute
for Occupational Safety and Health, the University of Iowa, Battelle Centers
for Public Health Research and Evaluation in North Carolina and other research
institutions.
Certified farmer pesticide applicators and their spouses from North Carolina
and Iowa and licensed commercial pesticide applicators from Iowa volunteered to participate in this one-of-a-kind study. Thanks to the generosity of
the study’s 89,658 participants, scientists have begun to better understand the
relationship of pesticides, other agricultural exposures, and health. The Agricultural Health Study will provide information that those who work in agriculture
can use in making decisions about their health and the health of their families.
About this Series
Understanding the Agricultural Health Study
Part 1: Overview, Part 2: Pesticide Exposure,
Part 3: Health Findings is an educational
resource for the agricultural community.
The series was developed through a
collaboration of North Carolina State
University and Iowa State University
Extension educators and Agricultural
Health Study scientists and was funded
by the National Institute for Occupational
Safety and Health.
Agricultural Health Study
at a Glance
Lead scientists
• National Cancer Institute
• National Institute of Environmental Health
Sciences
• United States Environmental Protection Agency
Collaborating scientists
• National Institute for Occupational Safety
and Health
• University of Iowa College of Public Health
• Battelle Centers for Public Health Research
and Evaluation (North Carolina)
Study design: long-term follow-up
• Begin with large group of participants
• Evaluate health status into the future
Participants: certified pesticide applicators and
spouses (89,658)
• North Carolina (31,094)
- Farmers (20,518) and spouses (10,576)
• Iowa (58,564)
- Farmers (31,877) and spouses (21,771)
- Commercial pesticide applicators (4,916)
• Enrolled from 1993 to1997 at pesticide
safety classes or at home
Collection of information
• Participants provide information about pesticide
use, work habits, lifestyle habits and medical
history at enrollment and periodic updates.
Parents provide information on children under
age 18.
• Participants provide mouthwash sample
(cheek cells for genetic studies)
• Scientists collect information on deaths, cancers
and other diseases from health databases.
Measurement of pesticide exposure
(selected farms)
• Hand wipes, skin patches and air samples
from farmer pesticide applicators
• Urine samples from farmers, spouses, children
• House dust samples
Assessment of disease rates and risk factors
• Cancers
• Diseases or conditions of the immune,
respiratory, reproductive and nervous systems
• Other medical conditions
• Cause of death or injury
ICULTURA
GR
L
lymphoma, and cancers of the lip,
stomach, prostate, skin, brain, and connective tissue. Although there is uncertainty
about some of these studies, scientists suspect that pesticides may be linked to some
of these cancers. Laboratory animal studies
and some human studies indicate that
some farm environment exposures, mainly
pesticides, may influence some non-cancer
health problems of the immune system,
nervous system, kidneys, respiratory
system, and male and female reproductive
systems.
The Agricultural Health Study
addresses the weaknesses and gaps
in the previous population studies of
pesticide exposure and human health.
In addition, the study examines new
information about the whole array of
agricultural exposures and their relationship to health effects.
pants. They also obtain health information from state and national health
statistic databases. They ensure that
all information provided by or about
the participants is kept secure and
confidential. Project managers from
Westat, Inc. coordinate study activities among all of the collaborating
organizations.
Iowa and
North Carolina
EA
H
Farmers are healthier than the general
population in some respects: they live
longer and are less likely to die from
heart disease than the general population. Fewer farmers die of certain cancers
(lung, esophagus, bladder, and colon),
probably because farmers, in general,
are less likely to smoke, eat a healthy diet,
and get more physical activity. However,
farming is hazardous, and farmers are at
high risk for injury, non-cancerous respiratory disease, and skin problems. Farmers
are exposed to hazards such as pesticides,
infectious agents, naturally-produced
toxins, dusts, fuels, oils, engine exhaust,
fertilizers, dangerous equipment, weather
extremes, sunlight and noise.
According to some previous studies,
farmers have higher rates of some cancers, including Hodgkin’s disease, leukemia, multiple myeloma, non-Hodgkin’s
Dr. Michael Alavanja of the National
Cancer Institute (NCI) is the Director
of the Agricultural Health Study. Dr.
Alavanja and Dr. Aaron Blair of NCI,
Dr. Dale Sandler and Dr. Jane Hoppin
of the National Institutes of Environmental Health Sciences (NIEHS), and
Mr. Kent Thomas of the United States
Environmental Protection Agency
(EPA) collaborate to direct the study.
Ms. Cynthia Hines is the study liaison
at the National Institute for Occupational Safety and Health (NIOSH).
NCI scientists conduct the cancer
studies, while NIEHS scientists study
other chronic diseases. EPA and
NIOSH scientists assess pesticide
exposure. University scientists and
other researchers collaborate on
selected projects.
Study operations in North Carolina and Iowa are directed by Mr.
Charles Knott of the Battelle Centers
for Public Health Research and Evaluation and Dr. Charles Lynch of the
University of Iowa’s College of Public
Health respectively. These scientists
are in charge of enrolling and communicating with study participants
in their states. They collect and manage information from the surveys
and phone interviews and collect the
mouthwash samples from partici-
Y
Nervous System
The Agricultural Health Study is the
largest, most comprehensive study
of agricultural health ever conducted
in the United States. Several features
make the study unique and valuable.
The study design allows scientists to evaluate many diseases at the
same time. Because a large number
of participants are enrolled, even rare
diseases can be studied. Also, because
a comprehensive set of information
is collected and updated periodically
researchers can conduct many types of
health studies.
Because the study started with a
defined population, follows the participants into the future, and updates
information every few years, the information collected is of high quality.
The agricultural exposure and lifestyle
information is the most detailed ever
collected.
The Agricultural Health Study is
the first study to look comprehensively
at the health of women in an agricultural setting. Female certified pesticide
applicators and women living on farms
are participating in the study.
The Agricultural Health Study is
one of several long-term health studies
to collect genetic samples. The scientists asked participants to provide a
DNA sample using a simple technique:
rinse and spit. Those who agreed to
submit a genetic sample were provided
mouthwash and a sample container.
All they had to do was rinse their
mouths with the mouthwash, spit into
the container, and return the sample to
the scientists. The rinse contains cheek
cells from the inside lining of the
mouth. Like other cells in the body,
these cells contain DNA. By collecting
DNA samples, scientists will be able
to learn even more about the disease
process, including why some people
exposed to certain substances develop
disease while others exposed to the
same substances do not.
Health Scientists Collaborate on Agricultural Health Study
A
Agricultural Health Study
Has Unique Strengths
LT H S T U
D
www.aghealth.org
Agricultural Health Study Scientists Navigate a Maze of Information
Questions
Enroll people into the study
The study population is North Carolina and
Iowa farmers who are certified pesticide applicators, their spouses, and licensed commercial
applicators from Iowa. About two-thirds of
the 89,658 people in the study are applicators,
and one-third are spouses. Farmers and commercial applicators volunteered to participate
in the study at Cooperative Extension pesticide
applicator training classes held from 1993 to
1997. Spouses enrolled through the mail or over
the phone.
Collect exposure and health
information from participants
The scientists developed a formula to estimate pesticide exposure based
on participants’ pesticide use and work practices, using data from the
Pesticide Handlers Exposure Database and published exposure studies
as a guide. The formula estimates a level of exposure for each person
in the study for each chemical they used. To test the formula scientists
measured pesticide levels in urine and on skin of members of about 100
farm families before, during, and after a pesticide application. This and
other pesticide exposure studies are summarized in Understanding
the Agricultural Health Study Part 2: Pesticide Exposure.
Applicators filled out surveys at the
pesticide safety class and at home;
spouses filled out surveys at home or on
the phone. Parents provided information about children under age 18. For
participants, every step of the process is completely
voluntary. Scientists keep all information confidential
and secure, reporting results only in summary form so
that no individual information is ever reported. There
were about 250 questions in the initial survey, including
questions about:
farm-work-related exposures and practices
Participants were asked details about their use of
chemicals, including solvents, fertilizers and 50 specific
pesticides; their method of applying pesticides; and the
personal protective equipment they use. Other questions
addressed exposures such as dust, infectious agents and
toxins.
4
Our DNA serves as a genetic blueprint—the instructions for how our bodies function, including
how our bodies break down chemicals that we are
exposed to. Many study participants volunteered
to submit DNA samples through
the quick and easy rinse-andspit mouthwash method.
Scientists will use these samples
to learn more about how chemical exposures lead to illness.
environmental exposures
Participants were asked about their environment, such
as sources of drinking water, laundry and house cleaning practices, and home location in relation to fields, to
assess any potential for harmful exposures.
lifestyle choices
Participants provided information about their diet and
cooking practices, smoking,
alcohol consumption, and
physical activity.
PATIENT RECORD
001010110100011010001001010010010100000101001010
101001010001010110100010000101101000101011010001010110100000101011010
001100001001010010010100000101001010101001010001010110100010000101101
5
000101011010001010110100000101011010001101000100101001001010000010100
101010100101000101011010001000010110100010101101000101011010000010101
101000110100010010100100101000001010010101010010100010101101000100001
Collect information from health databases
011010001010100101011010001101000100101001001010000010100101010100101
000101011010001000010110100010101101000101011010000010101101000110000
Every year, scientists check North Carolina and
100101001001010000010100101010100101000101011010001000010110100010101
10100010101101000001010110100011010001001010010010100000101001010101
Iowa cancer registries for newly diagnosed can00101000101011010001000010110100010101101000101011010000010101101000
cers
among study participants. They also check
11010001001010010010100000101001010101001010001010110100010000101101
00010101001010110100011010001001010010010100000101001010101001010001
the North Carolina and Iowa death certificate
01011010001000010110100010101101000101011010000010101101000110000100
databases and the National Death Index to learn
10100100101000001010010101010010100010101101000100001011010001010110
10001010110100000101011010001101000100101001001010000010100101010100
if any participants have died.
10100010101101000100001011010001010110100010101101000001010110100011
01000100101001001010000010100101010100101000101011010001000010110100
01010100101011010001101000100101001001010000010100101010100101000101
Analyze the exposure and health
information
6
7 Repeat Steps 2, 5 & 6
A primary purpose of a long-term follow-up study is
to determine disease rates, focusing on the diseases
Scientists
are conducting
several types
that are diagnosed
in participants
after enrollment.
Theof studies, focusing Collect new or updated information
on the diseases
that are in
newly
diagnosed
scientists
are interested
the overall
rate in
of participants
cancer and after enrollment. from participants and databases
the rates of particular types of cancer in the Agricultural
A primary
purpose
of a prospective
cohort
is to
determine disHealth
Study
population.
After adjusting
forstudy
gender
and
As they follow the participants in
age,
they
compare
these
rates
to
those
of
the
general
ease rates. The scientists are interested in the overall rates of cancer and the Agricultural Health Study into
populations
in North Carolina
Iowa
same
the future, scientists use periodic
the rates of particular
types of and
cancer
in for
thethe
Agricultural
Health Study
diseases.
If
the
dispopulation. After adjusting for gender telephone interviews and mail
ease occurs more ofpare these rates to surveys to collect new or updated
and age, they comten in the Agricultural
health and exposure information.
those ofStudy
the general
populations in
Health
popuEven if applicators retire or change
North they
Carolina
Iowa for the same
lation,
wantand
to
jobs, scientists continue to include
diseases.
the disease occurs more
know
why.IfScientists
them in the study.
assess
whether
partural Health Study
often in
the Agriculticipants
withthey
greater
population,
want to know why.
exposures
are
More Questions
Scientists canassocialso
determine cancer
ated with greater risk
rates
for
participants
using
a
particular
of disease. Scientists
pesticide.
Scientists within the cohort over time to will use compariwill
use comparisons
sons within
therates
cohort
timeother
to learn
the rates of diseases other
learn
about the
of over
diseases
thanabout
cancer.
than cancer.
The
studies about
to evaluThe scientists
scientists conduct
look forcross-sectional
clues, or associations,
what factors may
ate
information
about
exposures
and
self-reported
have contributed to the disease by conducting nested case-control studsymptoms or diseases. These studies help scientists
ies. The
scientists
compare the
various
exposures
and lifestyles
learn
about
many ofclosely
the non-cancer
health
issues
that
of
people
within
the
cohort
diagnosed
with
the
disease
(cases)
to those
aren’t tracked in databases.
of people within the cohort without the disease (controls). A Parkinson?s
disease
study is understudies
way and
others the
are biological
scheduled.
Some
cross-sectional
evaluate
plausibility of health findings. Biologic samples such
The
scientists
conduct
cross-sectional
studies
to evaluate
information
as
urine
or blood
are collected
to identify
markers
of
about
exposures
and
self-reported
symptoms
or
diseases
that
was colexposure or early signs of disease. For example, a study
of
corn
growers
will
examine
measures
of
immune
lected entirely from the participant surveys. These studies help scientists
system
function
inof
relation
to pesticide
application
over
learn about
many
the non-cancer
health
issues that
aren?t tracked in
adatabases.
12 month period.
Scientists may follow up these studies with more in-depth
case-control studies. Other cross-sectional studies will evaluate the bioThe
scientists
look for
clues, findings.
or associations,
about will collect biologic
logical
plausibility
of health
These studies
factors
that
may
contribute
to
disease
by
conducting
samples such as urine or blood to identify markers of exposure or early
case-control
studies.
scientists
closely
compare
the will examine
signs of disease.
For The
example,
a study
of corn
growers
various exposures and lifestyles of people in the cohort
measures of immune system function in blood in relation to pesticide
diagnosed with the disease (cases) to those of people in
application
over a the
12 month
the
cohort without
diseaseperiod.
(controls). A Parkinson’s
disease study is underway and others are scheduled.
To underTo understand more about the role of genetics in disease, scientists will conduct laboratory studies of DNA
from participants who supplied mouthwash samples.
Answers
Health findings are summarized in Understanding the Agricultural Health Study Part 3: Health
Findings.
ULTUR
A
RIC
G
L
medical history and health status
Participants gave details about their medical history:
whether they or their close family members have been
diagnosed with such diseases as cancer, arthritis and
Parkinson’s disease; symptoms related to asthma and
other respiratory problems; and symptoms like numbness and blurry vision. Women provided information
about their menstrual cycles, pregnancies, and other
aspects of their reproductive health.
Collect a genetic sample from participants
6
Iowa and
North Carolina
H
EA
Y
1
2
x+y=z
3 Develop and test pesticide exposure estimates
A
Through the Agricultural Health Study, scientists are
looking for answers to many questions raised about
cancer and other health issues in the agricultural
population. The study is a long-term follow-up study
called a prospective cohort study. This means the study
involves a large group of volunteer participants (the cohort) who are followed into the future (prospective) to
determine who gets sick and who does not. The scientists look for associations, or links, between substances
the participants are exposed to and the health problems
they have over time. Follow the steps the scientists take
as they navigate a maze of information to discover the
answers to these questions.
LT H S T U
D
www.aghealth.org