ML20151L992
| ML20151L992 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 04/30/1987 |
| From: | Hillman R BATTELLE NEW ENGLAND MARINE RESEARCH LABORATORY |
| To: | |
| Shared Package | |
| ML20151L940 | List: |
| References | |
| NUDOCS 8804220213 | |
| Download: ML20151L992 (9) | |
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- ATTAC!! MENT 2 a
%f Battelle New England Marine Research Laboratory l
Determination of Neoplasia in Sof t-Shell Clams MYa arenaria Near the Seabrook Nuclear Plant to Yankee Atomic Electric Company l
April 30,1937
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Study No. N-0954-9901 Report 8804220210 eso40s PDR ADOCK 05000443 I R f6ffc0 _ _ _ _ _______J
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Final Report ,
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I on Determination of b coplasia in Soft-Shell Clams Mya al enaria Near the i Seabrook lluclear Plant t
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I i Yankee Atomic Electric Company
! l April ,10,1987 l I
! Study No. N-0954-9901 ,
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, i R.E. Hillma n ,
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- BATTELLE OCEAN SCIENCES - .
! 397 Washington Street' L
- Duxbury, MA 02332 D
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4 TABLE OF CONTENTS Page i EX E C U TI V E S U M M A R Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 I N TR O D U CTI O N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . !
Ba ck gr o un d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 O b j e cti v e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 M ATERI A LS A N D M ETH O DS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 RESULTS.................................................................. 3
. D IS C U S S I O N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 R E F ER E N C ES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 LIST OF TABLES Table 1. Incidence of Neoplasia in Sof t-Shell Clam Populations Near the Seabrook Nuclear Power S tation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 e
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4 EXECUTIVE SUMM ARY There hsee been recent indications of an increase ia prevalence of neoplasia in sof t-shell clams along the east coast of the United States. The disease has been implicated in increased mortalities in those populations. To determine ws. ether the disease is present in sof t-shell clam populations near the Seabrook Nuclear Power Station, and whether the incidence increases seasonally, representative samples of clams were collected in October 1936 and February 1987 from three clam flats routinely monitored as part of the Seabrook monitoring program. The clams were delivered to Battelle Ocean Sciences in Duxbury, Massachusetts, for histological examination. In October,1 of 30 clams from Flat i and 2 of 23 clams from Flat 2 showed low levels of neoplastic cells. By February, the incidence of infection had risen to 2 of 30 clams from Flat I and S of 30 clams from Flat 2. Thirty clams from Flat 4 were examined during each period. No evidence of neoplastic cells was found in any clams from Flat 4.
The histological technique used to identify the neoplastic cells provides the most conservative estimate of the number of infected clams from a given population. It is likely that the estimate of 27 percent incidence of the disease in the Flat 2 populations is low, and that significant mortalities in that population might be expected this spring and summer. Disease-related mortalities are also likely to be elevated on Flat 1, but not to the extent of those on Flat 2. ;
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1 Final Report on ,
Determination of Neoplasia in Sof t-Shell Clams Mya arenaria Near the Seabrook Nuclear Plant to Yankee Atomic Electric Company April 30,1987 by R.E. Hillman BATTELLE OCEAN SCIENCES 397 Washington Street Duxbury, M A 02332 INTRODUCTION l Background j
Reports of neoplasms in field-collected bivalve molluscs have increased in recent years (e.g., see Lauckner,1983, and Couch and Harshbarger,1935, for reviews).
The incidence of a sarcomatous neoplasm in the sof t-shell clam Mva arenaria has especially increased in certain areas of the United States east coast (e.g., Barry r.nd 3
Yevich,1975; Farley,1976, Yevich and Barczsz, 1976, 1977, Brown et al., 1977, 1979; ,
Brown,1980; Walker et al.,1981; Cooper et al.,1982; Reinisch et al.,1984), and is !
considered epidemic in some locations of Maine, Massachusetts, and Maryland (Farley et al.,1986). Evidence for a viral etiology for the sarcomatous neoplasm was provided by i Appeldoorn and Oprandy (1980) and Oprandy et al. (1981), with possible enhancement of the disease by chemical pollutants (Reinisch et al.,1934).
Although the disease has been reported in most coastal states from Maryland north, no information was available from New Hampshire. In light of the possibility of neoplasms occurring in clam populations near the Seabrook Nuclear Power Station, with subsequent large-scale clam mortalities due to the disease, irrespective of plant operations, Yankee Atomic Electric Company contracted wit:. Battelle Ocean Sciences to
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determine whether neoplasms do indeed exist in ' Mva arenaria populations near t,'ie Seabrook Nuclear Power Station. Samples of clams were collected from three flats near the plant in October 1986 and processed histologically for evidence of the disease. It was ,
found that the disease existed at two of the three flats, but at low levels. Because the clams were collected at a time of year (early autumn) when the disease was less likely to be prevalent (Reinisch et al.,1984), and because the technique used to diagnose the disease (histological observations of fixed tissues) would most probably yield the most conservative results,it was felt that a second sampling later in the winter would be useful to determin:: whether the incidence was higher than in October.
Objective The objective of the study was to determine whether neoplasms exist in any of the sof t-shell clam populations near the Seabrook Nuclear Power Station, and whether there might be seasonal differences in prevalence of the disease. The existence of the disease was determined through histological examination of clams representative of the different populations. !
MATERIALS AND METHODS ,
Samples of sof t-shell clams Mva arenaria were collected from three clam 3 flats, Flat 1, Flat 2 and Flat 4, in the vicinity of the Seabrook Nuclear Power Station by personnel of Yankee Atomic's contractor. Clams were collected during the regular ;
sampling program in October 1986 and again in February 1987. In each case, the clams f were placed whole in Dietrich's fixative (Preece,1965) and delivered to Batte!!e for histological examination for neoplasia.
Upon arrival at the iaboratory, the clams were removed from their shells, rinsed briefly in running tap water, and transferred to 80 percent ethanol. Each clam was cross-sectioned into 3 to 5-mm cross sections. One to four sections were selected as j representative of the animal and processed for sectioning and staining. i The tissues were processed in an automatic tissue processor for routine paraffin sectioning. The paraffin-impregnated tissues were embedded in paraffin, sectioned at a thickness of 5 to 7 pm, and stained with Feuigen picromethyl blue (Farley, 1969). The stained slides were examined by light microscopy for evidence of neoplastic I
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cells. The slides were examined under high power (400x) for up to 10 minutes per slide. If no neoplastic cells were seen af ter 10 minutes, the tissue was rated as negative.
RESULTS The results of histological observations carried out on clams from the October 1986 and February 1937 samplings from three clam flats near the Seabrook Nuclear Power Station are summarized in Table 1.
Neoplastic cells were found in clams from Flats I and 2 during both the October and Februry samplings, with an increase in prevalence of the disease between October and February in the clams from each site. In February,2 of the 30 clams from Flat I contained neoplastic cells in an intermediate developmental stage as compared to 1 of 30 clams in an early stage in October, an increase in prevalence from 3 percent in October to 6 percent in February. In October, 2 of 23 clams showed eviderice of the disease, a prevalence of 7 percent. Both clams were in an early stage of infection. In February, 3 of 30 clams contained neoplastic cells, a prevalence of 27 percent. In addition, 2 other clams from Flat 2 contained cells that were possibly early neoplastic cells. These clams were rated negative. Five of the 8 infected clams were in an early stage of the disease,2 were in an intermediate condition, and I was in an advanced stage of the disease.
DISCUSSION Sarcomatous neoplasms of the type discussed in this study have been reported in east coast populations from both polluted and non-polluted areas (Barry and Yevich, 1975; Farley,1976, Yevich and Barszcz,1977; Brown et al., 1977,1979; Brown,1980; Cooper et al.,1982; Reinisch et al.,1980; Farley et al.,1936). The apparent initial cause of the disease is a virus similar to the B-type retroviruses (Oprandy et al.,1931), although the effects may be enhanced by environmental f actors, including domestic and industrial po!!utants (Reinisch et al.,1984).
1.aboratory and field studies indicate that infected clams die from the disease.
Farley et al. (1986) reported that individual diseased clams monitored in laboratory aquaria for a 3-month period progressed from early to advanced stages with 100 percent mortality, in addition, the same authors reported declines in prevalence on natural clam flats from high prevalences to zero back to high prevalences, again indicating 100 percent mortality among the infected clams and subsequent infection of the new year class.
4 On the basis of the existence of the disease in populations near the Seabrook Nuclear Power Station, it can be precicted that there will be some neoplasia-related mortalities, irrespective of power plant operations, in those populations. The highest prevalence of the disease was found on Flat 2. The techniques used in this study to ascertain the existence of neoplasia are very conservative. That is, they will confirm the existence of neoplasias but the prevalence is likely to be considerably higher than the technique reveals. It would seem, therefore, that significant disease-related mortalities of clams on at least Flat 2 are likely by late spring and early summer. Plat 1, where the prevalence of the neoplasias was only 6 percent in our study, may also have noticeable mortalities.
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5 REFERENCES Appeldoorn, R.S. and J.J. Oprandy. 1930. Tumors in soft-shell clams and the role played by a virus. Maritimes 24:4-6.
Barry, M.M. and P.P. Yevich. 1975. The ecological, chemical, and histopathological evaluation of an oil spill site. Part 111. Histopathological studies. Mar. Pollut.
Bull 6:171-173.
Brown, R.S. 1930. The value of the multicisciplinary approach to research on marine pollution effects as evidenced in a three-year study to determine the etiology and pathogenesis of neoplasia in the sof t-shell clam, Mva arenaria. Rapp. P.-
- v. Reun. Cons. int. Explor. Mer 179:125-123.
Brown, R.S., R.E. Wolke, S.B. Salla, and C.W. Brown. 1977. Prevalence of neoplasia in 10 New England populations of the sof t-shell clam (Mya arenaria). Ann. N.Y.
Acad. Sci. 298:522-534.
Brown, R.S., R.E. Wolke, C.W. Brown, and S.B. Sails. 1979. Hydrocarbon pollution and the prevalence of neoplasia in New England soft-shell clams (Mva arenaria).
In: Animals as Monitors of Environmental Pollutants. Nat. Acad. Sci.,
Washington, D.C., pp. 41-51. .
Cooper, K.R., R.S. Brown and P.W. Chang.1932. Accuracy of blood cytological screening techniques for the diagnosis of a possible hematopoietic neoplasm in the bivalve mollusc, Mva arenaria. J. Invert. Path. 39:291-298.
Couch, J.A. and J.C. Harshbarger. 1985. Effects of carcinogenic agents on aquatic animals: an environmental and experimental overview. Environ.
Carcinogenesis Revs. 3:63-105.
Farley, C.A. 1969. Probable neoplastic disease of the hematopoietic system in oysters (Crassostrea vireinica and Crassostrea gleas). Nat. Cancer Inst. Monogr.
31:541-555.
Farley, C.A.1976. Prollierative disorders in bivalve mollusks. Mar. Fish. Rev. 3S(10):30- ,
- 33. ,
Farley, C.A., S.V. Otto, and C.L. Reinisch. 1986. New occurrence of epizcotic sarcoma in Chesapeake Bay sof t shell clams, Mva arenaria. Fish. Bull. 34(4):351-357. ;
Lauckner, G. 1983. Diseases of Mollusca: Bivalvia. in: Kinne, O. (Ed.). Diseases of ;
Marine Animals. Vol.II. Biologische Anstalt Helgoland, Hamburg, pp. 477-961. !
Oprandy, J.J., P.W. Chang, A.D. Pronovost, K.R. Cooper, R.S. Brown, and V.J. Yates. I 1931. Isolation of a viral agent causing hematopoietic neoplasia in the sof t-shell clam, Mva arenaria. J. Invert. Path. 33:45-51. .
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TABLE 1. INCIDENCE OF NEOPLASIA IN SOFT-SHELL CLAM POPULATIONS NEAR
.; THE SEABROOK NUCLEAR POWER STATION i Number of Clams Number Prevalence of Examined Infected Infection (%)
d Site Oct. Feb. Oct. Feb. Oct. Feb.
Flat 1 30 30 1 2 3 6 Flat 2 23 30 2 3 7 27 Flat 4 33 30 0 0 0 0 a
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