EPA-600/3-77-122
October 1977
Ecological Research Series
MOVEMENT OF MERCURY-203 IN PLANTS
Environmental Monitoring and Support Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas, Nevada 89114
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S.
Environmental Protection Agency, have been grouped into five series. These
five broad categories were established to facilitate further development and
application of environmental technology. Elimination of traditional grouping
was consciously planned to foster technology transfer and a maximum
interface in related fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ECOLOGICAL RESEARCH series. This
series describes research on the effects of pollution on humans, plant and
animal species, and materials. Problems are assessed for their long- and
short-term influences. Investigations include formation, transport, and
pathway studies to determine the fate of pollutants and their effects. This work
provides the technical basis for setting standards to minimize undesirable
changes in living organisms in the aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical
Information Service, Springfield, Virginia 22161.
-------
EPA-600/3-77-122
October 1977
MOVEMENT OF MERCURY-203 IN PLANTS
Don D. Gay and Gene P. Butler
Monitoring Systems Research and Development Division
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada 89114
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
LAS VEGAS, NEVADA 89114
-------
DISCLAIMER
This report has been reviewed by the Environmental Monitoring and
Support Laboratory-Las Vegas, U.S. Environmental Protection Agency, and
approved for publication. Mention of trade names or commercial products
does not constitute endorsement or recommendation for use.
ii
-------
FOREWORD
Protection of the environment requires effective regulatory actions
which are based on sound technical and scientific information. This infor-
mation must include the quantitative description and linking of pollutant
sources, transport mechanisms, interactions, and resulting effects on man
and his environment. Because of the complexities involved, assessment of
specific pollutants in the environment requires a total systems approach
which transcends the media of air, water, and land. The Environmental
Monitoring and Support Laboratory-Las Vegas contributes to the formation
and enhancement of a sound integrated monitoring data base through multi-
disciplinary, multimedia programs designed to:
develop and optimize systems and strategies for moni-
toring pollutants and their impact on the environment
demonstrate new monitoring systems and technologies by
applying them to fulfill special monitoring needs of
the Agency's operating programs
Two varieties of peas were each planted in soil containing one of
three radioactive forms of mercury. The total uptake and distribution
of the three forms of mercury in the two pea varieties are not equal,
suggesting at least two separate pathways for mercury uptake and distri-
bution in plants. The conclusions can be beneficial in designing experi-
ments dealing with mercury compounds and plants and also in the interpre-
tation of data gathered by other investigators. Users who should find
the report of value include the Office of Air Programs, Office of Toxic
Substances, laboratories within the Office of Research and Development,
other Federal agencies, and university and industrial research staffs.
George B. Morgan
Director
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada
iii
-------
ACKNOWLEDGMENT
The authors gratefully acknowledge the assistance of Professor
Aaron Goldman, Department of Mathematics, University of Nevada, Las Vegas,
in the statistical treatment of the data obtained from this experiment.
iv
-------
INTRODUCTION
With the findings that the toxic methylmercury compound is being formed
in the environment through microorganisms-mediated transformation of inorganic
mercury compounds (Bisogni and Lawrence, 1973; Jensen and Jernelov, 1969;
Jernelov, 1970; Landner, 1971; McKinney, 1972; Spangler et_ alU , 1973; Wood
et^ al., 1968; Yamada, 1972; Yamada and Tonomura, 1972), through soil-mediated
transformation of mercury compounds (Alberts et^ al., 1974; Kimura and Miller,
1964; Jernelov, 1970; Beckert et^ al^. , 1974) and through plant-mediated trans-
formations of inorganic and organic mercury compounds (Fukunaga et_ al., 1972;
Gay, 1975; Gay, in press), the investigation of plant uptake of mercury needs
to be expanded to include the examination of the uptake and distribution of
different mercury species in plants.
The movement and storage of mercury in a variety of plants has been
determined by numerous investigators (Aarkrog and Lippert, 1971; Alvarez,
1974; Anderson and Nilsson, 1972; Barker, 1972; Bowden and McArthur, 1972;
Dae _et al. , 1966; DeGoey e± al., 1971; Fang, 1973; F.indenegg and Haunold,
1972; Friedman and Waiss, 1972; Fukunaga e_t al. , 1972; Gerdes £t al. , 1974;
Hauskrecht and Hajduuk, 1966; Imre and Berencsi, 1972; James e* al., 1971;
John, 1972; Lee e^ al., 1972; Nardin, 1971; Pickard e£ a^., 1963; Rao et^ _al. ,
1966; Ross and Steward, 1962; Saha e£ al. , 1970; Shacklette, 1965; Smart, 1964;
Smith, 1972; Stewart and Ross, 1967; Tanner et^ al., 1972; Tkachuk and Kuzina,
1972; Van Loon, 1974; Yamada, 1968; Yeaple, 1972). Almost all of this work
has shown the total levels of mercury in plants and plant parts via analyses
by atomic absorption spectrophotometry, by neutron activation or by gamma
spectroscopy using radioactive tracers. These investigations assume that
the mercury compound used to treat the plant remains the same throughout the
experiment.
Recent evidence suggests that this assumption-is not necessarily
warranted. Fukunaga et al. (1972) showed a trace amount of methylmercury
in rice plants treated with various phenylmercury compounds. Gay (1975)
and Gay (in press) showed that methylmercury is indeed formed in the garden
pea when it is treated with ionic mercury or phenylmercury compounds through
in vivo and in vitro studies. Siegel et al. (1974) have shown that a volatile
form of mercury is released from plants harvested near a volcano and allowed
to stand for periods of time before analysis. The mercury compound volati-
lized was not identified. Beauford et al. (1975) reported the release of
heavy metals from plants as being associated with the loss of cuticular wax
particles.
It is evident from these studies that the uptake of mercury by plants
is not a simple matter. The biological pathways of the various forms need
to be examined for an understanding of the potential hazard of mercury
pollution to mankind via the food chain.
-------
The present study was designed to assess the uptake, translocation and
storage of three forms of mercury via root uptake from contaminated soil.
Radioactive mercury-203, in the forms of mercuric acetate, methylmercuric
chloride and phenylmercuric acetate, were used. The garden pea, Pisum
sativum, was the plant of choice and two distinct varieties were used, a
dwarf variety, Little Marvel, and a normal variety, Alaska.
CONCLUSIONS
Two varieties of the garden pea, Pisurn sativum, were used. The dwarf
variety, Little Marvel, accumulated and stored about twice as much mercury
through root uptake from contaminated soils as the normal variety, Alaska'.
Phenylmercury was accumulated and stored in the dwarf and normal
varieties of peas at levels 7 and 10 times greater, respectively, than
methylmercury or ionic mercury. Phenylmercury was also stored at higher
levels in the pods than in the leaves or stems.
Two apparent pathways exist in peas for the movement and storage of
the three mercury compounds used. Ionic and methylmercury utilize one
pathway and phenylmercury utilizes another.
MATERIALS AND METHODS
Soil for the experiment was obtained from the University of Nevada
Agricultural Experiment Station at Logandale, Nevada, and had the follow-
ing characteristics: 54% sand, 11% clay, 35% silt, 1.3% organic carbon
and pH 8.6.
Three radioactive mercury-203 compounds (mercuric acetate, methyl-
mercuric chloride and phenylmercuric acetate) were obtained from New
England Nuclear at concentrations of one millicurie each. Each isotope
was handled separately to prevent any cross-contamination.
Sixty 12.7 centimeter (cm) plastic pots filled with approximately
1.3 kilograms of soil were used for each isotope. The total amount of soil
needed for each isotope was sieved through 12-mesh screen into plywood boxes
(91 cm in length, 61 cm in width, and 30 cm in height). The radioactive
mercury compounds were each added to one liter of distilled water and the
original containers were rinsed twice. Large plastic watering cans were
used to slowly spray the radioactive mercury solutions onto the soil in each
box while the soil was being mixed with a hoe. After the addition of the
radioactive mercury solutions, it was noted that small wet dirt balls had
formed throughout the soil. The soil mixture was dumped out of the boxes
onto large heavy pieces of plastic and sieved again a shovelful at a time.
In the sieving of each shovelful of soil, the small wet dirt balls were broken
up by scraping a trowel across the screen. When all of the soil was sieved
again, the box of soil was mixed again with a hoe and the 12.7 cm plastic
-------
pots were filled. Four pea seeds were planted in each pot; 30 pots received
the seeds from the dwarf variety and 30 pots received seeds of the normal
variety.
To prevent cross-contamination three special exposure chambers were
designed and built for each of the three radioactive mercury compounds.
The chambers were made of redwood and cedar frames covered with clear ace-
tate. All joints were sealed with 5 cm Permaseal plastic tape. The dimen-
sions of each chamber were 137 cm in height, 152 cm in length, and 91 cm in
width. A constant air flow of 1.7 m3 min~l was maintained through each
chamber. The air flow was through holes in the lower edge of the long sides
of each chamber, through a 12.7 cm diameter acetate plenum mounted length-
wise across the top of each chamber, through 12.7 cm stove pipe mounted down
one end of each chamber with a damper control, through a prefilter and two
activated charcoal filters mounted inside a fiberglass-lined plywood box and
through an exhaust fan, rated at 0.235 m^s"1 air flow,^ to the outside. Air
from all three chambers converged into the box containing the filters. A
platform made of redwood slats was placed 15.24 cm above the bottom of each
chamber on which the pots were placed. Each pot was watered twice a day at
8 a.m. and 4 p.m. A door 61 cm by 61 cm was made in the middle of one long
side of each chamber and a rubber gasket surrounded each opening. A 0.64 cm
thick piece of plexiglass was used for each door and each was secured by
eight bolts.
Two varieties of Pisum sativum in terms of overall growth were selected
for the experiment. A dwarf variety, Little Marvel, was selected because
it is a short plant displaying thick stems and large leaves. A normal
variety, Alaska, was selected because it attains a height 2 to 3 times
that of the dwarf and has smaller leaves and much less thickened stems
than displayed by the dwarf variety.
The peas were planted December 23 and the first harvest was on February
21 with subsequent harvests on February 28 and March 7. The plants were
divided into stems, leaves and pods to assess the amount of translocation
and storage occurring with each form of mercury. The plants from five pots,
randomly selected for each variety of pea, were harvested and pooled to
make up the sample from each mercury-amended soil. Each fraction was
weighed and sealed in 5 cm aluminum cans. The samples were analyzed at
the Las Vegas Laboratory and the results were corrected for background and
decay.
To assess significant differences among all the variables, a least
squares three-way analysis of covariance statistical procedure was used.
With the collection of plant samples weekly for 3 weeks, a test was needed
which would determine if there were any differences in sampling over time.
In the analysis of covariance test the covariant is the weekly sampling of
plant parts and is represented by the regression factor.
The interactions having significant differences at the 95% confidence
interval were further broken down by way of a Studentized Range Test to
determine where the differences occurred.
-------
RESULTS AND DISCUSSION
The soil-mixing technique was evaluated for thoroughness of distri-
bution of the radioactive mercury isotopes by taking 12 random samples
from each of the contaminated soils. The amount of soil used for each
sample was 100 grams and the soil was sealed in 5 cm aluminum cans and
analyzed by Nal (Tl) gamma spectroscopy. The 95% confidence intervals
for the different contaminated soils was the mean value ±1.3% for ionic
mercury, ±1.2% for phenylmercury and ±1.1% for methylmercury. The mixing
technique, though simple, is extremely thorough in distributing the radio-
active mercury throughout the soil.
The data realized from the experiment (see Table 1) is expressed in
picocuries per gram fresh weight of tissue. The data show the two pea
varieties used did not take up and store in their respective tissues, pods,
leaves, and stems, equivalent amounts of the three forms of mercury added
to the soil.
To determine where significant differences in mercury levels occurred
a least squares three-way analysis of covariance statistical procedure was
applied to the data (see Table 2). This analysis showed that significant
differences exist (1) among the three forms of mercury used, (2) between
the dwarf and normal varieties of peas, and (3) among selected pea tissues
analyzed.
A Studentized Range Test (SRT) at the 95% probability level showing
significant differences was used to determine where the significant dif-
ferences occurred.
When the measured levels of the three forms of mercury used in this
experiment are treated with the SRT, we find that the methylmercury level
does not significantly differ overall from ionic mercury level. However,
both methylmercury and ionic mercury levels differ significantly from the
phenylmercury level.
When the two pea varieties are treated with the SRT, we again find
overall significant differences in mercury levels between stems and leaves
and stems and pods but no significant difference between leaves and pods.
Applying the SRT to the form of mercury versus the pea variety factor,
we find that ionic mercury and methylmercury levels in Little Marvel or
Alaska peas differ significantly from phenylmercury levels in either Little
Marvel or Alaska peas and that the phenylmercury level in the Alaska peas
differs significantly from the phenylmercury level in the Little Marvel
peas. No significant difference was found between methylmercury and ionic
mercury levels in either Little Marvel or Alaska peas. Figure 1 depicts
the mean values for each form of mercury found in Alaska or Little Marvel
varieties of peas.
-------
TABLE 1. THE WET WEIGHTS AND AMOUNTS OF MERCURY-203 IN pCl/g
OF SELECTED PLANT PARTS HARVESTED WEEKLY FOR THREE
WEEKS FROM LITTLE MARVEL AND ALASKA PEAS
February 21
Hg Source
Methyl
Methyl
Ionic
Ionic
Phenyl
Phenyl
Peas
Alaska
Little
Marvel
Alaska
Little
Marvel
Alaska
Little
Marvel
Parts
Pods
Leaves
Stems
Pods
Leaves
Stems
Pods
Leaves
Stems
Pods
Leaves
Stems
Pods
Leaves
Stems
Pods
Leaves
Stems
Weight
0.69
3.74
3.33
7.20
4.62
2.00
1.46
3.01
2.78
6.27
3.67
1.57
1.79
5.47
5.48
4.40
3.20
1.17
pCi/R
39
62
38
31
140
57
18
79
23
110
220
140
780
540
480
980
880
630
February 28
Weight
(R)
1.97
6.14
6.60
7.88
4.30
1.89
3.00
5.37
4.98
5.07
2.59
1.22
3.49
4.89
5.68
3.48
3.11
1.20
pCi/l
44
51
28
140
180
130
39
65
24
65
150
74
710
470
370
1200
690
670
March 7
Weight
* (R)
1.24
4.25
5.51
8.23
4.07
1.38
4.77
3.17
3.55
3.37
1.40
0.87
2.72
7.30
8.02
2.73
0.98
0.99
pCi/s
42
43
14
70
110
57
53
110
27
150
380
270
490
310
230
1300
1100
540
-------
TABLE 2. LEAST SQUARES THREE-WAY ANALYSIS OF COVARIANCE
Source
DF
SS
MS
Form of Mercury
Pea Variety
Plant Parts
Form of Mercury
vs.
Pea Variety
Form of Mercury
vs.
Plant Parts
Pea Variety
vs.
Plant Parts
2
1
2
4,177,030 2,088,520 230.45*
494,256 494,256 54.54*
179,106 89,553 9.88*
285,798
399,450
17,562
142,899
99,863
8,781
*Denotes significance at the 95% confidence level,
DF = degrees of freedom
SS = sums of squares
MS = mean square
F = Fisher variance ratio
15.77*
11.02*
0.97
Form of Mercury
vs.
Pea Variety 4
vs.
Plant Parts
Regression 1
Error 35
42,547 10,637 1.17
67 67 0.007
317,203 9,063
-------
1000
900
800
METHYLMERCURY
ALASKA
LITTLE MARVEL
PEA VARIETY
Figure 1. Mean values of the total mercury found in the Alaska and
Little Marvel varieties of peas.
-------
1000
IONIC MERCURY
PHENYLMERCURY
POOS
LEAVES
PLANT PARTS
STEMS
Figure 2. Mean values of the amount of mercury in various parts of
the pea plant.
-------
Looking at the interaction between the three forms of mercury and
the three plant parts by way of the SRT, we find again the major differ-
ence between phenylmercury and each of the other two forms. Methylmercury
in the stems, leaves or pods and ionic mercury in the stems, leaves or
pods both differ significantly from phenylmercury in the stems, leaves or
pods. In addition it was noted that phenylmercury in the stems and leaves
differs significantly from phenylmercury in the pods.
Figure 2 depicts the mean values of the amounts of mercury found
in the various plant parts. The graph shows the close relationship
between methylmercury and ionic mercury and the disparity in relation
of each of these to phenylmercury.
Because no significant difference was noted for pea variety versus
plant parts in the analysis of covariance, the Studentized Range Test was
not applied.
The results from this experiment consistently show that phenylmercury
does not have the same pathway in either variety of peas as ionic or methyl-
mercury, which utilize the same pathway.
In a previous paper (Gay, 1975), it was shown that phenylmercury and
ionic mercury had different sites for their transformation to methylmercury.
Although both mercurials give rise to methylmercury when incubated with
plant tissues, maximum formation of methylmercury from phenylmercury
occurred in the apical regions while maximum formation of methylmercury
from ionic mercury occurred in subtending internodal regions. That
methylmercury is formed from either mercury compound is unusual, but to
have two apparent pathways for these transformations is totally an unexplor-
ed region.
This experiment supports the theory of separate but distinct pathways
for the metabolism and storage of different mercury compounds in plants.
Ubiquitous mercury levels in similar plants cannot be assumed because
this experiment, utilizing peas from the same genus and species but different
varieties, shows that highly significant differences in mercury levels exist
between two pea varieties.
REFERENCES
Aarkrog. A. and J. Lippert. "Direct contamination of barley with Cr,
59Fe, 58Ce, 65Zn, 203Hg, and 210Pb." Radiation Botany 11;6. pp. 462-72.
1971
Alberts, J. J., J. E. Schindler, R. W. Miller and D. E. Nutter. "Elemental
mercury evolution mediated by humic acid." Sci_ence_ 18^, pp. 895-897. 1974
Alvarez, R. "Sub-microgram per gram concentrations of mercury in orchard
leaves determined by isotope dilution and spark-source mass spectrometry."
Analytica Chimica Acta 73. pp. 33-38. 1974
-------
Anderson, A. and K. 0. Nilsson. "Enrichment of trace elements from sewage
sludge fertilizer in soils and plants." Ambio 1:5, 176-9. 1972
Barker, W. G. "Toxicity levels of mercury, lead, copper and zinc in tissue
culture systems of cauliflower, lettuce, potato, and carrot." Can. J. Bot.
50.:5, pp. 973-976. 1972
Beauford, W., J. Barber, and A. R. Barringer. "Heavy metal release from
plants into the atmosphere." Nature 256:5512, pp. 35-37. 1975
Beckert, W. F., A. A. Moghissi, F. H. F. Au, E. W. Bretthauer and J. C.
McFarlane. "Formation of methylmercury in a terrestrial environment."
Nature 249(5458), 674-675. 1974
Bisogni, J. J. and A. W. Lawrence. "Kinetics of microbially mediated
methylation of mercury in aerobic and anaerobic aquatic conditions."
U.S. Nat. Tech. Inform. Serv., PB Rep. No. 222025/9, 195 p. 1973
Bowden, J. A. and C. L. McArthur, III. "Mercury in bryophytes (mosses)."
Nature 235, pp. 229-230. 1972
Dae, H. A., J. C. Van Raaphorst, D. Hoede, and J. Zonderhulus. "The
determination (neutron activation analysis) of mercury in potato flour."
International Journal of Applied Radiation Isotopes 17:4, pp. 252-253. 1966
DeGoey, J. J. M. , J. P. W. Houtman, P. S. Tjioe, and J. H. Koeman. "Mercury
distribution levels observed in various ecosystems as determined by neutron
activation analysis." Report LRL-133-72-4. 1971
Fang, S. C. "Uptake and biotransformation of phenylmercury acetate by aquatic
organisms." Arch. Environ. Contain. Toxicol. !_:!, pp. 18-26. 1973
Findenegg, G. R. and E. Haunold. "Mercury uptake from various soils by summer
wheat." Bodenkultur 23;3. pp. 252-255. 1972
Friedman, M. and A. C. Waiss, Jr. "Mercury uptake by selected agriculutral
products and by-products." Environ. Sci. and Technol. j^:457. 1972
Fukunaga, K. , Y. Tsukano, and J. Kanazawa. "Residue analysis of organo-
mercury fungicides sprayed on rice plants." Environ. Toxicol. of Pesticides.
Academic Press, N.Y., pp. 177-191. 1972
Gay, D. D. "Methylmercury: Formation in Plants." International Conference
on Environmental Sensing and Assessment, Las Vegas, Nevada. 1975
Gay, D. D. "Biotransformation and Chemical Form of Mercury in Plants."
International Conference on Heavy Metals in the Environment Symposium (in
press). Toronto, Canada.
Gerdes, R. A., J. E. Hardcastle, and K. T. Stabenow. "Mercury content of
fresh fruits and vegetables." Chemosphere !_, pp. 13-18. 1974
10
-------
Hauskrecht, I. and J. Hajduuk. "Contents of Hg and other elements in the
leek Alium montanum F,.W. Schmidt, growing around exhalation sources of the
iron-ore factory in Rudnay." Biologia (Bratislava) 23. :9, pp. 676-680.
1966
Imre, R. A. and G. Berencsi. "Is contamination of the soil with mercury
reflected by the plants grown on it?" Zentralbl Bakteriol Parasitnekd
Infektionskr Hyg Erste Abt Prig Reihe B Hyg Praev Med 155:5,6, pp.
482-487. 1972
James, P. E., J. V. Lagervwerf, and R. F. Dudly. "Translocation of
mercury from seed treatment." Int. Symp. Ident. Meas. Envir. Pollut.
Proc., pp. 213-5. 1971
Jensen, S. and A, Jernelov. "Biological methylation of mercury in aquatic
organisms." Nature 223:753. 1969
Jernelov, A. "Release of methylmercury from sediments with layers contain-
ing inorganic mercury at different depths." Limnol. Oceanogr. l-5_:6, pp.
958-960. 1970
John, J. K. "Mercury uptake from soil by various plant species." Bull.
Environ. Contain. Toxicol. 8^2, pp. 77-80. 1972
Kimura, Y. and V. L. Miller. "The degradation of organomercury fungi-
cides in soil." Agricultural and Food Chem. JL2j3, pp. 253-257. 1964
Landner, L. "Biochemical model for the biological methylation of mercury
suggested from methylation studies in vivo with Neurospora crassa."
Nature 230, pp. 452-452. 1971
Lee, D. F., B. Thomas, J. A. Roughan, and E. D. Watters. "Mercury content
of some foodstuffs of vegetable origin." Pesticide Science 3, pp. 13-17.
1972
McKinney, Mi "Factors in the biochemical conversion of mercury pollutants
to toxic methylmercury effected by micro-organisms in marine sediment."
U.S. Nat. Tech. Infor. Serv. and Rep., No. 749674. 1972
Nardin, H. F. "Mercury residues in apple fruit sprayed with phenyl mercuric
chloride." Aust. J. Exp. Agr. Anim. Husb. 11:49, pp. 252-253. 1971
Pickard, J. A., J. T. Martin, and J. Grainger. "Spray application problems:
LXVIII. Mercury residues in ground crops." Long Ashton Agric. Hort. Res.
Sta. Univ. Bristol Ann. Rept. 1902, pp. 65-69. 1963
Rao, A. V., E. Fallin, and S. C. Fang. "Comparative study of uptake and
cellular distribution of 203Hg-labeled phenylmercuric acetate and mercuric
acetate by pea roots." Plant Physiol. ^L:443. 1966
11
-------
Ross, R. G. and D. K. R. Stewart. "Movement and accumulation of mercury
in apple trees and soil." Can. J. Plant Sci. 4.2:2, pp. 280-285. 1962
Saha, J. G., Y. W. Lee, R. D. Tinline, S. H. F. Chinn, and H. M. Austenson.
"Mercury residues in cereal grains from seeds or soil treated with organo-
mercury compounds." Can. J. Plant Sci. 5£:5, pp. 597-599. 1970
Shacklette, H. T. "Bryophytes associated with mineral deposits and solutions
in Alaska. U.S. Geol. Survey Prof. Paper, 1198C. 1965
Siegel, S. M., N. J. Puerner, and T. W. Speitel. "Release of volatile
mercury from vascular plants." Physiologia Plantarum 32;2, p. 174. 1974
Smart, N. A. "Mercury residues in potatoes following application of
foliar spray containing phenylmercuric chloride." J. Sci. Food Agric.
JL5, pp. 102-108. 1964
Smith, W. H. "Lead and mercury burden of woody plants." Science 180,
pp. 192-3. 1972
Spangler, W. J., J. L. Spigarette, J. M. Rose, and H. M. Miller.
"Methylmercury: Bacterial degradation in lake sediments." Science
180, pp. 192-2. 1973
Stewart, D. K. R. and R. G. Ross. "Mercury residues in apples in rela-
tion to spray date, variety and chemical composition of fungicide."
Can. Jour. Plant Sci. ^7:2, pp. 169-174. 1967
Tanner, J. T., M. H. Friedman, D. N. Lincoln, L. A. Ford, and M. Jaffee.
"Mercury content of common foods determined by neutron activation analysis."
Science 177:4054. pp. 1102-1103. 1972
Tkachuk, R. and F. D. Kuzina. "Mercury levels in wheat and other
cereals, oilseed and biological samples." J. Sci._ Food Agr. 23^:~LQ, pp.
1183-1195. 1972
Van Loon, J. C. "Mercury contamination of vegetation due to application
of sewage sludge as fertilizer." Environ. Letters 6:3, pp. 211-218. 1974
Wood, J. M., F. S. Kennedy, and C. G. Rosen. "Synthesis of methylmercury
compounds by extracts of a methanogenic bacterium. Nature 220, pp. 173-174.
1968
Yamada, M. "Microbial methylation of mercury in l^S environment." Hakko
Kogku Zasshi 50;12, pp. 901-909. 1972
Yamada, M. and K. Tonomura. "Formation of methylmercury from inorganic
mercury by Clostridium." Hakko Kogku Zasshi 50:12, pp. 893-900. 1972
Yamada, M. "Uptake of phenylraercuric acetate through the root of rice
and distribution of mercury in the rice plant." Nippon Nogei Kaishi
.42:7, pp. 435-439. 1968
12
-------
Yeaple, D. S. "Mercury in Broyophytes." Nature 235:5335, pp. 229-230
1972
13
*U. S. GOVERNMENT PRINTING OFFICE: 1977-785-182
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
1. REPORT NO.
EPA-600/3-77-122
3. RECIPIENT'S ACCESSION-NO.
4. TITLE ANDSUBTITLE
MOVEMENT OF MERCURY-203 IN PLANTS
5. REPORT DATE
October 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Don D. Gay and Gene P. Butler
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Monitoring and Support Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas. NV 89114
10. PROGRAM ELEMENT NO.
1AA602
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency-Las Vegas, NV
Office of Research and Development
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada 89114
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/07
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Seeds of Pisum sativum, varieties Little Marvel and Alaska, were planted in soils
contaminated with radioactive ionic mercury, methylmercury or phenylmercury
compounds. After maturation, stems, leaves, and pods were harvested and analyzed
by gamma spectroscopy. Utilizing a least squares three-way analysis of covariance
coupled with a Studentized Range Test, significant differences were noted among
the levels of the three mercury compounds in the plants, between mercury levels
in the two pea varieties and among mercury levels in the different pea tissues
examined.
Phenylmercury levels differed consistently from levels of ionic mercury and
methylmercury suggesting a separate pathway for it in peas.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIEBS/OPEN ENDED TERMS C. COSATI Field/Group
Plant physiology
Plant chemistry
Mercury
Trace elements
Leguminous plants
Absorption
Methylmercury
Phenylmercury
Mercurial transforma-
tion
Mercury uptake
Pisum sativum
06A
06C
06F
07B
07C
17C
8. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (THIS Report)
UNCLASSIFIED
21. NO. OF PAGES
20
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
------- |