Field report
Pesticides, Agriculture, and Hot Weather
in the Mississippi Delta
Steve Shapiro
Occupational Safety Branch
Field Operations Division
Office of Pesticide Programs
October 1990
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INTRODUCTION
I visited Mississippi during the week of August 27 - 31, 1990,
to assess problems of heat stress, pesticide handling, and the use of
protective clothing and equipment in agriculture under very hot, humid
conditions and to assess how these problems are managed. Earl
Dotter, a photographer under contract with EPA, travelled with me.
Robert McCarty of the Mississippi Department of Agriculture
and Commerce (MDAC) provided members of his staff to take us
around. Mike Ledlow, Mickey Sims, and Bobby Moore were
thoroughly knowledgeable guides. They took us to over 19 sites
where pesticides were handled and numerous other places where
people were doing field work in the heat.
After arriving in Jackson, we travelled west through
Mississippi's "Hill Country," visiting three aerial pesticide applicators,
and continued on to the Mississippi Delta, where we spent the
remainder of the week. On three afternoons, the temperature was
around 105°F. There had been no rain since about May 21. The
main crops we saw in the Delta were cotton, soybeans, and rice.
There were also significant crops of milo (a grain sorghum) and
pecans, and extensive "aquacultural" farming of catfish. We were told
that catfish ponds generally were built on pans of farms where the
soil was poorest.
AWARENESS OF PESTICIDE SAFETY
My impression from talking to aerial pesticide applicators was
that the State of Mississippi's pesticide program had an excellent
working relationship with them. Many people felt that pesticide
safety has improved greatly over the years and is continuing to
improve. The flying services we visited usually had one or two
planes. We were told that this is characteristic of flying services in
Mississippi and throughout the United States. Most aerial applicators
spoke with pride about their practices and the way their
mixing/loading stations were set up. Almost all the aerial
mixing/loading stations we saw were neat and well-kept. The ground
at most loading areas was covered with concrete, sloped towards a
drain for collecting the planes' wash water. Many aerial applicators
expressed interest in and enthusiasm for the work of EPA's
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Occupational Safety program. Some asked us what we thought they
might do to improve their operations.
The mixing/loading stations which we saw for ground
applications did not compare with those for aerial applications. One
aerial applicator complained that ground applicators were not
effectively regulated and "can do anything they want." A second
aerial applicator said that farmers who apply pesticides with ground
machines are allowed to do sloppy work and get away with illegal
disposal. One of our guides said that the state may increase
enforcement at "High Boy" tractor applications next year.
Many pilots, especially older pilots, spoke with respect about
the toxicity of pesticides and appreciated the trend towards pesticides
that were less "hot" (toxic). The loaders we met (people who mix
and load pesticides, who are called "loader boys" in Mississippi) did
not express an opinion about this issue. Most of these loaders were
younger men, who may have been working for the season at
minimum wage.
The loaders concentrated on loading the planes quickly. Some
wore shorts. Half wore tennis shoes. We saw only two loaders
wearing long-sleeved shirts. The choice of clothing most by loaders
was dictated more by the hot weather than concern about being
splashed or coming into routine contact with pesticide-covered
surfaces. Some loaders wore rubber gloves. Most did not. Few
wore protective aprons, although loaders at two different locations,
who had been working without aprons (one was wearing a sleeveless
shirt, the other a short-sleeved shin), put aprons on to demonstrate
mixing and loading in protective clothing for Earl's photographs. The
loader wearing a sleeveless shirt got very hot working with the apron
on.
We saw one loader with ten years' experience loading methyl
parathion. He wore a short-sleeved shirt and jeans with holes in the
front, but no protective clothing or equipment. The cuffs of his jeans
hung below his heels and were soaked with methyl parathion wash
water. Methyl parathion is a Tox I insecticide. More on methyl
parathion under "Hygiene and Protective Clothing" below.
At the only active ground application mixing/loading operation
we observed, two workers were mixing and loading pesticides into a
tank on a "High Boy" tractor. The loader wore a cap, a short-sleeved
shirt, long pants, leather shoes, and rubber gloves. The tractor driver
put on leather gloves when he helped with the loading. The
pesticides were Prep (Prep is ethephon, a plant growth regulator, Tox
I eye and skin irritant; full-length trousers, long-sleeved shirt,
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protective gloves, and goggles or face shield required on the label)
and Def 6 (Def 6 is butifos, a cotton defoliant, Tox IE; hat, long-
sleeved shirt, long-legged trousers, rubber or neoprene gloves required
on the label). The "High Boy" tractor had an enclosed cab with air-
conditioning and was similar to the other "High Boy" tractors that we
saw.
If loaders and applicators wore the protective clothing and
equipment required under EPA's proposed Worker Protection
Standards, it would be a significant departure from what we observed.
One pilot active with the Mississippi Agricultural Aviation Association
said that loaders wear protective clothing and equipment until the
weather gets hot. Another pilot said that the heat was "too much for
suiting up in protective clothing." More on protective clothing
below.
I was impressed by the levels of pride and awareness about
pesticide safety and the quality of the mixing/loading stations at the
aerial pesticide application operations we visited. Most aerial
applicators expressed a desire to do things right and were receptive to
making further improvements. While none of the handlers I observed
wore all the protective clothing and equipment required on the
pesticide labels, I believe that most would readily follow appropriate
protective measures, if these measures made sense in their working
environment.
PILOTS, COCKPITS, PESTICIDES, AND HEAT
The cockpits of agricultural aircraft can get very hot, due to a
"greenhouse effect" from the sun's radiation and to a tremendous
amount of heat coming off the engine, which is in front of the
cockpit. We were told that about half of all agricultural aircraft has
air-conditioning. Nearly every plane that we saw had air-conditioned
cockpits. Most pilots swore by their air-conditioning. A typical
comment was, "Air-conditioning is about the best thing that ever
happened to a pilot." Another pilot who had installed air-conditioning
on his planes said that he would no longer try to operate his business
without it. A third pilot said that pilots are "more alert" with air-
conditioning than they are without it. Most aerial applicators with
whom I spoke said that they appreciated the engineering controls
which have become available over the years to reduce their exposure
to pesticides.
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We saw several cockpit air-conditioning systems: air-driven,
electric, and engine-driven. One person told us that air-conditioning
pressurizes a cockpit with clean air. (The cockpit is either totally
enclosed or has a small air port on top towards the rear.) Another
person told us that cockpit seals are not sufficient to keep cockpits
free of pesticides. Most systems deliver cool air in front of the pilot,
directed towards the chest. One configuration that we saw delivers
air in two streams behind the pilot, above each shoulder.
Some pilots spoke about their experiences spraying pesticides
before they had air-conditioning. In Flora, Mississippi, Rudy _
Holcomb, a pilot who is also the president of the Mississippi
Agricultural Aviation Association, said that before air-conditioning in
cockpits became available, he would have a continual headache
throughout the flying season each year from May through October,
due to "poison" (pesticides) and the heat. He would also get what he
described as a "low burning" all over his body, lie awake all night,
and use nerve pills in order to sleep. These effects obviously
decrease a pilot's ability to fly safely.
Edgar Hobbs of the Mississippi Agricultural Aviation Board
(and a former spray pilot himself) and Buddy Box, an aerial
applicator, told how they used to experience psychotropic effects from
methyl parathion. They said they also knew other pilots who
experienced these effects. Methyl parathion would make them "do
crazy things." A powerful impulse would come over them and they
would find themselves flying their plane into familiar obstacles on a
field, such as a tree, because they felt a strong desire to clear these
obstacles out of the way. They also spoke about "pilot exhaustion"
arising from both the heat and long hours of flying. The issues of
psychotropic effects and exhaustion among pilots who do not have
air-conditioning may bear further investigation. [The subject of
psychotropic effects among aerial applicators is discussed in
"Organophosphorus Ester Insecticides: Chronic Toxicity:
Psychopathological Effects," in Ecobichon and Joy's Pesticides and
Neurological Diseases, CRC Press, Boca Raton, 1982, pp. 167-171.]
Other anecdotes we heard about pesticides and aerial
application safety included:
t A pilot said that he got sick from methyl parathion
last year during take off. Just before he took off,
he had helped "load" (perhaps both mix and load?)
methyl parathion.
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t A pilot found pyrethroids (such as Payoff, a Tox
I insecticide) going through the air-conditioning
system into the cockpit after the rubber cockpit
seals were no longer performing like new.
Pyrethroids are toxic to the nervous system. This
pilot said that, even though he has replaced the
rubber seals, his face "bums up" when he flies all
day long. His loader's face gets bumed too. He
stresses washing, but last year his loader got
pyrethroid in his eye. The loader had ignored the
pilot's instructions. The pilot said that he plans
next year to get a face guard for his establishment.
He also said that the "mental stress of the job and
mental fatigue" lead to pilot accidents.
A pilot gave us his assessment that most accidents
characteristically happen with a tank overload on a short strip, "usually
a heavy load, after lunch, mostly about 1 p.m." He and one other
applicator also noted that "when you're sweating, pesticides go right
through your skin."
One pilot said that, before he got air-conditioning, he would
keep cool by soaking towels in an ice water tank and flying with the
towels wrapped around him. On occasion, he would also have his
cockpit filled with cool water while he sat in it, transforming the
cockpit into a bathtub to cool him off.
We did not observe any pilots wearing protective clothing or
equipment for pesticides. The standard protective gear we saw pilots
using were crash helmets and shoulder harnesses. The pilots wore t-
shirts, short-sleeved shirts, trousers, and regular footwear.
The frequency that flying services washed the exteriors of their
planes differed from place to place. Some applicators said that they
routinely washed their planes daily or more often. Others said that
they did this once or twice a week. Many cockpit interiors are
coated with epoxy. Washing the interiors of planes ranged from once
a week to twice a year.
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MIXING AND LOADING
"Closed" mixing systems were used at many of the aerial
application establishments we visited. We saw a variety of models.
One applicator, Buddy Box, was building a mixing system himself
with his own innovative design. Another applicator showed us a
"totally hands-off mixing system he plans to install. Where closed
systems were used, we saw some loaders still doing secondary mixing
in open buckets and collecting and carrying dilute pesticides in open
buckets from washing out spray systems.
I have questions about the design of at least one of the
"closed" systems we saw. At one airstrip, a loader, dressed in shorts,
a short-sleeved jersey, a billed cap worn backwards, and tennis shoes,
was using a "Captain Crunch" system to mix methyl parathion. The
"Captain Crunch" slashes a five-gallon metal can through the bottom
and crushes and rinses it. As the loader crushed and rinsed one can,
I saw parathion splash out the rear of the device. I wonder whether
the parathion could have just as easily splashed out the front on the
loader. More on methyl parathion under "Hygiene and Protective
Clothing" below.
We saw some loaders using a "probe," a specially-designed
nozzle with a pointed end. (This device is also known as a "pressure
rinse nozzle.") A probe screws onto a standard water hose and serves
the combined functions of puncturing plastic containers, "triple-
rinsing" (actually power rinsing), and rendering the containers useless.
Probes were distributed widely under a special program of MDAC.
Many places used a device called a "dry couple," which
connects the hose coming off the mixing tank or holding tank to a
connection to a plane's pesticide tank. This seems like a good
device. We saw some spillage where dry couples were not used.
But there was also a little spillage with some of the dry couples we
saw. Some loaders wore rubber gloves when connecting and
disconnecting hoses to aircraft pesticide tanks, others did not.
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PESTICIDE CONTAINERS
One aerial applicator recounted how loaders used to get sick
from handling bags of Lannate insecticide because there were no
warnings on the bags. (Lannate is methomyl, a wettable powder, Tox
I; protective clothing, goggles, and respirators now required on the
label.) He also showed us containers of Blazer (the herbicide
acifluorfen, a Tox I eye and skin irritant) and Triton CS-7 (a Tox II
oil emulsifier spreader binder), which look similar and have the same
shape and colors. He was concerned that there could be accidental
poisoning if workers confuse these similar containers. This applicator
said that handling bags of pesticides used for rice was particularly hot
work. Another aerial applicator had a forklift truck for moving 55-
gallon pesticide drums, eliminating most manual handling of these
heavy containers.
We learned of several ways of how empty pesticide containers
were disposed. Some pesticide manufacturers and formulators have a
"boomerang" system, where they take back their 15- or 20-gallon
stainless steel drums for re-use. MDAC established a pilot program
in Washington County with the National Agricultural Chemicals
Association to collect triple-rinsed or power-rinsed containers. Plastic
and metal containers are separated and compacted and baled at a gin.
About 500 plastic containers make a bale. The products from
recycling include plastic flower pots and ~ pesticide containers. This
program is being expanded to other counties.
DRINKING WATER AND REST BREAKS
The most common vessels in which workers carried drinking
water to the fields were two- and three-gallon portable water coolers.
Equipment operators typically carried a cooler by their seat. Field
workers got water from coolers kept in the beds of pickup trucks.
Some workers said that they found the coldness of ice water
disagreeable and preferred cool water to ice water. Some farmers
supplemented drinking water for their workers with cans of soft drinks
kept in cooler chests. Three women "chopping cotton" (hoeing weeds
in a cotton field), who were not regular field workers, said they often
went the entire workday in the field from 7 a.m. to 1 p.m. without
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drinking any water because "it took too much time" to walk across
the field to the pickup truck to get water. No other workers indicated
that they found it inconvenient to go for drinking water. Drinking
water was available at virtually every work site we visited. Other
field workers told us how much water on average they drank during
the workday. This ranged from one gallon to two gallons.
The workers we observed seemed to pace themselves, taking
breaks when they thought they needed to. Two workers who were
Army veterans indicated the greatest awareness of keeping well-
hydrated and taking rest breaks to cool off. This is understandable,
given the Army's extensive program to prevent heat illness. One
worker, a member of a crew hand-rouguing a rice field, said that he
will customarily take a break for fifteen minutes, even for an hour, if
he gets very hot. The second worker, a Vietnam veteran who works
for his brother, offered a program on the spot to manage heat stress:
drink plenty of water, take breaks when you need them, and don't let
any employer push you to keep on working when you need a break
from the heat.
The Army had made believers in heat stress prevention out of
the two veterans. This is encouraging. Employer commitment and
effective worker training should be able to reduce substantially the
incidence of heat illness throughout agriculture, although use of
protective clothing presents some special problems.
One of the workers hand-rouguing rice said he often gets heat
cramps at night. We discussed the standard remedy for normally
healthy persons with heat cramps — light salting of food.
CANOPIES AND REDUCING HEAT
AT PESTICIDE MIXING STATIONS
While enclosed, air-conditioned cabs on mobile equipment were
in wide use, we also saw many open tractors. Canopies, which give
shade, were universally popular with workers. One tractor driver with
many years' experience said that this was the first year his tractor had
been equipped with a canopy. He said he didn't like air-conditioning,
but he liked his canopy.
There were canopies over many of the aerial applicator mixing
stations we visited. Loaders said that canopies made a big difference
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TRAINING
in reducing heat. One aerial applicator who had a canopy over the
mixing station at his home airstrip said that he did not have canopies
at his satellite air strips, but he was going to put them up.
Some mixing stations were equipped with fans, both to cool
the loaders and to blow pesticide fumes away. Most mixing stations
that we visited were not equipped with fans. In Yazoo City, an
applicator said that a fan had not worked out for his mixing station
because the wind often shifted in three different directions.
One farmer who operated his own flying service said his
pesticide handlers were given training every year. He said he didn't
see the need for the federal government to require training because he
already takes care of this on his own. No other person mentioned
training to us during the week.
HEAT STRESS AND PROTECTIVE CLOTHING
I sympathize with applicators over the problem of working in
protective clothing and equipment in the heat. One applicator said
that "the main threat to the loader is heat exhaustion." This sentiment
was echoed by others. We observed only one loader wearing nearly
all required protective clothing for the pesticide he was mixing, and
he was very hot. He was mixing and loading the insecticide Larvin
3.2 (thiodicarb, a Tox II insecticide/ovicide) in 105-degree heat. He
wore all the clothing indicated on the label, except for a head
covering. In addition, he wore a face shield, a rubber apron, and
rubber boots, which were not required by the Larvin label and which
undoubtedly added to his heat stress. He was still cooler than he
would have been had he been mixing methyl parathion wearing the
chemical-resistant protective coveralls required for handling methyl
parathion. All but one of the other loaders we saw mixed and loaded
pesticides, which just happened always to include methyl parathion or
Prep (both Tox I), in short-sleeved shirts and various inadequate
clothing ensembles.
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One person spoke of his and his workers' abhorrence of
wearing rubber boots on concrete. A loader at another establishment
spoke of the "impossibility" of wearing rubber boots on concrete.
What can be done for people for whom rubber boots are a problem?
Rubber boots are required for handling certain pesticides; concreting
the ground is an effective means to keep mixing/loading stations
sanitary and control pesticide-contaminated wash water from planes.
I discussed the use of cooling vests to make protective clothing
more tolerable for loaders in the heat. No one had ever heard of
cooling vests, but several applicators said they would like to try Them
out. I also discussed cooling vests with Robert McCarty. He said
that MDAC is amenable to a trial program to assess their suitability.
Most applicators may understandably consider it inhumane to
make their workers wear the full protective clothing ensembles
required on the labels of Tox I and Tox II pesticides in very hot
weather, unless effective cooling devices, such as cooling vests,
become available. I hope that EPA's heat stress management
program, the training requirements under the new Worker Protection
Standard, and related activities by MDAC will help.
HYGIENE AND PROTECTIVE CLOTHING
With few exceptions, the clothing we saw worn by most
loaders, pilots, and ground applicators seemed to be the same clothing
they wore outside of work. Most loaders and applicators wore regular
hot weather clothes, including short-sleeved or sleeveless shirts, shorts
or long-legged pants, and tennis shoes. Avoiding heat stress only
partially explains this.
At one operation, an aerial applicator said that he and his
workers do not wear protective gloves because the gloves are
uncomfenable. He also noted that methyl parathion is particularly
hard on the diaphragms inside aircraft spray nozzles. It distorts the
diaphragms' shape and they have to be replaced. He said that he and
his employees use their bare hands when they worked on sprays,
relying on "plenty of soap and water" to wash pesticides off
themselves. We watched one of his workers replacing spray
diaphragms with his bare hands after a plane had made a run with
methyl parathion. I told the applicator that there are manufacturers
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who make specially-lined gloves, which they claim are comfortable,
and I suggested that he ask MDAC where he can obtain these gloves.
Interestingly, one of the pilots who works for this applicator does not
get out of the cockpit at all during the workday, even to eat lunch.
He eats his lunch in the cockpit.
Two applicators told us that they used surgical gloves for
protection, throwing them away after each use.
Most applicators we met expressed a sincere desire to work
safely, but many did not view wearing protective clothing and
equipment as very important. Some pilots expressed awareness of
low-level and sub-clinical effects of exposures to pesticides. This is
understandable, given that the demands of flying safely require pilots
to have unimpaired mental performance. It may be that ground
workers accept or even ignore low-level symptoms and subtle
neurobehavioral effects of exposures to pesticides. Pilots are probably
getting exposures when they hold on to the exterior surfaces of their
planes with their bare hands while climbing in and out between loads
when they are applying Tox I and Tox II pesticides. (See
requirements for methyl parathion below.) Pesticides can also enter
enclosed cockpits through leaking cockpit seals, air ports, and, of
course, open air vents. I wonder how much exposures to certain
pesticides also affect applicators and loaders when they drive motor
vehicles outside of work.
Although some aerial applicators told us that their employees
were generally familiar with the requirements on pesticide labels, what
we saw indicated that they mainly relied for protection on their
mixing/loading equipment, minimal protective clothing (gloves) to no
protective clothing, and, at aerial stations, wash water for emergencies.
Some aerial applicators said that they and their workers wore
protective gloves or surgical gloves faithfully, although it was clearly
the preference of pilots and loaders at many establishments not to
wear gloves at all. At many of the aerial application establishments
we visited, the requirements for protective clothing and equipment
printed on the pesticide labels did not seem to be much of a concern;
the focus of attention, understandably, was on accomplishing the
immediate mixing/loading and application tasks at hand.
We did not see any handlers or applicators wearing ordinary
coveralls or chemical-resistant suits, nor did we see anyone wearing a
respirator for protection, even when a respirator was required, as it is
for open mixing of methyl parathion. Loaders would show us their
respirators when we asked to see them. All the respirators were the
dual-cartridge type and looked like new. We also saw two new
respirators hanging on a coat rack on the wall of the office of one
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flying service.
EPA's registration standard and the pesticide label for the Tox
I insecticide methyl parathion require loaders to wear a long-sleeved
shirt, long-legged pants, chemical-resistant gloves, a chemical-resistant
apron, and shoes and socks when closed mixing/loading systems are
used. Goggles or a face shield, must be worn when the system is
under pressure. A protective coverall or two-piece protective suit,
goggles or a face shield, a hood or wide-brimmed hat, chemical-
resistant shoes (or chemical-resistant shoe coverings or chemical-
resistant boots), and a pesticide respirator must be available nearby
and worn during repair and cleaning of application equipment or if
open mixing/loading is done. Pilots in enclosed cockpits must wear a
long-sleeved shirt, shoes, and socks; and wear chemical-resistant
gloves when getting in and out of the plane. Loaders and applicators
must shower and change to clean clothes before leaving the job.
Except for pilots wearing long-legged trousers, we saw no indication
that any of the above provisions were followed.
Some flying services used mobile homes or modular structures
for their offices. We saw bathtub/showers in the bathrooms of some
of them. The showers did not seem to be actively used. We saw
one bathtub used to store manuals and other documents. I don't think
it would be difficult for most flying services to upgrade their hygiene
program for pilots and loaders who handle methyl parathion and other
pesticides requiring stringent hygiene. But even if existing showers at
flying service offices were put into use, the problem of pilots and
loaders entering offices in contaminated clothing would remain, unless
a company built a change room connected to the bathroom, with a
separate entrance to the outside.
* * *
This trip broadened my perspective on problems of pesticide
handling and agriculture under very hot conditions. These problems
are common to other parts of the United States. I hope that the
insights gained from this trip can improve the work of EPA.
My travel was funded by the Agricultural Research Institute.
ARI was established by the National Academy of Sciences National
Board of Agriculture to link agricultural research in academia,
industry, and government. ARI's support and MDAC's assistance,
particularly that of Robert McCarty, Mike Ledlow, Mickey Sims, and
Bobby Moore, are deeply appreciated.
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