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r PERSONNEL EXPOSURE TO HEXACHLORINATED ORGANICS AT THE CHLORINATED SOLVENTS PLANT 1981 DO 010800 CONFIDENTIAL r ENVIRONMENTAL HEALTH SURVEY REPORT 1981 PERSONNEL EXPOSURE TO HEXACHLORINATED ORGANICS AT THE CHLORINATED SOLVENTS PLANT INTRODUCTION A survey of personnel exposure to chlorinated hex compounds was conducted between August and October, 1981. Chemicals monitored were hexachloroethane (TLV 1,000 ppb), hexachlorobutadiene (TLV 50 ppb), and hexachloro- benzene (TLV 100 ppb). This report describes the time weighted average exposures of plant personnel over an 8 hour period. ANALYTICAL PARAMETERS A Varian, Model A600, gas chromatograph equipped with a Ni^ electron capture detector was used for the analyses. Chromatographic conditions were as follows: COLUMN 6' X " glass column, 3% SP2250 on Supelcoport TEMPERATURES Oven: Detector: Injector: 120C (5 minutes) programed at 25/min to 195C 300C 250C CARRIER GAS Nitrogen SAMPLE SIZE 1 microliter MONITORING PROCEDURE SP-1 personal sampler pumps were worn by employees while performing their normal duties. A k" X 0.25" glass tube, prepacked with Poropak QS chromato graphic column packing was attached to the end of a 2 foot length of PVC tubing connected to the sample pump inlet. The tube assembly was attached to the employee's clothing in the vicinity of the air breathed by the employee. SAMPLE PREPARATION Samples were desorbed by placing the Poropak packing into 10 ml. of Hexane and shaking periodically for 1 hour. Analysis was then performed by electron capture detection gas chromatography and the resulting peak area measured via integrator, calibrated daily. HEXACHLORINATED ORGANICS 1981 SURVEY Page - 2 ~ CALCULATIONS ppb(v) Where: ng X 2k.kS L X MW X RR ng - nanograms from integrator data 2k.kS - liters occupied by I mole of gas at sampling conditions L = liters of air sampled MW = molecular weight of component RR = recovery rate of component RESULTS AND DISCUSSION Table I gives individual hex exposures, grouped by job classification. Table II is a summary of 1981 survey results according to the job each person was performing at the time they were monitored. Table III is a comparison of overall survey results from 1976 through the current survey. Tables IV, V, and VI are survey comparisons for each of the three hexes broken down by job type. Table VII gives wipe sampling results. Table VIII is a summary of hex blood level results from 197^ through 1981. Reading from left to right in a straight line, the average blood level for personnel working in the block for the number of years given at the top of thecolumn is indicated. Directly below is the "high11 for that particu lar group. The next line, labelled indicates the number of people in each group. By reading diagonally, from upper left to lower right, It is possible to follow the yearly progress of each particular group of people. On the right side of the Table are three additional columns. The first gives the percent of all blood levels done each year (excluding those on persons in the block less than 1 year) that were above 150 ppm. The second column gives the number of levels above 150 ppm. The last column is the average of all those levels above 150 ppm in the given year. Because a change was made in 1981 in the analytical method used to determine blood hex levels, the values used on the chart for '81 are calculated values representing 73% of the blood levels actually reported. (This factor was determined by comparison of values reported on split samples run by both methods.) On next year's report, actual values from this year will be substituted for the calculated figures used in this report. 00 01080? CONFIDENTIAL HEXACHLORINATED ORGANICS 1981 SURVEY Page - 3 - RESULTS AND DISCUSSION (cont.) Survey results overall seem to indicate a leveling off of hex exposure following the dramatic drop seen after the major block clean-up in mid-'78. 1981 results show only slight variations (3 ppb) overall from the preceeding two surveys. The same trend is seen in levels of HCBz in the blood of block employees. Prior to 1978, HCBz blood levels of operations personnel hired into the block normally reached or exceeded 100 ppb within 2 to 3 years. However, of 35 people hired from 1976 to 1980, only 1 has exceeded 100 ppb (in '80) and this level returned to around the 60 to 70 ppb range on subsequent blood tests. Wipe samples were somewhat lower than in previous years. The highs on the '81 survey were just under 11,000 nanograms per wipe. And all samples exceeding 5,000 ng. were located in the hex area of Per/Tet and in the Thermal Oxidizer area. In the past, levels of 6 figures were common in these areas. Inside samples did not exceed 125 except on the floor just inside the control room outside door which was about 3700 ng. The good plant housekeeping which has been heavily encouraged for the past 3 years, appears to make a considerable difference, both in levels of hexes in the air and in the blood levels. It no longer seems quite so imperative to determine the exact source of hex accumulation in the blood - inhalation or skin absorption. Good operating practice, which has included respiratory protection and skin protection in the form of protective clothing, gloves and boots, combined with good plant housekeeping which prevents build-ups of hexes on outside equipment, seems to have arrested the climb of blood hex levels somewhere under 100 ppb in recent hires (last 5 years) while persons with previous high concentra tions continue to improve-although somewhat more slowly, perhaps, than might have been expected given the 2i year half-life of HCBz. However, it is a little early - at just under 3 years - to draw any firm conclusions about the effect of the plant clean-up on long-time block personnel with high blood levels. Perhaps the failure of new personnel to build levels above the 150 ppb biological limit can be considered an adequate indication of the effectiveness of the block hex control program. Sharon Miller Chlorinated Solvents DO 010803 CONFIDENT IAI TABLE I CHLORINATED SOLVENTS INDIVIDUAL HEX EXPOSURES BY JOB CLASSIFICATION 1 981 COMPONENT: TLV (ppb): ENGINEERS/OFFICE Bob Rouse Don Kruelskie Charlie Heard Jimmy J un k i n Steve Newe11 J.D. 0rr Steve Settle Leslee Grace Brett McLeod AVERAGE SHIFT SUPERVISORS Wayne DeLaune John Grissom Jesse Chemin Joe Debetaz Cliff Thibodeaux Wayne Landry AVERAGE HCE 1 ,000 .27 .95 .43 2.75 1 . 20 1.37 2.08 .57 1 .24 1.21 1.68 3.65 .67 . 14 2.85 2.80 1 .96 HCBd 50 .03 .23 .03 .51 .23 .50 .78 .25 .44 33 .52 1 .63 .23 .39 .29 .44 .58 HCBz 1 00 .38 .54 .79 .46 . 42 .36 .72 .96 .97 .62 ppb REMARKS: 14 hr.outside block, 1 plant walkthrough, inside Pint walkthrough,trip to bone yard,bal.inside Con.rm.4 hr, Vj 1 one hr, bal. in cont. bldg. 30 min.pint tour-TOX & back of pint,balance inside V201 4, TOX 4, comp.hs 4, inst.shpi,inside Hex 6 acid area walk through. balance inside. Acid sys 1, to warehouse once. balance inside. Secretary. Inside all day. Inst.shop 2 hr,outside 4 hr, balance inside 1.09 1 .83 .47 1 .00 .45 1 .82 1.11 ppb TOX area 4, warehs i,plnt rnd 3/4,inst.shp 4, maint.shp 4, D2C 5 min,balance inside. Meetings 7 hours, shop S cont. rm. 1 hr. Plant round. Inside balance. Walk thr: RiC, TOX, T16-17- AHC1 trlr maint. Plant rnd and inside. Plant rnd and inside. DO 0 1 0 8 0 4 CONFTDFNTT TABLE l (Page 2 ) INDIVIDUAL HEX EXPOSURE 1981 COMPONENT: HCE TLV (ppb): 1,000 O.S.'s James Godeaux Rickey Vaughn Clayton Duck Elmer Bourgeois 1.32 1.69 4.72 .67 Jesse Theriot Neal Donatto Wayne T. Landry Joe Doucette Don Zeringue Glen Rachal Ernest Lee Jeff Carpenter John Thibodeaux Sidney Hearns Wayne Miller .52 .49 4.24 5.78 1.41 1.00 2.14 5.70 3.34 1.89 2.50 AVERAGE 2.49 HCBd 50 .32 .39 1.79 .24 .20 .18 1.32 1.85 .54 .36 .55 .83 .32 .60 .78 .67 HCBz 100 -74 1.01 3-00 .57 1.49 1.03 5.19 8.19 .77 1.25 1.50 1.55 .79 .65 .65 1.89 REMARKS: 1/3 board, msiae ai i day. P/T board. Inside all day. P/T board. Inside all day. 123 SOT relief. T0X 1 hr, D55A i, C7D 1, wrehse 1 V2 area 1, AHC1 car . P/T board. Inside all day. 123 board. Inside all day. Rel .S.S. in Cn.Rm 4 hrs, train.in P/T 3i hrs, Rel .S.S. in Cn.Rm 11 hrs, ck.tnk.area Jr hr. P/T board. Inside all day. P/T board. Inside all day. P.T board. Bleed off C42 P.C. loop i bal. inside. Sample man relief.P/T smpls i, lab 2, inside balance. Rel. S.S. Plant walk thr., inside balance. EDO. T66 firewtch, E55C reboiler safety mtng li. Lab. catch 2 samples, rep.both crude GC's all day. TABLE I (Page 3) INDIVIDUAL HEX EXPOSURE 1981 COMPONENT: TLV (ppb): S.O.T.1s Ralph Butler Art Jackson Jerry Jackson Sidney Carriere Barry Boudreaux HCE 1 ,000 .83 5.36 1.47 6.56 5.00 Mike Brown 1.25 John Mathis Butch Prestonback 4.07 6.25 Huey Young Ralph Amar Alton Anderson Chip Brown Gary May Glyn Boudreaux Greg Chustz Mac McCraine Sharon Miller AVERAGE 4.97 4.79 2.97 2.63 .31 1.69 6.94 .53 .63 3.57 HCBd 50 .29 1.56 .40 1.96 1.32 .39 .72 .89 1.31 1.19 .79 .74 1.04 .55 2.57 .32 .23 1.02 HCBz 100 REMARKS: 38 .93 .84 2.93 7.16 .94 .73 1.02 4.42 .68 2.42 1 .24 .78 1.04 6.53 1.04 1.61 Load.coor. H2SO4 area 1, ck.tnk.area & shop, inside T0X man. Firewtch in T0X area 2, balance inside. P/T outside man. T0X SOT.Bleed DTH line , #'s area , T0X maint. 2, C-1002 smple, E16C work, D-13/F-700 area (purge hex 1ine) hr. TOX SOT. D67C hv.evap.2. Unplug D67C vent pot btm. line 2 hr, chk for P/T leak 1 hr, hook N2 to T96 vent 1 hr. TOX SOT. Pull strngr D67C pot - 2 min, ck tnk area , TOX area 1, shop , balance inside. P/T outside. Rod taps D67C reblr - 1 hr, comp.hse , drain C-59 frwrd flow 1, V201 & 1002 area round and sample. P/T outside. --rEDO.Stenci1 lines:T/C rck & Cdn.rck, TF to T63, T95 to T/C rack. Safety meeting. 123 outside SOT. Samples ea. 3 hrs, R52A temp probe, ck.tnk.area samples, C70 samples. P/T outside man. TOX SOT.System down. Safety observer 4, HC1 & P/T. 123 outside 3 hrs, 123 board train, balance. P/T SOT. round 1 hr, unplg E16 , prime ck.tnk pump 1 hr, C train , unplg D2c level , comp.rnd 1. Material Cont. Warehouse all day. Lab.Sample collect. , TOX (down) , bal.inside. 1.99 ppb DO 0 1 0 8 0 6 CONFTDFNTI 3> no 010807 TABLE 1 (Page 4 ) INDIVIDUAL HEX EXPOSURE 1981 COMPONENT: TLV (ppb): HCE 1,000 O.T.1s Randy Landry Craig Landry Rusty Carpenter Rodney Roubique Bobby Arnold Jeff Cooper Brian Joffrion Dean Hebert Ken Hal 1 Sidney Hotard AVERAGE .46 7.30 .19 2.68 1.06 1.75 .44 1.45 9.51 .84 2.57 NOT INCLUDED IN SURVEY: Darryl Lafleur 26.81 INSTRUMENT DEPARTMENT Leo Dronett Mark Rome Ernest Garner Mike LeBlanc Ernest Garner AVERAGE 3.16 .34 1.60 1.74 .15 1.40 HCBd 50 .18 10.23 .11 .41 .47 .37 .18 .45 .33 .22 1.30 12.21 .60 .19 .58 .42 .07 .37 HCBz 100 REMARKS: .88 .45 .77 .72 .71 .47 .69 1.07 .60 .42 .68 ppb ----EDO. AHC1/V2 i. Tank farm (107A,B) all day. Sample man. Smple collec. , lab l, AHC1 car leak 3i, cont. room 1 hr. AHC1 man. Routine. Sample man. Routine sample collection analysis. Strong hex smell on route between labs. AHC1 man. Routine. 123 samples i, CR 1, AHC1 4 hrs. AHC1 man. Sample man. Smple collec. 2 hr,lab 2, saf.mtng 3/4. Sample man. Routine smpling + T-5&6 (P/T) , AHC1 aid Load Man. Tnk.frm CR 1, lab 3 3/4, Cn.Rck , HC1 TT rck 2 hr. 2.23 Load man. Wore pump 4 hours then got per spilled on him. Not around concentrated hexes at all. 8.16 2.52 .67 13-76 1.81 5.38 ppb Inst. Super. Inst, shop 3 hr, PCS. 2 hr, Con.rm. 1, Contr.Rm. 1. Calibrate oxygen analyzers 1 hr, block limit 2 hr, balance in C.R. shop. Ret.canal pH, Inst, shop, tank farm pH. sosoto OCJ TABLE I (Page 5 ) INDIVIDUAL HEX EXPOSURE 1981 COMPONENT: HCE TLV (ppb): 1 ,000 MILLWRIGHTS Al Bahan 1.61 HCBd 50 .26 Huey White, Jr. AVERAGE 4.93 3.27 2.54 1.40 PIPEFITTERS John Tul1ier Warren 01ivier Al Falcon Dan Falcon Joe DeRose Greg Marks Greg Marks Jackie Haydel Daryl Levigne Robert Richard Daryl Levigne AVERAGE PAINTER Willie Cooley o SUPERVISOR Phil Dozier 2.53 .11 1 .06 1.95 .80 18.15 3-29 5.67 2.10 14.62 37.09 7.94 8.81 1 .00 .20 .09 .22 91 30 10.43 3.87 2.50 .50 1.97 14.61 3.24 12.19 32 HCBz 100 REMARKS: .52 2.40 1.46 ppb P22D (acid) 1 hr, P93A & C91 reflx (B-tri), C70 in shop (123), balance inside. Change hex pump 1 hr (FF mask), P22D. .81 .40 .63 2.76 .84 7.14 3-47 2.79 .93 2.32 21.02 3.92 ppb AHC1 for measurements, balance shop. Tank farm, acid system (alot of fumes) Acid area 2 hr, shop 6 hours. Remove hex line from 123 to oxydizer 7 hrs. P/T 4 hrs., street 4 hrs (AHC1 car spill) In shop al1 day. T14 top i, piperack by C.R. 4, shop rest of day. Hex piping removal. Remove hex line 123 to oxydizer 7 hrs. .86 Worked on T0X ditch putting material in buckets. 2.68 TABLE I (Page 6 ) INDIVIDUAL HEX EXPOSURE 1981 COMPONENT: TLV (ppb): LABORERS Willy Hynes Greg Skidmore Dennis Thomas HCE 1 ,000 1.61 1.65 3.02 AVERAGE 2.09 ELECTRICIANS Roy Hebert Ron Ducote AVERAGE 3.48 5.62 4.55 HCBd 50 1.29 .24 1.19 .90 .90 .53 -72 HCBz 100 1.13 -99 5-36 2.49 ppb REMARKS: Janitor. Inside all day. 123 area in AM, street in PM (AHC1 car spill) 11 n 4.34 3.20 3-77 ppb All day in cont. rm. & N.W. motor cont. center. DO 0 1 0 8 0 9 CO NFIDENT! OVERALL CONTRACT AVG. 6.22 OVERALL DOW AVERAGE 2.47 2.88 .80 3.26 1.76 j> 'l Q `w i| d 8 2O 6 TABLE 11 1981 HEX SURVEY RESULT SUMMARY BY JOB (Results in parts per billion) Engineers, office Shift SuDervisors Relief Supervisors Lab Loading EDO........ Per/Tet Board 123 Board Per/Tet Outside Man 123 SOT Instrument Men AHC1 Man Sample Man TOX Man Material Cont. HCE 1.21 1.96 45 1.56 .84 2.38 1.91 .90 5.49 1.64 1.4o .86 5.33 4.52 .53 HCBD .33 .58 1.17 50 .26 .66 .64 .25 1.49 49 37. .28 2.45 1.35 .32 HCBz .62 1.11 4.72 1.13 .40 .74 .74 .89 3.23 1.24 5.38, .66 .88 2.14 1.04 tD Overall Averaae 2.5.. . .8 1.8 fl dz T.L.V. 1000 50 100 Exp. as % of TLV 0/3* 2% 1% o DO 01 OHIO CONFIDENTIAL TABLE 111 'Solvents HEX Survey Comparison --a 1 *n-- <rr- irr -.i -s -- - =!r. f76 '77 '77 '78 '78 '79 '81 Hexachloroethane nnw CONTRACT / 7.3 27.8 3.8 19.8 56.3 37.8 29.2 2.6 6.1 2.5 1.8 9.4 6.2 HFXAr.m ORORUTADIFNF DOW CONTRACT 20. ^ ?q.8 20.7 29.2 11 .q 7.1 q.6 7.0 2.3 0.8 2.6 3.2 2.9 HFXArHI nRDRFN7FNF DOW CONTRACT 3.9 13.0 2.7 10.1 10.4 9.8 8.9 1.0 1.5 _ J J3 . .6 1.3 3.3 TLV 1000 - 50 inn tUOJ tUoJ <L/U5 iUhJ - to" UJ "UtoJ1" O<to a5." <to ay. <to Q'T<to Da3:to Ds_: sto t". r^. 00 O' " 1 ------ zo-- --- --2Q- z /"* -------LtO-U----CD ------ t^LoU---CO ------ UCOJ CO---- - ' U*tCoaOJr oo LTV z - o z 3 ------ *UtoJ--m tUoJ --------CO : tUoJ OX<to - 00 z . 0 .. LtoU CD _z c LJL7 U l UEJ 1 1 CONFTDFNTTAL TLV 1,000 PPb TABLE IV * PERSONNEL EXPOSURE TO HEXACHLOROETHANE BY JOB CLASSIFICATION (in PPb ) 0i \0 '75 '76 '77 '77 00 '79 '81 Enaineers. office Shift Supervisors O.S. Per/Tet Relief Vo. 123 S.O.T. Per/Tet Sample Man 123 TOX Material Cont. O.T. Sample Man AHC1 69.8 32.7 17.2 23.4 10.0 7.8 9.5 20.3 23.0 5.9 14.6 42.1 20.0 5.2 17.3 18.5 22.0 2.6 3.3. 2.5 6.0 1.4 l.7_ 3.0 2.5 2.5 1 .2 2.0 1.9 4.5 0.9 6.5 7.6 38.4. 40.0 _ 3._5 16.5 2.7 2.5 13.2 _ 5-^5.______ see O.T. 1.6 4.5 0.5 25.5 3,6 _ 5.. 3_ 1.4 5.4 0.9 _ Lab Loadinq EDO Instrument men Contract Laborers Pipefitters Mi 1Iwrights Electrician Pa i nter -v 30.3 6.4 14.4 19-0 3.8 16.5 26,_5 24.4 76.7 32.9 35.0 22.5 2.1 3,6 _ 1.6 0.8 2.6 7.5 4.1 10.9 2.4 1.4 1.0 3.8 0.9 _4.3_ ... 52.8 4.6 2.1 7.9 3.3 4.6 8.8 .OVERALL AVERAGE._D0W. OVERALL AVERAGE,. CONTRA :t. DO 010817 CONFTDFNT TA1. 7.3. 3.8 27,8 19.8 56.3 37.8 29.2 _ 2.6 1.8 6.1 9.4 2.5 _ 6.2 TLV 50 PPb Table v PERSONNEL EXPOSURE TO HEXACHLOROBUTADIENE by JOB CLASSIFICATION (PPb) 0 o 0 aa Z< o100' 0zk 8: IS "a 00X0u Sfc *m 20 tWK 5 K#o0 z Ma L-0 111 @5 05*0 o i t0ai B. 3fit 0. fJ<uz(9t t *1 aZ < 0< pi oz '75 76 '77 n 78 78 79 '81 Engineers, office 5.7 14.2 17.9 13.8 5-5 3.3 1.6 0.3 Shift Supervisors 6.2 24.2 9.9 5.9 7-0 1.7 3.5 0.6 O.S. 23.5 39-0 11.5 Per/Tet (board) 3.A 17.4 22.1 4.9 1.1 0.6 0.6 _ Relief 1.0 1-3 1.2 V,. 123 5.0 4.0 1.5 0.7 0.3 S.O.T. Per/Tet Sample Man 123 TOX Material Cont. O.T. Sample Man AHC1 19.6 28.6 17.7 10.7 35.6 34.1 5.0 3.0 4.3 1.5 2.0 44.1 19.0 2.0 see 'OT" 0.5 1.4 1.0 0.3 0.6 0.8 1.6 2.8 2.5 0.3 Lab ., Load Ina EDO Instrument Men Contract Laborers P i Defitters Mi 1Iwriqhts Electrician Painter A.6 13.7 23.0 2.7_ 20.1 30.0 13.1 5.7_ 22.9 6.6 4.6 2.6 K8 - T. 3 0.5 2.6 1.1 4.2 3.0 0.3 _ 0.7 0.4 0.7 7.1 0.9 2.0 15.0 1.9 0.9 3.2 1.4 0.7 12.2 0 Overall Avg. DOW 20.3 ?n 7 29.8 29.2 11.5 7. 1 010833 CONFTDFMTTai 5.6 2.0 2.6 2.3 3.2 0.8 2.9 --1 1 OO CO LH -4* TLV 100 PPb (To go to 150 nq in blood) PERSONNEL EXPOSURE TO HEXACHLOROBENZENE By JOB CLASSIFICATION (In PPb) OO OO vj '75 '76 '77 '77 Enqineers. office Shift Supervisors 1 A.7 5.A O.S. Per/Tet (board) Relief V2, 123 0.8 1 .A S.O.T. Per/Tet Sample Man 123 TOX Material Cont. 6.0 O.T. Sample Man AHC1 0.7 1.7 1.9 5.7 7.8 3.1 13.7 11.6 10.3 10.A 3.A 2.9 5.5 8.0 6.0 oo 3.q 16.7 15.0 8,A 16.0 2.1 13.6 A. 1 2A.3 5.2 A.5 Lab Loading EDO Instrument men Contract Lahnrers P i pefitters Mi 1lwrights Electrician Pa inters 3-3 7.3 10.1 6.A 2.7 10.8 10.0 5.2 11.A 10.6 7.1 0.9 U"1 '79 1 .2 i.i 0.6 0.8 1.3 1.1 1.1 1.1 1.2 1.5 1.0 0.8 A.7 1.1 1.0 0.9 1.3 2.6 3.2 1.3 see OT" 1 .2 2.1 1.3 1 .0 1.5 0.9 0.6 0.8 0.7 1.1 0.9 1.1 0. A 0.8 1.8 0.7 1.0 1.9 _ ..5.A 0.3 1.0 1.2 3.1 2.5 0.A 1.1 3.9 1.5 3.8 0.9 Overall Avg. "" DOW Contract 3.5 13.0 10.A 8.9 1.0 1.5 1.8 2.7 10.1 9.8 0.6 1 - 3__ 3-3 | on 01081.4 CONFIDENTIAL /1 TABLE VIII YEARLY COMPARISON OF BLOOD HEX LEVELS / No.years g in <1plant-* i 2 3 4 5 6 7 8 9 10 11 / 1974 A 20 53 55 \ H 65 93 n531 367 472 553 666 528 310 434 417 698 1121 930 515 2 1 342 2 2 12 13 14 15 16 513 452 707 561 22 17 18 19 20 21 22 1975 A li 45 148 97 K 20 72 203 2 4 J 340 266 546 754 418 192 389 353 940 990 500 420 22 J322 2 1976 A 5 37 65 106 95 H 10 60 106 216 44531 193 280 356 400 267 200 413 600 430 21J42 20 217 237 12 529 416 688 441 22 273 264 378 305 22 1977 A 28 38 109 96 139 85 H 30 55 210 144 163 #2 56 s3 1 174 235 309 348 309 118 198 404 467 432 22 3423 274 351 2 202 229 261 275 22 1978 A 7 42 44 136 97 114 92 H 11 54 69 199 128 172 3J6 s531 109 256 276 271 281 122 319 383 360 2i342 150 192 234 32 199 228 258 296 22 1979 A <3 18 33 44 93 109 111 93 H < 3 29 68 71 157 206 170 # 11 3 3 6 5 3 1 140 198 217 235 256 332 1 2 J4 305 115 186 451 220 21 2 193 192 298 264 22 1980 A <3 19 42 49 37 75 124 88 39 H 7 110 54 60 58 127 163 142 # 6 13 J 3 5 6 5 2 2 83 164 223 235 112 198 250 233 41 59 139 151 I2 159 122 218 140 22 1981 A <3 16 33 48 99 59 110 93 54 K 6 23 57 53 82 180 133 # 7 13 3 1 6 5 5 J 83 210 12 224 236 380 118 231 335 24 1 J 173 174 2 212 216 248 12 1982 A H # O' oZ oO -0-t o_ OT\ O Z CD -4 ^ -4 O' T> (0 O SLoA >4-1.-- A o --t> ToJ O c0 ---3u t>-.--Xu V a(.l ti-IV-- zo 73.9 17 a <4- LoA -- L. 4) <> -- 555.2 19 73.1 19 460,2 19 56.3 18 304.9 19 55.3 21 264.2 19 41.8 18 244.3 19 38.6 17 227.2 19: 20.4 10 204.6 191 23.1 12 232.0 191 TABLE V]]] YEARLY COMPARISON OF ELOOD HEX LEVELS No.years in plants <1 i 23 1974 A " 20 53 55 H 65 93 if 5 3 2 4 5 6 7 8 9 10 11 367 472 553 666 528 310 434 417 698 1121 930 515 22342 J2 12 13 14 15 16 513 452 707 561 22 17 18 19 20 21 22 1975 A li 45 148 97 H 20 72 203 #24 3 1 340 266 546 754 418 192 389 353 940 990 500 420 223 3222 529 416 688 441 22 1976 A 5 37 65 106 95 H 10 60 106 216 # 4453 1 193 280 356 400 267 200 413 600 430 22 3 42 20 217 237 22 273 264 378 305 22 1977 A 28 38 109 96 139 85 H 30 55 210 144 163 #2 565 32 174 235 309 348 309 118 198 404 467 432 21 342 2 274 351 2 202 229 261 275 22 1978 A 7 42 44 136 97 114 92 H 11 54 69 199 128 172 ft 3 3 6 5 5 3 2 109 256 276 271 281 122 319 383 360 2234 2 150 192 234 J2 199 228 258 296 22 1979 A <3 18 33 44 93 109 in 93 H <3 29 68 71 157 206 170 # 12 3 3 6 6 5 3 1 140 198 217 235 256 332 2 2 34 305 115 186 451 220 21 2 193 192 298 264 22 1980 A <3 19 42 49 37 75 124 88 39 H 7 110 54 60 58 127 163 142 6# 6 23 3 3 5 522 1981 A <3 16 33 48 99 59 110 93 54 H 6 23 57 53 82 180 133 # 6 7 13 3 2 6 5 5 2 83 164 223 235 127 198 250 233 42 59 139 151 12 83 210 21 224 236 380 118 231 335 24 I J 173 174 2 159 122 218 140 22 212 216 248 X2 1982 A H U 10 *Q-* uO- OLA /v --WC>J.---o. '--a> TJ *cA-) -- u>'---U UL av. 3Itur>t s/ X(J oIOIAA /Sin V>U zo 73.9 17 10 Mo- OIA -- CCillJll ^--IA <> -->flJ 555.2 < \ M \ H V. CO Z C U; O CM c Uzl c cc 1974 73.1 19 460.2 1975 56,3 18 304.9 1976 55.3 21 264.2 1977 41.8 18 244.3 1978 38.6 17 227.2 1979 20.4 10 204.6 1980 23.1 12 232.0 1981