Evaluation of Pesticides in Ground Water - ACS Publications

30 Two Ground Water Contamination Problems Case Studies Nancy K. Kim, Anthony J. Grey, Ronald Tramontano, Charles Hudson, and

Downloaded by RUTGERS UNIV on February 29, 2016 | http://pubs.acs.org Publication Date: July 17, 1986 | doi: 10.1021/bk-1986-0315.ch030

Geoffrey Laccetti Bureau of Toxic Substance Assessment, New York State Department of Health, Rockefeller Empire State Plaza, Albany, NY 12237

In New York State, three types of chemicals are found to cause most groundwater contamination: solvents, petroleum products, and pesticides. Two different contamination scenarios involving sandy soil and pesticides are described. In Fort Edward, an investigation of drinking water contamination near an industrial plant was conducted. During sampling, chemicals not associated with the industrial plant were detected. This identification resulted in another sampling program which showed drinking water wells and springs contaminated with atrazine and alachlor; the highest levels were 260 ug/1 and 660 ug/1 respectively. In Suffolk County following the removal of aldicarb from the Long Island market, oxamyl was used as an alternative pesticide under an experimental use permit. After several years of use, monitoring indicated increasing levels of oxamyl contamination in groundwater, and by January 1984, oxamyl was removed from the Long Island market. F o r t Edward. N.Y. The p e s t i c i d e c o n t a m i n a t i o n i n t h i s s m a l l , u p s t a t e New York town was d i s c o v e r e d i n March, 1984, b u t t h e events l e a d i n g t o t h e s e f i n d i n g s began t o u n f o l d i n 1983. In 1983, t h e s t a t e r e c e i v e d t a s t e and odor c o m p l a i n t s about d r i n k i n g water o b t a i n e d from p r i v a t e ' w e l l s i n t h e v i c i n i t y of a l o c a l i n d u s t r i a l p l a n t (See F i g u r e 1 ) . The p l a n t , l o c a t e d i n a r e s i d e n t i a l a r e a n o t s e r v i c e d by p u b l i c w a t e r , used l a r g e q u a n t i t i e s o f s o l v e n t s , p a r t i c u l a r l y t r i c h l o r o e t h y l e n e and PCBs. A l t h o u g h water samples taken s e v e r a l y e a r s e a r l i e r from t h e r e s i d e n c e s near t h e p l a n t had n o t c o n t a i n e d PCBs, because o f t h e c o m p l a i n t s , water samples were t a k e n a g a i n from houses on Park Avenue ( s e e map) and a n a l y z e d f o r 0097-6156/ 86/ 0315-0530S06.00/ 0 © 1986 American Chemical Society

In Evaluation of Pesticides in Ground Water; Garner, Willa Y., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.


Figure

1.

Map

o f study

a r e a i n F o r t Edward,

NY.



532

EVALUATION O F PESTICIDES IN G R O U N D

WATER

PCBs and v o l a t i l e c h l o r i n a t e d h y d r o c a r b o n s . The samples were found t o c o n t a i n PCBs, t r i c h l o r o e t h y l e n e p l u s o t h e r r e l a t e d solvents. Because of t h e s e f i n d i n g s , groundwater a t t h e p l a n t s i t e was sampled and found t o c o n t a i n t r i c h l o r o e t h y l e n e . Apparently, improper h a n d l i n g and s p i l l p r o c e d u r e s l e d t o t h e b u i l d - u p of a pool of h i g h l y contaminated groundwater o n - s i t e . The S t a t e began an o f f - s i t e m o n i t o r i n g program. As c o n t a m i n a t i o n was f o u n d , t h e a r e a l e x t e n t f o r sampling p r i v a t e w e l l s was i n c r e a s e d . S i n c e l i t t l e was known about groundwater f l o w , water samples were taken from most of t h e s u r r o u n d i n g homes and a n a l y z e d f o r v o l a t i l e s o l v e n t s and PCBs. The groundwater and w e l l depths were not a v a i l a b l e f o r most l o c a t i o n s . Generally, the groundwater i s a t 15 t o 20 f e e t i n a s h a l l o w a q u i f e r . Well depths ranged from about 10 t o 200 f e e t . A f t e r s e v e r a l rounds of s a m p l i n g , w i t h most of t h e sampling c o n c e n t r a t e d i n t h e a r e a w e s t , s o u t h w e s t , and south of t h e p l a n t ( s e e F i g u r e 1 - t h e a r e a c l o s e s t t o t h e Hudson R i v e r ) , d r i n k i n g w a t e r from homes on Stevens Lane were found t o be h i g h l y c o n t a m i n a t e d w i t h t r i c h l o r o e t h y l e n e , w i t h the most contaminated w e l l s h a v i n g c o n c e n t r a t i o n s g r e a t e r than 50 m i l l i g r a m s p e r liter. The homeowners were a d v i s e d not t o use t h e w a t e r . Because of t h e h i g h l e v e l s and c o n c e r n s about i n h a l a t i o n and dermal e x p o s u r e , a l i m i t e d e x p e r i m e n t was undertaken i n an attempt to q u a n t i f y i n h a l a t i o n exposure. F i v e a i r samples (1) were c o l l e c t e d a t a r e s i d e n c e on S t e v e n s Lane a t d i f f e r e n t times o r l o c a t i o n s ( s e e T a b l e I ) . (1)

Taken on k i t c h e n c o u n t e r p r i o r t o t u r n i n g f a u c e t s ; doors and windows c l o s e d .

(2)

Taken on bathroom s i n k c o u n t e r w i t h d o o r and window c l o s e d ; no w a t e r use d u r i n g t e s t . Taken c o n c u r r e n t l y w i t h number 1.

(3)

Taken on uncovered p a t i o w i t h number 1.

(4)

Taken on k i t c h e n c o u n t e r (same l o c a t i o n as number 1) between d o u b l e s i n k and s t o v e . Water t a k e n from t h e home's w a t e r s u p p l y was b o i l e d on t h e s t o v e d u r i n g sample c o l l e c t i o n . A p p r o x i m a t e l y two i n c h e s of t a p water was p l a c e d i n a 12 i n c h s a u c e - r o a s t i n g pan which was not c o v e r e d . Make-up w a t e r was added once d u r i n g the sampling p e r i o d . S t a f f attempted t o s i m u l a t e d i s h w a s h i n g by c o n t i n o u s l y s c r u b b i n g and r i n s i n g a pot i n t h e double s i n k . T h i s sample ran f o r 57 m i n u t e s . Towards the end of t h i s time p e r i o d , one member of t h e s t a f f commented s e v e r a l times t h a t he " f e l t f u n n y . "

(5)

Taken i n bathroom/shower and run c o n c u r r e n t l y w i t h number 4. Sample head was hung i n s i d e shower

i n r e a r of

on the

house c o n c u r r e n t l y


30.

KIM ET AL.

Two Ground Water Contamination Problems

533

enclosure. The shower was run on a " h o t " s e t t i n g . The i n i t i a l f l o w r a t e was t h r e e l i t e r s / 2 5 seconds a t 42oc and f i n a l f l o w r a t e was t h r e e l i t e r s / 2 7 seconds a t 390c. The shower ran c o n t i n u o u s l y and t h e door remained c l o s e d d u r i n g s a m p l i n g . T h i s sample ran f o r 22 m i n u t e s . When r e - e n t e r i n g bathroom t o remove t h e sample, a v e r y s l i g h t sweet odor was d e t e c t e d . This sample would s i m u l a t e c o n d i t i o n s i n a bathroom w i t h showers b e i n g t a k e n s e q u e n t i a l l y by two r e s i d e n t s .


The f o l l o w i n g water samples were c o l l e c t e d (see T a b l e before a i r sampling.

I):

(1)

Taken a t k i t c h e n s i n k

Cold water.

(2)

Taken a t bathroom tub s p i g o t b e f o r e a i r Water a t " h o t " shower t e m p e r a t u r e .

(3)

Taken by s a m p l i n g water i n tub t h a t remained a f t e r r u n n i n g shower f o r a i r sample. Taken a f t e r a i r sampling.

sampling.

A h e a r i n g was h e l d t o o b t a i n p u b l i c water f o r t h e p e o p l e on Stevens Lane. T h i s s t r e e t i s j u s t n o r t h of t h e n e a r e s t p u b l i c water so an e x t e n s i o n was f a i r l y easy t o o b t a i n . The i n d u s t r y agreed t o pay t o have t h e s e f a m i l i e s hooked up t o t h e p u b l i c water s u p p l y and t o u n d e r t a k e a sampling program t o d e t e r m i n e i f any o t h e r l o c a l i z e d " h o t s p o t s " e x i s t e d i n t h e a r e a ; t h e S t a t e a n a l y z e d a s m a l l number of d u p l i c a t e samples.

T a b l e I. T r i c h l o r o e t h y l e n e C o n c e n t r a t i o n s i n Micrograms Per L i t e r (ug/1) o r Micrograms Per Cubic Meter (ug/m3)

Water

Kitchen Cold 34,000 ug/1

Air ambient background

Kitchen 35 ug/m3

a f t e r water use

2000 ug/m

Bathroom Hot 29,000 ug/1

Bathroom 230 ug/m3 3

38,000

Bathroom Tub 13,000 ug/1

Ambient 35 ug/m3

ug/m * 3

^ b r e a k t h r o u g h on c a r t r i d g e ; minimum l e v e l

During t h e sampling program, s e v e r a l w e l l s from homes on Ethan A l l e n and Putnam S t r e e t s were found t o be c o n t a m i n a t e d w i t h PCBs. Along w i t h t h e PCBs, t h e gas chromotograph p i c k e d up several u n i d e n t i f i e d peaks. On March 2, 1984, one w e l l was found t o be c o n t a m i n a t e d w i t h 35 ug/1 of PCBs, an u n u s u a l l y h i g h level. F o l l o w - u p samples were taken from the same r e s i d e n c e and nearby r e s i d e n c e s . By March 8, 1984, t h e o r i g i n a l PCB r e s u l t was c o n f i r m e d and t h e samples w i t h unknown peaks had been a n a l y z e d by


EVALUATION OF PESTICIDES IN GROUND WATER

534


a mass s p e c t r o p h o t o m e t e r . The compounds p r e s e n t a t h i g h c o n c e n t r a t i o n s were i d e n t i f i e d as a l a c h l o r and a t r a z i n e , chemicals not a s s o c i a t e d with the i n d u s t r y . The p o t e n t i a l s o u r c e f o r t h e s e compounds was a l o c a l a g r i c u l t u r a l s u p p l y s t o r e . L a b o r a t o r y s t a n d a r d s were o b t a i n e d f o r t h e s e new compoundsand t h e sampling a r e a was expanded. By March 2 1 , 1984, s i x p r i v a t e w e l l s were found t o be c o n t a m i n a t e d , two w i t h PCBs and f o u r w i t h pesticides. By t h e m i d d l e of May, 15 w e l l s had been found t o be c o n t a m i n a t e d w i t h p e s t i c i d e s , s i x w i t h PCBs a n d / o r c h l o r i n a t e d h y d r o c a r b o n s o l v e n t s and one w i t h both p e s t i c i d e s and PCBs. In a d d i t i o n t o d r i n k i n g water w e l l s , s p r i n g s i n t h e a r e a s were found t o be c o n t a m i n a t e d . The h i g h e s t l e v e l s found f o r t h e p e s t i c i d e s were 260 ug/1 f o r a t r a z i n e and 660 ug/1 f o r a l a c h l o r . Atrazine A t r a z i n e i s a w i d e l y used p r e - and post-emergency h e r b i c i d e f o r s e l e c t i v e l y c o n t r o l l i n g b r o a d l e a f and g r a s s y weeds i n c o r n , sorghum, a s p a r a g u s , m i l l e t , p i n e a p p l e , f r u i t t r e e s , s u g a r c a n e , and summer f a l l o w ; i t i s a l s o used t o c o n t r o l v e g e t a t i o n i n land not used f o r c r o p s . Sugar b e e t s , t o b a c c o , o a t s and many o t h e r vegetable crops a r e very s e n s i t i v e t o a t r a z i n e . T r i a z i n e h e r b i c i d e s a r e m o d e r a t e l y p e r s i s t e n t i n s o i l s and w a t e r (10-18 months) w i t h a t r a z i n e b e i n g one of t h e more p e r s i s t e n t of t h e g r o u p . L a b o r a t o r y and f i e l d d a t a have shown t h a t t h e d i s a p p e a r a n c e of a t r a z i n e from s o i l i s i n f l u e n c e d by t e m p e r a t u r e , pH, m o i s t u r e c o n t e n t , and o r g a n i c m a t t e r c o n t e n t ; t h e e f f e c t of t e m p e r a t u r e and pH on t h e h a l f - l i f e of a t r a z i n e i n s o i l ( s i l t loam - l a b o r a t o r y s t u d y ) i s as f o l l o w s ( 2 ) : Temperature

250C 250C 50C 50C

pH[

Half-life

4.9 7.0 4.9

250

7.0

439

(days)

35 72

R e s p i r a t o r y d i f f i c u l t i e s , loss of muscular c o o r d i n a t i o n , c o n v u l s i o n s , and t h y r o i d d y s f u n c t i o n have been observed i n l a b o r a t o r y a n i m a l s g i v e n h i g h l e v e l s of a t r a z i n e . The o r a l LD50 i s 2,090 mg/kg f o r r a t s , 1,750 mg/kg f o r m i c e , and 750 mg/kg f o r r a b b i t s . In one a c u t e experiment (3) w i t h sheep and c a t t l e , symptoms of a t r a z i n e p o i s o n i n g i n c l u d e d m u s c u l a r spasms, s t i f f g a i t , and i n c r e a s e d r e s p i r a t i o n r a t e s ; a t n e c r o p s y , compound d e g e n e r a t i o n and d i s c o l o r a t i o n of t h e a d r e n a l g l a n d s , and c o n g e s t i o n of t h e l u n g s , l i v e r and k i d n e y s were o b s e r v e d . No cases of p o i s o n i n g i n humans were found i n the l i t e r a t u r e . A t r a z i n e appears t o have a r e l a t i v e l y low c h r o n i c t o x i c i t y v i a t h e o r a l r o u t e , but t h e d a t a base i s l i m i t e d . The N a t i o n a l Academy of S c i e n c e s (4) c a l c u l a t e d an a c c e p t a b l e d a i l y i n t a k e (ADI) u s i n g a n o - o b s e r v e d ~ e f f e e t l e v e l (NOEL) from an 80 week mouse ( d i e t a r y ) t u m o r i g e n i c i t y s t u d y (5.) and an u n c e r t a i n t y f a c t o r of 1,000; a suggested g u i d e l i n e of


30.

KIM ETAL.



150 ppb f o r a t r a z i n e i n d r i n k i n g water was c a l c u l a t e d , assuming a human weight of 70 k g , consumption of two l i t e r s of water p e r day and 20% of t h e ADI a l l o t t e d t o d r i n k i n g w a t e r . Review of t h e e x p e r i m e n t a l p r o t o c o l f o r t h e mouse s t u d y i n d i c a t e s , however, t h a t the average d a i l y dose of a t r a z i n e was c a l c u l a t e d i n c o r r e c t l y ; t h e r e v i s e d d r i n k i n g w a t e r g u i d e l i n e would be 60 ppb. Because o n l y one dose l e v e l was used and t h e s t u d y was d e s i g n e d as a s c r e e n i n g s t u d y f o r c a r c i n o g e n i c i t y , i t i s i n a d e q u a t e t o d e r i v e a NOEL f o r non-carcinogenic e f f e c t s . In 1981, t h e U.S. EPA (6) e v a l u a t e d u n p u b l i s h e d t o x i c o l o g i c a l d a t a s u b m i t t e d i n s u p p o r t of a proposed t o l e r a n c e f o r a t r a z i n e i n o r on o r c h a r d g r a s s and o r c h a r d g r a s s hay, which i n c l u d e d : (1)

2-year r a t chronic feeding/oncogenic NOEL = 100 ppm (5 mg/kg/day)

(2)

2 - y e a r dog c h r o n i c f e e d i n g s t u d y NOEL = 150 ppm (3.75 mg/kg/day)

(3)

Three-generation rat reproduction NOEL = 100 ppm (5 mg/kg/day)

study

study

The c h r o n i c r a t s t u d y i s c o n s i d e r e d i n a d e g u a t e (some e f f e c t s observed a t 100 ppm) and i s b e i n g r e p e a t e d by t h e m a n u f a c t u r e r . Data l a c k i n g f o r t h i s p e s t i c i d e i n c l u d e d t e r a t o l o g y s t u d i e s i n two s p e c i e s ( p r e f e r a b l y r a t and r a b b i t ) and an o n c o g e n i c i t y s t u d y in mice. Most of t h e t o x i c o l o g i c a l s t u d i e s on a t r a z i n e were conducted i n t h e I960*s and t h e r e g u i r e m e n t s f o r an adeguate s t u d y have become much g r e a t e r o v e r t h e l a s t 10 y e a r s , p a r t i c u l a r l y w i t h r e g a r d t o p a t h o l o g i c a l , h i s t o p a t h o l o g i c a l , and b i o c h e m i c a l parameters. Some of t h e s t u d i e s were conducted by I n d u s t r i a l B i o t e s t L a b o r a t o r i e s and a r e c o n s i d e r e d i n a d e g u a t e o r a t b e s t supplemental f o r r e g u l a t o r y purposes. In a d d i t i o n t o c o n c e r n s regarding the c h r o n i c t o x i c i t y data base, another concern i n v o l v e s the p o s s i b l e a d v e r s e e f f e c t s of c h r o n i c i n g e s t i o n on c a r b o h y d r a t e m e t a b o l i s m and DNA, RNA and p r o t e i n s y n t h e s i s . U n t i l t h e r e s u l t s of t h e r e p e a t c h r o n i c r a t f e e d i n g s t u d y and r a t t e r a t o l o g y s t u d y a r e a v a i l a b l e , t h e 70 ppm d i e t a r y l e v e l ( r a t f e e d i n g s t u d y , i n p r o g r e s s ) o r t h e 2 - y e a r dog c h r o n i c f e e d i n g s t u d y and an u n c e r t a i n t y f a c t o r of 1,000 can be used t o c a l c u l a t e t h e ADI. A d r i n k i n g water g u i d e l i n e of 25 ug/1 i s c a l c u l a t e d assuming a human weight of 70 k g , consumption of two l i t e r s of w a t e r p e r day and t h a t 20% of t h e ADI can come from d r i n k i n g water. Alachlor A l a c h l o r i s a h e r b i c i d e used t o c o n t r o l annual g r a s s e s and c e r t a i n b r o a d l e a f weeds i n soybeans, c o r n , p e a n u t s , d r y beans, s u n f l o w e r s , m i l o , and p o t a t o e s . The pure i n g r e d i e n t i s a s o l i d


535


536


which melts a t about 4 0 ° c e n t i g r a d e (C) and i s s o l u b l e i n water t o about 240 m i l l i g r a m s p e r l i t e r ( m g / Ί ) a t 25c. The body of t o x i c o l o g i c a l d a t a on a l a c h l o r c o n s i s t s of unpublished manufacturer-sponsored s t u d i e s (Monsanto A g r i c u l t u r a l Products). No l o n g - t e r m animal s t u d i e s were a v a i l a b l e i n t h e p u b l i s h e d l i t e r a t u r e which would c o n t r i b u t e i n f o r m a t i o n on r e p r o d u c t i v e e f f e c t s o r c a r c i n o g e n i c p o t e n t i a l of a l a c h l o r . The i n f o r m a t i o n used by t h e New York S t a t e Department of H e a l t h was o b t a i n e d from t h e U.S. EPA summary ( 7 - 8 ) and Monsanto ( 9 ) . A l a c h l o r does not appear t o be h i g h l y t o x i c on an a c u t e basis. The o r a l LD50 v a l u e f o r r a t s was r e p o r t e d t o be 930 mg/kg and t h e dermal LD50 was 13,300 mg/kg i n r a b b i t s . A l a c h l o r was r e p o r t e d t o be o n l y s l i g h t l y i r r i t a t i n g t o r a b b i t skin. The U.S. EPA O f f i c e of P e s t i c i d e Programs (7) reviewed and e v a l u a t e d t h e t o x i c o l o g i c a l d a t a base submitted by Monsanto i n s u p p o r t of a p e t i t i o n f o r t o l e r a n c e l e v e l s f o r a l a c h l o r i n o r on raw a g r i c u l t u r a l c o m m o d i t i e s * . Data c o n s i d e r e d i n s u p p o r t of t h e p e t i t i o n and summarized i n t h e F e d e r a l R e g i s t e r , i n c l u d e d : 0)

Rat t e r a t o l o g y s t u d y No observed t e r a t o g e n i c i t y a t 400 mg/kg [ h i g h e s t dose tested] NOEL = 150 mg/kg f o r maternal t o x i c i t y and f e t o t o x i c i t y

(2)

3-generation r a t reproduction NOEL = 10 mg/kg/day

(3)

18-month mouse c h r o n i c f e e d i n g / o n c o g e n i c i t y study P o s i t i v e oncogenic response i n females ( b r o n c h i o l a r alveolar tumors) a t 260 mg/kg/day

(4)

2 - y e a r r a t c h r o n i c f e e d i n g / o n c o g e n i c i t y study P o s i t i v e o n c o g e n i c response a t 42 mg/kg/day (both sexes - n a s a l t u r b i n a t e tumors) and 126 mg/kg/day (both sexes - n a s a l and stomach tumors; males - t h y r o i d f o l l i c u l a r t u m o r s ) ; no c a r c i n o g e n i c e f f e c t s were observed a t 14 mg/kg/day.

*

R e c e n t l y t h e U.S. EPA (10) i n i t i a t e d a s p e c i a l r e v i e w of a l l p e s t i c i d e p r o d u c t s c o n t a i n i n g a l a c h l o r based on t h e oncogenic f i n d i n g s .

study

A c c o r d i n g t o EPA, d a t a l a c k i n g i n c l u d e d a 2 - y e a r c h r o n i c f e e d i n g s t u d y ( r a t s ) , a 1 - y e a r f e e d i n g study ( d o g s ) , a t e r a t o l o g y study ( r a b b i t s ) , a metabolism study ( r a t s ) , a s k i n s e n s i t i z a t i o n s t u d y ( g u i n e a p i g s ) , and m u t a g e n i c i t y s t u d i e s . The Agency a l s o s t a t e d t h a t a l a c h l o r had been d e t e r m i n e d t o be an oncogen i n mice and r a t s . In a d d i t i o n t o m u l t i - s i t e o n c o g e n i c i t y , c o n c e r n has a l s o been r a i s e d r e g a r d i n g e f f e c t s on t h e eyes o f r a t s . An


30.

KIM ET AL.

537


a c c e p t a b l e d a i l y i n t a k e has not been e s t a b l i s h e d f o r a l a c h l o r . In New York S t a t e , n o t i f i c a t i o n i s r e q u e s t e d i f d r i n k i n g water l e v e l s exceed 1 u g / 1 . In

Summary


As a r e s u l t of t h e s e groundwater were t a k e n .

contamination

findings,

actions

(1)

Homes w i t h p r i v a t e w e l l s contaminated w i t h PCBs a n d / o r s o l v e n t s were hooked up t o p u b l i c water s u p p l i e s by t h e company.

(2)

Wells contaminated with p e s t i c i d e s water s o u r c e s .

Suffolk

County.

Long I s l a n d .

a r e on a l t e r n a t e

N.Y.

By 1978, a l d i c a r b had been a p p l i e d t o p o t a t o f i e l d s i n t h e n o r t h and south f o r k s of Long I s l a n d f o r s e v e r a l y e a r s . Approximately 200 farms c o n s i s t i n g of 22,000 a c r e s a r e l o c a t e d i n t h e a r e a . F i v e t o t e n thousand water s u p p l y w e l l s a r e e s t i m a t e d t o be n e a r these potato farms. In 1978, a t t h e u r g i n g of a t e c h n i c a l a d v i s o r y committee of t h e N a s s a u / S u f f o l k p l a n n i n g b o a r d , Union C a r b i d e a n a l y z e d samples from skimming w e l l s b e f o r e and a f t e r t h e a p p l i c a t i o n of a l d i c a r b t o t h e p o t a t o f i e l d s on f o u r d i f f e r e n t f a r m s . Samples were c o l l e c t e d i n t h e s p r i n g and a l d i c a r b was d e t e c t e d i n 20 of 31 samples. A d d i t i o n a l samples were c o l l e c t e d i n A p r i l of 1979 and s i m i l a r r e s u l t s were f o u n d . In A u g u s t , 1979, 14 w a t e r samples were taken from p r i v a t e w e l l s a t farm homes near t h e p o t a t o f i e l d s , o t h e r s h a l l o w water w e l l s and somewhat deeper m u n i c i p a l water supply w e l l s . S i x of n i n e farm w e l l s showed a l d i c a r b l e v e l s between 4 and 140 u g / 1 . These f i n d i n g s l e d t o an e x t e n s i v e s u r v e y f o r a l d i c a r b c o n t a m i n a t i o n (H). Once e x t e n s i v e c o n t a m i n a t i o n was f o u n d , a l d i c a r b was removed from t h e Long I s l a n d market. With a l d i c a r b b e i n g withdrawn from t h e m a r k e t , Long I s l a n d p o t a t o f a r m e r s needed an a l t e r n a t e i n - g r o u n d use p e s t i c i d e . S e v e r a l thousand a c r e s of farm land a r e g u a r a n t i n e d f o r growing p o t a t o e s because of t h e Golden Nematode. A suggested a l t e r n a t i v e was oxamyl which was b e i n g used f o r f o l i a r a p p l i c a t i o n s . The i n - g r o u n d use of t h i s p e s t i c i d e o c c u r r e d under an e x p e r i m e n t a l use p e r m i t and w i t h a m o n i t o r i n g program t o d e t e r m i n e i f t h i s compound would c o n t a m i n a t e groundwater. A s o i l and water m o n i t o r i n g program was c a r r i e d out t h r o u g h o u t t h e summer of 1980. I n i t i a l r e s u l t s looked promising. The compound was not d e t e c t e d i n groundwater. The s o i l sampling r e s u l t s a l s o i n d i c a t e d t h a t oxamyl was decomposing r a p i d l y i n t h e t o p s o i l l a y e r s and o n l y one s i t e showed a low l e v e l of c o n t a m i n a t i o n i n t h e 20 i n c h c o r e s .


538



F o r t h e 1981 s e a s o n , oxamyl was a l l o w e d t o be used on t h e p o t a t o f i e l d s a g a i n w i t h a m o n i t o r i n g program. The program was t o address s e v e r a l concerns r a i s e d the previous y e a r . (1)

S o i l samples were t a k e n f u r t h e r i n t o t h e f a l l because some c o r e l e v e l s i n c r e a s e d d u r i n g t h e l a t t e r h a l f of t h e summer.

(2)

R a i n f a l l was 6" l e s s than normal i n 1980 which may have d e c r e a s e d t h e m i g r a t i o n compared t o normal y e a r s .

(3)

Deeper s o i l c o r e s were needed because oxamyl was d e t e c t e d i n t h e d e e p e s t c o r e sampled.

The 1981 r e p o r t (12.) c o n c l u d e d , " T h a t under normal use c o n d i t i o n s oxamyl does not c o n t a m i n a t e w e l l water on Long I s l a n d . " Oxamyl was used a g a i n d u r i n g t h e 1982 growing s e a s o n . However, i n 1982, t h e S u f f o l k County H e a l t h Department took o v e r t h e Union C a r b i d e ( m a n u f a c t u r e r o f a l d i c a r b ) sampling program f o r a l d i c a r b i n d r i n k i n g water and surveyed a r e a s not p r e v i o u s l y covered. The County a l s o began m o n i t o r i n g f o r oxamyl. By November, 1982, 27 homeowner w e l l s had been found t o c o n t a i n oxamyl a t c o n c e n t r a t i o n s l e s s than t h e New York S t a t e H e a l t h Department g u i d e l i n e of 50 u g / 1 . In 1983, t h e d e c i s i o n was a g a i n t o a l l o w oxamyl t o be used i n p o t a t o f i e l d s and f o r above ground a p p l i c a t i o n s because t h e g u i d e l i n e had n o t been e x c e e d e d . By November, 1983, t h e County H e a l t h Department (H) had d e t e c t e d oxamyl ( d e t e c t i o n l i m i t - 1 ug/1) a t 75 of 3,000 sampling s i t e s . C a l c u l a t i n g the percentage of p o s i t i v e s i t e s u n d e r e s t i m a t e s t h e p o t e n t i a l c o n t a m i n a t i o n because t h e sampling program was o r i g i n a l l y d e s i g n e d f o r a l d i c a r b and t h e sampling s i t e s were g e n e r a l l y n o t c l o s e t o farm a r e a s . Oxamyl c o n t a m i n a t i o n was p r o b a b l y w i d e s p r e a d c l o s e t o use a r e a s as e x e m p l i f i e d by t h e m o n i t o r i n g r e s u l t s from t h e Town of Laurel. In 1983 f o r t h i s town, p o s i t i v e r e s u l t s (16 s i t e s , 23 samples) ranged from 1 ug/1 t o 106 ug/1 w i t h two s i t e s (6 samples) equal t o o r e x c e e d i n g t h e 50 ug/1 g u i d e l i n e . Oxamyl's c o n t i n u e d use was p r o d u c i n g i n c r e a s i n g l e v e l s i n groundwater. Most of t h e c o n t a m i n a t e d w e l l s were s h a l l o w , but oxamyl was found i n w e l l s d e e p e r than 100 f e e t . In a d d i t i o n , a t L a u r e l , oxamyl had been found t o have m i g r a t e d s e v e r a l hundred f e e t from t h e s i t e of a p p l i c a t i o n . By J a n u a r y 1984, t h r e e w e l l s had been found t o c o n t a i n oxamyl above t h e g u i d e l i n e s and t h e m a n u f a c t u r e r removed i t from t h e market on Long I s l a n d . Oxamyl Oxamyl i s a s y s t e m i c o r c o n t a c t i n s e c t i c i d e , m i t i c i d e and nematocide. The h a l f - l i f e f o r oxamyl i n s o i l r e p o r t e d l y ranges from 1-6 weeks depending on s o i l t y p e , pH, m o i s t u r e c o n t e n t , and t e m p e r a t u r e ( 1 4 ) . Some c h e m i c a l and p h y s i c a l p r o p e r i t i e s a r e :


30.

KIM ET AL.


Physical State Vapor P r e s s u r e


Specific Gravity S o l u b i l i t y i n Water Melting Point

crystalline solid 2.3 χ 10-4 mm Hg a t 25c 7.6 χ 10-3 mm Hg a t 70C 0.097 . . 280 g/1 a t 25oc 100O-102OC changing t o a d i f f e r e n t c r y s t a l l i n e from which from which m e l t s a t 1 0 8 0 - n o o c

Oxamyl has a h i g h a c u t e t o x i c i t y d i s p l a y i n g t h e t y p i c a l e f f e c t s of carbamate i n s e c t i c i d e s , e . g . r a p i d o n s e t of c h o l i n e s t e r a s e i n h i b i t i o n f o l l o w e d by r a p i d r e c o v e r y . Symptoms of a c u t e i n t o x i c a t i o n i n a n i m a l s i n c l u d e d t r e m o r s , s a l i v a t i o n , l a c r i m a t i o n , b u l g i n g e y e s , and m u s c u l a r t w i t c h i n g . The o r a l LD50 f o r oxamyl i n t h e r a t i s t h e range of 5 t o 15 mg/kg. The World H e a l t h O r g a n i z a t i o n (WHO) ( 1 5 ) , i n 1981, s e t a temporary ADI f o r oxamyl based on a n o - e f f e c t l e v e l from a 2 - y e a r dog s t u d y . The Committee e x p r e s s e d c o n c e r n , however, t h a t the dog i s somewhat l e s s s e n s i t i v e t o oxamyl than the r a t and t h a t a c l e a r n o - e f f e c t l e v e l had not been e s t a b l i s h e d i n t h e r a t . A d d i t i o n a l c o n c e r n was e x p r e s s e d o v e r t h e l a c k of i d e n t i f i c a t i o n of 50% of t h e t i s s u e r e s i d u e s of oxamyl. The WHO was r e q u i r i n g t h a t by 1983 t i s s u e r e s i d u e s be i d e n t i f i e d and t h a t the n o - e f f e c t l e v e l i n t h e r a t be c l a r i f i e d . Based on t h e WHO temporary ADI, a d r i n k i n g water g u i d e l i n e of 70 ug/1 can be c a l c u l a t e d . The U.S. EPA has used an ADI based on a 2 - y e a r c h r o n i c r a t d i e t a r y study. A d r i n k i n g water g u i d e l i n e of 175 ug/1 was c a l c u l a t e d u s i n g t h i s ADI. The New York S t a t e Department of H e a l t h e s t a b l i s h e d a p r e l i m i n a r y g u i d e l i n e of 50 ug/1 because of u n c e r t a i n i t i e s i n t h e n o - e f f e c t l e v e l i n r a t s and l a c k of d a t a on c h o l i n e s t e r a s e i n h i b i t i o n i n humans. A d d i t i o n a l c o n c e r n s c e n t e r e d on the r e s u l t s of a r a b b i t t e r a t o l o g y s t u d y which i n d i c a t e d NOELs f o r e m b r y o t o x i c i t y and f o r m a t e r n a l body weight changes which a r e lower than t h e e s t i m a t e d NOEL from c h r o n i c r a t d a t a .

Literature Cited (1)

(2) (3) (4)

"Air Sample collection technique for aromatic hydrocarbons, and related volatile organic compounds," Wadsworth Center for Laboratories and Research, New York State Department of Health, 1981. Nearpass, D.; Edwards, W.M.; Taylor, A.W. Agronomy Journal 1978, 70, 937-40. Palmer, J.; Radeleff, R. Ann. N.Y. Acad. Sci. 1964, 111(2), 729-36. "Drinking Water and Health," National Academy of Sciences, 1977, Volume 1.


539

540



(5)

Innes, J.; Ulland, B.; Valerio, M.; Petrucelli, L.; Fishkein, L.; Hart, E.; Pallotta, Α.; Bates, R.; Falk, H.; Gart, J . ; Klein, M.; Mitchell, I.; Peters, J. J. Natl. Canc. Inst. 1969, 42, 1101-14. (6) "Atrazine: Proposed Tolerance," U.S., Food and Agriculture Organization of the United Nations, Rome, Report Number 56, 1984. (7) "Tolerances and Exemptions from Tolerances for Pesticide Chemicals in or on Raw Agricultural Commodities: Alachlor," U.S. Environmental Protection Agency, Federal Register, 48(62):13173-4, 1983. (8) U.S. Environmental Protection Agency, Office of Drinking Water, personal communication, April, 1984. (9) Monsanto Agricultural Products, Alachlor, Information sheets submitted to the New York State Department of Health, April, 1984. (10) "Alachlor: Special Review of Certain Pesticide Products," U.S. Environmental Protection Agency, Federal Register, 50(6):115-19, 1985. (11) Zaki, M.H.; Moran, D.; Harris, D. Am. J. Publ. Hlth. 1982, 72, 1291-95. (12) E.I. duPont de Nemours and Co., Inc., Biochemicals Department, January 1982, Data supporting the use of Vydate L insecticide/nematicide on potatoes. Groundwater analyses and soil residue determination of oxamyl, Long Island, New York, 1981. (13) Mr. Baire, November 15, 1983, Oral presentation to Oxamyl Task Force. Suffolk County Department of Health Services, Hauppauge, NY 11788. (14) Harvey, J.; Han, J. J. Agric. Food Chem. 1978. 26, 536-41. (15) "Pesticide Residues in Food," FAO/WHO, Food and Agriculture Organization of the United Nations, Rome, Report Number 56, 1984. Two recent reviews of the toxicological effects of trichloroethylene and PCBs have been published: Safe, S. CRC Critical Rev. Toxicol. 1984, 13, 319-395. Kimbrough, R.; Mitchell, F.; Hunk, V. J. Toxic. and Environ. Health 1985, 15, 369-383. RECEIVED March 25, 1986


Evaluation of Pesticides in Ground Water - ACS Publications

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