Water Florae as Indicators of Irrigation Water Contamination by DDT 1 by G. W. WARE, M. K. DEE, and W. P. CArULL
Department o] Entomology, the University o] Arizona, Tucson
C e r t a i n c r o p s have been shown tO be good i n d i c a t o r s of soil contamination by c h l o r i n a t e d i n s e c t i c i d e s .
L i c h t e n s t e i n and Schulz (1)
found that the c a r r o t a b s o r b e d m o r e i n s e c t i c i d a l r e s i d u e s f r o m soil t r e a t e d with aldrin and h e p t a c h l o r than did potato, beet, lettuce, r a d i s h , c u c u m b e r , turnip, cabbage, b r o c c o l i , c e l e r y or p a r s n i p . C a r r o t s (Daucus carota), p a r t i c u l a r l y the White Belgium v a r i e t y , w e r e shown by L i c h t e n s t e i n e t al. (2) to have a high affinity for the cyclodiene g r o u p of o r g a n o c h l o r i n e i n s e c t i c i d e s .
This v a r i e t y a b s o r b e d
m o r e alclrin, dieldrin, heptachlor and its epoxide than did four other v a r i e t i e s grown f o r two y e a r s in t r e a t e d soil. In e x p l o r i n g DDT r e s i d u e s and buildup in the food web of a Long Island e s t u a r y , t r e a t e d 20 y e a r s for mosquito control, Woodwe11 (4) found that DDT r e s i d u e s in the u p p e r l a y e r of mud r a n g e d up to 32 pounds per acre.
At the s a m e t i m e he found m a r s h plant shoots to contain 0.33
1Contribution to Regional P r o j e c t W-45, " R e s i d u e s of Selected P e s t i c i d e s - T h e i r Nature, Distribution, and P e r s i s t e n c e in Plants, A n i m a l s and the Physical E n v i r o n m e n t . " U n i v e r s i t y of A r i z o n a A g r i c u l t u r a l E x p e r i m e n t Station journal s e r i e s #1378.
333 Bulletin of EnvironmentalContamination&Toxicology, Vol. 3, No. 6, 1968,publishedby Springer-VerlagNew YorkInc.
ppm DDT and its derivatives, while Cladophora contained only 0.08 ppm, all on a wet weight basis. Meeks and Peterle (3) found that the alga, Clad0phora, in a Lake Er ie m a r s h treated with 36C1-DDT at the rat e of 0. 2 l b . / a c r e , concentr ated DDT far
m or e than other plants or animals.
After three days
the alga contained 96 ppm while bladderwort and soft-stem bulrush contained 10.81 and 3. 16 ppm respectively. Some other levels r e p o r t e d after three days exposure were sago pondweed, 205; cur l y- l eaf pondweed, 2.16; duckweed, 2.34; muskgrass, 2.52; and b u r - r e e d , 3.06. In this same study Cladophora still retained 1.62 ppm nine months a f t e r treatment, and was the only one of 15 plants followed closely having a residue in excess of 1.0 ppm. It was the purpose of this study to examine irrigation canals, flowing through a r e a s normally treated with organochlorine insecticides, for plants which might serve as DDT collectors or indicators of DDT usage by concentrating this m a t e r i a l and its metabolites.
Materials and Methods In late October and ear l y November, 1966, after DDT applications had subsided, canal surveys were made in the four major i rri gat ed agricultural di s t r i c t s of Arizona: Phoenix (Buckeye-Litchfield Park), Casa Grande, Phoenix (Mesa-Chandler), and Yuma.
334
These canals are
all f e d by the Salt River Project, with the exception of Yuma which r e c e i v e d its irrigation water f r o m the Colorado and Gila Rivers. Plants f r o m the ear l y samplings w e re identified by herbarium personnel in the Department of Botany. Subsequent collections were identified by comparison with the previously identified specimens.
Two
plants were commonly found in all ar e a s sampled, Potamogeton pectinatus, a member of the pondweed family commonly known as sago, and Cladophora, a filamentous alga.
Other species collected
wer e another alga, Oscillatoria, submerged bermuda g r a s s , Cynodon dactylon, and the giant r e e d, Arundo donax. One-gallon water samples w e r e collect ed in glass jugs f r o m all canals sampled for plants, while sediment samples w ere collected only when p r es en t in quantity on the canal floor. On returning to the laboratory dry weight determinations were made on all plant and sediment samples.
Extraction and Cleanup ,. --Unfiltered water samples were extracted by adding 250 ml of redistilled hexane to 1500 ml of water in a s e p a r a t o r y and shaking for one minute.
The water was discarded and the r e m a i n d e r
of the 3-liter sample added to the s e pa rat ory for similar extraction.
The
hexane was passed through a 1-inch column of sodium sulfate into a storage bottle.
The s e p a r a t o r y funnel was ri nsed with 25 ml of hexane
which was added to the extract.
The ext ract was evaporated to 10 ml
which was placed on the column for cleanup. 335
Sediment s a m p l e s (100 g m aliquots) w e r e e x t r a c t e d with 400 m l of h e x a n e : a c e t o n e (1:1) f o r 10 m i n u t e s in an o m n i m i x e r .
After f i l t e r -
ing, the e x t r a c t w a s w a s h e d t h r e e t i m e s with 1500 m l d i s t i l l e d w a t e r . The hexane e x t r a c t w a s then d r i e d and e v a p o r a t e d f o r cleanup as de s c r i b e d . Plant s a m p l e s w e r e e x t r a c t e d for 10 m i n u t e s with 300 m l of hexane:ethanol (2:1) in an o m n i m i x e r .
The s a m p l e w a s f i l t e r e d and
the r e m a i n i n g plant m a t e r i a l and f i l t e r p a p e r p l a c e d in a Soxhlet e x t r a c t i o n thimble.
T h i s w a s r e f l u x e d f o r 16 h o u r s , with c h l o r o f o r m :
m e t h a n o l (1:1), a f t e r which the e x t r a c t w a s e v a p o r a t e d to d r y n e s s and r e d i s s o l v e d in hexane f o r cleanup.
The o m n i m i x e r e x t r a c t w a s w a s h e d
t h r e e t i m e s with d i s t i l l e d w a t e r , then d r i e d and e v a p o r a t e d for cleanup as d e s c r i b e d . F o r cleanup, the 10 m l hexane e x t r a c t was p a s s e d through an a c t i v a t e d F l o r i s i l column, 1:4:1 inch (sodium s u l f a t e : F l o r i s i h s o d i u m sulfate).
The s a m p l e w a s eluted with 200 m l of 20~o m e t h y l e n e chloride
in p e t r o l e u m e t h e r , the eluant e v a p o r a t e d just to d r y n e s s , and r e s i d u e d i s s o l v e d in 5 m l of hexane.
R e s u l t s and D i s c u s s i o n All s a m p l e s w e r e a n a l y z e d for p, p' DDT, o, p DDT and DDE (DDTR) by ECGC.
E x t r a c t i o n and cleanup e f f i c i e n c i e s f o r the t h r e e
m e t h o d s w e r e (1) hexane:ethanol, 82.4~o; (2) h e x a n e : a c e t o n e , 75.5~o, and (3) c h l o r o f o r m : m e t h a n o l Soxhleting, 1097o. 336
In T a b l e 1 a r e p r e s e n t e d the a n a l y t i c a l r e s u l t s of the canal study. Because s o m e of the canals w e r e molded c o n c r e t e t h e r e w a s little or no c o l l e c t a b l e s e d i m e n t and o c c a s i o n a l l y no plant s a m p l e s w e r e found. G e n e r a l l y , t h e highest DDTR r e s i d u e s w e r e found in Cladophora, 19 ppm, followed by Potamogeron, 9 ppm, and finally O s c i l l a t o r i a , 5 ppm. C o n s i d e r i n g the e a s e with which C l a d o p h o r a or Potamogeton a r e collected and t h e i r a p p a r e n t c o n c e n t r a t i n g c h a r a c t e r i s t i c s , as also found by M e e k s and Peterle (3) and Woodwell (4), both p l a n t s could conveniently s e r v e as i n d i c a t o r s of w a t e r contamination by DDT and r e l a t e d m e t a b o l i t e s .
References i. E. P. L I C H T E N S T E I N and K. R. SCHULZ, J. Agro Food Chem. 13(I):57-63 (1965). 2. E. P. LICHTENSTE]N,
G. R. M Y R D A L ,
and K. R. SCHULZ, J. Agr.
Food Chem. 13(2):126-131 (1965). 3. R. L. M E E K S
and T. J. P E T E R L E ,
RF Project 1794, Report No.
COO-1358-3, The Ohio State Univ. Res. Found., Columbus, 43212. Ref. pp. 71-84 (1967). 4. G. M. W O O D W E L L ,
Sci. Amer. 216(3):24-31 (1967).
337
TABLE DDTR RESIDUES LOCATION
IN ARIZONA
WATER (PPB)
CANALS.
OCT-NOV.
PPM DRY WT. PLANTS
Buckeye- Litchfield Park . . . . . i 1 0.2 7 2 0.14 3 0.22 4 0.32 5 6 7 8
i
0.27 0.28 0.24 0. 17
Potamogeton . . Potamogeton Cladophora Potamogeton . . . . Cladophora Potamogeton Cladophora
1966. SEDIMENT
1.86 .
. 4. 72 i. 64 9.63
. .
. . 4.58 2.90 5.57
Grande
Casa
1 2 3
O. 12 0. 10 O. t 5
. . Cladophora Potarnogeton
.
0.47
. 18. S0 19.42 139.13
Cladophor a 4
5 6
.
.
0.13 0.09
.
.
.
. .
O. 19 O. 43 0.43
.
. .
.
.
.
2.34
.
Mesa-Chandler I
2 3 4 5 6 7 8 Wullla 1 2 3 4 5 6 7 8 9 10 11 12
0. I i O. 15 O. 23 O. 11 1.60 0. 19 O. 19 O. 40
. . Cladophora Cladophora Cladophora . . Oscillatoria . . Oscillatoria
O, O, O. O,
Potamogeton . . Reed Cladophora
10 08 08 16
.
. O. 62 O. 49 O. 10
.
.
.
.
0. 85
3.58
2 6 . O0 .
. 2 0 . 02 O. 76
0.16 O. 4 7 --
. . Potamogeton 0 scillator ia
O. 6 0 O. 2 6 1.12 i. 83 O. 19
. . . . Bermuda grass (dry) -Oscillatoria .
. 338
.
. O. 24 2.89
.
.
2. :32
12.42
O. 08
Department o] Entomology, the University o] Arizona, Tucson
C e r t a i n c r o p s have been shown tO be good i n d i c a t o r s of soil contamination by c h l o r i n a t e d i n s e c t i c i d e s .
L i c h t e n s t e i n and Schulz (1)
found that the c a r r o t a b s o r b e d m o r e i n s e c t i c i d a l r e s i d u e s f r o m soil t r e a t e d with aldrin and h e p t a c h l o r than did potato, beet, lettuce, r a d i s h , c u c u m b e r , turnip, cabbage, b r o c c o l i , c e l e r y or p a r s n i p . C a r r o t s (Daucus carota), p a r t i c u l a r l y the White Belgium v a r i e t y , w e r e shown by L i c h t e n s t e i n e t al. (2) to have a high affinity for the cyclodiene g r o u p of o r g a n o c h l o r i n e i n s e c t i c i d e s .
This v a r i e t y a b s o r b e d
m o r e alclrin, dieldrin, heptachlor and its epoxide than did four other v a r i e t i e s grown f o r two y e a r s in t r e a t e d soil. In e x p l o r i n g DDT r e s i d u e s and buildup in the food web of a Long Island e s t u a r y , t r e a t e d 20 y e a r s for mosquito control, Woodwe11 (4) found that DDT r e s i d u e s in the u p p e r l a y e r of mud r a n g e d up to 32 pounds per acre.
At the s a m e t i m e he found m a r s h plant shoots to contain 0.33
1Contribution to Regional P r o j e c t W-45, " R e s i d u e s of Selected P e s t i c i d e s - T h e i r Nature, Distribution, and P e r s i s t e n c e in Plants, A n i m a l s and the Physical E n v i r o n m e n t . " U n i v e r s i t y of A r i z o n a A g r i c u l t u r a l E x p e r i m e n t Station journal s e r i e s #1378.
333 Bulletin of EnvironmentalContamination&Toxicology, Vol. 3, No. 6, 1968,publishedby Springer-VerlagNew YorkInc.
ppm DDT and its derivatives, while Cladophora contained only 0.08 ppm, all on a wet weight basis. Meeks and Peterle (3) found that the alga, Clad0phora, in a Lake Er ie m a r s h treated with 36C1-DDT at the rat e of 0. 2 l b . / a c r e , concentr ated DDT far
m or e than other plants or animals.
After three days
the alga contained 96 ppm while bladderwort and soft-stem bulrush contained 10.81 and 3. 16 ppm respectively. Some other levels r e p o r t e d after three days exposure were sago pondweed, 205; cur l y- l eaf pondweed, 2.16; duckweed, 2.34; muskgrass, 2.52; and b u r - r e e d , 3.06. In this same study Cladophora still retained 1.62 ppm nine months a f t e r treatment, and was the only one of 15 plants followed closely having a residue in excess of 1.0 ppm. It was the purpose of this study to examine irrigation canals, flowing through a r e a s normally treated with organochlorine insecticides, for plants which might serve as DDT collectors or indicators of DDT usage by concentrating this m a t e r i a l and its metabolites.
Materials and Methods In late October and ear l y November, 1966, after DDT applications had subsided, canal surveys were made in the four major i rri gat ed agricultural di s t r i c t s of Arizona: Phoenix (Buckeye-Litchfield Park), Casa Grande, Phoenix (Mesa-Chandler), and Yuma.
334
These canals are
all f e d by the Salt River Project, with the exception of Yuma which r e c e i v e d its irrigation water f r o m the Colorado and Gila Rivers. Plants f r o m the ear l y samplings w e re identified by herbarium personnel in the Department of Botany. Subsequent collections were identified by comparison with the previously identified specimens.
Two
plants were commonly found in all ar e a s sampled, Potamogeton pectinatus, a member of the pondweed family commonly known as sago, and Cladophora, a filamentous alga.
Other species collected
wer e another alga, Oscillatoria, submerged bermuda g r a s s , Cynodon dactylon, and the giant r e e d, Arundo donax. One-gallon water samples w e r e collect ed in glass jugs f r o m all canals sampled for plants, while sediment samples w ere collected only when p r es en t in quantity on the canal floor. On returning to the laboratory dry weight determinations were made on all plant and sediment samples.
Extraction and Cleanup ,. --Unfiltered water samples were extracted by adding 250 ml of redistilled hexane to 1500 ml of water in a s e p a r a t o r y and shaking for one minute.
The water was discarded and the r e m a i n d e r
of the 3-liter sample added to the s e pa rat ory for similar extraction.
The
hexane was passed through a 1-inch column of sodium sulfate into a storage bottle.
The s e p a r a t o r y funnel was ri nsed with 25 ml of hexane
which was added to the extract.
The ext ract was evaporated to 10 ml
which was placed on the column for cleanup. 335
Sediment s a m p l e s (100 g m aliquots) w e r e e x t r a c t e d with 400 m l of h e x a n e : a c e t o n e (1:1) f o r 10 m i n u t e s in an o m n i m i x e r .
After f i l t e r -
ing, the e x t r a c t w a s w a s h e d t h r e e t i m e s with 1500 m l d i s t i l l e d w a t e r . The hexane e x t r a c t w a s then d r i e d and e v a p o r a t e d f o r cleanup as de s c r i b e d . Plant s a m p l e s w e r e e x t r a c t e d for 10 m i n u t e s with 300 m l of hexane:ethanol (2:1) in an o m n i m i x e r .
The s a m p l e w a s f i l t e r e d and
the r e m a i n i n g plant m a t e r i a l and f i l t e r p a p e r p l a c e d in a Soxhlet e x t r a c t i o n thimble.
T h i s w a s r e f l u x e d f o r 16 h o u r s , with c h l o r o f o r m :
m e t h a n o l (1:1), a f t e r which the e x t r a c t w a s e v a p o r a t e d to d r y n e s s and r e d i s s o l v e d in hexane f o r cleanup.
The o m n i m i x e r e x t r a c t w a s w a s h e d
t h r e e t i m e s with d i s t i l l e d w a t e r , then d r i e d and e v a p o r a t e d for cleanup as d e s c r i b e d . F o r cleanup, the 10 m l hexane e x t r a c t was p a s s e d through an a c t i v a t e d F l o r i s i l column, 1:4:1 inch (sodium s u l f a t e : F l o r i s i h s o d i u m sulfate).
The s a m p l e w a s eluted with 200 m l of 20~o m e t h y l e n e chloride
in p e t r o l e u m e t h e r , the eluant e v a p o r a t e d just to d r y n e s s , and r e s i d u e d i s s o l v e d in 5 m l of hexane.
R e s u l t s and D i s c u s s i o n All s a m p l e s w e r e a n a l y z e d for p, p' DDT, o, p DDT and DDE (DDTR) by ECGC.
E x t r a c t i o n and cleanup e f f i c i e n c i e s f o r the t h r e e
m e t h o d s w e r e (1) hexane:ethanol, 82.4~o; (2) h e x a n e : a c e t o n e , 75.5~o, and (3) c h l o r o f o r m : m e t h a n o l Soxhleting, 1097o. 336
In T a b l e 1 a r e p r e s e n t e d the a n a l y t i c a l r e s u l t s of the canal study. Because s o m e of the canals w e r e molded c o n c r e t e t h e r e w a s little or no c o l l e c t a b l e s e d i m e n t and o c c a s i o n a l l y no plant s a m p l e s w e r e found. G e n e r a l l y , t h e highest DDTR r e s i d u e s w e r e found in Cladophora, 19 ppm, followed by Potamogeron, 9 ppm, and finally O s c i l l a t o r i a , 5 ppm. C o n s i d e r i n g the e a s e with which C l a d o p h o r a or Potamogeton a r e collected and t h e i r a p p a r e n t c o n c e n t r a t i n g c h a r a c t e r i s t i c s , as also found by M e e k s and Peterle (3) and Woodwell (4), both p l a n t s could conveniently s e r v e as i n d i c a t o r s of w a t e r contamination by DDT and r e l a t e d m e t a b o l i t e s .
References i. E. P. L I C H T E N S T E I N and K. R. SCHULZ, J. Agro Food Chem. 13(I):57-63 (1965). 2. E. P. LICHTENSTE]N,
G. R. M Y R D A L ,
and K. R. SCHULZ, J. Agr.
Food Chem. 13(2):126-131 (1965). 3. R. L. M E E K S
and T. J. P E T E R L E ,
RF Project 1794, Report No.
COO-1358-3, The Ohio State Univ. Res. Found., Columbus, 43212. Ref. pp. 71-84 (1967). 4. G. M. W O O D W E L L ,
Sci. Amer. 216(3):24-31 (1967).
337
TABLE DDTR RESIDUES LOCATION
IN ARIZONA
WATER (PPB)
CANALS.
OCT-NOV.
PPM DRY WT. PLANTS
Buckeye- Litchfield Park . . . . . i 1 0.2 7 2 0.14 3 0.22 4 0.32 5 6 7 8
i
0.27 0.28 0.24 0. 17
Potamogeton . . Potamogeton Cladophora Potamogeton . . . . Cladophora Potamogeton Cladophora
1966. SEDIMENT
1.86 .
. 4. 72 i. 64 9.63
. .
. . 4.58 2.90 5.57
Grande
Casa
1 2 3
O. 12 0. 10 O. t 5
. . Cladophora Potarnogeton
.
0.47
. 18. S0 19.42 139.13
Cladophor a 4
5 6
.
.
0.13 0.09
.
.
.
. .
O. 19 O. 43 0.43
.
. .
.
.
.
2.34
.
Mesa-Chandler I
2 3 4 5 6 7 8 Wullla 1 2 3 4 5 6 7 8 9 10 11 12
0. I i O. 15 O. 23 O. 11 1.60 0. 19 O. 19 O. 40
. . Cladophora Cladophora Cladophora . . Oscillatoria . . Oscillatoria
O, O, O. O,
Potamogeton . . Reed Cladophora
10 08 08 16
.
. O. 62 O. 49 O. 10
.
.
.
.
0. 85
3.58
2 6 . O0 .
. 2 0 . 02 O. 76
0.16 O. 4 7 --
. . Potamogeton 0 scillator ia
O. 6 0 O. 2 6 1.12 i. 83 O. 19
. . . . Bermuda grass (dry) -Oscillatoria .
. 338
.
. O. 24 2.89
.
.
2. :32
12.42
O. 08
