6/94) = 3.855 3 6 angoo= 2.6 ooroo0 Fercent Alerrants, Propnase — Metaphase Plus Anaphase [ - Telophase ! oOcaec-a Percent Aberrants, Propnase | — Metaphase 1 (4.6 Total Aberrations) oewrococsa 'Cignt orvalents ana twa univalents. “Seve NM bivaleats and one quadrivalent. Nine bivalents and one fragment or ring. “Sampias 121 and 135 were collected in the vicinity of the other samples it were not close to a puint of known dase, ‘Values are not stattetically different at conventional levels based an “ain Whitney test, (2.4 Total Aberrations) Percent Aberrants, Anaghase | — Telophase ! a 100.0 323 57.6 2.4 610 160.0 582 96.4 23 we F Ooo Totals 3 JPercents 355 354 Om FO ee = Percents PK FRM OR OR Nh = NNO OG SHRUBS TROM OUTSICE [RRADIATED AREA nw Tatals Percent Aberrants, Anaphase | — Telophase | (9.3 Tatal Aberratrens} eoeceo-oge oro (15.7 Tata) Aberrations) Tha wo Q acraGooeoaoMmsoonm - 49 COK oR ooG0D0— 0.4 BE Tm - oo Percent Aberrants, Proonase | - Metaphase Plus Anaghase | — Telophase i « 254/1791 = 14.2% 148 1352 99.9 eo-oo00-NRK COON 149 TO TUmt roe = 213 27 1339 44.2 4] 34 159 61 “ 144 9 148 19 148 138 139 33 143 $a 133 “formal" Tatet Aberrat iuas al m~ ~ = Percent Aberrants, Prophase I — Metaphase I 160 398 0.7 a 0 2 12 213 Q 439 190.0 Nasa R/10 Year” Tatal Norma |" Tatal Anaphase I — Telophase I Abe rration s ONOTOooOwW- C000 Tolal (Qiceatrics oOnowroowe & ooon 2? x 3 There are still other uncertainties about the radiation history of this area which prevent assigning dose estimates to vegetation of the area with confidence. Although the area is at present accurately described as a chronic, low-level radiation area, there may have been, during the period of above ground tests at NTS fallout patterns which covered the area, since it lies to the east of Yucca Flat. This fact also casts some doubt on the radiation doses to those shrubs used as controls in this experiment which now occur in an area with In any event these latter what is considered a normal radiation background. shrubs are not subject to long-term chronic radtation, Fragments The radiation doses to vegetation at Site D, Area 11 were discussed in some detail earlier (Rhoads and Franks, 1975). Dose measurements from thermoluminescent dosimeters (TLDs) in the Field for 69 days extrapolated to a ten-year period provided estimated doses from 35 R to 140 R/10 years, at a height of 25 cm above the soil surface. These estimates at or near sampled shrubs are shown in Table 1. Since most of the shrubs, if not all, have been there since the initial contamination of the area in 1956, the doses will be uncertain for a shrub or a portion of a particular shrub. ‘These uncertainties will be discussed in some detail in a later section. In addition there is an uncertainty about a possible dose contribution from fission products which may or may not have accompanied the initial distribution of plutonium. Neither was the dose from americium production from decay of plutonium calculated in the dose. Because of these factors our dose estimates are probably low. The area can be characterized, however, as an area with a chronic dose from low-energy gamma emitters over a relatively long period of time. The beta component is thought to be small, but until there is a characterization of the radionuclides present this component of the radiation field cannot be evaluated. ‘ Multivatents Photographs were made of chromosomes using a 4 by 5 inch Polaroid-camera attachment providing both negative and positive images. Photographs reproduced herewith are from enlargements made from the Polaroid negatives. Propnase | - Aetapnase | K. parvifolia QL1,a,4* tions are only detectable in one or the other of these categories. was handled differently because only two of the ten plants examined were suitable for scoring in the late prophase I to metaphase I category. Most of the chromosomes in these stages were indistinguishable because they were clumped together. However, many cells in later stages were present and anaphase I to telophase I was scored separately from anaphase II to telophase II in the kK. parvifolia plants examined. About 150 cells were scored for each category per plant when suitable material was available. 7IT,al In both A. spinescens and M. tortifolia late prophase I to metaphase I cells were scored separately from anaphase I to telophase I because certain aberra- 81; ,21' those cells appearing to be Sample Nunber relative to SHRUAS FRO ST ED, AMZA 17, NTS (TARADIATEO! in several categories normal by using a hand-tally instrument to keep running counts. Pollen mother cell chromosomal aberrations in Artemisia spinescens aberrant celis Table l. Anthers were squashed directly on slides and cells were examined using Beeks' (1955) acetocarmine squash technique. Vials with buds collected in the field were coded when collected and this code number was carried over to the miecroscope slide. These were not decoded until after scoring, 1.e., scoring of the chromosome conditions was done blindly. Scoring was done in the following manner. The slides were systematically scanned under 200X magnification with a Zeiss phase contrast microscope. Detailed analysis of selected cells was done at 100X under an ofl immersion lens. Scoring consisted of counting