- Email: [email protected]
Accumulation and excretion of organophosphorous pesticides by carp Cyprinus carpio
0306.4492/93 $6.00 + 0.00
Comp. Biochem. Physiot.Vol. 104C,No. 2, pp. 275-278, 1993
0 1993Pergamon Press Ltd
Printed in Great Britain
ACCUMULATION AND EXCRETION OF ORGANOPHOSPHOROUS PESTICIDES BY CARP CYPRINUS T. TSUDA, S.
CARP10
AOKI, M. KOJIMA and T. FUJITA
Shiga Prefectural Institute of Public Health and Environmental Science, 13-45, Gotenhama, Ohtsu, Sltiga 520, Japan (Received 7 August 1992; accepted for publication 25 September 1992)
The average bioconcentration factors (BCF) in the whole body of carp (Cyprinus curpio L.) after 24-168 hr exposure were 10.5 for dichlorvos, 7.4 for salithion, 29 for phenthoate, 2.8 for methidathion, 4.7 for pyridaphent~on, 26 for fenthion and 1.7 for phosmet. Further, the BCF value of EPN after I68 hr exposure was 85. 2. The correlation between n-octanol-water partition coefficients (P,,) and BCF in carp was investigated for 13 pesticides studied here and already reported. The correlation factor (r) was not very high (0.5139, N = 13) but higher (0.7005, N = 12) in the case of excluding captan. 3. The excretion rate constants (k) from the whole body of carp were 0.54 hr-’ for salithion, 0.52 hr-’ for phenthoate, 0.54 hr-’ for methidathion, 0.43 hr-’ for pyridaphenthion, 0.34 hr-’ for fenthion and 0.18 hr-’ for EPN. Abstract-l.
In recent years, a large number
of pesticides have been produced and discharged into the environment. The data on their bioconcentration and excretion by fish are useful for the evaluation of their safety to man and their contamination of fish in lakes, rivers and the sea. We have already studied accumulation and excretion of herbicides (~nthio~~b, simetryne, oxadiazon, CNP, chlomethoxynil and simazine), insecticides (diazinon, malathion, fenitrothion, chlorpyriphos, isoxathion, dichlorvos, salithion, phenthoate, methidathion, pyridaphenthion, fenthion, EPN and phosmet) and fungicides (IBP, tolclofos-methyl, flutolanil, isoprothiolane, chlorothalonil, captan and iprodione) using the freshwater fish, willow shiner (Tsuda et al., 1988, 1989a, 1990b, 1992a, submitted for publication) and carp (Tsuda et al., 1989b, 1990a, 1992a). In this study, we carried out the accumulation and excretion experiments, using carp, for the same eight organophosphorous pesticides (dichlorvos, salithion, phenthoate, methidathion, pyridaphenthion, fenthion, EPN and phosmet) as in our previous report (Tsuda et al., submitted for publication). MATERIALS
AND METHODS
Chemical Dichlorvos (2,2-dichlorovinyl dimethyl phosphate), salithion (2-methoxy-4H-1,3,2-benzodioxaphosphorin-2-sulfide), phenthoate {S-[a-(ethoxycarbony)-benzyl] dimethyl phosphorothiolothionate>, methidathion [S-(Z-methoxy-5-oxo-1,3,~thiadiCBP(C)
104/2-F
~olin~ylmethyl) dimethyl phosphorothiolothpyridaphenthion (2,3-dihydro-3-0x0-2ionate], phenyl&pyridazinyl diethyl phosphorothionate), fenthion (dimethyl 4-methylthio-m-tolyl phosphorothionate), EPN (ethyl p-nitrophenyl phenylphosphonothionate), phosmet [dimethyl S-(phthalimidomethyl) phosphorothiolothionate] were purchased from Wako Pure Chemical Industries Ltd (Osaka, Japan). These chemicals were more than 98.0% pure and were used without further pu~fication. Test jsh Carp (Cyprinus carpio L.) were obtained from Nango Suisan Center (Shiga Prefecture, Japan). The body length and body weight of the fish were 8.5-10.0 cm and 14.0-20.8 g, respectively. Ail these pesticides were not detected in the fish before exposure to them. Commercial assorted feed was given, about 200mg per fish, once a day throughout the experimental period. Test system The study was carried out with aeration under the continuous flow-through system. The experimental arrangements were the same as our previous report (Tsuda et al., 1987). For ambulation experiments, stock solutions A (dichlorvos, salithion, phenthoate and methidathion, each SOOpgl-‘, 101) and B (pyridaphenthion, fenthion, EPN and phosmet, each 500 pg l-l, 10 1) were each diluted continuously 150 times with dechlorinated city water and supplied to each of the two aquaria containing 25 fish. During the test, the flow rate and temperature of each test water were maintained 18 1hr-’ and 23 f l”C, respectively. The 275
216
T. TsUDAet al.
concentrations of these chemicals in each test water were mean + S.D. (N = 5) of 1.0 f 0.3 pg 1-l for dichlorvos, 2.4 + 0.2 pg 1-l for salithion, for methidathion (experiment I), and 3.4 f 0.2 pg 1-l for pyridaphenthion, 0.3 f 0.1 pg 1-l 1.6 f 0.2 pg 1-l for phenthoate and 3.3 + 0.1 pg 1-l for fenthion, 1.9+O.lpgl-’ for EPN and 1.7+0.1pgl-’ for phosmet (experiment 2). Measurements were carried out at 0,24,72, 120 and 168 hr. Three fish were taken at 24, 72, 120 and 168 hr. The concentrations of these pesticides in each test water were fixed by reference to the data of 48 hr LC~,, to carp (Tanaka, 1978). The low concentrations of these chemicals are probably because they are absorbed to the tubes of the experimental arrangements or the walls of the aquaria. The pH, the concentrations of dissolved oxygen and the hardness in each test water were 6.8-7.0, more than 7mgl-’ and 3437 mg 1-l as CaCO,, respectively. Measurements were carried out every 24 hr for pH and once after 72 hr for dissolved oxygen and hardness. For excretion experiments, 13 fish remaining in each aquarium were separately transferred into each of the other two aquaria and dechlorinated city water was supplied to each of them. During the test, the flow rate and temperature of each test water were maintained 60 1hr-’ and 24 f 1°C respectively. Three fish were taken at 6, 12, 24 and 72 hr. The pH and the concentrations of dissolved oxygen in each test water were 6.9-7.0 and more than 7 mg l-‘, respectively. Measurements were carried out every 24 hr, for pH, and once after 24 hr, for dissolved oxygen. Under these conditions, none of the fish showed signs of tiredness and agitation during the accumulation and excretion experiments.
40°C and the residue was dissolved
in lOm1 of hexane. The hexane solution was shaken with 30ml of acetonitrile saturated with hexane and the acetonitrile layer was retained. The operation was repeated and the combined acetonitrile layer was rotaryvacuum evaporated just to dryness at 40°C. The residue was dissolved with 5 ml of acetone, and the acetone solution was passed through a column (a mixture of 0.2 g activated charcoal and 0.2 g microcrystalline cellulose). The concentration of each pesticide in the eluate was measured by FPDGC after rotary-vacuum evaporation to l-5 ml. Average recoveries (whole body of fish 5 g, N = 3) were 92% for dichlorvos, 100% for salithion, 100% for phenthoate, 98% for methidathion, 97% for pyridaphenthion, 74% for fenthion, 95% for EPN and 98% for phosmet at 100 ngg-’ spiked levels. The GC (Shimadzu GC-9AM) operating conditions were as follows: GC column: J&W DB - 1701 (30 m x 0.53 mm 4, film thickness 1.0 pm); Carrier: Nz 30 ml min-‘; Air: 60 ml min-‘; H,: 75 ml min-‘; Temperatures: injection and detector 280°C; column 100°C (Omin); lO”Cminto 270°C. Analysis was carried out as three separate samples for each sampling time. Calculation of BCF and excretion rate constants
BCF was calculated BCF =
by the following equation:
chemical concentration in whole body of fish chemical concentration in water .
The chemical concentration in the water at each sampling time was used for the calculation of BCF. The excretion rate constants (k) of the chemicals from the whole body of the fish were calculated assuming that the excretion process follows first-order kinetics.
Analysis RESULTS
The concentration of each of the pesticides in water samples was determined by the following procedure. A measured volume (200ml) of water was shaken with 100ml of dichloromethane after addition of 20 g of NaCl. The organic layer was rotary-vacuum evaporated just to dryness at 40°C. The residue was dissolved with 4 ml of hexane and analyzed by a gas chromatograph equipped with a flame photometric detector (FPD-GC). Average recoveries (N = 3) were 91% or dichlorvos, 99% for salithion, 93% for phenthoate, 100% for methidathion, 100% for pyridaphenthion, 99% for fenthion, 100% for EPN and 100% for phosmet at 2pgl-’ spiked levels. Determination of each pesticide in fish samples was performed by the following method (Goto and Kato, 1980). A fish sample (about 5 g) was homogenized with 30 ml of acetonitrile using a high-speed homogenizer (Ultra-Turrax, Germany) after the addition of 5 g of anhydrous Na,SO,, and the organic layer was filtered. The residue was again homogenized and filtered in the same manner. The combined filtrate was rotary-vacuum evaporated just to dryness at
AND DISCUSSION
Accumulation of pesticides
The experimental results are shown in Table 1. The concentrations of pesticides in the whole body of carp reached plateaus after 24 hr exposure for salithion, methidathion, pyridaphenthion, fenphenthoate, thion and phosmet, but not until 168 hr for EPN. For dichlorvos, the period was unknown because its concentration in the fish was very low and could not be determined at all sampling times. The period of Table 1. BCF of pesticides
in carp
BCF’ in whole body of fish Pesticides Dichlorvos Salithion Phenthoate Methidathion Pyridaphenthion Fenthion EPN Phosmet
24 hr
12 hr
120 hr
168 hr
<0.5 9.9 f 3.9 31* 15 3.5 f 1.4 4.6kO.7 22 + 3 3Ok 13 1.6kO.7
<0.5 7.4 + 1.6 27 f 7 2.7 f 0.5 4.6+ 1.6 29 f 6 29 + 6 1.5kO.4
<0.5 4.5 f 0.9 20 f 4 1.8 +0.4 3.7 f0.6 27 f 6 49* 15 1.8kO.9
co.5 7.1+ 0.4 32 + 2 3.1 kO.4 6.OkO.3 26 + 8 85 5 28 1.8 k 0.5
*Mean value f S.D. (N = 3).
211
OPs in carp
Log Pow
Fig. 1. Relationship between log P,, and log BCF in carp. (1) Chlorothalonil; (2) captan; (3) chlorpyriphos; (4) isoprothiolane; (5) isoxathion; (6) iprodione; (7) salithion; (8) phenthoate; (9) methidathion; (10) pyridaphenthion; (11) fenthion; (12) EPN; (13) phosmet. phenthoate (24 hr) in carp was considerably shorter than that in willow shiner (2 168 hr) (Tsuda et al., submitted for publication). The average BCF values (N = 4) in the whole body of the fish after 24-168 hr exposure were 7.4 for salithion. 29 for phenthoate, 2.8 for methidathion, 4.1 for pyridaphenthion, 26 for fenthion and 1.7 for phosmet. The BCF values of these pesticides in carp were l/1&1/20 times as high as those in the willow shiner. This tendency was the same as in other chemicals (BCF: Bu,SnCl 3600, Ph,SnCl 2300 in willow shiner and Bu,SnCl 1500, Ph,SnCl 500 in carp) in our previous report (Tsuda et nl., 199Oc, 1992b). The order of BCF in carp was EPN > phenthoate > fenthion > salithion > pyridaphenthion > methidathion > phosmet > dichlorvos. This order was about the same as that in the willow shiner (EPN > phenthoate > fenthion > salithion > phosmet > pyridaphenthion > methidathion > dichlorvos). These orders were slightly different from that of P,, (EPN > fenthion > methidathion > salithion > pyridaphenthion > phenthoate, phosmet > dichlorvos). It is generally known that there is
t!
6
24
Ti me(hr) Fig. 3. Excretion thion;
of pesticides
n fenthion;
(2) from carp. 0 Pyridaphen-
q EPN; A phosmet.
linearity between log P,,wand log BCF in fish, but the BCF value of phenthoate was considerably higher than the value estimated from PO,. This was the same as in the willow shiner. In our previous report (Tsuda et al., submitted for publication), the correlation between log PO,,,and log BCF in willow shiner was investigated for 19 pesticides. In this report, the same correlation in carp was investigated for 13 pesticides already reported (Tsuda et al., 1992a) and studied here. The data of log POW were also cited from the studies by Okumura and Imamura (1991) and Kanazawa (1981). This correlation is shown in Fig. 1. The r value was not so high (0.5139, N = 13) but higher (0.7005, N = 12) in the case of excluding captan, which was the same as in our previous report (Tsuda et aI., submitted for publication). Excretion of pesticides
The experimental results are shown in Figs 2 and 3. From these data, the excretion rate constants (k) and biological half-lives of the fish were calculated by assuming that the excretion process follows firstorder kinetics and these are shown in Table 2. The concentrations of dichlorvos and phosmet in the fish were low and rapidly decreased, so could not be measured by FPDW after 6-72 hr (all sampling times). For this reason, the k values of dichlorvos and Table 2. Excretion rate constants and biological half-lives of pesticides by carp Pesticides
1dL
0
12
6
2.5
Time(hr) Fig. 2. Excretion
of pesticides
l phenthoate;
(1) from carp. @ methidathion.
0
Salithion;
Dichlorvos Salithion Phenthoate Methidathion Pyridaphenthion Fenthion EPN Phosmet
k (hr-‘)
Half-lives (hr)
0.54 0.52 0.54 0.43 0.34 0.18 -
1.3 1.3 1.3 1.6 2.0 3.9
T.
278
-bJDA
phosmet
could not be calculated. The excretion rate of these pesticides in carp was Z-10 times as rapid as that in willow shiner (Tsuda et al., submitted for publication). The order of their excretion rate was methidathion = salithion 2 phenthoate > uvridaphenthion > fenthion > EPN.- As described *above, the order of their BCF values was EPN > phenthoate > fenthion > salithion > pyridaphenthion > methidathion. The order of their excretion rate was approximately reversed compared with that of their BCF values. That is, the greater the BCF value, the slower the excretion rate. This tendency was the same as in our previous studies (Tsuda et al., 1988, 1989a, 1990b, 1992a, submitted for
publication). REFERENCES
Goto S. and Kato S. f 1980) Analyticat methods of Pesticide Residues. Soft Science, Tokyo-(in Japanese). Kanazawa J. (1981) Measurements of the bioconcentration factors of pesticides by freshwater fish and their correlation with physiochemical properties or acute toxicities. Pestic. Sci. 12, 4177424.
Okumura T. and Imamura K. (1991) Simultaneous determination of pesticides by capillary gas chromatography/ mass spcctrometry. Jpn. J. Water Pollut. Res. 14, 109.-122 (in Japanese). Tanaka J. (1978) Suisei Seibutsu To Nouyaku (Kyusei Dokusei Shiryou Hen). Scientist, Tokyo (in Japanese). Tsuda T., Aoki S., Kojima M. and Harada H. (1988) Bioconcentration and excretion of benthiocarb and
et al.
simetr~e by willow shiner. Toxic. enuiron. C&m. IS, 31-36. Tsuda T., Aoki S., Kojima M. and Harada H. (1989a) Bioconcentration and excretion of diazinon, IBP, malathion and fenitrothion by willow shiner. Toxic. enuiran. Chem. 24, 185-190. Tsuda T., Aoki S., Kojima M. and Harada H. (1989b) Bioconcentration and excretion of benthiocarb and simetryne by carp. Water Res. 23, 529-531. Tsuda T.. Aoki S.. Koiima M. and Harada H. (199Oa) Bi~on~entratio~’ ad excretion of diazinon: IBP: malathion and fenitrothion by carp. Con+ B&hem. Physiol. %C, 23-26.
Tsuda T., Aoki S., Kojima M. and Harada H. (1990b) Accumulation and excretion of oxadiazon, CNP and chlomethoxvnif bv willow shiner. ComD. Biochem. Phvsiol. %C, 373-3751 Tsuda T., Aoki S., Kojima M. and Harada H. (1990~) The influence of OH on the accumulation of tri-n-butvltin chloride and’triphenyltin chloride in carp. Camp. kothem. Phyfiol. #C, i51-153. Tsuda T., Aoki S., Kojima M. and Fujita T. (1992a) Accumulation and excretion of pesticides used in golf courses by carp (Cvprinlrs cq&) and willow shiner (Gnathopogon caerulescens). lOlC, 63-66.
Comp.
Biochem.
Physioi.
Tsuda T., Aoki S., Kojima M. and Fujita T. (1992b) Accumulation and excretion of tri-n-butyltin chloride and triphenyltin chloride by willow shiner. Comp. Biochem. Physiol. ZOlC, 67-70.
Tsuda T., Aoki S., Kojima M. and Fujita T. Accumulation and excretion of organophosphorous pesticides by willow shiner. (submitted for publi~tion). Tsuda T., Nakanishi H., Aoki S. and Takebayashi J. (1987) Bioconcentration and metabolism of phenyitin chlorides in carp. Water Res. 21, 949-953.
Comp. Biochem. Physiot.Vol. 104C,No. 2, pp. 275-278, 1993
0 1993Pergamon Press Ltd
Printed in Great Britain
ACCUMULATION AND EXCRETION OF ORGANOPHOSPHOROUS PESTICIDES BY CARP CYPRINUS T. TSUDA, S.
CARP10
AOKI, M. KOJIMA and T. FUJITA
Shiga Prefectural Institute of Public Health and Environmental Science, 13-45, Gotenhama, Ohtsu, Sltiga 520, Japan (Received 7 August 1992; accepted for publication 25 September 1992)
The average bioconcentration factors (BCF) in the whole body of carp (Cyprinus curpio L.) after 24-168 hr exposure were 10.5 for dichlorvos, 7.4 for salithion, 29 for phenthoate, 2.8 for methidathion, 4.7 for pyridaphent~on, 26 for fenthion and 1.7 for phosmet. Further, the BCF value of EPN after I68 hr exposure was 85. 2. The correlation between n-octanol-water partition coefficients (P,,) and BCF in carp was investigated for 13 pesticides studied here and already reported. The correlation factor (r) was not very high (0.5139, N = 13) but higher (0.7005, N = 12) in the case of excluding captan. 3. The excretion rate constants (k) from the whole body of carp were 0.54 hr-’ for salithion, 0.52 hr-’ for phenthoate, 0.54 hr-’ for methidathion, 0.43 hr-’ for pyridaphenthion, 0.34 hr-’ for fenthion and 0.18 hr-’ for EPN. Abstract-l.
In recent years, a large number
of pesticides have been produced and discharged into the environment. The data on their bioconcentration and excretion by fish are useful for the evaluation of their safety to man and their contamination of fish in lakes, rivers and the sea. We have already studied accumulation and excretion of herbicides (~nthio~~b, simetryne, oxadiazon, CNP, chlomethoxynil and simazine), insecticides (diazinon, malathion, fenitrothion, chlorpyriphos, isoxathion, dichlorvos, salithion, phenthoate, methidathion, pyridaphenthion, fenthion, EPN and phosmet) and fungicides (IBP, tolclofos-methyl, flutolanil, isoprothiolane, chlorothalonil, captan and iprodione) using the freshwater fish, willow shiner (Tsuda et al., 1988, 1989a, 1990b, 1992a, submitted for publication) and carp (Tsuda et al., 1989b, 1990a, 1992a). In this study, we carried out the accumulation and excretion experiments, using carp, for the same eight organophosphorous pesticides (dichlorvos, salithion, phenthoate, methidathion, pyridaphenthion, fenthion, EPN and phosmet) as in our previous report (Tsuda et al., submitted for publication). MATERIALS
AND METHODS
Chemical Dichlorvos (2,2-dichlorovinyl dimethyl phosphate), salithion (2-methoxy-4H-1,3,2-benzodioxaphosphorin-2-sulfide), phenthoate {S-[a-(ethoxycarbony)-benzyl] dimethyl phosphorothiolothionate>, methidathion [S-(Z-methoxy-5-oxo-1,3,~thiadiCBP(C)
104/2-F
~olin~ylmethyl) dimethyl phosphorothiolothpyridaphenthion (2,3-dihydro-3-0x0-2ionate], phenyl&pyridazinyl diethyl phosphorothionate), fenthion (dimethyl 4-methylthio-m-tolyl phosphorothionate), EPN (ethyl p-nitrophenyl phenylphosphonothionate), phosmet [dimethyl S-(phthalimidomethyl) phosphorothiolothionate] were purchased from Wako Pure Chemical Industries Ltd (Osaka, Japan). These chemicals were more than 98.0% pure and were used without further pu~fication. Test jsh Carp (Cyprinus carpio L.) were obtained from Nango Suisan Center (Shiga Prefecture, Japan). The body length and body weight of the fish were 8.5-10.0 cm and 14.0-20.8 g, respectively. Ail these pesticides were not detected in the fish before exposure to them. Commercial assorted feed was given, about 200mg per fish, once a day throughout the experimental period. Test system The study was carried out with aeration under the continuous flow-through system. The experimental arrangements were the same as our previous report (Tsuda et al., 1987). For ambulation experiments, stock solutions A (dichlorvos, salithion, phenthoate and methidathion, each SOOpgl-‘, 101) and B (pyridaphenthion, fenthion, EPN and phosmet, each 500 pg l-l, 10 1) were each diluted continuously 150 times with dechlorinated city water and supplied to each of the two aquaria containing 25 fish. During the test, the flow rate and temperature of each test water were maintained 18 1hr-’ and 23 f l”C, respectively. The 275
216
T. TsUDAet al.
concentrations of these chemicals in each test water were mean + S.D. (N = 5) of 1.0 f 0.3 pg 1-l for dichlorvos, 2.4 + 0.2 pg 1-l for salithion, for methidathion (experiment I), and 3.4 f 0.2 pg 1-l for pyridaphenthion, 0.3 f 0.1 pg 1-l 1.6 f 0.2 pg 1-l for phenthoate and 3.3 + 0.1 pg 1-l for fenthion, 1.9+O.lpgl-’ for EPN and 1.7+0.1pgl-’ for phosmet (experiment 2). Measurements were carried out at 0,24,72, 120 and 168 hr. Three fish were taken at 24, 72, 120 and 168 hr. The concentrations of these pesticides in each test water were fixed by reference to the data of 48 hr LC~,, to carp (Tanaka, 1978). The low concentrations of these chemicals are probably because they are absorbed to the tubes of the experimental arrangements or the walls of the aquaria. The pH, the concentrations of dissolved oxygen and the hardness in each test water were 6.8-7.0, more than 7mgl-’ and 3437 mg 1-l as CaCO,, respectively. Measurements were carried out every 24 hr for pH and once after 72 hr for dissolved oxygen and hardness. For excretion experiments, 13 fish remaining in each aquarium were separately transferred into each of the other two aquaria and dechlorinated city water was supplied to each of them. During the test, the flow rate and temperature of each test water were maintained 60 1hr-’ and 24 f 1°C respectively. Three fish were taken at 6, 12, 24 and 72 hr. The pH and the concentrations of dissolved oxygen in each test water were 6.9-7.0 and more than 7 mg l-‘, respectively. Measurements were carried out every 24 hr, for pH, and once after 24 hr, for dissolved oxygen. Under these conditions, none of the fish showed signs of tiredness and agitation during the accumulation and excretion experiments.
40°C and the residue was dissolved
in lOm1 of hexane. The hexane solution was shaken with 30ml of acetonitrile saturated with hexane and the acetonitrile layer was retained. The operation was repeated and the combined acetonitrile layer was rotaryvacuum evaporated just to dryness at 40°C. The residue was dissolved with 5 ml of acetone, and the acetone solution was passed through a column (a mixture of 0.2 g activated charcoal and 0.2 g microcrystalline cellulose). The concentration of each pesticide in the eluate was measured by FPDGC after rotary-vacuum evaporation to l-5 ml. Average recoveries (whole body of fish 5 g, N = 3) were 92% for dichlorvos, 100% for salithion, 100% for phenthoate, 98% for methidathion, 97% for pyridaphenthion, 74% for fenthion, 95% for EPN and 98% for phosmet at 100 ngg-’ spiked levels. The GC (Shimadzu GC-9AM) operating conditions were as follows: GC column: J&W DB - 1701 (30 m x 0.53 mm 4, film thickness 1.0 pm); Carrier: Nz 30 ml min-‘; Air: 60 ml min-‘; H,: 75 ml min-‘; Temperatures: injection and detector 280°C; column 100°C (Omin); lO”Cminto 270°C. Analysis was carried out as three separate samples for each sampling time. Calculation of BCF and excretion rate constants
BCF was calculated BCF =
by the following equation:
chemical concentration in whole body of fish chemical concentration in water .
The chemical concentration in the water at each sampling time was used for the calculation of BCF. The excretion rate constants (k) of the chemicals from the whole body of the fish were calculated assuming that the excretion process follows first-order kinetics.
Analysis RESULTS
The concentration of each of the pesticides in water samples was determined by the following procedure. A measured volume (200ml) of water was shaken with 100ml of dichloromethane after addition of 20 g of NaCl. The organic layer was rotary-vacuum evaporated just to dryness at 40°C. The residue was dissolved with 4 ml of hexane and analyzed by a gas chromatograph equipped with a flame photometric detector (FPD-GC). Average recoveries (N = 3) were 91% or dichlorvos, 99% for salithion, 93% for phenthoate, 100% for methidathion, 100% for pyridaphenthion, 99% for fenthion, 100% for EPN and 100% for phosmet at 2pgl-’ spiked levels. Determination of each pesticide in fish samples was performed by the following method (Goto and Kato, 1980). A fish sample (about 5 g) was homogenized with 30 ml of acetonitrile using a high-speed homogenizer (Ultra-Turrax, Germany) after the addition of 5 g of anhydrous Na,SO,, and the organic layer was filtered. The residue was again homogenized and filtered in the same manner. The combined filtrate was rotary-vacuum evaporated just to dryness at
AND DISCUSSION
Accumulation of pesticides
The experimental results are shown in Table 1. The concentrations of pesticides in the whole body of carp reached plateaus after 24 hr exposure for salithion, methidathion, pyridaphenthion, fenphenthoate, thion and phosmet, but not until 168 hr for EPN. For dichlorvos, the period was unknown because its concentration in the fish was very low and could not be determined at all sampling times. The period of Table 1. BCF of pesticides
in carp
BCF’ in whole body of fish Pesticides Dichlorvos Salithion Phenthoate Methidathion Pyridaphenthion Fenthion EPN Phosmet
24 hr
12 hr
120 hr
168 hr
<0.5 9.9 f 3.9 31* 15 3.5 f 1.4 4.6kO.7 22 + 3 3Ok 13 1.6kO.7
<0.5 7.4 + 1.6 27 f 7 2.7 f 0.5 4.6+ 1.6 29 f 6 29 + 6 1.5kO.4
<0.5 4.5 f 0.9 20 f 4 1.8 +0.4 3.7 f0.6 27 f 6 49* 15 1.8kO.9
co.5 7.1+ 0.4 32 + 2 3.1 kO.4 6.OkO.3 26 + 8 85 5 28 1.8 k 0.5
*Mean value f S.D. (N = 3).
211
OPs in carp
Log Pow
Fig. 1. Relationship between log P,, and log BCF in carp. (1) Chlorothalonil; (2) captan; (3) chlorpyriphos; (4) isoprothiolane; (5) isoxathion; (6) iprodione; (7) salithion; (8) phenthoate; (9) methidathion; (10) pyridaphenthion; (11) fenthion; (12) EPN; (13) phosmet. phenthoate (24 hr) in carp was considerably shorter than that in willow shiner (2 168 hr) (Tsuda et al., submitted for publication). The average BCF values (N = 4) in the whole body of the fish after 24-168 hr exposure were 7.4 for salithion. 29 for phenthoate, 2.8 for methidathion, 4.1 for pyridaphenthion, 26 for fenthion and 1.7 for phosmet. The BCF values of these pesticides in carp were l/1&1/20 times as high as those in the willow shiner. This tendency was the same as in other chemicals (BCF: Bu,SnCl 3600, Ph,SnCl 2300 in willow shiner and Bu,SnCl 1500, Ph,SnCl 500 in carp) in our previous report (Tsuda et nl., 199Oc, 1992b). The order of BCF in carp was EPN > phenthoate > fenthion > salithion > pyridaphenthion > methidathion > phosmet > dichlorvos. This order was about the same as that in the willow shiner (EPN > phenthoate > fenthion > salithion > phosmet > pyridaphenthion > methidathion > dichlorvos). These orders were slightly different from that of P,, (EPN > fenthion > methidathion > salithion > pyridaphenthion > phenthoate, phosmet > dichlorvos). It is generally known that there is
t!
6
24
Ti me(hr) Fig. 3. Excretion thion;
of pesticides
n fenthion;
(2) from carp. 0 Pyridaphen-
q EPN; A phosmet.
linearity between log P,,wand log BCF in fish, but the BCF value of phenthoate was considerably higher than the value estimated from PO,. This was the same as in the willow shiner. In our previous report (Tsuda et al., submitted for publication), the correlation between log PO,,,and log BCF in willow shiner was investigated for 19 pesticides. In this report, the same correlation in carp was investigated for 13 pesticides already reported (Tsuda et al., 1992a) and studied here. The data of log POW were also cited from the studies by Okumura and Imamura (1991) and Kanazawa (1981). This correlation is shown in Fig. 1. The r value was not so high (0.5139, N = 13) but higher (0.7005, N = 12) in the case of excluding captan, which was the same as in our previous report (Tsuda et aI., submitted for publication). Excretion of pesticides
The experimental results are shown in Figs 2 and 3. From these data, the excretion rate constants (k) and biological half-lives of the fish were calculated by assuming that the excretion process follows firstorder kinetics and these are shown in Table 2. The concentrations of dichlorvos and phosmet in the fish were low and rapidly decreased, so could not be measured by FPDW after 6-72 hr (all sampling times). For this reason, the k values of dichlorvos and Table 2. Excretion rate constants and biological half-lives of pesticides by carp Pesticides
1dL
0
12
6
2.5
Time(hr) Fig. 2. Excretion
of pesticides
l phenthoate;
(1) from carp. @ methidathion.
0
Salithion;
Dichlorvos Salithion Phenthoate Methidathion Pyridaphenthion Fenthion EPN Phosmet
k (hr-‘)
Half-lives (hr)
0.54 0.52 0.54 0.43 0.34 0.18 -
1.3 1.3 1.3 1.6 2.0 3.9
T.
278
-bJDA
phosmet
could not be calculated. The excretion rate of these pesticides in carp was Z-10 times as rapid as that in willow shiner (Tsuda et al., submitted for publication). The order of their excretion rate was methidathion = salithion 2 phenthoate > uvridaphenthion > fenthion > EPN.- As described *above, the order of their BCF values was EPN > phenthoate > fenthion > salithion > pyridaphenthion > methidathion. The order of their excretion rate was approximately reversed compared with that of their BCF values. That is, the greater the BCF value, the slower the excretion rate. This tendency was the same as in our previous studies (Tsuda et al., 1988, 1989a, 1990b, 1992a, submitted for
publication). REFERENCES
Goto S. and Kato S. f 1980) Analyticat methods of Pesticide Residues. Soft Science, Tokyo-(in Japanese). Kanazawa J. (1981) Measurements of the bioconcentration factors of pesticides by freshwater fish and their correlation with physiochemical properties or acute toxicities. Pestic. Sci. 12, 4177424.
Okumura T. and Imamura K. (1991) Simultaneous determination of pesticides by capillary gas chromatography/ mass spcctrometry. Jpn. J. Water Pollut. Res. 14, 109.-122 (in Japanese). Tanaka J. (1978) Suisei Seibutsu To Nouyaku (Kyusei Dokusei Shiryou Hen). Scientist, Tokyo (in Japanese). Tsuda T., Aoki S., Kojima M. and Harada H. (1988) Bioconcentration and excretion of benthiocarb and
et al.
simetr~e by willow shiner. Toxic. enuiron. C&m. IS, 31-36. Tsuda T., Aoki S., Kojima M. and Harada H. (1989a) Bioconcentration and excretion of diazinon, IBP, malathion and fenitrothion by willow shiner. Toxic. enuiran. Chem. 24, 185-190. Tsuda T., Aoki S., Kojima M. and Harada H. (1989b) Bioconcentration and excretion of benthiocarb and simetryne by carp. Water Res. 23, 529-531. Tsuda T.. Aoki S.. Koiima M. and Harada H. (199Oa) Bi~on~entratio~’ ad excretion of diazinon: IBP: malathion and fenitrothion by carp. Con+ B&hem. Physiol. %C, 23-26.
Tsuda T., Aoki S., Kojima M. and Harada H. (1990b) Accumulation and excretion of oxadiazon, CNP and chlomethoxvnif bv willow shiner. ComD. Biochem. Phvsiol. %C, 373-3751 Tsuda T., Aoki S., Kojima M. and Harada H. (1990~) The influence of OH on the accumulation of tri-n-butvltin chloride and’triphenyltin chloride in carp. Camp. kothem. Phyfiol. #C, i51-153. Tsuda T., Aoki S., Kojima M. and Fujita T. (1992a) Accumulation and excretion of pesticides used in golf courses by carp (Cvprinlrs cq&) and willow shiner (Gnathopogon caerulescens). lOlC, 63-66.
Comp.
Biochem.
Physioi.
Tsuda T., Aoki S., Kojima M. and Fujita T. (1992b) Accumulation and excretion of tri-n-butyltin chloride and triphenyltin chloride by willow shiner. Comp. Biochem. Physiol. ZOlC, 67-70.
Tsuda T., Aoki S., Kojima M. and Fujita T. Accumulation and excretion of organophosphorous pesticides by willow shiner. (submitted for publi~tion). Tsuda T., Nakanishi H., Aoki S. and Takebayashi J. (1987) Bioconcentration and metabolism of phenyitin chlorides in carp. Water Res. 21, 949-953.