Human Experimentation at Hanford |
| YUFFEE: | Was it the first time that you were ever sort of a subject in
a research? |
| GAMERTSFELDER: | No. The first human experiment I know about was Dr.
Cantril. He wore a piece of uranium metal taped on his arm for quite a long
time, and it probably showed [slightly] red sometimes from chemical irritation.
(Material deleted. Dr. Gamertsfelder inserts the following for clarity
and accuracy:) |
| FISHER: | Some sort of irritation? |
| GAMERTSFELDER: | I think it was slight, but I never saw any report
about the experiment. And I doubt there was any formal report written.
I was involved in three separate experiments. The first of these experiments
involved four people who had a plutonium solution painted in a one-
inch-diameter circle on their upper arms. A protective plastic cup was taped
over the test area so the plutonium would not be removed while bathing.
Measurements of alpha radiation61 from the contaminated areas were
made with a cylindrical ionization chamber with thin plastic film.
Initial readings on all subjects were similar. Subsequent readings, taken at
various intervals over the next week, showed reduced detection of the alpha
radiation. The last reduction was about 20 percent, and the largest (mine) was
about 50 percent. The plutonium was removed after one week, by washing. Analysis
of urine samples from participants showed no positive results. |
| FISHER: | That's right. You were talking about some of the experiments. |
| GAMERTSFELDER: | We had a lab that routinely took samples of urine from
people in the plant, delivered bottles to the front door. |
| YUFFEE: | Sort of like the milkman?
(Material deleted. Dr. Gamertsfelder inserts the following for clarity
and accuracy:) |
| GAMERTSFELDER: | The process of measuring the plutonium content of
urine samples is quite complicated because the materials of which the counters
are made are also contaminated with natural radioactive elements which emit
alpha particles. The analytical procedure included tests of known standard
samples. The best people doing the analyses seemed to possess a combination of
neatness and precision that some otherwise-competent chemists could not supply. |
| YUFFEE: | That's funny. |
| GAMERTSFELDER: | It was peculiar. |
| FISHER: | Were these sort of tests done under the biology section that
you mentioned? |
| GAMERTSFELDER: | No, this was done under our regular—well, the
work started in our regular laboratory. When we got to where we thought we were
doing [well], we [made a separate] operation out of it. It was located in
downtown [Richland]. |
| YUFFEE: | Were you and your colleagues the only subjects in this
particular experiment? |
| GAMERTSFELDER: | Oh, no. [What I just described was the laboratory
which routinely tested people who worked with plutonium. The experiment with
plutonium on the arms was only done once.] |
| FISHER: | You said that [these were] the [only] experiments that you
knew of. Were there any other ones that you knew of? |
| GAMERTSFELDER: | [These were the only ones during the first time at
Hanford.] |
| FISHER: | Well, there was the milk, the ingestion of milk. |
| GAMERTSFELDER: | There was the milk. Yes, I drank milk and had my
thyroid measured. That was when I was there the second time.
The day after—well, my first measurement was very shortly after I drank
it, and the amount in the thyroid was low. I had a count the next day, and the
amount in the thyroid was high[er—about where it was expected to be]. That
day, I got on a train—no, I guess I flew—to Chicago. I had my thyroid
counted out at the Argonne Labs,62 and I was going to go down to Oak
Ridge, but I stopped. I had to see somebody down in Indiana, the University of
Indiana. I had to see somebody who Parker was on a committee with. |
| YUFFEE: | In Bloomington? |
| GAMERTSFELDER: | Yes. Then I went down to Oak Ridge, and got my thyroid
counted down there. And then I went to—I saw somebody that had nothing to
do with [the experiment]. Then I went to New York and went up to the place that
the state was running (where they sampled milk and things) and had my thyroid
counted there. [The lady in charge] wanted to know where I had been, so I had to
tell her a little bit about what was going on.
Then I got back and had my thyroid counted some more at Hanford. And all of
the points fell [into a nice smooth line, where thyroid iodine uptake63
was plotted against time on logarithmic paper]. The instruments at Argonne Labs—
they had a system which used four different counters, and one wasn't working.
But apparently, they had calibrated each counter separately so that they were
arranged in different places. Oak Ridge had two. What we had at Hanford was one
big one, right under the chin. |
| YUFFEE: | Were there any other subjects who drank milk, or was it just
yourself? |
| GAMERTSFELDER: | Oh, there were others. I don't remember what all of
the— |
| YUFFEE: | Were they all volunteers? |
| GAMERTSFELDER: | Oh, yes. |
| YUFFEE: | And all were people who worked at Battelle? |
| GAMERTSFELDER: | Yes. |
| YUFFEE: | Well, I guess, at that point it probably wasn't Battelle yet. |
| GAMERTSFELDER: | No, it wasn't. That was before Battelle. [It was
General Electric Company.] |
| FISHER: | Were they all lab—they were all scientists? They weren't
atomic workers or anything? |
| GAMERTSFELDER: | No. Well yes, they were. I don't guess there were any
weekly[-paid] [(semiskilled or trade)] personnel involved. They were all
monthly-paid people [(professionals with the requisite advanced degrees)], and
they knew something about what was going on. |
| YUFFEE: | Sure. And were there any other experiments or research with
human subjects that you know of? |
| FISHER: | There is a great story that I read about in Newell Stannard's64
book65 about a little joke you played on [Dr.] Harry Kornberg. |
| GAMERTSFELDER: | Oh, he put that in there? |
| FISHER: | He did. He certainly did. It takes up almost the whole page.
(laughter) |
| GAMERTSFELDER: | Yes, that was—oh yes, that was the tritium one. |
| FISHER: | That's right. He was running the Biology Division. |
| GAMERTSFELDER: | That was the tritium one. |
| YUFFEE: | He could not understand? |
| GAMERTSFELDER: | No. I—well, when I was in grade school, I made a
beautiful scar on my arm with ink and a red pencil. I tried that here, and I
couldn't get any thing that looked reasonable. Then, somebody suggested to me
that you could dissolve some red lead in Duco cement and put it on. That looked—that
could have been acceptable, except that when it got completely dry, it turned
the most horrible shade of pink.
(laughter) |
| GAMERTSFELDER: | In the process of getting that Duco cement off my arm,
I had a beautiful [appearance of] erythema.66 |
| FISHER: | Oh, boy. |
| YUFFEE: | I'm sure. |
| GAMERTSFELDER: | And I told Herb Parker about it. We were having a
staff meeting, and Harry Kornberg was there. We were waiting in his outer office
while Herb was finishing up with his visitor.
[The visitor left, and Herb came out, and without saying anything, gave
Harry a look that said, "How could you make such a mistake [as to let Carl
suffer a radiation burn]!" I relented the next day. Harry was leaving
town[, and I thought I should tell him].
(laughter) |
| FISHER: | He was apparently very frantic. |
| GAMERTSFELDER: | I called up to tell him, and he wasn't—he was
deliberately not available, I think. |
| FISHER: | That's very funny. Dr. Kornberg was quite concerned,
apparently, that he had made a mistake somewhere. |
| GAMERTSFELDER: | Well, he hadn't made it. |
| YUFFEE: | Oh, that's funny. |
| GAMERTSFELDER: | Well, I had to liven things up a little bit. |
|
|
| FISHER: | It's a great story. It's a great story.
Dr. Gamertsfelder, you mentioned once that the dust that was swirling all
throughout the southwest central Washington state on the Hanford reservation did
a number on some of your monitoring stations, on the bearings and
instrumentation like that. |
| GAMERTSFELDER: | Well, it did that. And we had some other—these
chambers, essentially large pencil chambers, large like this. (demonstrates
with his fingers) They [measured gamma radiation]. They worked fine.
We had some of them where we had punctured lots of holes and put some
aluminum foil in there. They didn't work at all. The birds[, attracted to shiny
objects,] just loved to punch holes in the aluminum foil. |
| FISHER: | I bet. |
| YUFFEE: | Oh, that's funny. |
| FISHER: | Well, was the dust a major consideration; the resuspension of
materials into the air? |
| GAMERTSFELDER: | No, the dust—the bearings, no. We could collect
the dust on the samples. It didn't interfere that way. Nothing indicated that
radioactivity was associated with the dust that we collected. |
| FISHER: | But the fact that the materials (not just the radioiodine but
maybe the plutonium) that would be released could blow around and would be
difficult to measure accurately, because it would blow from one spot to the
next, to the next, to the next. |
| GAMERTSFELDER: | Well, no. I've looked at that kind of stuff, and the
heavy stuff doesn't resuspend quite as easily as sand does. |
| FISHER: | Really? So you think the plutonium is more— |
| GAMERTSFELDER: | Well, I don't. And besides, plutonium you can
work on chemically to see if it's there. You don't have to test the whole bulk
of the sample. You can run it through a chemical process. I just don't think
plutonium travels much. There were—well, the major part of these were in
tanks in the 200 areas. |
| FISHER: | Sure. |
| GAMERTSFELDER: | Some dilute wastes were dumped into the ground out
there; enough to disturb the water table in the 200 areas. They ended up being
mounds of water. And being mounds, and left alone, they tend to distribute. Some
radioactivity got through and showed up in wells at the 300 area. |
| FISHER: | Sampling wells? |
| GAMERTSFELDER: | Yes. Well, they were [water] wells that were used.
They weren't drilled for samples. We drilled lots of wells for sampling, but I
don't think we drilled many in the 300 area. Some of those just existed, because
people had used that land beforehand. |
| FISHER: | Were you ever involved, or did you do any work, with a
special-hazards group? Did the Health Instruments Division ever participate in
any, or do any work that was done specially on command for a special hazards
group that may have existed? |
| GAMERTSFELDER: | That doesn't ring any bells. |
| FISHER: | —providing technical assistance to groups that were
responsible for emergency evacuation and things like that, making preparations? |
| GAMERTSFELDER: | You mean, at Hanford? |
| FISHER: | Yes. |
| GAMERTSFELDER: | I don't know. We had emergency practices. I remember
one practice, where the air in the valley seemed to be doing this (swirls
his finger). (laughs) |
| FISHER: | Swirling? |
| GAMERTSFELDER: | I wasn't sure that everybody who was taking data knew
the proper way to take meteorological data. Some of the people would call a
north wind [(a wind blowing from the north)] a south wind. |
| FISHER: | That's not good. |
| GAMERTSFELDER: | We had, at least during the early days, a 24-hour
coverage with somebody who knew health physics. He had a car, signed on at the
guard station. Sometimes you would find yourself talking to somebody in Texas.(laughs)
No, we had somebody who had a badge of some kind, had a car. The guards always
knew where somebody [who understood health physics] was. |
|
|
| FISHER: | You were on call in case something happened?
(Material deleted. Dr. Gamertsfelder inserts the following for clarity
and accuracy:) |
| GAMERTSFELDER: | Yes, I got called once. That was the second time I
was at Hanford. There had been a nuclear excursion in a plutonium recovery
operation, from waste materials no longer suitable for the production line.
I had never been in the building where the excursion happened. Here I was,
one of the first people called down to emergency headquarters, and some of the
other people who knew about the facility were off—Saturday morning, doing
other things. |
| FISHER: | Sure. |
| GAMERTSFELDER: | They dragged-in at various times. The manager of all
the on-plant health physics groups showed up, and took charge of all the health
physics data that was coming in.
Then, Herb Parker finally got around. He was one of the last ones to hear of
it. |
| FISHER: | Did that particular incident that you've described to us end
up having a name? Or, how did people refer to that? Did the committee you sit on
have some sort of name? |
| GAMERTSFELDER: | I don't know what the thing was called. If I take a
minute, I might be able to find a report on it—see if it has a name on it. |
| FISHER: | Well, okay. All right. |
| GAMERTSFELDER: | [Here are the titles of the official reports on the
nuclear excursion: An "Official Use Only" report titled Final
Report of Accidental Nuclear Excursion Recuplex Operation 234-5 Facility.
Date of incident: April 7, 1962. Prepared by: Investigating Committee, August
1962. The report has no document number. It was accompanied by an unclassified
document HW 61010 titled Accidental Nuclear Excursion Recuplex Operation
234- 5 Facility, April 7, 1962 Final Medical Report. There is also an
article in Health Physics 1963 Vol. 9, pages 757 to 768, titled "Dosimetry67
Investigation of the Recuplex Criticality Accident."
An appropriate name could be "The Recuplex Criticality Accident
Investigating Committee]."
The thing happened, and GE immediately formed a committee, with Miles
Leverett in charge of the committee. The next day, the AEC said they had to run
the committee. (laughs)
(Material deleted. Dr. Gamertsfelder inserts the following for clarity
and accuracy:)
In compliance with AEC Manual Chapter 0703, an AEC–HAPO commit
tee composed of two AEC employees (one of whom was the chairman) and five
General Electric employees was appointed by the manager, HOO (Hanford Operations
Office). The GE people were the ones originally picked by GE. The AEC chairman
then ran the meetings.
When we got to the technical [material], Miles Leverett ran the meetings.
Everything just worked just as smooth as anything. |
| YUFFEE: | Sure.
(Material deleted. Dr. Gamertsfelder inserts the following for clarity
and accuracy:) |
| GAMERTSFELDER: | There were three things necessary for the accident to
occur: (1) There had to be a plutonium solution on the floor with a depth
sufficient to cover the end of the hose; (2) the valve in the pipe connecting to
the hose line had to be open; and (3) there had to be at least a partial vacuum
in the tank in which the excursion happened. It was known that the tank that
collected the concentrated plutonium nitrate had overflowed. The problem with
this list is the fact that none of the operators remembers opening the valve.
The nuclear excursion did happen, and the three men nearest to the facility
saw the "blue glow," and all of them immediately left the building.
One of the men reacted rather poorly—he thought he was going to die. |
| FISHER: | The nervous guy? |
| GAMERTSFELDER: | Yes. |
| FISHER: | Doctor, was there any other AEC "interference"—I'll
use that term in quotation marks—like on this committee, on other
committees; you know, where they would demand to run, say, a human use
committee? Was there a human use committee established at Hanford while you were
there? |
| GAMERTSFELDER: | Not that I know of. |
| FISHER: | Not that early? |
| GAMERTSFELDER: | Well, this was— |
| FISHER: | In either the '40s or the '60s? |
| GAMERTSFELDER: | The '60s? No, I—no. |
| YUFFEE: | But you would have been aware had there been a human use
subcommittee in regard to using people? |
| GAMERTSFELDER: | I think so. [I do not know what you mean by "using
people."] I think so. Herb was—when I was at University of Chicago,
Herb was just like any other researcher, and everything. He was cooperative.
When he ended up being in charge, he was a difficult personality [some of the
time].
There was a time fairly early, when Herb was out of town, and I ran this
staff meeting for him. The guys unloaded on me. They had been trained [by] Du
Pont [and] had ideas on [how] things [operated], and Herb didn't behave that
way. (laughs)
When Herb came back, I told him what had happened, and he called a meeting,
and none of the guys would [say anything]. But Herb then tried to change. I
think he learned how to get along a little bit better. |
| YUFFEE: | Was that one of the reasons why you decided to go to
Cincinnati? |
| GAMERTSFELDER: | It was part of it. But I think my wife was another
part of it. I think if I could have taught her to wear green goggles, she might
have liked it better, but— (laughs) |
| FISHER: | What do you mean by that? |
| GAMERTSFELDER: | Things out there are brown, not green.
(laughter) |
| FISHER: | Oh, I got you. |
| GAMERTSFELDER: | She grew up in this country [(meaning Tennessee)]. |
| FISHER: | I understand. I went there for a week, and I was longing to
see green and trees myself.
Certainly your observations on Herb Parker are to be taken at face value,
because nobody worked more closely with him than you did. |
|
Work on the Apollo Project |
| (Material deleted. Dr. Gamertsfelder inserts the following for clarity
and accuracy:) |
| GAMERTSFELDER: | Well, that's right. I guess some other people were
close to him—C.M. Patterson and Jack Healy. C.M. Patterson (one of the Du
Pont trainees) went with Du Pont when they built the Savannah [River] plant. |
| FISHER: | When you left the second time, that was the last time you
worked out of Hanford? |
| GAMERTSFELDER: | Yes. That's when I went with the—well, into
essentially, the rocket business. I went with the group that was making a power
supply for the Apollo missions, using plutonium-238 as the source of heat to
generate electricity, using thermocouples.68 The fuel was carried
separately in a pyrolytic69 graphite container on the outside of the
Lunar Excursion Module (LEM) [(the moon landing vehicle)], and had to be put
into the generator after the astronauts landed on the moon.
After the Apollo missions, our source of funds was considerably reduced. And
for a while, I was involved in writing proposals for developing instrumentation
for earth resources satellites. And while that was interesting, I thought I was
better qualified to remain in the health physics field.
After some preliminary contact with friends in the AEC, I accepted an offer
to be interviewed by Dr. Forest Western, who was the Director of Radiation
Standards. During the interview, which included Lester Rogers who was Dr.
Western's deputy, I was told that Dr. Western was going to retire and Lester
Rogers would become the Director.
After the interview, I received an offer, which I accepted.
From then on I was mostly involved in defining "As Low As Possible"
(ALAP) standards by comparing the costs for the design, manufacture, and use of
waste treatment systems against costs to individuals and populations in the
vicinity of a reactor.
What had been known a ALAP became ALARA (As Low As Reasonably Achievable).
Lester Rogers left, and while there were things to do, there were other people
who could do them. So I decided to retire. And with my wife's blessing, we
bought a home in Knoxville, Tennessee.
. . . One guy wanted to hold the thing at pole-vaulter's pole length; the
most awkward way to handle the thing you could possibly think of.
Just a moment. (walks to the next room) |
| FISHER: | Sure. |
| GAMERTSFELDER: | (returns with a model of the Apollo spacecraft)
Well, we built it. We had to write a safety report about the thing. We talked to
GE management about it. We talked to the AEC about it. I don't know whether what
I have to say next ought to be recorded or not. I think you better turn it off.
(tape recorder turned off) |
|
Accidents at Hanford and Idaho |
| FISHER: | Okay. We're talking about the redox facility, or the "Parker
problem." |
| GAMERTSFELDER: | I was talking about a separate facility which was put
at the base of each stack [in the separations areas which was meant for gas
analyses. The B plant was never operated, and we used it for a laboratory.] |
| YUFFEE: | And this was to— |
| GAMERTSFELDER: | [We put a soil scientist in to test fission product
retention in soils. Every thing in this] building was stainless steel, if it was
metal. In the plant, everything was stainless steel except, somewhere in the
ductwork, some thing was not stainless steel that should have been [but rather,
a corrodible grade of steel], and they got rust particles that had contamination
on them. So that was one of our— |
| YUFFEE: | And these were getting through the [tall venting] stacks or
through the scrubbers [designed to cleanse the exhaust of radioactive
particles]? |
| GAMERTSFELDER: | They were getting through the stack, and they didn't
have scrubbers [at] that point. |
| YUFFEE: | Sure. |
| GAMERTSFELDER: | And they ended up putting in the sand filters, all of
that stuff, afterwards. But it was peculiar, because [the] safety showers in our
labs were stain less steel. (laughs) |
| FISHER: | That's funny. |
| GAMERTSFELDER: | We got some rust through. I guess I don't know any
more things. If you've got questions, I'll sure try to answer them. |
| FISHER: | I think we've got a couple. I'm still a little bit concerned
about what you thought, or how your ideas were received, on the feasibility of
trying to do—of trying to chart internal doses to people. That was an idea
that Herb Parker thought about a lot, I understand, about internal doses. |
| GAMERTSFELDER: | Well, I guess the most important one would be thyroid.
That was—we had methods of measuring what was actually in people's
thyroids. We had ways of measuring plutonium in people. |
| FISHER: | In the lungs? |
| GAMERTSFELDER: | That's the urinalysis. |
| FISHER: | How about in the lungs? |
| GAMERTSFELDER: | You would have to depend on knowing what they were
breathing. You don't go putting neutrons in people, trying to find a plutonium
particle. I guess that it could get into the bloodstream eventually—small
ones, right [(you understand)]? |
| FISHER: | But you did manage to persuade people in authority that
measurements of the thyroid were accurate and that it was feasible to measure
product [(plutonium)]? |
| GAMERTSFELDER: | Oh, sure. The thyroid measurements, after you got
these big sodium iodide crystals, it got to be an easy job and an accurate one. |
| FISHER: | And you feel that they were accurate, that you could stand by
those measurements? In fact, all of the procedures that you were involved with,
with the pencils and badges and the rings and film (film badges on people) you
thought that those, and still think I suppose, that they were reasonable and
acceptable and they did the job that was necessary? |
| GAMERTSFELDER: | Well, I would guess I—beta70
radiation to the hands, in uranium processing—I don't think we did a very
good job. I'm not sure a good job is possible. |
| FISHER: | Why is that? |
| GAMERTSFELDER: | Just, it's a hard problem. |
| FISHER: | Because of the hand, and— |
| GAMERTSFELDER: | The hands. We had rings on the fingers. We had little
pads put on finger tips, film. The film was a little sensitive to pressure, too.
I think we did the things we could do.
I only know of one guy who got in trouble and got some redness [(erythema)]
on his hands. That was down at Oak Ridge, and he was the optician who was making
gadgets for them to look through; to look at the back side of the pile, and
stuff of this kind. They were running a test of some kind on one of his
instruments. It hadn't behaved properly, and he couldn't wait to get his hands
on it. (laughs) |
| YUFFEE: | And it was hot [(radioactive)]? |
| GAMERTSFELDER: | And it turned out to be hot, and nobody caught him. He
got some redness on his hands. |
| YUFFEE: | Just erythema, nothing else? |
| GAMERTSFELDER: | I don't think there was any other damage. I don't know
how long he was around, either. It was known; we reported it. (laughter)
[(So the incident may have cost him his job.)] |
| YUFFEE: | Sure. |
| FISHER: | When we were talking earlier about the Green Run— I'm
wondering if you're aware of any other similar releases like that, either before
'49 or after '49, while you were there or while you were away. |
| GAMERTSFELDER: | Well, at the Idaho facility[, in the '50s] where we
were testing the jet engine running on our reactor, there were some releases.
There was the nuclear excursion [we discussed earlier].
As far as I know, everything that came out headed off down towards the south
end of the site—we were at the north end—or at the southwest side of
the site. And they ran out of being able to track the [radioactive] plume before
it had got to the edge of the Idaho test station. That was because it ran into
the mountains. |
| FISHER: | What was released? |
| GAMERTSFELDER: | All kinds of fission products. |
| FISHER: | And this was an excursion, not an intentional release? |
| GAMERTSFELDER: | This was an excursion. The rules were violated, and
the instrumentation was incapable of stopping itself. Mechanically, it could
work, but it couldn't get a signal. There was a second one, which was
deliberate. We had them fix up a special fuel element. Fuel elements were
something about that big (indicating) in layers. |
| YUFFEE: | Were they round, about two inches around? |
| GAMERTSFELDER: | Round, round. |
| FISHER: | About like a golf ball? |
| GAMERTSFELDER: | No, not—they were cylinders. |
| YUFFEE: | Oh, okay. |
| GAMERTSFELDER: | One cylinder inside another cylinder in segments about
this long (indicating). The fuel element was— |
| FISHER: | Oh, I see, like slugs. A couple of inches, almost like a big
slug? |
| GAMERTSFELDER: | It was this long. Well, a long slug, but with air
spaces in it. |
| YUFFEE: | Okay. |
| GAMERTSFELDER: | And we fixed this up with a device to chop off the
airflow to it. We had the slugs irradiated for a while, and then we let them
cool for a while so that we were only having iodine-131, really, to worry about.
We had a report on what kinds of things we expected to happen and whether we
wanted to run it in, and had a disagreement with the health physics group. The
health physics group there was run by the AEC, John Horan. He was more
conservative [about dose] than I think was necessary, and we argued for quite a
while.
In fact, I was in town arguing, when eventually our manager says, "Go
ahead and run it the way they want to run it." So I was on my way out to
the site [(50 miles away)] when it was run. It was run under weather conditions
which were rather more dispersive than what we had wanted to do. [During the
experiment, the wind direction did not change much, but the velocity increased
considerably.]
There was—the surveying offsite was done by the AEC. There were people
living about seven miles away, and I don't think they [(the health physics
group)] found anything of any significance there. If they had, they were on good
relations with the people there and would have given them milk and confiscated
any milk that—they had other people who had some cows there.
We found some iodine, something like 50, 60 miles away, in a slightly
different direction. And that turned out to be something that had been released
down in Nevada, gone west over the Pacific Ocean, up along the coastline, and
came back in, up the Columbia River Gorge. We could tell it was the bomb debris,
because we analyzed it, measured the half-lives, and [found] iodine around that
we hadn't put out there. |
| FISHER: | What year was this? |
| GAMERTSFELDER: | This would have been in the late ['50s]. I don't
remember exactly. |
| FISHER: | Sure. This was when you were working out of [Cincinnati]. |
| GAMERTSFELDER: | Yes. |
