Uptake and excretion of chlorinated diphenyl ethers and brominated toluenes by fish

Chemosphere No. 6, pp 293 - 301, 1977.

Pergamon Press.

Printed in Great Britain.

U P T A K E AND E X C R E T I O N OF C H L O R I N A T E D D I P H E N Y L ETHERS AND B R O M I N A T E D T O L U E N E S BY FISH

V.

Zitko and W. G. Carson

E n v i r o n m e n t Canada, Fisheries and Marine Service, St. Andrews,

New Brunswick,

Canada

E0G 2X0

(Received in The Netherlands 4 April 1977; accepted for publication 14 April 1977) The uptake and e x c r e t i o n of 2,4,4'-tri-, 2,2',4,4',5-pentachlorodiphenyl

ether,

2,3',4,4'-tetra-,

tetrabromo-2-chloro,

from water and from food were studied in juvenile A t l a n t i c

and

and p e n t a b r o m o t o l u e n e salmon

(Salmo salar).

The uptake and e x c r e t i o n of the c h l o r i n a t e d d i p h e n y l ethers r e s e m b l e that of the c o r r e s p o n d i n g chlorobiphenyls. ly low a c c u m u l a t i o n coefficients,

The b r o m i n a t e d toluenes have relative-

and are e x c r e t e d very slowly.

C h l o r i n a t e d diphenyl ethers have some a p p l i c a t i o n s similar to those of PCB's.

In addition,

several of these c o m p o u n d s may be present as i m p u r i t i e s in

c h l o r i n a t e d phenols.

The c h e m i s t r y of c h l o r i n a t e d diphenyl ethers was r e v i e w e d

r e c e n t l y 1.

The a c c u m u l a t i o n of 2 , 2 ' , 4 , 4 ' - t e t r a e h l o r o d i p h e n y l ether in trout was

higher than that of h e x a c h l o r o b e n z e n e 2.

There are no reports on the o c c u r r e n c e

of c h l o r i n a t e d d i p h e n y l ethers in the environment. B r o m i n a t e d toluenes are used as fire r e t a r d a n t s 3. the b e h a v i o u r of these c o m p o u n d s in aquatic

fauna.

b r o m o b e n z e n e either from water or from food 4. were d e t e c t e d in sewage sludge

5

Little is k n o w n about

Fish did not a c c u m u l a t e hexa-

Penta- and two t e t r a b r o m o t o l u e n e s

. EXPERIMENTAL

C h l o r i n a t e d d i p h e n y l ethers and b r o m i n a t e d toluenes were o b t a i n e d from the RFR Corporation,

EnChem Environmental Division

Organic C h e m i c a l s Kit, Chem Service

(Hope, Rhode Island),

(Media, Pennsylvania),

293

respectively.

and from

294

~o. 6

The c o m p o u n d s were a d m i n i s t e r e d to the fish as m i x t u r e s A and B (Table i).

The two r e f e r e n c e compounds,

2,4',5-tri-,

and 2 , 2 ' , 4 , 5 ' - t e t r a b r o m o -

biphenyl, were added to make this study c o m p a r a b l e to a p r e v i o u s study of halogenated biphenyls

4 .

Table 1 The c o m p o s i t i o n of a d m i n i s t e r e d m i x t u r e s of c h l o r i n a t e d d i p h e n y l ethers Mixture

(B).

A 2,4,4'

Concn.

(A) and b r o m i n a t e d toluenes

2,3',4,4'

B

2,4',5*

2,2',4,4',5

CIBr 4

Br 5

0.171

0.196

2,2',4,5'*

in

hexane,

0.118

0.100

0.094

0.114

0.126

mg/m£

R e f e r e n c e compounds,

bromobiphenyls

W a t e r exposure.

The solutions

the bottoms of 4-£ E r l e n m e y e r flasks. (3 £) was added. extractable

(Table i, 1 and 3 m£) were applied to Hexane was left to e v a p o r a t e and water

Three fish, average length 9.65 cm, w e i g h t 8.48 g, and hexane-

lipid 2.66%, were used per flask.

A gentle a e r a t i o n was p r o v i d e d and

the t e m p e r a t u r e was m a i n t a i n e d at II°C by a water bath.

E x p o s u r e was c o n t i n u e d

for 96 h in uptake experiments, w h e r e a s in uptake and e x c r e t i o n e x p e r i m e n t s the fish w e r e e x p o s e d for 48 h and then placed in running clean water Food exposure. mixtures

Food samples were c o n t a m i n a t e d by adding aliquots of the

(Table i) to Ewos dry food,

suspended in hexane,

and e v a p o r a t i n g hexane in a r o t a t o r y evaporator.

for 30 min

sample was

for 42 days.

Sub-

clean food was offered for an a d d i t i o n a l 42 days.

The average

length, w e i g h t and h e x a n e - e x t r a c t a b l e

the feeding e x p e r i m e n t were: Analysis. fish),

equilibrating

Each c o n t a m i n a t e d

offered to 20 fish, kept in 30 £ of running water at 16°C, sequently,

for up to 384 h.

10.67 cm, 12.82 g, and 2.94%,

The e x t r a c t i o n of samples

c l e a n u p of the extracts,

lipid of the fish in respectively.

(water, c o n t a m i n a t e d

gas chromatography,

food, whole

and gas c h r o m a t o g r a p h y - m a s s

No. 6

295

s p e c t r o m e t r y w e r e p e r f o r m e d as p r e v i o u s l y d e s c r i b e d 4.

Two fish per sample were

a n a l y z e d i n d i v i d u a l l y and a r i t h m e t i c m e a n s are reported.

RESULTS AND D I S C U S S I O N Water exposure.

The c o n c e n t r a t i o n of the c o m p o u n d s in w a t e r d e c r e a s e d

e x p o n e n t i a l l y d u r i n g the exposure period

(Table 2).

Table 2 Decrease of c o n c e n t r a t i o n in w a t e r e x p o s u r e e x p e r i m e n t s (c = a exp(-bt),

c = c o n c e n t r a t i o n r e l a t i v e to nominal,

t = time in h; e q u a t i o n I). Compound

2,4,4'

2,3',4,4'

2,4',5*

2,2',4,4',5

CIBr 4

Br 5

2,2',4,5'*

Coefficient a

÷

0.610

÷

0.836

0.401

0.460

0.379

b

+

0.10

+

0.068

0.0089

0.011

0.014

Reference compounds, bromobiphenyls

The a c c u m u l a t i o n c o e f f i c i e n t s of c h l o r i n a t e d d i p h e n y l ethers

(Table 3)

are similar to that of 2 , 4 ~ 5 - t r i b r o m o b i p h e n y l and do not show a trend d e p e n d i n g on the n u m b e r of chlorines.

The r e l a t i v e l y lower a c c u m u l a t i o n c o e f f i c i e n t of the

p e n t a c h l o r o c o m p o u n d is the result of its h i g h e r average c o n c e n t r a t i o n during the experiment.

It can be seen from Table 3 that the a c c u m u l a t i o n c o e f f i c i e n t s are

concentration-dependent. In the previous

study 4, the a c c u m u l a t i o n c o e f f i c i e n t of 2,4',5-

t r i b r o m o b i p h e n y l was close to that of two t e t r a c h l o r o b i p h e n y l s and about 75% of that of h e x a c h l o r o b e n z e n e .

Accordingly,

under the given e x p e r i m e n t a l c o n d i t i o n s

fish a c c u m u l a t e c h l o r i n a t e d diphenyl ethers from water a p p r o x i m a t e l y to the same extent as c h l o r o b i p h e n y l s w i t h a similar number of c h l o r i n e atoms per molecule.

~:~o. 6

296

Table 3 A c c u m u l a t i o n of c h l o r i n a t e d d i p h e n y l ethers from w a t e r Compound

2,4,4'

Concentration,

2,3',4,4'

2,2',4',5

~g/£

Nominal

39.3

i18

33.3

2.45 7.35

Average** Concentration

2,4',5*

100

38.0

ll4

31.3

94.0

2.07 6.23

2.37 7.10

4.01 12.0

in fish, ~g/g wet w e i g h t

48-h e x p o s u r e * * *

4.40

4.14

3.70

4.20

96-h e x p o s u r e

5.63 7.00

5.63 6.39

4.73 6.00

5.67 7.07

Accumulation coefficient 96-h e x p o s u r e

2298

952

2720

1025

1996

845

1414

588

115

188

ll5

172

96

162

116

190

84

47

123

67

A m o u n t in fish, ~g 96-h e x p o s u r e A m o u n t in water,

~g

at 96 h

N E G L I G I B L E

A m o u n t in fish,

% of added

R e f e r e n c e compound,

97

53

115

57

2,4 ', 5 - t r i b r o m o b i p h e n y l

C a l c u l a t e d by i n t e g r a t i n g e q u a t i o n I from 0 to 96 h *** Used i n

excretion

studies

The a c c u m u l a t i o n c o e f f i c i e n t s of t e t r a b r o m o - 2 - c h l o r o toluene

and p e n t a b r o m o -

(Table 4) are about i0 times lower than that of 2 , 2 ' , 4 , 5 ' - t e t r a b r o m o -

b i p h e n y l which,

in the previous

study 4, was a p p r o x i m a t e l y 75% of the a c c u m u l a t i o n

c o e f f i c i e n t of 2 , 4 ' , 5 - t r i b r o m o b i p h e n y l . The c o n c e n t r a t i o n of the studied compounds then placed in c l e a n water,

in fish, exposed for 48 h and

d e c r e a s e d e x p o n e n t i a l l y w i t h time

tive data for chloro- and b r o m o b i p h e n y l s are not available. A r o c l o r 1242 and C h l o r a l k y l e n e and 71 h, r e s p e c t i v e l y

6

.

(Table 5).

Compara-

The h a l f - l i v e s of

12, d e t e r m i n e d under similar conditions,

were 207

It appears that c h l o r i n a t e d d i p h e n y l ethers are somewhat

m o r e p e r s i s t e n t in the fish than the c o r r e s p o n d i n g c h l o r o b i p h e n y l s .

The

No. 6

297

Table Accumulation

of b r o m i n a t e d

Compound

57

Average**

15.3 in fish,

0.161

96-h e x p o s u r e

0.118 coefficient

;~nount in fish,

in water,

~g

Calculated Used

55.6

126

8.78

26.3

0.182 1.79

2.53

0.262

1.32

3.30

11.4

14.2

23.7

376

3.18

50.7

7.08

37.5

89.4

94.5

12.5

474

323

87.4 138

31.5 38.6

132

102

37.4 360

% of

as % of added

Reference

18.5

42

39.0

32.3

added Found

195

7.7

29.1

in fish,

46.0

65

~g

at 96-h

Amount

171

~g

96-h e x p o s u r e

found,

2,2',4,5'*

at

96-h e x p o s u r e

Total

Br 5

~g/g wet w e i g h t

48-h e x p o s u r e * * *

Amount

from w a t e r

~g/Z

Nominal

Accumulation

toluenes

C1Br 4

Concentration,

Concentration

4

compound,

36.7

22.5

28.4

87.7

89.6

18.9

26.9

19.8

22.6

80.9

95.3

2,2 ' , 4,5 ' - t e t r a b r o m o b i p h e n y l

by i n t e g r a t i n g

in e x c r e t i o n

10.9

studies

equation

I from 0 to 96 h

298

~o. 6

Table 5 Rate of excretion of chlorinated diphenyl ethers and brominated toluenes,

following uptake from water

Compound

Half-life,

2,4,4'-trichlorodiphenyl

ether

2,3',4,4'-tetrachlorophenyl

h

235

ether

370

2,4',5-tribromobiphenyl*

310

2,2',4,4',5-pentachlorodiphenyl

ether

370

tetrabromo-2-chlorotoluene

856

pentabromotoluene

770

2,2',4,5'-tetrabromobiphenyl*

495

Reference compounds

brominated toluenes are 2-3 times more persistent than chlorinated diphenyl ethers and the reference compounds. Food exposure.

Equilibrium concentrations

in the fish were reached with-

in the period of feeding food contaminated with chlorinated diphenyl ethers (Table 6).

The accumulation coefficients are similar to those of halogenated

b i p h e n y l s 4'6 Equilibrium concentrations toluenes,

in the fish were reached for the brominated

but not for the reference tetrabromobiphenyl

(Table 7).

The accumulation

coefficients of the former are about i0 times lower than those of halogenated biphenyls and chlorinated diphenyl ethers. tetrabromo-2-chlorotoluene

On the other hand, the half-life of

is similar and that of pentabromotoluene

is much longer

than the half-lives of the other compounds. Highly brominated biphenyls yielded partially debrominated degradation products in the fish, particularly when administered degradation was not observed with hexabromobenzene debrominated toluenes were not detectable

4

in food 7. and,

in this work.

An analogous

similarly,

partially

No. 6

299

Table 6 Accumulation of chlorinated diphenyl ethers from food Compound

2,4,4'

2,3',4,4'

2,4',5*

2,2',4,4',5

Nominal

2.95

2.50

2.35

2.85

Actual

2.65

2.64

2.35

2.85

Concentration in food, ~g/g

Feeding contaminated food Days

Concentration in fish, ~g/g wet weight

14

0.32

0.85

0.88

1.06

28

0.45

0.58

0.59

0.66

42

0.81

0.86

0.85

1.03

14

0.38

0.72

0.60

0.86

28

0.21

0.54

0.38

0.68

42

0.34

0.69

0.72

0.62

0.31

0.33

0.36

0.36

15

55

26

55

Feeding clean food Days

Accumulation coefficient Excretion half-life,

Reference compound,

days

2,4',5-tribromobiphenyl

300

No. 6

Table 7 Accumulation of brominated toluenes from food Compound

ClBr 4

Br 5

2,2',4,5'*

Nominal

3.42

3.92

2.52

Actual

3.82

4.46

3.14

Concentration in food, ~g/g

Feeding contaminated Days

food

Concentration in fish, ~g/g wet weight

14

0.14

0.17

0.34

28

0.14

0.15

0.80

42

0.13

0.15

1.28

14

0.13

0.22

0.98

28

0.09

0.12

0.66

42

0.04

0.Ii

0.18

0.035

0.035

0.41

Feeding clean food Days

Accumulation c o e f f i c i e n t Excretion half-life,

Reference compound,

Conclusions. pentachlorodiphenyl bromobiphenyls.

days

34

83

28

2,2 ' ,4,5 '-tetrabromobiphenyl

The accumulation and excretion patterns of tri- to

ethers resemble closely those of the corresponding chloro- and

The diphenyl ethers may be somewhat more persistent

Tetrabromo-2-chlorotoluene

and pentabromotoluene

in the fish.

accumulate about 10 times

less than chlorinated diphenyl ethers, but are excreted more slowly.

The

possibility of the formation of non-extractable degradation products from highly brominated aromatic hydrocarbons

in the fish should be investigated.

No. 6

301

Due to the relatively environment of aquatic

low a c c u m u l a t i o n

by highly brominated

coefficients,

contamination

toluenes may not be detectable

of the

readily by analyses

fauna. ACKNOWLEDGMENTS

We thank Mr. C.D. Metcalfe

for efficient

Madelyn M. Irwin for typing the manuscript. commented

technical

assistance,

and Mrs.

Drs. A.W. White and D.J. Wildish

on the manuscript. REFERENCES

i. G. Sundstrom, 2. W.B. Neely,

D.R.

3. O. Hutzinger, 4. V. Zitko,

and O. Hutzinger, Branson,

and G.E. Blau,

G. Sundstrom,

and O. Hutzinger,

5. P.E. Mattson,

A. Norstrom,

6. V. Zitko,

and W. G. Carson,

7. V. Zitko,

Bull.

Environ.

Chemosphere

and S. Safe, Bull.

Chemosphere,

Contam.

Environ.

(1976). Sci. Tech. 8, 1113

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and C. Rappe,

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