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Industry Perspective on Pesticide and Ground Water Legislation Loy C. Newby and Charles G. Rock Agricultural Division, CIBA-GEIGY Corporation, Greensboro, NC 27419
Groundwater must be protected - society is in agreement. It is the focus and level of regulatory protection which concerns the agricultural chemical industry. Groundwater is not pure. It contains many substances, both natural and man-made, for most of which, minimal safety information is available. With continually improving analytical capability, additional products are certain to be detected in even the most pristine aquifers. A few pesticides have already been detected and it seems likely that others will be found. In most cases, these will be substantially below the levels which could result in adverse effects. Regulatory efforts should be directed to establishing acceptable levels, while industry should act to minimize the movement of all chemicals to groundwaters. Acceptable levels of chemicals in groundwater should be uniform throughout the nation. They should be set at the federal level or by uniform procedures among the state agencies. A r e c e n t n a t i o n a l p u b l i c o p i n i o n s u r v e y (_1) conducted by the N a t i o n a l A g r i c u l t u r a l Chemicals A s s o c i a t i o n (NACA) r e v e a l e d t h a t 47% o f a l l Americans b e l i e v e t h a t p e s t i c i d e s and farm f e r t i l i z e r s are a "major n a t i o n a l problem;" 55% i n c l u d e c h e m i c a l s i n d r i n k i n g water i n t h i s c a t e g o r y ; and 48% o f a l l Americans a l s o c o n s i d e r p o l l u t i o n o f underground water as a "major n a t i o n a l problem." These r e s u l t s r e i n f o r c e the t i m e l i n e s s and importance o f t h i s t h r e e - d a y symposium. The v i e w p o i n t s e x p r e s s e d h e r e i n g e n e r a l l y r e f l e c t those o f the a g r i c u l t u r a l c h e m i c a l i n d u s t r y as r e p r e s e n t e d by NACA. NACA i s a n o n - p r o f i t t r a d e o r g a n i z a t i o n l o c a t e d i n Washington, DC and r e p r e s e n t s those companies who manufacture and f o r m u l a t e pest c o n t r o l p r o d u c t s employed i n a g r i c u l t u r a l p r o d u c t i o n . Two and one h a l f y e a r s ago, the a g r i c u l t u r a l c h e m i c a l i n d u s t r y c o n c l u d e d t h a t groundwater was g o i n g to be t h e i s s u e o f the decade. C o n s e q u e n t l y , NACA e s t a b l i s h e d an ad hoc Group on
0097-6156/ 86/ 0315-0478$06.00/ 0 © 1986 American Chemical Society
Garner et al.; Evaluation of Pesticides in Ground Water ACS Symposium Series; American Chemical Society: Washington, DC, 1986.
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Groundwater P r o t e c t i o n c u r r e n t l y c h a i r e d by the p r i n c i p a l a u t h o r . The c o - a u t h o r i s a member o f NACA s S t a t e A f f a i r s Committee (SAC) which a d d r e s s e s proposed s t a t e l e g i s l a t i o n and r e g u l a t i o n s i n c l u d i n g those d e a l i n g w i t h groundwater. I t seems redundant, almost t r i t e , to say t h a t groundwater i s a v a l u a b l e n a t i o n a l r e s o u r c e , but i t i s and i t must be p r o t e c t e d — no one d i s a g r e e s ! The degree o f p r o t e c t i o n and the means may not y i e l d the same consensus, however. E x c e l l e n t papers have been p r e s e n t e d d u r i n g t h i s symposium on the r e t r o s p e c t i v e and p r o s p e c t i v e appearance o f a g r i c u l t u r a l c h e m i c a l s i n groundwater. S u b j e c t matter has i n c l u d e d c o n t r i b u t i n g f a c t o r s to m o b i l i t y such as s o i l and p e s t i c i d e p h y s i c a l and c h e m i c a l p a r a m e t e r s , how to i n c o r p o r a t e these i n t o p r e d i c t i v e models and t o x i c o l o g i c a l s i g n i f i c a n c e and r i s k assessment o f p e s t i c i d e s i n groundwater. I t i s c e r t a i n l y a p p r o p r i a t e t h a t the t o p i c o f l e g i s l a t i o n / r e g u l a t i o n f o l l o w s the s u b j e c t o f t o x i c o l o g i c a l s i g n i f i c a n c e because any r e g u l a t o r y a c t i o n s h o u l d be dependent on the former. The mere presence o f a s p e c i f i c c h e m i c a l i n groundwater does not n e c e s s a r i l y mean t h a t t h e r e i s cause f o r alarm about h e a l t h e f f e c t s . I t i s acknowledged t h a t c e r t a i n a g r i c u l t u r a l c h e m i c a l s have been d e t e c t e d i n groundwater and o t h e r s may be found i n the f u t u r e . D e t e c t s have been at v e r y low c o n c e n t r a t i o n s and the f i n d i n g s have g e n e r a l l y been a s s o c i a t e d w i t h unusual combinations o f s o i l t y p e , h i g h water t a b l e and o t h e r unique e n v i r o n m e n t a l f a c t o r s . A nationwide g e n e r i c groundwater problem as a r e s u l t o f p e s t i c i d e a p p l i c a t i o n s f o r r e g i s t e r e d uses seems u n l i k e l y . A comprehensive d a t a base to support t h i s o r the opposing p o s i t i o n i s l a c k i n g , however, because a nationwide groundwater m o n i t o r i n g program has never been undertaken f o r a g r i c u l t u r a l chemicals. I t s h o u l d be n o t e d , though, t h a t a n a t i o n a l s u r v e y i s b e i n g planned by EPA a t t h i s t i m e . The a v a i l a b i l i t y o f f u n d i n g w i l l d i c t a t e when the s u r v e y w i l l b e g i n . Currently, only localized s t u d i e s are a v a i l a b l e and t h e s e can be s e l e c t i v e l y used to support or argue a g a i n s t the e x t e n t and s e r i o u s n e s s o f a p e s t i c i d e / g r o u n d water problem. Of the a v a i l a b l e d a t a , one o f the b e t t e r assessments o f o v e r a l l r u r a l d r i n k i n g water q u a l i t y i s p r o v i d e d by a C o r n e l l U n i v e r s i t y s t u d y completed f o r EPA i n 1982 ( 2 ) . On a s t a t i s t i c a l b a s i s , i t r e p r e s e n t s 22 m i l l i o n r u r a l h o u s e h o l d s i n the U.S. B a s i c a l l y , r e p r e s e n t a t i v e water samples were a n a l y z e d f o r about 30 s e p a r a t e b i o l o g i c a l , p h y s i c a l , c h e m i c a l or r a d i o l o g i c a l p r o p e r ties. The s t u d y r e p o r t e d the number o f h o u s e h o l d s where the a n a l y s e s exceeded the Maximum Contaminant L e v e l s (MCLs) as e s t a b l i s h e d by the EPA, O f f i c e o f D r i n k i n g Water (ODW). The MCL i s b a s i c a l l y a s t a n d a r d which d e f i n e s a s a f e l e v e l . The C o r n e l l s t u d y found t h a t most h o u s e h o l d s had problem l e v e l s w i t h at l e a s t one o f the c o n s t i t u e n t s f o r which an MCL has been e s t a b l i s h e d . The presence o f c o l i f o r m b a c t e r i a was the most common problem and was i n excess o f the s t a n d a r d i n 28.9% o f the households. I r o n , manganese and sodium l e v e l s were a l s o found to be h i g h f o r a l a r g e number o f the h o u s e h o l d s . N i t r a t e concentrat i o n s above the s t a n d a r d o c c u r r e d among 2.7% of the h o u s e h o l d s , l e a d i n 16.6%, selenium i n 13.7%, mercury i n 24.1%, and a r s e n i c i n 0.8% of the h o u s e h o l d s . 1
Garner et al.; Evaluation of Pesticides in Ground Water ACS Symposium Series; American Chemical Society: Washington, DC, 1986.
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There are s i x p e s t i c i d e s which have MCLs and t h e y were a l s o a n a l y z e d f o r i n the s t u d y . E n d r i n , Toxaphene, 2,4-D, and 2,4,5-T were not d e t e c t e d and Lindane and methoxychlor were found o n l y at e x t r e m e l y low c o n c e n t r a t i o n s a t a few s i t e s . These p r o d u c t s are no l o n g e r used on c r o p s , so s i g n i f i c a n t r e s i d u e s were p r o b a b l y not e x p e c t e d and were not found. In summary, 64% o f a l l households were found t o have e x c e s s i v e c o n c e n t r a t i o n s o f at l e a s t one c o n s t i t u e n t . Over 30% were too h i g h on two or more c o n s t i t u e n t s . While these f i n d i n g s are somewhat s t a r t l i n g and were not e x p e c t e d , widespread w a t e r - r e l a t e d h e a l t h problems were not apparent throughout the r u r a l U.S., a c c o r d i n g to the C o r n e l l s t u d y . H e a l t h problems may not be common s i m p l y because MCLs g e n e r a l l y i n c o r p o r a t e s u b s t a n t i a l s a f e t y margins. R e s u l t s from a more l i m i t e d s t u d y were r e c e n t l y r e p o r t e d by K e l l y ( 3 ) . Iowa s c i e n t i s t s a n a l y z e d water samples from 128 w e l l s i n v o l v i n g 58 p u b l i c water s u p p l i e s between May 1984 and March 1985. One o r more s y n t h e t i c c h e m i c a l s were found i n 57 w e l l s r e p r e s e n t i n g 33 water s u p p l i e s . T r i h a l o m e t h a n e s , as a group, were the most commonly o c c u r r i n g s u b s t a n c e s . The most f r e q u e n t l y d e t e c t e d s i n g l e p r o d u c t was a t r a z i n e , found i n 24 w e l l s . O v e r a l l , o n l y 6, o f 34 p e s t i c i d e s a n a l y z e d , were d e t e c t e d . None were above e s t a b l i s h e d s t a n d a r d s or s t a n d a r d s t h a t c o u l d be s e t by methodology d i s c u s s e d l a t e r i n t h i s r e p o r t . The h i g h e s t l e v e l r e p o r t e d f o r any p e s t i c i d e was 16.6 ppb f o r a l a c h l o r . The most comprehensive i n f o r m a t i o n about the presence o f p e s t i c i d e s i n groundwater seems to be t h a t c o m p i l e d by the EPA. D u r i n g t h i s symposium ( 4 ) , the Agency r e p o r t e d t h a t a t o t a l o f 16 d i f f e r e n t p e s t i c i d e s have been found i n a t o t a l o f 23 d i f f e r e n t states. F i n d i n g s were a t t r i b u t e d to a g r i c u l t u r a l use. While the p u b l i c may have a p e r c e p t i o n t h a t groundwater s h o u l d be pure — perhaps would be pure i f not f o r a g r o - and o t h e r s y n t h e t i c c h e m i c a l s — many s t u d i e s , i n a d d i t i o n to the C o r n e l l s t u d y , show the presence o f n a t u r a l s u b s t a n c e s , some at h i g h e r than desired levels. Groundwater i s not pure! D r i n k i n g water i s not pure! C h l o r i n a t i o n can form t r i h a l o m e t h a n e s , the most w i d e l y i d e n t i f i e d t o x i c o r g a n i c c h e m i c a l s i n U.S. water s u p p l i e s (_5). Page's r e v i e w (5) o f t o x i c contaminants i n d r i n k i n g water noted t h a t the EPA's water s u p p l y s u r v e y o f f i n i s h e d d r i n k i n g water from b o t h s u r f a c e and ground waters showed p r a c t i c a l l y a l l systems c o n t a i n e d c h l o r o f o r m , one o f the t r i h a l o m e t h a n e s . S h a c k l e f o r d and K e i t h (6) r e p o r t e d i n a 1977 paper t h a t 1,259 d i f f e r e n t compounds had been i d e n t i f i e d i n water s u p p l i e s . A s i g n i f i c a n t paper (7) on t h i s s u b j e c t was p u b l i s h e d i n 1977 by Dr. B i l l Donaldson o f the Athens, G e o r g i a EPA L a b o r a t o r y . Dr. Donaldson s a y s , "More than two m i l l i o n o r g a n i c c h e m i c a l s have been i d e n t i f i e d . The number o f these compounds d e t e c t e d i n a sample o f water i s r e l a t e d to the s e n s i t i v i t y o f the measurement t e c h n i q u e : as the d e t e c t i o n l e v e l d e c r e a s e s by an o r d e r o f magnitude, the number o f compounds d e t e c t e d i n c r e a s e s a c c o r d i n g l y . Based on the number o f compounds d e t e c t e d by c u r r e n t methods, one would expect t o f i n d e v e r y known compound at a c o n c e n t r a t i o n o f 10~12 g/i h i g h e r i n a sample o f t r e a t e d d r i n k i n g water." Page (5) i n h i s 1984 a r t i c l e , s u p p o r t s Donaldson's t h e s i s by s u g g e s t i n g t h a t v i r t u a l l y any substance i n s u f f i c i e n t q u a n t i t y and w i t h adequate time has the p o t e n t i a l to r e a c h groundwater. o
r
Garner et al.; Evaluation of Pesticides in Ground Water ACS Symposium Series; American Chemical Society: Washington, DC, 1986.
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T h i s means s y n t h e t i c and c e r t a i n l y n a t u r a l p r o d u c t s cannot be kept out o f groundwater. In f a c t , the n a t u r a l p r o d u c t s have p r o b a b l y been t h e r e f o r many l i f e t i m e s a l r e a d y and the s y n t h e t i c s much l o n g e r than thought. Many, i f not most, people r e f e r t o some or most o f these s u b s t a n c e s t h a t have been d e t e c t e d , p a r t i c u l a r l y the s y n t h e t i c s , as c o n t a m i n a n t s . I t seems t h a t any a g r i c u l t u r a l c h e m i c a l d e t e c t e d i n groundwater i s r e f e r r e d to as a contaminant o r p o l l u t a n t . Just what does i t mean to contaminate o r p o l l u t e ? Webster's (8) says contaminate means to make u n f i t f o r use by i n t r o d u c t i o n o f unwholesome o r u n d e s i r e a b l e elements. A r e c e n t groundwater p u b l i c a t i o n by the American Chemical S o c i e t y (9) d e f i n e s a p o l l u t a n t as any s u b s t a n c e , n a t u r a l or human-made, t h a t degrades water q u a l i t y , p r e v e n t i n g the use o f water f o r some s p e c i f i c p u r p o s e . Mere p r e s e n c e , t h e n , s h o u l d not connote c o n t a m i n a t i o n o r p o l l u t i o n . More o f t e n t h a n not though, i t does, and c o n s e q u e n t l y i m p l i e s health concerns. As mentioned at the b e g i n n i n g o f t h i s p r e s e n t a t i o n , the industry p u b l i c o p i n i o n survey r e v e a l e d t h a t about h a l f o f the U.S. p o p u l a t i o n b e l i e v e s p o l l u t i o n o f underground water i s a major n a t i o n a l problem. Seven out o f 10 b e l i e v e f e r t i l i z e r s and p e s t i c i d e s used on farms are at l e a s t a minor cause o f such p o l l u t i o n and 23% t h i n k they are a major c a u s e . What f a c t o r s c o n t r i b u t e to these b e l i e f s as e x p r e s s e d i n the survey? Any time a p u b l i c problem a r i s e s , s p e c i a l i n t e r e s t s l i k e to blame the media, sometimes w i t h r e a l j u s t i f i c a t i o n . In t h i s i n s t a n c e , they are o n l y one o f s e v e r a l f a c t o r s c o n t r i b u t i n g to the p u b l i c p e r c e p t i o n s h e l d about p e s t i c i d e s i n groundwater. The media do not t e l l us what t o t h i n k , but t h e y do i n f l u e n c e what we t h i n k about. G e n e r a l l y , the d a t a g e n e r a t o r s , i n c l u d i n g those i n i n d u s t r y , government and academia, must share r e s p o n s i b i l i t y . The i n v e s t i g a t i v e f o c u s by s c i e n t i s t s , and c o n s e q u e n t l y by media, may be on p e s t i c i d e s s i m p l y because t h e r e are much more d a t a a v a i l a b l e on t h i s use c a t e g o r y o f c h e m i c a l s than any o t h e r c l a s s . C o n t r a r y t o a p o p u l a r p e r c e p t i o n , e x t e n s i v e s a f e t y and e n v i r o n mental d a t a are r e q u i r e d f o r a g r i c u l t u r a l c h e m i c a l s b e f o r e r e g i s tration. S e n s i t i v e a n a l y t i c a l methodology i s d e v e l o p e d f o r each p r o d u c t by the r e g i s t r a n t and i s s u b s e q u e n t l y p u b l i s h e d by the r e g i s t r a n t and/or the r e g u l a t o r y agency. B a s i c a l l y , p e s t i c i d e s are e a s i e r t o l o o k f o r because methodology i s a v a i l a b l e . It i s i n t e r e s t i n g t o note t h a t one o f the c r i t e r i a f o r c h o o s i n g p r o d u c t s to be i n c l u d e d i n the EPA's N a t i o n a l Groundwater Survey i s the a v a i l a b i l i t y o f good, s e n s i t i v e , a n a l y t i c a l methodology. In c o n j u n c t i o n w i t h method a v a i l a b i l i t y i s the f a n t a s t i c p r o g r e s s made by the a n a l y t i c a l c h e m i s t s i n r e c e n t y e a r s . Such p r o g r e s s i s p a r t i c u l a r l y a p p l i c a b l e to the a n a l y s i s o f p e s t i c i d e s . To put t h i s i n p e r s p e c t i v e , c h e m i s t s c o u l d r o u t i n e l y d e t e c t a p a r t per m i l l i o n (ppm) i n the I960's, a p a r t per b i l l i o n (ppb) i n the 1970's and low p a r t s per t r i l l i o n ( p p t ) h e r e i n the 1980's. T h i s r e p r e s e n t s more than a m i l l i o n f o l d i n c r e a s e over the past 25 y e a r s i n our a b i l i t y to d e t e c t a g r i c u l t u r a l c h e m i c a l s . Great p r i d e i s t a k e n i n such p r o g r e s s , but i t has caused a lot of confusion i n s o c i e t y . Substances have been d i s c o v e r e d which were not known or thought to be p r e s e n t . Terms o f p a r t s per m i l l i o n , b i l l i o n and t r i l l i o n are used many times w i t h o u t
Garner et al.; Evaluation of Pesticides in Ground Water ACS Symposium Series; American Chemical Society: Washington, DC, 1986.
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c o n s i d e r i n g what they r e a l l y mean to the media and the g e n e r a l public. They need t o be put i n t o a p e r s p e c t i v e which can be v i s u a l i z e d by everyone. A m e a n i n g f u l example may be: 1 ppm e q u a l s 1 minute i n two y e a r s , 1 ppb e q u a l s 1 second i n 32 y e a r s , and 1 ppt e q u a l s 1 second i n 32,000 y e a r s . E s s e n t i a l l y , the a n a l y s t s have gone from the e q u i v a l e n t o f 1 minute i n 2 y e a r s t o almost 1 second i n 32,000 y e a r s i n t h e i r a b i l i t y t o r o u t i n e l y d e t e c t . The media and the p u b l i c more o f t e n f o c u s on the a n a l y t i c a l f i n d i n g s ( a c h e m i c a l i s p r e s e n t ) and l e s s o f t e n on the a s s o c i a t i o n of the l e v e l s w i t h any h e a l t h e f f e c t . The p e s t i c i d e d a t a p r e s e n t a t i o n i n the C o r n e l l Groundwater Study and a subsequent media r e p o r t p r o v i d e good examples o f these o b s e r v a t i o n s . The MCLs f o r the s i x p e s t i c i d e s a n a l y z e d and the amounts detected are:
MCL (ppb)
Method Sensitivity (ppb)
100
*
0/267
0
Not
Detected
10
*
0/267
0
Not
Detected
Toxaphene
5
0.17
0/267
0
