Dermal Exposure Related to Pesticide Use - ACS Publications

21

Downloaded by UNIV OF ROCHESTER on June 11, 2018 | https://pubs.acs.org Publication Date: February 25, 1985 | doi: 10.1021/bk-1985-0273.ch021

Potential Exposure in the Application of Pesticides to Orchard and Field Crops TERRY D. SPITTLER and JOHN B. BOURKE Pesticide Residue Laboratory, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456 Dermal exposure to pesticides in the cultivation of apples, green beans, onions, and cabbage was measured for a variety of defined tasks including mixing, application, and harvesting. Exposures resulting from applications using a variety of sprayer types were compared. Enclosed spray cabs on tractors reduced exposure to applicators using airblast sprayers for orchard work by a factor of four, but no effect was evident for low-boom field crop uses. Spray cabs might reduce the exposure noted for drop nozzle applications, however, no rigs so fitted were available for comparison. Instances were observed where the use of a spray cab i n field crop application led to relatively higher potential exposure than that experienced by an adequately clothed operator on an open tractor. A significant percentage of exposure was shown to be received during m i x - f i l l operations which were independent of crop and spray protection equipment. Little significant exposure was registered for scouts or harvesters. Our p a r t i c i p a t i o n i n the surge o f i n t e r e s t i n w o r k e r exposure t o p e s t i c i d e s t h a t took p l a c e w i t h i n the l a s t f i v e y e a r s was p r e d i c a t e d on the premise that* worker exposure assessments should be a u x i l i a r y s t u d i e s o f ongoing o p e r a t i o n s . This p r e f e r e n c e f o r m o n i t o r i n g a c t u a l p r a c t i c e u n q u e s t i o n a b l y had i t s r o o t s i n the p r e v a i l i n g economic r e a l i t i e s , i . e . t h e r e was not enough r e s e a r c h money a v a i l a b l e i n t h i s a r e a t o conduct f u l l scale simulated applications. B u t , t h e r e were a l s o the f o l l o w i n g advantages t o a s s e s s i n g exposure i n an e x i s t i n g operation:

0097-6156/85/0273-O297S06.00/0 © 1985 A m e r i c a n C h e m i c a l Society

Honeycutt et al.; Dermal Exposure Related to Pesticide Use ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

298

DERMAL EXPOSURE RELATED TO PESTICIDE USE

A* The o p e r a t i o n was p r o b a b l y a l r e a d y funded, and, therefore, only supplementary support f o r the m o n i t o r i n g needed t o be o b t a i n e d .


B. An o p e r a t i o n conducted f o r a r e a l purpose, and n o t j u s t f o r t h e sake o f d o i n g an exposure s t u d y , was more likely to reflect true s i t u a t i o n s and c o n d i t i o n s , and be conducted by persons e x p e r i e n c e d in those procedures who, a r e l e s s l i k e l y t o commit routine e r r o r s r e s u l t i n g i n m i s l e a d i n g exposure determinations. C. Because such p r o j e c t s u s u a l l y were a t t e m p t i n g t o make a s p e c i f i c p o i n t o r t o answer a s p e c i f i c q u e s t i o n , a concurrent exposure assessment with t h e same parameters y i e l d e d u s e f u l exposure d a t a on c u r r e n t o r proposed p r a c t i c e s . D. The s i g n i f i c a n c e (and f u n d i n g p o t e n t i a l ) o f a p r o j e c t was enhanced by t h e a d d i t i o n o f an exposure phase when care was taken i n i t s proposal and implementation. U t i l i z a t i o n o f an e x i s t i n g r e s o u r c e , in t h i s case a h o s t p r o j e c t a l s o h e l p e d o b t a i n independent support f o r the exposure work. w

C e r t a i n l i m i t a t i o n s were a l s o i n h e r e n t t o these s t u d i e s . Care had t o be t a k e n t h a t measuring d e v i c e s d i d not i n t e r f e r e with, o r i n any way compromise t h e s a f e t y equipment o r p r o t e c t i v e d e v i c e s t h a t would o t h e r w i s e be u t i l i z e d , and f i e l d t e c h n i c i a n s had t o remain p a s s i v e o b s e r v e r s who n e i t h e r a d v i s e d nor a s s i s t e d i n any o f the t a s k s under s t u d y . Because time, itself, i s a v a l u a b l e commodity, m a n i p u l a t i o n s i n v o l v i n g t h e m o n i t o r i n g d e v i c e s c o u l d not unduly i n t e r f e r e w i t h the normal f l o w o f o p e r a t i o n s on the p r o j e c t s . The d e t e r m i n a t i o n o f a b s o l u t e o r " t o t a l exposure * h a s l o n g been e s t a b l i s h e d a s b e i n g beyond the scope o f our s t u d i e s o f v o l u n t e e r a g r i c u l t u r a l w o r k e r s i n ongoing o p e r a t i o n s . I n s t e a d , we f o c u s e d our a t t e n t i o n on i s o l a t i n g s p e c i f i c t a s k s o r p r a c t i c e s w i t h i n the p r o d u c t i o n scheme t h a t a l l o w e d us t o o b t a i n the r e l a t i v e worker exposure a s s o c i a t e d w i t h t h e v a r i o u s operations p e r t a i n i n g t o each j o b and/or f u n c t i o n . Once d e f i n e d , v a r i a b l e s such a s time, l b s a p p l i e d , g a l l o n a g e , and a c r e s t r e a t e d c o u l d be n o r m a l i z e d , and the consequences o f independent variables such a s s p r a y e r t y p e , f o r m u l a t i o n , protective devices, or application t e c h n i q u e s c o u l d be i n t e l l i g e n t l y gauged. Throughout a l l t h r e e o f t h e seasons t h a t t h i s work was carried o u t , we endeavored t o m a i n t a i n these comparative s t u d i e s , w h i l e s i m u l t a n e o u s l y k e e p i n g t h e measuring t e c h n i q u e s as c o n s i s t e n t as p o s s i b l e from y e a r t o y e a r . T o p i c a l , o r dermal exposure, one o f the more i m p o r t a n t g e n e r a l r o u t e s f o r p e s t i c i d e e n t r y , was measured u s i n g gauze patches p l a c e d a c c o r d i n g t o t e n e t s developed f o r these g e n e r a l o p e r a t i o n s (1.2). 1



21.

SPITTLER AND

BOURKE

Orchard

and Field

Crop

Pesticide

Exposure

In practice, three 4" χ 4" sixteen-layered gauze patches, with foil-backing, were pinned on the subjects; F(over the heart), B(on the center of the back), and L(on the outside of the l e f t l e g at knee l e v e l ) . At the end of a defined task or time interval — the p a r t i c u l a r s of which were recorded and frequently photographed — the patches were removed and a 26 cm c i r c l e was cut from the center and analyzed for the chemicals of i n t e r e s t . I t has been generally recognized that mixers register high potential exposure on gloves or other hand monitoring devices^. However, because the usual practice i s for mixers to wear their own "pesticide r e s i s t a n t " gloves, the employment of our absorbent cotton monitoring gloves might have compromised prudent practice and was accordingly not done. Whole body s u i t s (disposable coveralls) were employed f o r certain s p e c i f i c tasks, and a i r monitors were u t i l i z e d i n one f i e l d study. Four basic c u l t i v a t i o n programs were investigated during the course of our worker exposure studies. Each of these and the unique variables for which comparative potential exposure l e v e l s could be determined are l i s t e d below. A.

APPLE ORCHARDS, AIRBLAST APPLICATION (1980) 1. Chemical Control Centers 2. Spray Cabs

B.

GREEN BEANS, DRY FIELD (1981) 1. Spray Cabs 2. High Pressure Low Boom vs Low Pressure Low Boom Sprayers 3. Integrated planting/herbicide treatments vs separate operations

C.

CABBAGE, DRY FIELD (1982) 1. Low Pressure Low Boom vs Drop Nozzle Sprayers

D.

ONIONS, MUCKLAND (1982) 1. Low Pressure Low Boom vs High Pressure Low Boom vs High Pressure High Boom vs Drop Nozzle Sprayers.

In addition, the 1981 and 1982 studies looked at the exposure received by IPM scouts who frequented the treated f i e l d s to make damage assessments. Harvesters were also addressed i n the 81-82 work. Tables I-III give an outline of each years monitoring by chemical and devices. Extensive photodocumentation of our programs, p a r t i c u l a r l y of the mixing operations i n a l l four studies, proved invaluable i n i d e n t i f y i n g exposure mechanisms. Since reproduction of t h i s media i s not p r a c t i c a l here, conceptual observations from t h i s source w i l l be interjected i n t o the discussion of the four individual programs.



300 Table I .

P e s t i c i d e Exposure Samples Analyzed

Task M+A M+A M+A M+A

Pesticide Guthion Benlate Methyl Parathion Plictran

M+A

Imiton

1

i n Apple Orchard

^Patches (Sets) 36 (12) 9 (

3)

12 ( 4 ) 21 ( 7) 7*5 (2*)


M = Mixer, A = A p p l i c a t o r All chemical analyses, e x c e p t those f o r Manex, where performed u s i n g s t a n d a r d p e s t i c i d e a n a l y t i c a l methods such as t h o s e c o n t a i n e d i n t h e P e s t i c i d e A n a l y t i c a l Manual, and u t i l i z e d equipment and s u p p l i e s a v a i l a b l e through numerous commercial laboratory sources(4). Dermal p a t c h e s were c o n s t r u c t e d i n o u r l a b o r a t o r y by t a p i n g f o u r , f o u r - p l y s u r g i c a l d r e s s i n g s ( 4 χ 4 " ) to a 4 " χ 4 " square o f aluminum f o i l w i t h masking tape. The gauze was p r e e x t r a c t e d w i t h acetone. G l o v e s were o r d i n a r y , 100$ cotton, white gardening g l o v e s and were n o t p r e e x t r a c t e d . Estimations f o r Manex were performed by d i g e s t i n g t h e sample i n nitric acid, d i l u t i n g w i t h w a t e r , and d e t e r m i n i n g total manganese by a t o m i c a b s o r b t i o n s p e c t r o m e t r y (A.A.). The Mn background from t h e p a t c h e s o r g l o v e s was n e g l i g i b l e , b u t some contamination by windblown s o i l o c c a s i o n a l l y may have i n c r e a s e d the l e v e l s found, n

APPle Production

(1990)

Chemical C o n t r o l C e n t e r s were t h e d r i v i n g f o r c e f o r t h i s i n v e s t i g a t i o n , w i t h the primary concern being the environmental impact and t h e changes i n worker exposure p a t t e r n s , i f any, c o n s e q u e n t i a l t o t h e i r e s t a b l i s h m e n t and use. They c o n s i s t o f a s e c u r e c h e m i c a l s t o r a g e room, a w a t e r s u p p l y , a c o n c r e t e pad f o r m i x i n g , f i l l i n g and c l e a n i n g , and a c a t c h b a s i n w i t h l e a c h l i n e s f o r d i s p o s a l o f d i l u t e s p i l l a g e and r i n s e water. T h i s f a c e t has a l r e a d y been p u b l i s h e d ^ . I n c i d e n t a l t o t h i s , we were a l s o able t o d i r e c t l y compare two o p e r a t i o n s t h a t d i f f e r e d o n l y i n t h a t one used spray cab-equipped t r a c t o r s t o p u l l t h e i r a i r b l a s t s p r a y e r s , and t h e o t h e r d i d n o t . T a b l e IV and V g i v e r e s u l t s o b t a i n e d f o r Imidan, one o f t h e few m a t e r i a l s h a v i n g a s i g n i f i c a n t number o f o b s e r v a t i o n s from w h i c h t o graw c o m p a r a t i v e c o n c l u s i o n s . Data a r e g i v e n i n μ g chemical/cm a t each body l o c a t i o n , a l o n g w i t h a p p l i c a t i o n parameters u s e a b l e f o r n o r m a l i z a t i o n o f these numbers f o r comparative purposes. A l l m a t e r i a l s were a p p l i e d i n mature fruit t r e e p r o t e c t i o n programs u s i n g a i r b l a s t s p r a y e r s o f 500 g a l / l o a d c a p a c i t y w i t h 3 X low-volume n o z z l e s . The o n l y v i a b l e c o m p a r i s o n t o be made i s t h a t between Farm X h a v i n g no s p r a y cabs on t h e i r t r a c t o r s , and Farm Y h a v i n g spray cabs w i t h c h a r c o a l a i r f i l t e r s f o r t h e i r t r a c t o r s . A l l persons m o n i t o r e d both mixed and a p p l i e d t h e i r own m a t e r i a l s , thus each f i l l - s p r a y batch i s d e f i n e d a s a c y c l e ( C y ) . S i n c e t h e s u b j e c t s w i t h i n an


21.

SPITTLER AND

BOURKE

Orchard

and Field

Crop

Pesticide

Exposure

Table I I . Pesticide Exposure Samples Analyzed i n Green Bean


Operations, 1981 #Qthey(Type)

Pesticide Premerge Premerge Premerge

M A Mf A

3 ( 1) 6 ( 2) 12 ( 4)

Parathion Parathion Parathion Parathion

M A Mf A H

12 15 3 12

( ( ( (

Benlate Benlate Benlate Benlate Benlate

M A Mf A H S

30 42 3 21 33

(10) (14) ( 1) ( 7) (11)

Orthene Orthene Orthene Orthene Orthene

M A MfA H S

9 12 3 15 33

( 3) ( 4) ( D ( 5) (11)

2(Coveralls)

4) 5) 1) 4)

Sevin Sevin

H S

12 ( 4) 9 ( 3)

Treflan

H

42 (14)

4(Air Tubes)

Lorsban M 3(1) Lorsban A 6(2) Loxsbâfî UtA ÎL-L21 1 M = Mixer; A = Applicator; H = Harvester; S = Scout


302



Table I I I .

Pesticide Exposure Samples Analyzed In Onion and Cabbage Operations, 1Q82

Pesticide

lasjcj

Parathion Parathion Parathion Parathion Parathion Parathion Parathion Parathion Parathion Parathion

M-C MfA-C A-C H-C S-C M-0 Mf A-0 A-0 H-0 S-0

39 3 42 12 33 30 21 39 24 27

(13) ( 1) (14) ( 4) (11) (10) ( 7) (13) ( 8) ( 9)

Manex Manex Manex Manex Manex Manex

M-0 Mf A-0 A-0 H-0 S-0 S-C

30 21 39 24 15 15

(10) ( 7) (13) ( 8) ( 5) ( 5)

6 ( 3)

Bravo Bravo Bravo Bravo Bravo Bravo Bravo Bravo

M-C A-C S-C M-0 Mf A-0 M-0 H-0 S-0

6 ( 2) 6 ( 2) 18 ( 6)

6 ( 3)

Thiodan Thiodan Thiodan

M-C A-C S-C

Randox Randox Randox Randox Randox

M-0 Mf A-0 A-0 S-0 S-C

Systox Systox

H-C S-C

Pydrin Pydrin

#Patches(gets)

9 21 18 15 15

24 (12)

( 3) ( 7)

( 6) ( 5) ( 5)

30 (10) 39 (13) 30 (10) 9 3 12 3 15

EG loves (Pairs)

3) 1) 4) 1) 5)

8 ( 4)

6 ( 2) 15 ( 5)

6 ( 3)

M-C 9 A-C 9 Pydrin S-C 15 1 M = Mixer, A = Applicator, C = Cabbage, 0 = Onions

( ( ( ( (

16 ( 8)

( ( ( H

3) 3) 5) 6 ( 3) = Harvester, S = Scout,



21.

SPITTLER AND

Orchard

BOURKE

and Field Crop

Pesticide

Exposure

o r c h a r d o p e r a t i o n s w i t c h e d back and f o r t h on e q u i v a l e n t r i g s , no d i s t i n c t i o n was made between s u b j e c t s a t a g i v e n farm. Simple treatment o f these r e s u l t s a l l o w e d us t o f o r m u l a t e d some s i m p l e c o n c l u s i o n s ; t h i s was t h e i n t e n t o f t h e program, t o make straight-forward observations leading to p r a c t i c a l s u g g e s t i o n s t h a t c o u l d m i n i m i z e m i x e r / a p p l i c a t o r exposure. When t h e t o t a l Imidan exposure r e s u l t s a r e compared on n o r m a l i z e d bases (/Hr, /Cy, / L b ) , the o b v i o u s p o i n t i s t h a t t h e use o f a spray cab reduces the p o t e n t i a l dermal exposure t o about 1/3 o r 1/4 o f t h a t shown f o r an open t r a c t o r . Similar r e s u l t s were o b t a i n e d f o r G u t h i o n , where exposure r a t i o s ranged from 5.7 t o 3.1. In fact, these r a t i o , would be much h i g h e r i f o n l y t h e a p p l i c a t i o n s t e p were b e i n g c o n s i d e r e d , b u t , because o f t h e s h o r t time span, a t dawn, when t h e winds were s t i l l and these s p r a y i n g o p e r a t i o n s c o u l d be conducted, we were n o t a b l e t o r o u t i n e l y d e l a y t h e o p e r a t o r s by changing patches between t h e m i x i n g and a p p l i c a t i o n s t a g e s . M i x i n g e x p o s u r e i s , o f c o u r s e , not i n f l u e n c e d by s p r a y cabs and i s known t o be g e n e r a l l y h i g h (6.). Here i t was c o n s i d e r e d t o be e q u a l f o r both o p e r a t i o n s — t he v a r i a t i o n i n exposure was a t t r i b u t e d t o t h e spray cabs. Our photodocumentation o f f i l l i n g operations i n a l l four studies showed c l o u d s and e d d i e s o f d r y f o r m u l a t e d p e s t i c i d e s around t h e mixers a s they emptied bags o f m a t e r i a l i n t o t h e f i l l i n g hatches. T a b l e IV.

Imidan P a t c h Exposures and M i x / A p p l y P r o d u c t i v i t y f o r Two Orchard O p e r a t i o n s

EatstLLooation F

B

1

2

(PR/cm )

L =

Parameter T o t a l s —

T o t a l Exp

UOJK&

Cycles

Jointe

Farm X

27.6

8.8

19.9

56.3

14.0

18

185

Farm Y

n.2

11.1

16,0

40^

31.3

]U

Ê15_

1

F = F r o n t , Β = Back, L = Leg

T a b l e V. T o t a l Imidan P a t c h Exposure' f o r Two Orchard O p e r a t i o n s N o r m a l i z e d f o r Mix/Apply P r o d u c t i v i t y Parameters— £XEZHE

Farm

Exj>ZlXLlba

x

4.0

3.1

3.0

Y

1.3

1.0

0.67

U

3a£

!L5

JU1 1

EXBZCX

Exp = μ g/cm

2


304


I n summary, t h e r e i s a 3- t o 5 - f o l d decrease a s s o c i a t e d w i t h t h e use o f a spray cab i n a i r b l a s t o p e r a t i o n s , when t h e mixings and f i l l i n g s are done under s i m i l a r c o n d i t i o n s . There i s no evidence t h a t a Chemical C o n t r o l C e n t e r i n f l u e n c e s t h e p o t e n t i a l dermal exposure r e s u l t i n g from spray o p e r a t i o n s a s d e f i n e d i n t h i s study. P a t c h e s worn by o u r t e c h n i c i a n s i n t h e Chemical C o n t r o l C e n t e r s d u r i n g the course o f the study gave no e v i d e n c e o f p e s t i c i d e exposure t o c a s u a l f r e q u e n t e r s o f t h e area.


Green Bean P r o d u c t i o n (1Q81) The 1981 g r o w i n g season p r o v i d e d a unique o p p o r t u n i t y f o r a s s e s s i n g t h e impact o f a new c h e m i c a l p e s t i c i d e use p a t t e r n on the ecosystems i n and s u r r o u n d i n g the t a r g e t p l o t s . F o r t h e first time t h e w i d e s p r e a d use o f i n s e c t i c i d e s i n green bean production, t o combat i n f e s t a t i o n s o f the European c o r n b o r e r , was b e i n g recommended. P r i o r t o t h i s season o n l y h e r b i c i d e and f u n g i c i d e t r e a t m e n t s were u t i l i z e d i n commercial p r o d u c t i o n ; few i n s e c t p e s t s bothered t h e r e l a t i v e l y f a s t - g r o w i n g c r o p enough t o require regular control. I n a d d i t i o n , an I n t e g r a t e d Pest Management (IPM) p i l o t program was a l r e a d y i n p l a c e i n bean c u l t i v a t i o n and f i e l d p e r s o n n e l c o u l d be shared. T h i s program a l s o had the p r o f e s s i o n a l s t a f f r e q u i r e d t o conduct the s p e c i e s p o p u l a t i o n s t u d i e s on c o n t i g u o u s a r e a s and w i t h i n the s u b j e c t fields. The second o b j e c t i v e , however, was t o a s s e s s the p o t e n t i a l exposure t o p e s t i c i d e s o f a l l p e r s o n n e l i n v o l v e d i n g r e e n (snap) bean p r o d u c t i o n . Ground p r e p a r a t i o n , p l a n t i n g , maintenance s p r a y i n g , IPM s c o u t i n g , and h a r v e s t i n g were m o n i t o r e d throughout the 1981 season, u s i n g s e v e r a l a p p r o p r i a t e c o l l e c t i o n d e v i c e s d e s i g n e d t o measure p o t e n t i a l exposure v i a c e r t a i n r o u t e s d u r i n g the performance o f s p e c i f i c t a s k s . I n a d d i t i o n t o patches, d i s p o s a b l e c o v e r a l l s were worn f o r c e r t a i n t a s k s , t h e n c o l l e c t e d and analyzed. Patch s e t s p l a c e d under the Tyvex c o v e r a l l s measured any c h e m i c a l p e n e t r a t i n g t h e m a t e r i a l . For d i r e c t comparison, a s e t o f p a t c h e s was a l s o pinned t o the o u t s i d e , o f f s e t , o f c o u r s e , so a s n o t t o i n t e r f e r e w i t h those under t h e garment. A i r m o n i t o r s were a l s o u t i l i z e d i n one phase o f t h e program. Because much o f t h e equipment encountered i n f i e l d c r o p p r o d u c t i o n i s farm b u i l t and/or m u l t i p u r p o s e , we were n o t a b l e to o b t a i n l a r g e numbers o f comparative runs w i t h o n l y one independent v a r i a b l e as had been the case i n the o r c h a r d work. Most o f t h e d a t a support o n l y s e m i q u a n t i t a t i v e e v a l u a t i o n s o f a l t e r n a t i v e d e v i c e s and p r a c t i c e s u t i l i z e d a t s p e c i f i c s t e p s i n production(i). Analysis o f whole body s u i t s (by e x t r a c t i o n o f t h e quartered garment) showed that almost twice a s much c h e m i c a l / h o u r (Premerge) was d e p o s i t e d o v e r the e n t i r e body when Premerge alone was a p p l i e d from an open t r a c t o r u s i n g l o w pressure sprayers a s compared t o t h e s i t u a t i o n where a combination r i gf o r planting, f e r t i l i z e r i n c o r p o r a t i o n , and preemergent s p r a y i n g was employed (11 mg/hr j£S 6.5 mg/hr). However, because o f the more r a p i d coverage and g r e a t e r payload



SPITTLER AND

BOURKE

Orchard

and

Field

Crop

Pesticide

Exposure

o f the former equipment, the a c t u a l e x p o s u r e / a c r e t r e a t e d was c o n s i d e r a b l y l e s s when the s i n g l e purpose u n i t was used. The h i g h t o x i c i t y o f Premerge r e q u i r e d t h a t g l o v e s , a h a t , c o v e r a l l s and a r e s p i r a t o r be worn d u r i n g a l l s t a g e s o f t h e o p e r a t i o n , r e g a r d l e s s o f equipment t y p e . One a c c i d e n t was documentated i n w h i c h a p r e s s u r e hose s p l i t and sprayed the s u b j e c t a p p l i c a t o r w i t h Premerge. R e p a i r s were e f f e c t e d w i t h p a t c h e s s t i l l i n p l a c e on the c l o t h i n g ; the whole i n c i d e n t r e s u l t i n g i n a v e r y high potential exposure to an u n p r o t e c t e d worker. No p e n e t r a t i o n o f the s u i t was d e t e c t e d . Some exposure t o c h e s t p a t c h e s was r e g i s t e r e d f o r L o r s b a n seed treatment d u r i n g the p l a n t i n g / a p p l i c a t i o n o p e r a t i o n . This presumably came about from l i f t i n g seedbags t o f i l l the p l a n t e r hoppers. The amounts were s m a l l and because o f the presence o f Premerge i n the v i c i n i t y , the w o r k e r s were ( o r s h o u l d have been) generally w e l l protected. There appeared t o be l i t t l e , i f any, dermal exposure measured under normal a p p l i c a t i o n c o n d i t i o n s when low p r e s s u r e low boom s p r a y e r s (LPLB) were used on open t r a c t o r s : l i k e w i s e for our measurements o f a s i m i l a r truck-mounted d e v i c e i n w h i c h the s u b j e c t a p p l i c a t o r s worked i n a cab w i t h the windows down. I n s i t u a t i o n s where the s u b j e c t s were r e q u i r e d t o dismount i n the f i e l d t o c l e a r n o z z l e s o r move booms o r o b s t a c l e s , the l e g p a t c h e s i n v a r i a b l y r e c e i v e d m a t e r i a l from the newly t r e a t e d foliage. Chest p a t c h e s were o c c a s i o n a l l y contaminated a t t h i s stage also. Both t r u c k and t r a c t o r mounted s p r a y e r s showed s i m i l a r exposure p a t t e r n s f o r a p p l i c a t o r s . A p p l i c a t o r exposure w i t h h i g h p r e s s u r e low boom s p r a y e r s was found t o be even l e s s t h a n t h a t r e c o r d e d f o r LPLB d e v i c e s . T r a c t o r s w i t h and w i t h o u t spray cabs were t e s t e d , and t h e r e was seen no o v e r r i d i n g advantage t o the spray cab under normal c o n d i t i o n s . Under s e v e r e c o n d i t i o n s , l i k e g u s t i n g w i n d s o r l i n e ruptures, a cab would l o g i c a l l y a f f o r d more p r o t e c t i o n . However, winds s h o u l d g e n e r a l l y cause r e c o n s i d e r a t i o n o f t h e days o p e r a t i o n s . Again, extra-vehicular activity t o remove o b s t a c l e s o r a d j u s t booms r e s u l t e d i n some c o n t a c t exposure. The c h e m i c a l s studied were Benlate, Orthene and Parathion, with no p r e f e r e n t i a l t r a n s f e r being evident f o r the f r e s h l y a p p l i e d m a t e r i a l ( i . e . , contamination r a t i o s on p a t c h e s were r o u g h l y e q u a l t o the s t a t e d r a t i o i n the tank m i x e s ) . An attempt was made t o measure the c o n c e n t r a t i o n o f Orthene in a i r b o t h w i t h i n and o u t s i d e o f a s p r a y cab. A i r was drawn t h r o u g h two d i f f e r e n t g l a s s tubes, each c o n t a i n i n g 400 mg o f silica g e l , by MDA Model 808 A i r I n h a l a t i o n Pumps (MDA S c i e n t i f i c , G l e n v i e w , I L ) o p e r a t i n g a t 100 cm /min. and p l a c e d as d e s c r i b e d above. D u p l i c a t e e x p e r i m e n t s l a s t i n g 0.40 and 0.45 h r , and sampling 2400 cm and 2700 cm of a i r , r e s p e c t i v e l y , were conducted. Although r e c o v e r y was shown t o be 100? f o r e x t r a c t i o n of Orthene from the tubes, no measureable amount o f chemical (

Dermal Exposure Related to Pesticide Use - ACS Publications

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