Document mBkeweyr07oQgNL6BnzLDBx6g

r Ii 1 .-a n va V w.;j ? JcnT Uptake of Chlorinated Paraffins and PCB f/om Suspended Solids and Food by Juvenile Atlantic Salmon by V. Zitko ___ _ Department of Environment Biological SloJion, Si. Andrews, New Brunswick, FOG 2X0, Canada High molecular weight chlorinated paraffins were recently suggested as PCB substitutes in many applications [DOVER CHEMICAL CORPORATION 1972a]. Chlorinated paraffins have been marketed at least since 1946 [HOOKER CHEMICAL CORPORATION 1946) and used as fire retardants, plasticizers, lubricants, antistatic agents, and additives in paints, machine tool oils, and tanning compositions. In 1969 the U.S. annual production of chlorinated paraffins was 28 x 10* kg [UNITED STATES TARIFF COMMISSION 19711. There are no data on the behaviour and fate of chlorinated paraffins in the environment and little is known about their toxicological properties. Chlorin ated paraffins were not irritant to human skin [DOVER CHEMICAL CORPORATION 1972b]. The single-dose oral LDO was 2$ and SO g/kg in guinea pigs and Tats, respective ly [DOVER CHEMICAL CORPORATION 1972c]. Methods for the determination and confirmation of chlorinated paraffins have been recently published [ZITKO 1973, 1974]. This paper describes the uptake of chlorinated paraffins vj.tn 40 and 70t chlorine and of PCB with 54t chlorine, by juvenile Atlantic salmon (Salmo talar). The preparations were administered adsorbed on silica and in food. EXPERIMENTAL yoraff chlorine; and Chiorez 700 (Dover Chemical Corporation, 70t chlorine), and a PCB preparation Aroclor 1254 (Monsanto, $41 chlorine) were used. Suspended solids were simulated by SilicAR CC7 (Wallinckrodt,200-325 mesh). SilicAR (50 g) was sus pended in hexane (150 mi) in a 500-mi round-bottom flask, chlorinated paraffin or Aroclor 1254 (50 mg in 10 hexane) was added, the suspension was shaken on a !/;-, 1 >vv.; ^:;:;-r. ;* ' V'v,`i s''*; Vi < HONS 082245 "*` \','' ,'* >' ' ' '\\:'&ffi''S,:'t ":y: ttfriia-wnLuL: y^,-! nrYi iiW ek4 ded' i pee c and .1 I tf IIs r t 00 ft- t >n ! id II 1 1 I i t *k. wrist-action shaker for 1 h, and hexane was evaporated on a rotatory evaporator at 30*C. Dry fish food (Trout Chow, Purina) was contaminated as described [ttTKO and HUTZINGER 1972] to contain Cereclor 42 and Chlorez 700 at levels of 10 and 100 pg/g. Uptake from suspended solids. Juvenile Atlantic salmon were kept^or up to 144 h in 3-1 Erlenmeyer flasks (two 5-7 g fish per flask) in 2 1 of aerated fresh water at 7-8*0. The flasks contained contaminated SilicAR in a concentration of 1 g/1. One flask contained uncontamin ated SilicAR. Fish were sacrificed at different exposure times and kept frozen (-20*0) until analysis. Uptake from food. Juvenile Atlantic salmon were kept in 20-1 fiberglass tanks (20 fish per tank) in running fresh water (S00 mt/miu) at 10-15Ct 16 h light, 8 h dark photoperiod and fed manually several times a day, S days a week. The amount of food added weekly to a tank was approximately 8 g. The contaminated diet was fed for 181 days, followed by 74 days on a control diet. Fish in one tank were fed the control diet throughout the entire experiment. At times one fish from each tank was sacrificed and kept frozen until analysis. Analysis. PCB and chlorinated paraffins were determined as described [ZITKO 1971, 1973]. Two fish were analyzed at each exposure time in the suspended solids experiment, one fish in the feeding experiment. The analysis was always carried out on the whole fish. The concentration of chlorinated paraffins in fish is expressed as chlorine, Mg/ft wet weight* and can be converted into chlorinated paraffin concentration by multiplying by 2.38 and 1.43 for (Cereclor 42 and Chlorez 700, respectively. The concentration of PCB is expressed as Aroclor 1254, yg/g wet weight. RESULTS AND DISCUSSION Uptake of chlorinated paraffins and PCB from suspended solids Juvenile Atlantic salmon accumulated a relatively large quantity of PCB, but very little, if anv chlorin ated paraffins from suspended solids (Table 1). The origin of chlorine in the control fish is not known. None of the fish contained measurable amounts of p,p'-DDD, ?,p*-DDT, and dieldrin which would be eluted in the same ractlon as chlorinated paraffins in the analysis. Even in the case of fish exposed to chlorinated paraffins it is not certain that the detected levels of chlorine are due to these compounds, since the concentration is too low for the currently available confirmatory test [ZITKO 407 !! !i I if ! MQNS 001146 w n'migTrTnriMiavuraTiag^'7^mr7giCTir>T^;..^rr-r^f..TO7r,-r Ss *^ V'l i v. ; ; ; ,'j $| l' A,. `l . J * }. ;/ |1 II vC l 1974]. The increase of chlorine concentration with increasing exposure time may be an indication of a small uptake of chlorinated paraffins. TABLE 1 Uptake of chlorinated paraffins and PCB from suspended solids by juvenile Atlantic salmon Preparation Time of exposure,h Control Cereclor 42 Chlorez 700 Aroclor 1254 4B 48 144 48 144 24 48 144 Concentration in fish, chlorine. uk/k 0.34 0.44 0.75 0.22 o.4a 19.9* 28.3* 134 * Lipid 1 0.99 1.10 1.33 1.56 2.10 1.52 1.86 1.78 exprussed as Aroclor X2S4 It is not likely that the low concentration of chlorinated paraffins in fish is due to metabolic dechlorination of these compounds. The exposure times were quite short and fish are known to metabolize most lipid-soluble foreign compounds only very slowly. The uptake of chlorinated paraffins may bo limited by their highet average molecular weight (579-922) as compared to that uf Aroclor 1254 (327). In addition, chlorinated paraffins are more strongly adsorbed on silica than PCB. For example, 10% ether in hexane is needed to elute chlorinated paraffins from alumina and silica columns, whereas PCB Is in both cases eluted with hexane [ZITKO' 1973). It is interesting to note that the GLC pattern of Aroclor 1254, taken up by the fish was significantly different from that of the standard (Table 2) and indicated a relatively higher uptake of the components with shorter retention times. The differences in the relative uptake were somewhat less pronounced at longer exposure times. Higher water solubility or volatility of chlorobiphonyls with shorter retention times may be responsible for this effect. On the other hand, no change of the PCB pattern was observed during the 408 '. y?F7v' . wA\". MGNS 08224? .if CB. n .iy> r y feeding of Aroclor 1254 contaminated food to juvenile Atlantic salmon [ZITKO and HUTZINGER 1972]. TABLE 2 Changes of GLC pattern of Aroclor 1254 taken up from suspended solids by juvenile Atlantic salmon. Sample Areclor 1254 Fish exposed 24 h " " 48 h " ' 144 h Normalized peak heights 7.78 11.4 9.09 10 8.25 6.96 16.6 17.1 13.2 10 6.55 3.92 15.1 IS.9 12.6 10 6.68 4.48 14.9 15.7 12.6 10 6.65 4.55 Beak heights of the 6 major Aroclor 1254 peaks in order of increasing retention time, corrected to a height of 10 units for peak No. 4. Uptake of chlorinated paraffins from food Chlorinated paraffins did not accumulate in juvenile Atlantic salmon fed a diet containing 10 and 100 ug/g of Cereclor 42 and Chlorez 700 (Table 3). Residual levels of Aroclor 1254 obtained under similar feeding conditions [ZITXO and HUTZINGER 1972] are included for comparison. The levels of chlorine de tected after 53 days of feeding may be partly due to chlorinated paraffins, but were again too low for confirmation. Chlorine was not detectable after 109 rand 181 days of feeding. In the case of Aroclor 1254 the residues corresponding to the dietary level of liO vg/g reached an equilibrium within 30 days, whereas tut 100 ug/g an equilibrium was not reached within more than 200 days of feeding. It is possible that the high molecular weight of chlorinated paraffins slows down or completely inhibits their absorption in the digestive tract. However, the metabolism of chlorinated paraffins for example,by dechlorination cannot be excluded. Osal toxicity of chlorinated paraffins to juvenile Atlantic salmon Mortalities occurred among fish fed chlorinated paraffins, but also among fish on the control diet. Nutritionally deficient food is very likely responsible for the mortalities in the control group. It was noticed laile in the experiment that the crude lipid content of the fish food decreased to 2.47% from the normal value of 5-81. This decrease was probably caused by autoxidation 409 MUNS 002243 \ f va lu e s o f than th a t fi o s f hf i sfhe d o c n h lo th r e i nat co e n re s u lt in d ic a te s th a t c h lo rin a te d p a ra ffin s are p ro b a b ly (ue^o <* *- r* r* set* ?oy CM*O M rN N STM MM- O l**3 s c--m. o*o* a. H V> W a. z m - C O 3 art rt a STH-M. nooh O 30 r3Mh*>H a 03 3 g m. H H-rtHO'fl ta o 3* O X id fl t* sr 3 n o o B CH rt C HO Hn o wo a.*, 0 3 K' TABLE 3 Uptake of chlorinated paraffins and PCB fron food by juvenile Atlantic salnon. Days of feeding Diet 33 * Residue Lipid ! 109 * Residue Lipid 1 181 * Residue Lipid Control Cereclor 42, 10 vg/g 100 Vg/g Chlorez 700 10 Vg/g 100 Vg/g Aroclor 1254,, 10 Vg/g 100 Vg/g 0.30 1.03 0.11 0,51 1.30 1.22 0.29 0.49 3.B6*; 13.9 1.13 1.30 5.09 5.30 nd** nd nd nd nd S.SoJJ 24.0 0.65 0.69 0.49 0.40 0.56 3.10 2.73 nd* nd nd nd nd 3.88,, 30.0 0.47 0.49 0.34 0. 29 0.92 2.07 2.69 expressed as chlorine, vt/g wet weight, unless stated otherwise ** expressed as Aroclor 1254 *not detectable, <0.05 yg/g 1 I"' d tr o p l adr ai ef tf i n s (T a a b re le much 4 ). lo w e r T h is r 3t I t r i. V vl y toxic to juvenile Atlantic salmon. TABLE 4 LT50 of juvenile Atlantic salmon in the feeding experiment. Feeding LTSO, days Control 138 Cereclor 42,, 10 vg/g 100 Vg/g 47 80 Chlorez 700,, 10 vg/g 100 vg/g 71 39 The toxicity of both chlorinated paraffin preparations is approximately the same. Cereclor 42 was more toxic at 10 than at 100 yg/g. The feeding experi ment did not allow the determination of the amount of food actually invested by the fish. It is possible that fish could taste Cereclor 42 and fed less on food contain ing higher concentration of this preparation. CONCLUSION In contrast to PCB, chlorinated paraffins are much less, if at all, accumulated by juvenile Atlantic salmon when the fish are exposed to chlorinated paraffins adsorbed on silica or fed contaminated food. Chlorinated paraffins at 10 and 100 yg/g in food are very likely toxic to juvenile Atlantic salmon, but additional experiments are required to confirm this conclusion. ACKNOWLEDGMENTS I thank Mr.. W. G. Carson for skilful technical assistance and Mrs. Madelyn M. Irwin for typing the manuscript. r,. fft11. 411 -Y MGNS 062230 Aik.^ vf** ';\.' ' REFERENCES DOVER CHEMICAL CORPORATION, Bulletin 544, 545 (1972a). DOVER CHEMICAL CORPORATION, Bulletin 529, (1972b). DOVER CHEMICAL CORPORATION, Bulletin 530, (1972c). HOOKER CHEMICAL CORPORATION, Technical Bulletin (1946). KING, J.O.L., Vet. Rec. 92, 546 (1973). UNITED STATES TARIFF COMMISSION, Synthetic Organic Chemicals, U.S. Production and Sales, 1969, TC Publication <12, U.S. Government Printing Office, Washington, D.C., 1971. ZITXO, V. Bull. Environ. Contain. Toxicol. 6, 464 (1971). ZITKO, V., J. Chromatogr. 81, 1S2 (1973). ZITKO, V., Confirmation of chlorinated paraffins by dechlorination, Symposium on Water Quality Parameters: Selection, Measurement, and Monitoring, November 19-21, Burlington, Ontario, ASTM, in press (1974). ZITKO, V., and 0. HUTZINGER, ACS Division of Water, Air and Waste Chemistry 1(2), 157 (1972). 412 MQNS 082251 i'. or--y - r*ywye,.'eivn* rmt- r.