Chlorinated dioxin and dibenzofuran levels in food samples collected between 1985–1987 in the north and south of Vietnam

Chemosphere, Vol.18, Nos.l-6, pp 627-634, Printed in Great Britain

CHLORINATED

DIOXIN

BETweEN

AND

1989

DIBENZOFURAN

1985-87

IN THE

LEVELS

NORTH

AND

0045-6535/89 $3.00 + .O0 Peraamon Press plc

IN FOOD SOUTH

SAMPLES

COLLECTED

OF VIETNAM

Arnold Schecter*(1), R. Kooke, P. Serne, K. Olie Huy, Nguyen Hue (3), and J. Constable (4)

(2), Do 'Quang

(1)

Department of Preventive Medicine, Science Center, 88 Aldrich Avenue,

(2)

Laboratory of Environmental and Toxicological Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands

(3)

Dept.

(4)

Harvard Medical School, 02119

of Chemistry,

State University of New York-Health Binghamton, NY 13903

University of Hanoi,

Hanoi,

Vietnam

Massachusetts General Hospital,

Boston, MA

ABSTRACT

In a pilot study measuring PCDD/Fs in human tissues in the relatively non industrialized north of Vietnam and the more industrialized south of Vietnam, higher levels of tetra through octachlorinated dibenzodioxins and dibenzofurans were observed, on average in persons living in the south. This was believed due, partially at least, to environmental contamination with Agent Orange containing 2,3,7,8-TCDD, pentachlorophenol (PCP) and wood and paper preservative, and incineration products. In an attempt to begin to trace pathways of food and wildlife samples from the north collected and analyzed. These samples were and may not be representative. They are part variations of the dioxins within one country known to have occurred in discrete geographic least with respect to Agent Orange.

PCDD/Fs in the environment, and south of Vietnam were not systematically collected of a pilot study to measure where dioxin contamination is areas and at known times, at

INTRODUCTION

The environmental fate of the highly toxic and persistent chlorinated dioxins, especially 2,3,7,8-TCDD, is of great concern because of their potential to damage animals and humans. In a pilot study to determine the fate of dioxins in the environment, and later to explore the extent of their TCDD health effects, we began a study of TCDD in Vietnam (1-3). 2,3,7,8-TCDD was introduced by spraying with Agent Orange, a phenoxyherbicide consisting of half 2,4-D and half 2,4,5-T, the latter contaminated with 2,3,7,8-TCDD, in the south of Vietnam, during 1962-70, possibly as late as 1975. Ten percent of the land area of the south of Vietnam is believed to have been contaminated with TCDD from this well known environmental incident and

627

628

about 170 or m o r e kg of T C D D was i n v o l v e d as a c o n t a m i n a n t in the h e r b i c i d e s (i). The d i o x i n c o n t a m i n a t e d area has not b e e n c l e a n e d up nor have persons, farm a n i m a l s or w i l d l i f e been r e m o v e d from c o n t a m i n a t e d areas (4). Thus, u n f o r t u n a t e l y , V i e t n a m offers a u n i q u e o p p o r t u n i t y to study the e n v i r o n m e n t a l fate of T C D D and also its h u m a n (and animal) toxic effects. The n o r t h of Vietnam, and 90% of the south of Vietnam, was not sprayed with Agent Orange, and m a y serve as a control. P o s s i b l y m i l l i o n s of p e r s o n s in Vietnam, a c o u n t r y of 60 m i l l i o n persons, may have b e e n subject to chronic or long term e x p o s u r e to TCDD, e s p e c i a l l y from A g e n t Orange, but also from other p o s s i b l e sources. P r e v i o u s s t u d i e s (2-5) have d o c u m e n t e d c o n t a m i n a t i o n of a d i p o s e tissue and breast m i l k from n u r s i n g m o t h e r s w i t h T C D D (and o t h e r chemicals). Previous work by Baughman, M e s e l s o n and O'Keefe has shown e l e v a t i o n of T C D D in n u r s i n g m o t h e r s milk, up to 1450 ppt on a lipid basis, in 1970-73 specimens of h u m a n m i l k from the south of Vietnam, and also c o n t a m i n a t i o n of fish and s h r i m p in an inland s p r a y e d area, after A g e n t Orange e x p o s u r e (6). A b s e n t from m a n y c u r r e n t studies r e p o r t i n g d i o x i n c o n t a m i n a t i o n in humans or in the e n v i r o n m e n t , are reports of levels of d i o x i n food c o n t a m i n a t i o n in the same geographical locations. With elevated dioxin levels increasingly being found in human tissues, i n c l u d i n g m i l k and fat in industrial countries, the sources of such c o n t a m i n a t i o n b e c o m e s of concern from a p u b l i c h e a l t h perspective. In this p a p e r we p r e s e n t data from food and w i l d l i f e from the n o r t h and south of V i e t n a m from samples c o l l e c t e d in the 1980s, from 15 to 25 years a f t e r the e n v i r o n m e n t a l T C D D c o n t a m i n a t i o n from A g e n t Orange. This is p r e s e n t e d as the first data c o m p l e m e n t i n g our p r e v i o u s r e p o r t s on h u m a n tissue d i o x i n levels. MATERIALS

AND

METHODS

Field Food and w i l d l i f e s p e c i m e n s w e r e c o l l e c t e d by two of us (AS & JDC) from m a r k e t s in the n o r t h and south of Vietnam, from f i s h e r m e n and women and in fields, b e t w e e n 1985-1987. S p e c i m e n s were frozen and sent to the U n i v e r s i ty of A m s t e r d a m for c h e m i c a l analysis. They are a non random sample and, therefore, are not n e c e s s a r i l y r e p r e s e n t a t i v e of the c o u n t r y as a whole. Chemical Preparation: F r o z e n food or w i l d l i f e samples from the north and south of V i e t n a m were sent to the l a b o r a t o r y of E n v i r o n m e n t a l and T o x i c o l o g i c a l C h e m i s t r y of the U n i v e r s i t y of A m s t e r d a m . S a m p l e s ( a p p r o x i m a t e l y 50 g) were freeze-dried for m o r e t h a n 90 h o u r s and, after that, spiked with a m i x t u r e of the f o l l o w i n g compounds: 13C 2,3,7,8-TCDD; 13C 1,2,3,7,8-PCDD; 13C 1,2,3,6,7,8-HxCDD; 13C 1.2,3,4,7,8-HxCDF; 13C 1 , 2 , 3 , 4 , 6 , 7 , 8 - H p C D D ; 13C 1 , 2 , 3 , 4 , 6 , 7 , 8 - H p C D F and 13C-OCDD. The 13C d i o x i n s t a n d a r d s were o b t a i n e d from C a m b r i d g e Isotope L a b o r a t o r i e s , Woburn, MA, USA. Extraction: The s a m p l e was b r o u g h t into a soxhlet a p p a r a t u s and e x t r a c t e d with toluene for 25 h o u r s or more. The b u l k of the solvent was removed by distillation. Clean-up:

A carbon/glassfiber

(1:3) (Carbon PX 21 from Amaco).

column

was

used

as

the

first

c l e a n - u p step

(7)

The s a m p l e was b r o u g h t on the c o l u m n w i t h 10 ml cyclohexane/dichloromethane (I:i) and the c o l u m n was e l u t e d with 50 ml c y c l o h e x a n e / d i c h l o r o m e t h a n e (i:i) and 50 ml dichloromethane/methanol/toluene (75:20:5). "Back Elution" t o o k p l a c e w i t h 200 ml toluene. The t o l u e n e e l u e n t c o n t a i n s the PCDD's and

629

PCDF's. The toluene extract was concentrated drops of n - n o n a n e w e r e added. The next c l e a n - u p step was done m e t h o d of N e s t r i c k and L a m p a r s k i

by e v a p o r a t i o n

by m u l t i - l a y e r (8).

columns

and a few

comparable

with

(i0)

the

The first c o l u m n contained: 2 cm s i l i c a w i t h 22% H2SO4; I0 cm silica with 44% H2SO4; 1 cm silica; 9 cm silica with 33% IN NeOH; e l u t i o n took p l a c e with 50 ml hexane. The s e c o n d c o l u m n contained: 17 cm AI203 (Merck 90 b a s i c a c t i v i t y i) ; e l u t i o n w i t h 80 ml h e x a n e f o l l o w e d by 30 ml d i c h l o r o m e t h a n e . The latter f r a c t i o n w a s c o n c e n t r a t e d and i0 drops of n - n o n a n e w e r e added. The t h i r d c o l u m n c o n t a i n e d : 5 cm silica w i t h 10% A_NO3; the last column was p l a c e d u n d e r the t h i r d one and c o n t a i n e d 19 c~ A1203; e l u t i o n was p e r f o r m e d w i t h 80 ml hexane, 20 ml C C l 4 / h e x a n e (1:9) and e l u t i o n of the PCDDs and P C D F s was done w i t h 30 ml of d i c h l o r o m e t h a n e . The s a m p l e was c o n c e n t r a t e d to a few ul and 2 d r o p s of n - n o n a n e was added. Isomer specific analysis: High resolution G.L.C. combined r e s o l u t i o n MS was used. A S u p e l c o 60 m SD 2331, .32 mm I.D. was the G.L.C. p a r t and a H e w l e t t P a c k a r d M.S.D. for the MS part. three masses were used for the identification for each Generally, only the 2 , 3 , 7 , 8 s u b s t i t u t e d c o m p o u n d s were d e t e r m i n e d . Quantification

was performed

with

the

following

with low used for At least compound.

13C standards:

- 1 , 2 , 7 , 8 - T C D D and 2 , 3 , 7 , 8 - T C D F w i t h 13C 2 , 3 , 7 , 8 - T C D D - 1,2,3,7,8-PCDD, 1 , 2 , 3 , 7 , 8 - P C D F and 2 , 3 , 4 , 7 , 8 - P C D F w i t h 13C 1 , 2 , 3 , 7 , 8 - P C D D - 1.2,3,4,7,8-HxCDD, 1 , 2 , 3 , 6 , 7 , 8 - H x C D D and 1 , 2 , 3 , 7 , 8 , 9 - H x C D D w i t h 13C 1 , 2 , 3 , 6 , 7 , 8 - H x C D D - 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, 1 , 2 , 3 , 7 , 8 , 9 - H x C D F and 2 , 3 , 4 , 6 , 7 , 8 H x C D F w i t h 13C 1 , 2 , 3 , 4 , 7 , 8 - H x C D F - 1 , 2 , 3 , 4 , 6 , 7 , 8 - H p C D D w i t h 13C 1 , 2 , 3 , 4 , 6 , 7 , 8 - H p C D D - 1 , 2 , 3 , 4 , 6 , 7 , 8 - H p C D F and 1 , 2 , 3 , 4 , 7 , 8 , 9 - H p C D F with 13C 1 , 2 , 3 , 4 , 6 , 7 , 8 - H p C D F - O C D D and O C D F w i t h 13C O C D D As c e r t i f i c a t e d r e f e r e n c e s t a n d a r d s are not available, a s t a n d a r d used for "The W . H . O . / E U R O Q u a l i t y Control S t u d y of PCDDs and PCDFs in H u m a n Milk" (9) was u s e d as a r e f e r e n c e for the 13C mixture. RESULTS

The r e s u l t s are s h o w n in t a b l e s I-VII. A t u r t l e was s a m p l e d because t u r t l e s are k n o w n to c o n c e n t r a t e PCDD/Fs at high levels. T a b l e s I-IV show v a l u e s m e a s u r e d in a t u r t l e c o l l e c t e d in the south of Vietnam, in an area w h e r e d e f o l i a t i o n from h e r b i c i d e s occurred. T a b l e I s h o w s the P C D D / f isomers on a wet w e i g h t and on a d r i e d tissue basis in p a r t s per t r i l l i o n (PPT) in ovary. In typical a q u a t i c pattern, no O C D D was d e t e c t e d . The p r e s e n c e of i0 isomers was found. 2,3,7,8-TCDD a p p e a r e d h i g h e r r e l a t i v e to the penta t h r o u g h h e p t a c h l o r i n a t e d isomers than m i g h t be e x p e c t e d if the s o u r c e of d i o x i n was e ~ c l u s i v e l y i n c i n e r a t i o n or technical grade pentachlorophenol, w h e r e T C D D o r TCDF w o u l d not be found, in the l a t t e r instance. T a b l e II s h o w s the l i v e r P C D D / F isomers from the same turtle. The liver is well k n o w n as an o r g a n w h e r e T C D D is f r e q u e n t l y found at r e l a t i v e l y high levels, of the v a r i o u s o r g a n s and tissues. Again, the 2 , 3 , 7 , 8 - T C D D isomer is found at high l e v e l s as c o m p a r e d to the o t h e r isomers. Dn a wet weight basis, the 2 , 3 , 7 , 8 - T C D D is 21 ppt w h e r e the 2 , 3 , 7 , 8 - T C D F is 3.0 and the sum of t w o p e n t a d i b e n z o f u r a n s is 3.5. The H x C D D isomers a l s o are found at r e l a t i v e l y low c o n c e n t r a t i o n s here and the H x C D F s are also at r e l a t i v e l y low c o n c e n t r a t i o n s , 1.7 a n d 1.0 ppt, r e s p e c t i v e l y , on a wet w e i g h t basis.

630

It is of interest that the content of TCDD and PCDD/Fs in ovarian tissue is higher than in the liver, on a wet weight and also on a dry weight basis. For example, the TCDD is found at, on a wet weight basis, 21 ppt in liver and 67 ppt in ovaries from the same turtle. TABLE _I

TURTLE OVARIES PCDD/F 8outh

COMPOUND

of Vietnam

(1986)

PPT WET WEIGHT

PPT DRY WEIGHT

(.7 g)* 2378-TCDD 2378-TCDF 12378-PCDD 12378-PCDF 23478-PCDF 123478-HXCDD 123678-HXCDD 123789-WwCDD 123478-HXCDF 123678-HXCDF

(2.6

250.0 88.0 6.9 41.0 24.0 28.0 82.0 20.0 30.0 14.0

g)*

67.0 24.0 1.9 11.0 6.4 7.6 22.0 5.4 8.1 3.8

no higher chlorinated compounds were found * specimen weight TABLE II

COMPOUND

2378-TCDD 2378-TCDF 12378-PCDD 12378-PCDF 23478-PCDF 123478-HXCDD 123678-HXCDD 123789-HXCDD 123478-]LECDF 123678-WvCDF 1234678-HpCDF

TURTLE LIVER P C D D / F S (South of Vietnam 1986) PPT DRY WEIGHT (Ii.5 g)*

88.0 12.0 None Detected 9.4 4.8 5.9 ii.0 14.0 7.3 4.2 3.0

PPT WET WEIGHT (47.7 g)*

Due

21.0 3.0 to Interferences 2.3 1.2 1.4 2.8 3.4 1.7 1.0

0.7

(Dry weight 5.5 g used) * specimen weight no other chlorinated dioxins were found Table III, striatedor voluntary muscle from the s a m e turtle, shows lower levels of the dioxins and dibenzofurans than previous organs. A lesser number of isomers can be identified. Here, however, 2,3,7,8-TCDF is found at a higher level than TCDD, at 2.6 and 1.55 ppt wet weight respectively, somewhat surprisingly perhaps, since this tissue is from the same animal. This finding might well be consistent with a metabolic basis for this different ratio. Table IV, the last specimen analyzed from the turtle, shows the findings from gallbladder with its bile. Due to the enterohepatic circulation path, bile was of especial interest with respect to dioxin content. Again, many of the PCDD/F isomers can be identified, including 2,3,7,8-TCDD. Here, 2378-TCDD and 12378-PCDD levels are similar. 1234678-HpCDF is identified here, but not in ovary or muscle, and at lower levels in liver.

631

TABLE

III

TURTLE MUSCLE PCDD/Fs (South of Vietnam 1986)

COMPOUND

PPT DRY WEIGHT (3.73 g)*

2378-TCDD 2378-TCDF 12378-PCDD 123478-wVCDD 123678-w~CDD

7.8 13.0 1.6 16.0 19.0

PPT WET WEIGHT (19.3 g)*

1.5 2.6 0.3 3.1 3.7

no o t h e r c h l o r i n a t e d d i o x i n s were found *specimen weight

TABLE

IV

TURTLE GALLBLADDER CONTAINING (South of Vietnam 1986)

COMPOUND

PPT DRY WEIGHT (0.9 g ) *

2378-TCDD 2378-TCDF 12378-PCDD 12378-PCDF 23478-PCDF 123478-W~CDD 123678-1LIKCDD 123478-WWCDF 1234678-HpCDF

39.0 13.0 34.0 23.0 25.0 40.0 48.0 29.0 106.0

BILE

PPT WET WEIGHT (14 g ) *

2.5 0.9 2.1 1.5 1.6 2.5 3.1 1.8 6.8

no h i g h e r c h l o r i n a t e d c o m p o u n d s were found * specimen weight In T a b l e V, P C D D / F s found in a s p e c i m e n of pork fat p u r c h a s e d in a market in S o n g Be P r o v i n c e in the south of V i e t n a m are reported. In a pattern more t y p i c a l of non a q u a t i c species, OCDD is found, in its typical r e l a t i v e l y h i g h levels as c o m p a r e d to the o t h e r PCDD/Fs. The 58 ppt wet w e i g h t level of p o r k fat is lower than the usual h u m a n levels found in the south of Vietnam, in the h u n d r e d s of ppt, f r e q u e n t l y b e t w e e n 500 and 800 ppt. In t h i s i s o l a t e d specimen, not n e c e s s a r i l y r e p r e s e n t a t i v e of pork in the s o u t h of Vietnam, the 2 , 3 , 7 , 8 - T C D D level is 0.6 ppt on a wet weight basis, far b e l o w the m e a n of 22 ppt p r e v i o u s l y r e p o r t e d by us in humans from the south of V i e t n a m (2-4). Table VI, c h i c k e n fat from the m a r k e t in Hanoi, shows T C D D levels similar to the p r e v i o u s p o r k fat from the south of Vietnam. The levels of other isomers are s i m i l a r to what was found in the p r e v i o u s table, except that the h e p t a d i o x i n and d i b e n z o f u r a n and O C D D isomers are lower than reported here in p o r k fat from the south. Table VII r e p o r t s P C D D / F levels found in c h i c k e n fat from the south of Vietnam, from the same m a r k e t from w h i c h the p o r k fat in T a b l e V was purchased. H i g h e r levels of the PCDD/F isomers are seen in this chicken fat s p e c i m e n from the s o u t h of V i e t n a m as c o m p a r e d to that from the north of Vietnam. T h i s can be n o t e d in the 2 , 3 , 7 , 8 - T C D D levels (0.3 ppt in the n o r t h e r n s p e c i m e n and 3.5 ppt, wet weight, in the s o u t h e r n c h i c k e n fat) but also is s e e n in the o t h e r isomers such as the 7 and 8 c h l o r i n a t e d PCDD/Fs, c o n s i s t e n t w i t h s e v e r a l s o u r c e s of d i o x i n and d i b e n z o f u r a n c o n t a m i n a t i o n .

632

P O R K FAT, S O N G BE P R O V I N C E P C D D / F S (South of V i e t n a m 1986)

TABLE V

PPT DRY W E I G H T

COMPOUND

2378-TCDD 2378-TCDF 12378-PCDD

12378-PCDF 23478-PCDF 123478-HxCDD 123678-HXCDD 123789-HXCDD 123478-HXCDF 123678-HXCDF 1234678-HpCDF 1234678-HpCDD 1234678-HpCDF OCDD T A B L E VI

CHICKEN

COMPOUND

0.6 2.3 0.9

0.6 2.1 0.9

1.0 1.3 0.4 1.2 0.8 1.4 0.8 1.6 13.2 4.0 64.0

0.9 1.2 0.4 1.2 0.8 1.2 0.8 1.6 12.2 3.6 58.0

FAT F R O M THE M A R K E T (1986 PCDD/Fs)

AT H A N O I

PPT DRY W E I G H T

2378-TCDD 2378-TCDF 12378-PCDD 12378-PCDF

23478-PCDF 123678-HXCDD 123789-HXCDD 123478-HXCDF 123678-HXCDF 1234678-HpCDD 1234678-HpCDF OCDD CHICKEN

T A B L E VII

0.9 4.2 0.6 2.4

1.2 1.0 1.2 1.0 0.5 <4.5

I.i 0.9 I.I

FAT, S O N G BE P R O V I N C E M A R K E T (SOUTH OF V I E T N A M 1986)

PPT DRY W E I G H T

2378-TCDD 2378-TCDF 12378-PCDD 12378-PCDF 23478-PCDF 123478-EXCDD 123678-RXCDD 123789-RECDD 123478-HR:CDF 123678-HXCDF 123468-wVCDD* 234678-K,KCDF 1234678-KpCDD 1234678-HpCDF OCDD

not typically

4.1 9.9 10.0 9.0 9.9 6.9 27.0 5.4 10.4 3.7 18.0 1.3 71.0 9.9 75.0

found

PPT W E T W E I G H T

1.0 4.7 0.6 2.7

<1.0 <15,0

COMPOUND

* isomer

PPT W E T W E I G H T

in h u m a n / f o o d / a n i m a l

0.9

0.4 <4.1 <0.9 <14.0

PCDD/FS

PPT W E T W E I G H T

3.5 8.3 14.0 7.4 8.8 5.8 23.0 4.5 8.7 3.1 15,0 1.1 80.0 8.6 63.0

tissue

633

Table VIII presents the values found in cow's fat from a market in Hanoi, in the north of Vietnam. As expected from an herbivorous animal, living in a non industrial part of a developing country, the PCDD/F levels seem quite low. Of especial interest is the absence of the OCDD or HpCDD isomers, typically found in high levels in most human tissue and in the non aquatic specimens reported here from the south but not the north of Vietnam. TABLE

COW'S

VIII

FAT

FROM

(1985/7

COMPOUND

PPT

2378-TCDD 2378-TCDF 12378-PCDD 12378-PCDF 123478-~CDD 123678-WYCDD 123789-HXCDD 123478-HXCDF 123678-HXCDF

CONCLUSIONS

AND

MARKET

IN KANOI

PCDD/Fs)

DRY

WEIGHT

1.6 1.7 1.3 2.4 2.1 4.1 2.1 1.3 I.i

PPT

WET

WEIGHT

0.9 i.I 0.8 1.5 1.3 2.6 1.3 0.8 0.7

DISCUSSION

Chlorinated dioxins exist at the present time in food and wildlife in Vietnam, sometimes at higher levels in food from the south of Vietnam (in the non random and hence, not necessarily representative samples, from the Vietnam pilot study reported here). 2,3,7,8-TCDD, presumably at least partially from Agent Orange, the only known source of elevated levels of this isomer in the south of Vietnam, is still found at relatively elevated levels in some food and wildlife samples 15-25 years after environmental contamination with this compound. While TCDD contamination, presumably partially at least from Agent Orange, exists in animal tissue in Vietnam; contamination with other PCDD/Fs exists, which is similar to that found in human tissue in the south of Vietnam from the same time periods. This suggests that dioxin contamination from other sources may also lead to contamination of the food chain, whether of farm origin or from wildlife. As reported previously in human adipose tissue and milk from the south of Vietnam, the OCDD followed by HpCDD, are found at higest levels, and here we report similar findings from the chicken fat and pork fat from the south of Vietnam, Tables VII and Table V, respectively. we have no e x p l a n a t i o n for the finding of 123468-HxCDD in chicken fat (Table VII). It is possible that there was a local chemical contamination, about which we have no knowledge, which led to an acute exposure to this compound. Possible sources of the food and wildlife contamination, reported here, include the phenoxyherbicides, municipal incinerators, industrial incineration, technical grade pentachlorophenol (PCP) and pulp and paper processing. Although relatively low levels of PCDD/Fs are reported here for most specimens, with the exception of a turtle from the south of'Vietnam, there is a suggestion of higher levels of PCDD/Fs in specimens from the more industrialized south than from the less industrialized north in these data.

634

We believe this paper may represent one of the first attempts on an isomer specific basis to compare PCDD/F levels in humans and in the food that is consumed by these populations in a country where striking geographical variation in human tissue PCDD/F levels exist. ACKNOWLEDGEMENTS

This work was generously supported by grants from the Christopher Reynolds Foundation, the Samuel Rubin Foundation, the CS Fund, Church World Services, and from the "Die Schwelle" foundation.

i.

Herbicides in War, The Long Term Ecolouical Human Consequences, Ed Westing, A.H., Taylor and Francis, London and Philadelphia, 1984.

2.

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