Document n94YGeyNZwDnkpzj76jb5pJzz

Use and Health Effects of Aroclor 1242, a Polychlorinated Biphenyl, in an Electrical Industry IIOF.Y K. OUW, D.P.H., M. App. Sc. GEOFFREY R. SIMPSON DAV1NDKR S. SIYAL1 Health Commission of New South Wiles, Australia ABSTRACT Aroclor 1242, a chlorinated biphenyl, is widely used as a dielectric medium in transformers and capacitors. In this survey, thirty-four occupationally exposed workers were examined. Complaints consisted of a burning sensation of the face and hands, nausea, and a persistent body odor. One had diloracne.and five suffered from an eczematous rash on the legs and hands. Al though hepatic function tests were normal, the mean blood Aroclor level in the exposed group (approximately 400 ppb) was significantly higher than in the control group. A tentative value of 200 ppb is suggested for Aroclor 1242 as an acceptable level for occupationally exposed workers. The use of an efficient exhaust ventilation to maintain air concentrations below the threshold limit value, and the regular measurements of hepatic function and of blood Aroclor concentrations in exposed workers arc recommended. ALTHOUGH THE USE of polychlorinated biphenyls, or PCBs, began as early as 1881, Iheir widespread applica tion in industry did not begin until 1930.1 Because of their chemical and thermal stability the PCBs are used in various countries as dielectric fluids in transformers and capacitors; as plasticers in paints, plastics, resins, inks, and adhesives; and as components of hydraulic fluids. In this study employees of an electrical industry were ex amined. A typical condenser as manufactured in the electrical industry is mainly for powcr'factor correction in an electrical work and consists of a system of two conductors enclosed in a tin casing (80x60x30 cm). The toxicology of PCBs in man is less well known than that of the chlorinated hydrocarbon pesticides, e. g., DDT. Industrial exposure has been reported to cause chloracne,2-4 and Flinn et al. have described ten cases of fatal PCB or naphthalene poisonings, and, in all cases, found fatty degeneration, necrosis, and cirrhosis of the liver.5 Because of the potential adverse medical effects of Aroclor on the workers, the Division of Occupational Health and Radiation Control of the Health Commission in New South Wales conducted a survey in 1974 to de termine the degree of absorption and the toxicologic effects of this substance. . July/Aupust 1976 Methods Aroclor used in the industry was of electrical grade and did not contain any impurities. Aroclor concentrations in the air inside an industrial plant were measured and thirtyfour workers who were occupationally exposed for vary ing periods to Aroclor were examined. In addition to the occupational and past histories (including amount of alcohol, drug intake, and previous history of hepatitis), blood samples were collected for Aroclor estimations and hepatic function tests. Bromsulphalcin (BSP) excretion tests were also carried out on seven volunteers whose blood Aroclor contents were above 500 ppb. Glass syringes and containers wre used in blood collection, as plastic equipment may contain trace amounts of PCBs, which may cause erroneous analysis results* The anti coagulant used in the containers was heparin. Thirty control volunteers from the Division of Analytical Laboratories of the Health Commission of New South Wales, were also interviewed and examined; none had an occupational history of exposure to PCBs. The extraction of PCBs from blood samples, their separation from other pesticide residues, and their sub sequent chromatographic analyses, were carried out by the Division of Analytical Laboratories. Each 1-gram sample of whole blood was shaken for 5 minutes in a OSW 032544 189 STLCOPCB4016506 5 m! stoppered test tube with 2 ml of 2% sodium sulfate solution, and then shaken for a further S minutes with 2 ml of nanograde hexane. The mixture was then placed in an ultrasonic bath for 20 minutes and centrifuged for a further 5 minutes until there was clear separation of hexane and blood mixture. The hexane extract was dried over anhydrous sodium sulfate and injected directly into the gas chromatograph (Hewlett Packard 7610 GasLiquid Chromatograph) without any further clean up for identification and quantification. The column oven was equipped with a 5 foot long glass column packed with Varaport 30 coated with 3% silicone UCW98. The detector had a pulsed power supply witlr 53Ni as the radioactive source for ionization. A mixture of methane 5% and argon 95% was used as a carrier gas. The temperatures of the injection block, column oven and detector were maintained respectively at 220 C, 205C, and 280C. For the air analysis in industrial plants, the operators' breathing zones were sampled with a Grccnburg-Smith Impinger at 30 1/m into 75 ml of isopropanol. The iso propanol used for sampling was rendered PCB-frec by distillation. In most cases a sample volume of I mJ of air was taken. The isopropanol was analysed for PCUs using a gas-liquid chromatograph with a tritium detector. Because several peaks were found, the seven principal peak heights were considered. Since different PCB preparations give different peak heights and patterns, standards were prepared from the actual PCB in use. PCBs were analysed using Perkin Timer F.l 1 gas chromatograph. The column was packed with gaschrome A 80-100 mesh with 5% Q,P(. Nitrogen was used as a carrier gas. The temperatures of injection block, column, and detector were 210C, 200C, and 200C respectively. Table 2,-Btood Aroclor Levels and Abnormal Liver Function Test Results of Thirty-Four Exposed Workers No. Age, yr/Sex Duration of Exposure, yr Blood Aroclor Level (nph) Retention Times Relative to Aldrin t . 0.69 j 1.31 | 1.47 | 1.96 Bilirubin, pmol// Alkaline Phosphatase, fJtmot/l Total Protein, ill Impregnation Room Workers 1 51/M 2 35/M 3 56/M 4 41/M S 46/M 6 38/M 7 40/F 8 54/M 9 50/M 10 34/M 11 36/M 12 46/M 13 57/M 14 51/M IS 45/M 16 44/F 17 49/F 18 41/F 19 46/F 23 s 23 8 to 19 6 12 2 6 3 3 6 6 1/6 2 i 1/12 4 $80 179 130 too 540 570 1,580 240 650 280 1,470 440 1,378 550 555 - 170 149 181 1,700 370 117 170 140 210 450 790 150 320 130 194 1,037 290 91 69 79 729 240 85 150 340 600 120 340 620 230 1,099 160 287 879 10 1,540 270 80 e e 9 9 9 9 9 Process Workers 1 45/F 2 47/F 3 40/F 4 33/F 5 39/F 6 47/F 7 54/F 6 50/F 9 52/F 10 54/F It 53/M 12 47/F 13 42/F 14 33/F IS 48/F 7 7 4 1 2 2 3 2 5 6 1VI 6 2 3 3 153 115 192 102 76 33 82 198 374 215 172 80 79 93 Trace 60 .Trace 198 Trace Trace Trace Trace 76 Trace 68 66 42S 1,010 Trace Trace Trace 837 1,460 Trace 9, --Slight and moderate increases from normal values, respectively. -- Slight decrease from normal values. Bromsulphalein tests carried out in only seven workers. tuermititis of the hands and/or legs; burning of the face, eyes, and akin. *, ot - Mild and severe lesions and complaints, respectively, N --Normal values. 190 Archives of Environmental Health DSW 032545 STLCOPCB4016507 I* VrocJo* 1242 of FxpoKil tod Control C.roupi ^ Blood Atoclot Lrvri (ppb) MeintSD Vo mi Simpk 0.69 Retention Timet Relative to Aldtin l l.Jl I 1.47 I 196 H 7941461) 198 1 758 415 1479 475 1718 )0 N.D.* N.D. N.D. N.D. in . vj 4*<l<'r Levels in the Exposed and Control Groups jvK'Vd Aroclor 1242 contents among the control . -i* mhich consisted of twenty-three males and seven ** `T' females with ages ranging from 21 to 50 years, were zero (m = 30, Y= 0, SD = 0). Similar statistics for the exposed group, which consisted of fifteen males and nineteen females with ages ranging from 33 to 55 years, are shown in Table I. Comparison of the mean blood Aroclor levels of the exposed group with those of the control group demonstrates a statistically significant increase in blood levels among the former (P< .01). Aroclor Levels and Liver Function Tests in Thirty-Four Workers The thirty-four workers could also be divided into two groups according to the degree of exposure: one group of nineteen workers (fourteen males and five females) was employed in the impregnation room, so called because Aroclor was impregnated inside the capacitor casings. In the handling process, as the exposure to hot Aroclor (temp, 70C) could be excessive, undue absorption of this a Globulin, 1% a. Globulin, 2% B Globulin, 1% y Globulin, % GPT BSP* Stem and Svmntomst Burning & Dermatitis Irritation N N N +++ + 4 +4 4 4 + + + 4 / 4 + DSW 032546 191 STLCOPCB4016508 T*Me X --Comparaofl o f W <n Blood A rodof 1242 Lw eb m d Hepatic Function T t t t i b c tv w n the E xy o wed Wovfccrs Employed Icttido sad Outside Impre|na(lon Roomu ^ * --is r- 44 <c 00 00 ro cl os **1 sdc 0-10 a 4to( a zC oO a Os - Os -1 44 StoO sOC so *on it X 41 s--On -vhi t t- ri d *n* 0so0 OVS <N r* r- tn oo * S2 sNc ^-- 44 +4 rv-j or4s +4 -< oq >C -- +4 0to 44 Z Aaa 1 I In *--n ono rs n 44 OAs 6 dO Cc** 41sC so &O9 a Ooss oro oo n 44 Is 41 1 & 192 o a8 v A V I a 3 substance can occur unless suitable impervious gloves are worn and an efficient exhaust ventilation is operating. The second group consisted of process workers (one male and fourteen females) who were employed outside an impreg nation room and assembled Aroclor-dippcd capacitor components. Here the main route of absorption was through the skin and, in general, exposure was not so great as in the first group. No job rotation was carried out between the two groups. Table 2 shows the blood Aroclor levels and abnormal hepatic functions in these two groups of workers. The total periods of exposure to Aroclor 1242 and 42% chlorine containing PCBs arc shown in column 3. As the pathway of Aroclor metabolism in humans has not been completely worked out, the chemical identification of the metabolites corresponding to the peaks in the gas chrom atogram is at this stage not known. However, their sequence of appearance can be expressed as relative re tention times using that of aldrin as 1. Thus a metabolite with a relative retention lime of 0.69 appears before aldrin and those with relative retention times of 1.31, 1.47, and 1.96 appear after aldrin. The height of a peak indicates the concentration in blood. Abnormal hepatic function tests are shown in full to indicate values higher () or lower () than the accept able normal limits for the tests. These include measure ments of serum bilirubin, alkaline phosphatase, total protein, GPT, and BSP retention. No history of excessive intake of alcohol or drugs, or of hepatitis was found in the thirty-four exposed workers. In the impregnation room group, for example, seven protein levels are high, and four <tj globulin levels are low. Also three GPT and four BSP results are abnormal. BSP tests were carried out on seven workers with rel atively high blood Aroclor (i. c., above 500 ppb). Four our of seven results were above normal values of 5%, but because other conditions such as fever can also increase retention, the high BSP test results could not, by them selves, be taken as proof of hepatic damage. One case, who suffered from congestive cardiac failure and enlarged liver, had a normal liver function test. Despite some individual abnormal results, however, the mean of each hepatic function test for the whole group is within normal limits (Tabic 3). Aroclor Levels and Symptoms Exposed workers tend to complain of burning of eye, face and skin. Aroclor "fume" is an eye irritant, has a pungent smell, and often causes persistent body odor. One worker suffered from chloracnc without the systemic effects characterized by anorexia, nausea, edema of the face and hands and abdominal pain.7 Five workers com plained of eczematous rashes on the hands and legs. Al though there does not seem to be a clear correlation be tween severity of dermatitis and/or burning or irritation of the skin, and blood Aroclor levels, the dermatological complaints occur more often among workers with higher blood Aroclor levels. Table 3 shows the comparison of the mean blood Aroclor levels and hepatic function tests in the two Archives of Environmental Health OSW 032547 STLCOPCB4016509 Table 4.-Condition between BSP Retention Value*, Blood Arocfor levels, and Length of Exposure among Seven Impregnation Room Workers _________ ___________________ Pitient No. Length of Exposure to Aroclor, yr Btood Aroclor Level, ppb (Retention Time Relative to Aldrin 1 = 0.69) BSP Retention, % 1 23 2 4 5 8 J 10 6 19 8 12 to 6 580 7.1 179 5.2 100 10.5 540 9.2 570 5.0 240 3.4 280 11.5 groups of exposed workers. It can be seen that the im pregnation room workers tend to absorb more volatile * compounds with low relative retention times, while the process workers outside the impregnation room tend to absorb `heavier' compounds, as shown by the statistical differences in the two groups. If the BSP lest is used as an index of "hepatic" health of an exposed worker, poor correlations exist between the BSP retention values and blood Aroclor levels (r = - 0.1016), and between the former and length of exposure {r = - 0.3639), as shown in Table 4. Aroclor Levels of the Workplace Table 5 shows that the levels of Aroclor in the breath ing zones of the operators exceeded the threshold limit value (TLV) of 1.0 mg/m3. The Australian National Health and Medical Research Council publication, Atmospheric Contaminants (1970) recommended the TLVs for PCBs as follows: 42% chlorine (Aroclor 1242), 1.00mg/m3; 54% chlorine, 0.5 mg/nv\ In 1974 the Amer ican Conference of Governmental Industrial Hygienists recommended the same TLVs. When a more efficient ex haust ventilation was later installed, however, the air measurements were below 1.0 mg/m3. Two months following improvement of the exhaust ventilation system and the recommendation to wear suit able impervious gloves to lessen the absorption of Aroclor through the skin, further blood samples were taken to determine if there was any improvement in the blood Aroclor levels. Unfortunately only fifteen of the original thirty-four workers from inside and outside the im pregnation room areas participated in the second test. Although an efficient exhaust ventilation system had been installed and the concentrations in the air in side the plant were satisfactory (below 1.0 me/m3), the recommendation to wear suitable gloves to reduce skin absorption was not strictly followed. This could explain why, as shown in Table 6, there was no lowering of blood Aroclor levels in the "after" group. The failure to wear suitable gloves was due more to a lack of awareness of the toxicology of Aroclor than to the inconvenience of using them. Discussion It is interesting to find that no Aroclor was detected in the control group. In contrast, the PCB concentration Table 5.-Aroclor 1242 Concentre Mont In the Air Inride the PUnt Before and After Improvement of Exhaust Ventilation Svatrm ' 1== Area In Impregnation Room Aroclor Concentration. ------ ------ mg/m3 Before After Area in unloading tank in front of exhaust register from operator's breathing zone 1.44 0.75 Area In unloading tank not in front of ex haust register 2.22 0.7 General atmosphere near tank Soldering area 1.08 0.18 0.32 0.08 (arithmetic mean) is 2.3 ppb among the nonexposed urban white volunteers in the U. S. A., and 3.1 ppb among vol unteers from rural areas. Finklca suggested that in the U. S. A., urban exposure to PCBs was by way of polluted air and contaminated water. In New South Wales, Australia, preliminary surveys were carried out to determine whether PCBs constituted a significant liquid pollution in general sewerage outfalls. Small and insignificant traces of K'lls were found in the liquid specimens tested. (Personal communication to the Sydney Metropolitan Water, Sewerage and Drainage Board.) Similarly, no PCBs were found in such food items as fish, eggs, and milk. This may explain why no detectable amount of PCBs was found in the control group. Since some medical abnormalities were observed among the thirty-four in the exposed group, it is interesting to review the toxicology of PCBs, the understanding of which has increased since the unfortunate "Yusho" incident1 '* in 1968, in which 644 people in Yusho, Japan were poisoned after ingestion of PCB-conlaminated rice. The symptoms complained of included chloracnc, blindness, nausea, vomiting with jaundice, edema and abdominal pain. Further, it was reported that newborn babies of affected mothers had skin discoloration due to absorption of PCBs through the placenta. Gingival hyperplasia with pigmentation was reported in several cases. Table 6.-Mean Blood Aroclor 1242 Levels Before and After Improvement of Exhaust Ventilation and the Recommendation to Use Suitable Gloves Group Before Mean Btood Aroclor Level (ppb) Retention Times Relative to Aldrin 1 0.69 1.31 1.41 281.6 135.1 58.41 After 477.2* 225.4* 524.71 Indicates a not significant (/*>.01) difference from value immediately above. f Indicate! a significant {P <.05) difference from value immediately above. July/August 1976 DSW 032548 193 STLCOPCB4016510 The PCB which was responsible for the poisoning was Che heat exchanger, Kana-chlor 400, a Japanese-manufac tured PCB with 48% chlorine. The PCB level in the rice oil was estimated to be about 2,000 ppm. Exposure to the rice oil was estimated to be about 15,000 mg per day, with 3 mg as the lowest quantity producing minimal ef fects. Although valuable data have been gained from animal experiments and from fatal poisoning cases, the exact dose-response relationship of PCBs (and in particular Aroclor 1242) in man is still to be determined, largely because of the complexity and heterogeneity of the materials themselves. At this stage, therefore, one cannot accurately set acceptable PCB blood levels that will produce no toxic episodes or long-term sequelae. However, it is reasonable to set 200 ppb as a tentative upper limit of acceptable blood Aroclor content for the occupationally exposed workers (in any of the relative retention times mentioned), as no significant effects on health were ob served among the thirty-four exposed workers examined when their Aroclor levels were below 200 ppb. Further more, for pesticide workers this Division has set a tentative but acceptable upper limit of 200 ppb for blood DDT, which in animal experiments is about ten times more toxic than Aroclor 1242.' It must be emphasized, however, that the Final safe level of blood Aroclor can be determined only by proper evaluation of hepatic function tests, adipose tissue levels, and long-term follow-up of exposed workers. Unfortunately, few blood PCB levels have been reported for occupationally exposed workers in Australia or overseas. It is easier to obtain blood samples than ad ipose tissues, although the latter show more accurate PCB residue levels. However, for screening PCB workers, the former is more convenient. Studies to determine the effects of exposing animals to Aroclor vapor have been carried out. For example, Treon,0et al. exposed laboratory animals to 0.83 ppm of Aroclor 1242 vapor (7-hour periods for 17 days) and found no signs of intoxication in a group of thirty-one animals. In the industrial setting, Elkins 1 reported atmospheric concentration levels of 5.8 and 4.5 mg/m3 (average) in a condenser plant in Massachusetts and found no evidence of toxic effects among the exposed workers. However, in this survey, medical effects (e.g., eczema and skin burning) were observed even when the Aroclor con centration in the air was below the TLV.of 1 mg/m3. It is to be noted, however, that Aroclor "penetrates" the intact human skin13,13 and careless contact may result in its absorption approaching or exceeding the dose inhaled. The apparent excessive skin absorption has prevented us from agreeing on or recommending a new TLV fur Aroclor 1242 in air. However, because of the potential adverse effects on health, use of an efficient exhaust ventilation system to maintain air concentrations below the TLV, and the regular estimations of hepatic function and blood level in exposed workers are recommended. ***** From the Division of Occupational Health and Radiation Control (Dr. Ouw and Mr. Simpson) and (he Division of Analytical Labor atories (Mr. Siyali) of die Health Commission of New South Wales, Australia. Submitted May 14. 1975; revised: accepted September 30. 1975. -Reprints may be obtained from Dr. K. 11. Ouw, Division of Occupational Health and Radiation Control. P. O. Box 163, Lidcombc, Sydney, N. S. W. 2141, Australia. REFERENCES 1. Edwards. R. 1974. The polychlorinated biphenyls, their occurrence and significance; A review. Chem hid 47: 1340-48. 2. Schwartz. L. 1936. Dermatitis from synthetic resins and waxes. Am J Public Health 26: 586-92. 3. Schwartz, L. 1943. An outbteak of halowax acnc (cable rash) among electricians. JAMA 122: 158-61. 4. Schwartz, Lous, and Barlow, F. A. 1942. Chloracnc from cutting oils. US Public Health Rep 57: 1747-52. 5. Flihn, F. B., and Jarvik, N. E. 1936. Action of Certain Chlor inated naphthalenes on the liver. Proc Soe Uxp Biol Med 35: 118-20. 6. Siyali, D. S. 1973. Erroneous blood pesticide level due to sample containers with PCBs. MedJAusi 2: 832-33. (Letter.) 7. Kimbrough, R. D. 1974. The toxicity of polychlorinated polycyclig compounds and related chemicals. CRC Crtt Rev Toxicol 2: 445-98. 8. Interdepartmental Task Force on PCBs. 1971. Polychlorinated biphenyls and the environment. Washington. D. C.: Inter departmental Task Force on PCBs. 9. Kuratsunc, ct al. 1969. An epidemiological study on Yusho or chlorobiphcnyl poisoning. T'ukuoka Acta Med 60: 513. 10. Trcon, J. F.;Cleveland, F. P.;Cappcl. 1. W,; and Atehlcy, R. W. 1956. The toxicity of the vapors of Aroclor 1242 and Aroclor 1254. /4m Ind Hyg Assoc J 17: 204-13. 11. Elkins, H. E. 1950. Chemistry of industrial toxicology. New York: Wiley, p. 149. 12. Miller, J.W. 1944. Pathologic changes in animals exposed to commercial chlorinated diphenyl, ihiblic Health Rep 59: 1085 93. 13. Paribok, V. P. 1954. Mctodika izucheniia kombiniiovannogo dcistviia vtednykh gazov pvi dlitcl'noi dinamichcskoi zatiavkc zhivotnykh. IMctltod of the study of combined action of poisonous gases by prolonged experimentation on animals 1. Farmakol Toksikol 17: 55-57. 194 Archives of Environmental Health DSW 032549 STLCOPCB4016511