Kadar
Kejadian Barah di Kalangan Petani
- What
is the Agricultural Health Study?
In 1993, scientists from the National Cancer Institute, the
National Institute of Environmental Health Sciences, and the Environmental
Protection Agency (EPA) began a research project known as the Agricultural
Health Study (AHS) to evaluate the role of agricultural exposures in the
development of cancer and other diseases in members of the farming community.
The National Institute for Occupational Safety and Health joined the study in
2000.
The AHS is also providing an opportunity to assess the effects
of diet, cooking methods, and other lifestyle and genetic factors on the risks
of cancer and other diseases. The results will provide information that can be
used to create a safe work environment and a healthy lifestyle for agricultural
workers and their families.
- Who
are the participants?
The vast majority of the nearly 90,000 participants in the AHS
are either farmers or the wives of farmers; about 52,000 are farmers and 32,000
are wives of farmers. All of the participants were recruited in North Carolina
or Iowa.
Participants classified as "private pesticide
applicators" are farmers or nursery workers. The study also includes a
small percentage of "commercial pesticide applicators" from Iowa who
work for pest control companies or for businesses, such as warehouses or grain
mills, that use pesticides regularly; about 5,000 participants are commercial
applicators.
- What
are some of the cancer trends among farmers?
Farmers in many countries, including the United States, have
lower overall death rates and cancer rates than the general population. Lower
death rates among farmers for heart disease and cancers of the lung, esophagus, bladder, and colon, in particular, are thought to be due,
at least in part, to lower smoking rates, as well as more physically active
lifestyles and dietary factors.
However, compared with the general population, the rates for
certain diseases, including some types
of cancer, appear to be higher among agricultural workers, which may be related
to exposures that are common in their work environments. For example, farming
communities have higher rates of leukemia, non-Hodgkin lymphoma, multiple myeloma, and soft tissue sarcoma, as well as cancers of the
skin, lip, stomach, brain, and prostate.
Even though no one set of risk factors explains these higher
cancer rates, the range of environmental exposures in the farming community is
of concern. Farmers, farm workers, and farm family members may be exposed to
substances such as pesticides, engine exhausts, solvents, dusts, animal
viruses, fertilizers, fuels, and specific microbes that may account for these
elevated cancer rates. However, human studies reported to date have not allowed
researchers to sort out which of these factors may be linked to which cancer
types.
- What
types of information do AHS participants provide during the study?
From 1993 through 1997, when participants were being recruited
for the study, they completed a questionnaire about their crops and livestock,
the pesticides and personal protective equipment they used, how they applied
pesticides, and other things they may have been exposed to on the farm, such as
solvents, grain dusts, and welding fumes. They were also asked about nonfarm
activities and exposures that may affect disease risks, such as diet, exercise,
alcohol consumption, medical conditions, family history of cancer, other occupations, and
smoking history.
Since then, researchers have been using the following methods to
collect additional information:
o Computer-assisted
telephone interviews to gather information about pesticide use since study
enrollment, changes in health status, and detailed information about farming
and work practices.
o Mailed
dietary health questionnaires to gather detailed information about cooking
practices and diet.
o Collection
of buccal (cheek) cells to determine whether specific alterations found in DNA
are related to disease susceptibilities associated with agricultural exposures.
o Records
from cancer registries in each state to determine which participants developed
cancer.
o Records
from the U.S. National Death Index, a computerized index of death records
collected from all state vital statistics offices and available to scientists
for medical and health research.
In addition, a series of smaller analyses are focusing on risk
factors for specific diseases. These analyses may involve additional
questionnaires and the collection of blood, tumor, urine, or dust samples.
- What
have researchers learned so far about farmers and cancer risk?
Most of the cancer research in the AHS has focused on
pesticides, which are chemicals used to kill invasive insects, weeds, or small
animals. In some cases, relationships between these pesticides and human cancer
were examined for the first time in the AHS.
Thus far, researchers have evaluated more than 20 pesticides to
determine whether the farmers who use them have increased risks of developing
cancer. Some of these analyses have shown that people exposed to certain
pesticides have an increased risk of developing certain cancers, but further
research is needed to confirm these findings and to evaluate the potential
mechanisms by which pesticides might influence cancer risk.
For example, a study from the AHS reported in 2009 that people
who use the weed killer imazethapyr have increased risks of bladder cancer and
colon cancer. Imazethapyr is in a class of chemicals known as aromatic amines.
It was first used in the United States in 1989, and, since then, has been one
of the most commonly used herbicides for
killing weeds in soybean, dry bean, alfalfa, and other crop fields.
Studies in mice and rats led the EPA to classify imazethapyr as
unlikely to be a humancarcinogen. But, in the AHS, people with the
highest cumulative lifetime exposure had more than twice the risk (137 percent
increase in risk) of developing bladder cancer compared with those who had no
exposure to the chemical. Similarly, the risk of colon cancer (mostly tumors in
the proximal colon, where food enters during digestion) was nearly twice as
high as normal (78 percent increased risk) among farmers who had the highest
level of exposure compared with those who had no exposure to the chemical.
In addition, a condition called monoclonal gammopathy of undetermined significance (MGUS), which commonly precedes
multiple myeloma, was found in blood samples of men in the AHS at twice the
rate it was found in blood samples of men in Minnesota who were not part of the
AHS cohort. This increased risk of MGUS was observed among men who used the
chlorinated insecticide dieldrin, the fumigant mixture
carbon-tetrachloride/carbon disulfide, the fungicidechlorothalonil, and possibly other
pesticides. Now, a larger study within the AHS is looking more closely at the
risk of MGUS with use of specific pesticides.
In 2011, AHS researchers reported an analysis of farmers who use
the weed killer atrazine, which is a type of chemical known as a triazine. In
this analysis, farmers who used atrazine the most often had a similar overall
cancer risk to those who used atrazine the least often, but those with the
highest exposures had a slightly increased risk of thyroid cancer. However, the number of cancer
cases was too few for the finding to be considered conclusive.
Atrazine causes mammary tumors in rats but is not classified as
a carcinogen in humans. Atrazine is an endocrine disruptor—meaning that it
interferes with normal hormone signals in the body—as demonstrated in
amphibians, birds, and rodents that have been exposed to it at high
concentrations.
More information about what researchers have learned about
cancer, other health problems, and risk factors among farmers is available in
the AHS publications list.
Petani
petani di Amerika biasanya lebih cerdik dan lebih celik daripada petani petani
di Malaysia… Kebanyakan racun perosak tidak dapat mengenai kulit atau masuk
dalam rongga nafas petani di Amerika sebab mereka lebih cerdik dari kita…
Contohnya, mereka menggunakan helicopter kawalan jauh untuk aktiviti sembur
racun. Ada juga petani Amerika gunakan traktor yang bertutup cermin semasa
menyembur racun.
Lain
dengan petani2 di Malaysia, PPE yang digunakan hanyalah kulit mereka sahaja.
Racun dengan mudahnya menyerap melalui kulit dan seterusnya masuk ke dalam
aliran darah da nada kesan bioaccumulation. Selepas beberapa waktu, petani2
malang ini mungkin akan mendapat kanser, penyakit buah pinggang, sakit kulit,
sakit saraf, Parkinsonism, pekak dsbnya akibat keracunan bahan kimia!
Lebih
malang lagi apabila semburan Fogging nyamuk Aedes ada yang disembur kepada
masakan di restoran restoran makanan apabila aktiviti semburan wasap fogging
dilakukan dalam premis makanan.
Selain
itu, bagi membuatkan buah pisang masak dengan sekata, ada petani kita
menggunakan peraman buah bersama-sama karbaid!
.
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