Document J3LVNrBBO6MNvoE73aMGEOYra

FENSKE, ET AL. ble air wmpling pumps with flow rates of 2 L/niin werc calibrated with the sampling train in linc prior to md following the sampling pcriod. Chlorpyrifos vapors were collected with ORBO-44 tubes (Supelpak 20). Tubes wcrc capped and stored in an ice chest for transport to the laboratory. Aluminum foil squares (10 cm i( I O cm) were placed in the rooms before treatment to measure residues deposited on the carpet surface. Five squares were collected from each room i;iimcdiatcly following application (5 minutes). The wipc proccdurc was based on the standard method of the US Occupational Safety and Health Administration.'" Sets of three wipes were collected in each room at eight time intervals post-application: 20, 40, 80, 100, 170, 260, 380 minutes. and 24 hours. All areas to be wiped were marked by disposable cardboard frames with 10 cm X I O cm cut-out interiors. A new plastic glove was worn for each wipe sample to avoid cross-contamination of samples. The wipe consisted of three strokes across the surface with a 7.5 x 7.5 cm surgical gauze pad sprayed lightly with distilled water. This proccdurc WiI\ rcpcatctl with :\ second ~:\w.cpiid. chilngine the wipc orientation 90".I ' d $ were plirced in glass storagc jar5 in an ice chest for transport to the laboratory. All samples were stored at -20C until analysis. Granular contents of the Orbo-44 tubes were transferred into serum vials filled with 10.0 ml of pesticide-grade toluene. A subset of the samples were analyzed for breakthrough into the secondary section of the tubes, but such breakthrough was negligible. Capped vials were shaken at high speed ( I 0 0 cpm) for 5 minutes on a IT ,:hanical shaking table. allowed to sit for 30 minutes and the extracts transferred to GC vials for analysis. Both the foil and the pads were extracted in 30 ml of toluenc on the shaking table at high speed for 30 minutes and the extracts transferred into GC vials. Samples were analyzed on a Hewlett Packard 5890A gas chromatograph equipped with an electron capture detector. Hei-tachlor epoxide was added to all samples as an internal standard. The limit of detection for l - ~ linjections was 1 picogram/kl. The limi:s of detection for the sampling media were as follows: air samples, 83 nll/m3; foil and gauze samples, 0.6 ndcrn'. Solvent blanks run with each set of samples had no detectable chlorpyrifos. Fortification/ recovery studies were conducted for all sampling media. The mean and standard deviation from these studies were as follows: air samples, 85.3% C6.0; aluminum foil squares, 98.6% k2.5; gauze wipes, 84.0% ~ 1 0 . 1 .Data have been adjusted on the basis of these recovery values. Two air samples, thrce foil and three wipe samples were collccted in air concentrations-1OOcm 70 1 60 - 50 EGi" 4 0 .$ 30 oal 20 10 0 0.5 1 1.5 3 5 7 24 time interval (hrs post-application) Iw/o ventilation FIGURE I4hlorpyrUos Air Cwmtntlons In the Sitting Adult Breathing Zone (100 rm) air concentrations-25cm 1007 90 80 .'-L 70 9) 60 3 50 0 --. 4 0 0) 30 20 10 0 0.5 1 1.5 3 5 7 24 time interval (hrs post-application) without ventilation FIGURE 2-Chlorpyrifos Alr Concentrations in the Infant Breathing Zone (25 rm) broadcast application. The following assumptions were employed: I . Infant weight = 9.0 k p 2. lnfant respiratory volume = 2.1 Llmin rcsting (16 hours/day); 6.3 Umin active (8 hours/day)" 3. 100% respiratory absorption of chlorpyrifos vapors 4. Total carpet contacted in one day = 2.3 mz(25 ft2) 5. 100% transfer of available residues (wipe samplcs)to skin 6. 3% dermal absorption of chlorpyrifos"34 Estimated absorbed dermal doses for infants (Table 2) are the product of surface area contacted, available residues (Day 1 and Day 2 in Table I ) and percent absorbed, divided by body weight. The estimated dose in the nonventilated room is 0.120 mdkg on Day I , 3.2 times the dose for Day 2. Ventilation reduced the dose estimates approximately two- fold. Estimated absorbed respiratory doses are the product of time-weighted air concentrations, respiratory volume and percent divided by body weight. Estimated Ray 1 dose wi ilation is 0.038 m a g . more than twice the Day 2 dose. Ventilation reduced the dose on Day 1 by approximately one-third, but had little effect on Day 2 estimates. Total absorbed dose estimates for the day of application are 0.075 and 0.158 m a g for ventilated and nonventilated rooms, respectively. Day 2 estimates are approximately 2-3 times lower. Dermal exposure represents on avcrugc 68 pcrccnt of thc lotot absorbed dose. Discussion Chlorpyrifos residues following broadcast application were substantially higher than those reported for other types of residential applications. Total release aerosol applications have produced deposition levels of approximately 2 pg/cm2 and maximum air concentrations following ventilation of 14 pglm'.zs Crack-and-crevice or baseboard applications have resulted in deposition levels of from 1-3 pglcmz,ls.*2and air concentrations of 1-2 pg/m3.*o.21 Termiticide applications have produced air concentrations of <144.5 pg/m3.11-13 Broadcast applications thus appear to produce deposition levels 5-10 times higher and peak air concentrations approximately one to two orders of magnitude higher than other application procedures. Of further concern is the finding that vapor concentrations increase over the first few hours, peaking 3-7 hours post-application. The extent to which indoor pesticide applications might produce intoxicationsamong residents is lavely unknown. A recent risk assessment calculation of a 2.68 mg/kg absorbed dose for infants in chlorpyrifos-treated residences was based on several conservative assumptions, induding complete (100 percent) absorption of chlorpyrifos through the skin.* The risk assessment presented here avoids such worst-case assumptions. but includes major uncertainties in the dermal exposure estimates. The rate of transfer of pesticides from treated surfaces to skin and the amount of surface contacted over time are not known. Research has been initiated to adapt fluorescent tracer and video imaging techniques used in occupational exposure studies to address these issues.35.36 Several factors not included in the dose calculations suggest that chlorpyrifos abscrption could be substantially higher. First. a 3 percent dermal absorption estimate may be low. The conventional topical dose for pesticide absorption studies is approximately 40 &~m',~7 whereas the average dose applied to the skin in the chlorpyrifos absorption study was >4000 p@cm2.34High topical doses result in relatively low percent absorbed v a l u e s . ~ ~A~n~ 9estimate of the rate of chlorpyrifos penetration through the skin is needed to more accurately cstimate absorbed dermal dose. Second, infant skin niay be more permcable than the adult skin used to estimate chlorpyrifos absorption. Although the stratum cor- AJPH June 1990. Vol. 80.No. 6 691 TABLE 2-lotel Ertlmated Abrorbed Chlorpyrlfos Dose for Infants: Day of Appllmtlon (Day 1) and Day followlng Appllcstlon (Day 2) Room Condition Dermal Respiratorj Dose x Dose Yo Total Dose Percent of (mg'kgl Total (mgkg) Total (mgW NOEL' Day 1 Ventilated Nonventilated Day 2 Ventilated Nonventilated 0 052 0.120 0 022 0 037 69 76 58 67 'Human No Observable Efled Level = 0 03 mgikgldBy 0.023 0 038 0 016 0.018 31 0.075 24 0.158 250 527 42 0.038 33 0.055 127 183 neum of the infant is considered to be fully developed, the permeability of infant skin in humans has not been measured.39 Studies in infant rats have demonstrated increased percutaneous absorption of chlorpyrifos relative to adults.40 Third, ingestion from deposits on hands would increase the estimates, since chlorpyrifos is absorbed by the oral route more efficiently than by the dermal route.34Finally. skin conditions to which infants may bc particularly susccp- tible (e.g., dryness and rashes) are known to reduce the bam'er properties of the skin.39 The no observable effect level (NOEL) for chlorpyrifos is based on measurable changes in plasma acetylcholinest- erase. The NOEL in humans is 0.03 mdkglday.41 All of the absorbed dose estimates in Table 2 exceed the NOEL, with doses 2.5-5 times the NOEL on Day I , declining to 1.2-1.8 times on Day 2. The US Environmental Protection Agency has derived a "human reference dose"of 0.003m&g/day for chlorpyrifos by applying a IO-fold safety factor to the human NOEL.42 The dose estimates in this study exceed the human reference dose by 10-50 times. NOEL values are commonly employed to determine standards for human safety, but are based on an assumption of continuous exposure (e.g., Acceptable Daily Intakes of pesticide residues in foods). A similar assumption underlies the NAS guideline for indoor air concentrations.30 Since the potential exposures calculated here would be intermittent, their toxicological significance is difficult to interpret. As yet no short-term toxicological measure analogous to the NOEL is available. Despite uncertainties in exposure/absorption estimatcs and toxicological interpretation, the dose values derived in this study raise a public health concern. Broadcast applications and possibly total release aerosoUfogging applications of acutely toxic insecticides may result in dermal and respiratory exposures sufficient to cause measurable toxicological responses in infants. While such exposures are not likely to produce recognizable symptomsGf cholinesterase inhibition, the possibility of cases with subclinical effects cannot be ruled out. Confirmation of such exposures would requirc biological monitoring (e.g., detection of 3,5,6-!richIoro-2- pyridinal in the urine for chlorpyrifos). The potential for exposures great6.r than those reported here should also be noted. The training of many urban pesticide applicators is minimal and surveillance of application performance is nonexistcnt in most states. It is not unreasonable to assume that accidents and cases of inadvertent over-application will occur under these circumstanccs, albeit with low frequency. Furthermore, repeated applications for fleas and other household pests are not uncommon. Current federal regulatory requirements for indoor pes- ticide applications are limited to label instructions. The label for broadcast applications of the compound under study here is typical (K. Lunchick, USEPA; personal communication); Le., the premises should be vacated during application, and humans or pets should not contact treated surfaces until the spray has dried. These instructions are normally communi- cated by the applicator to occupants HS B 1-2 hour reentry period. 'rhc finding of elcvatcd air conccntrations 3-7 hours post-application and the potential for dermal contact indicate that this reentry period is inappropriate for infants and small children. Several strategies are available to reduce the risks associated with indoor pesticide applications. First. notification requirements could be established to inform occupants of potential health risks and means for minimizing exposure. Recommendationsfor broadcast applications of acutely toxic compounds such as chlorpynfos might inciude thorough ventilation prior to reentry regardless of seasonal conditions, and well-defined reentry periods beyond 1-2 hours with special warnings regarding contact with treated surfaces by infants and small children. Second, more rigorous training and licensing procedures for applicators and application surveillance programs could be developed. Finally, product registrations could be modified or withdrawn for specific applications if an acceptable level of risk cannot be demonstrated. ACKNO WLEDGMEUTS A preliminaryrepoffofthis work waspresentedac the AmericanInductrial Hygiene Conference. San Francisco, CA. May IS-20,1988.The authors wish to thnnk Drs.Molly Coye. Michael Gallo. Philip Landrigan, Thomas Ledoux. and Mark Rohson for their review of this manuscript.Special acknowledgment to David Hackathom and Delmont Eberharrfortheirearly insight into this field of investigation. The technical assistance of William Carey and Western Termite and Pest Control of New Jersey was greatly appreciated. This work was supported by State funds (NJAES Pub. No. D-07124-I-R9). REFERENCES I . National Academy of Sciences: Urban Pest Management. Wachington, DC: National Academy Press, 1980. 2. Gold RE, Holcslaw T, Tupy D. Ballard JB: Dermal and respiratory exposure to applicators and occupants of residences treated with dtchloN O S (DDVP). J Econ Entomol 1984; 77:430436. 3. Woody RC: The clinical spectrum of pediatric organophosphate intoxications. Neurotuxicology 1984;5:75. 4. Zwiener RJ, GinsburgCM: Organophosphateand carbamatepoisonin(l in infnnt\ and children. Pediatricc 19R8:81:121-126. 5. Knmk JU.Schreidcr 1. Bencau P: Hazard ascessmenr of indoor use of chlorpynfos. dichlorvos. propoxur and other organophosphates and Nmethyl carbamates. Worker Health and Safety Branch Report No. HS-1423. Sacramento. C A California Department of Food and A~rieullure. 1987. 6 Derteau PE. Knmk JB, Mengle DC: Insecticide absorption from indoor wrfuce~h:azardacsewnent and regulatory requirement%In. : Wanp RGM, 692 AJPH June 1990, Vol. 80.No.6 I I Franklin CA. Honeycutt RC. Reinert JC (ed$i):Biological Monitortng for Pcsticidc Exposure. ACS Symposium Series 382. Wmhington. DC: American Chemical Society. 1989. 7. Lowengart RA. Peters JM. Cicioni C, Buckley J. Bernstein L. Reston- MartinS . Rappaport E: Childhood leukemiaand parents' occupational and home exposures. JNCl 1987; 7939-46. 8. Livingston JM, Jones CR: Living area contamination by chlordane u$ed for termite treatment. Bull Environ Contam Toxicol 1981: 27:406. 9. Wright CG. Leidy RE: Chlordane and heptachlor in the ambient air of houses treated for termites. Bull Environ Contam Toxicol 1982; 20617. 10. Wright CG, Lcidy RB, Duptee HE. Sheets TJ: Subterranean termite control: chlordane residues in soil surrounding and air within houses. In: Honeycutt RC. Zweig G, Ragsdale NN (eds): Dermal Exposure Related to Pesticide Use. ACS Symposium Series 273. Washington, DC:Amencan Chemical Society, 1985. I I. Moye HA. Malagodi MH: Levels of airborne chlordane and chlorpyrifos in two plenum houses: saranex S-I5 a$ a vapor barrier. Bull Environ Contam Toxicol 1987; 39533-540. 12. Anderson DJ. Hites RA: Chlonnated pesticides in indoorar. Environ Sci Techno1 1988: 22:717-720. 13. Wright CG. Lcidy RB, Dupress HE: Chlorpynfos in the ambient air of houses treated for termites. Bull Environ Contam Toxicol 1988; 40561- 568. 14. Giilet JW. Ham JR, Linstrom lT,Mount DA. SI. Clair AD, Weber U: Evaluation of human health hawrds on use of dichlorvos (DDVP). especially in resin strips. Residue Rev 1972; 44:115-159. IS. Gillet JW. Han JR, St. Clair AD. Weber W :Comments on the di\tinction hctwccn hazards and ~nletyin evtiluationof human health h m r d s on use of dichlorvos, especiall) in rerin strips. Residue Rev 1972; 44:lhl-LtM. 16. Leary JS. Keane WT, Fontenof C.Feictmeir ES. Schultz D, Koox DA. Hirsch L. Lavor EM, Roan CC. Hine CH: Safety evaluation in the home of polyvinyl chloride resin strip containing dichlorvos (DDVP). Arch Environ Health 1974: 29:308-314. 17. Wright CG. Jackson MD:Propoxur. chlordane and diazinon on porcelain chinasaucersaflerkitchencabinet spraying. J Econ Entomol1971; 64:457. 18. Wright CG. Jackson M D Insecticide residues in non-target areas of rooms after two methods of crack and crevice application. Bull Environ Contam Toxicol 1975; 13:123. 19. Wright CG. Jackson MD Insecticide movement following application to crevices in rooms. Arch Environ Contam Toxicol 1976; 4:492. 20. Wright CG. Leidy RB: Chlorpyrifos residues in air after application to crevices in rooms. Bull Environ Contarn Toxicol 1978; 19:340. 21. Wright CG, Leidy RE, Dupree HE: Insecticides in the ambient air of rooms following their application for control of pests. Bull Environ Contam Toxicol 1981; 20548. 22. Wright CG. Leidy RB. Dupree HE: Chlorpyrifos and diazinon detection on surfacer in dormitory rooms. Bull Environ Contam Toxicol 1984; 32:259-264. 23. Hsu JP, Wheeler HG. Camann DE, Schattenbcrg HJ, Lewis RG, Bond AE: Analytical methods for detection of nonoccupational exposure to pesticides. J Chromatogr Sci 1988; 26:181-189. 24. Maddy KT, Lowe J. Saini N: Indoor air concentration of ethylene glycol monoethyl ether following application of propetamphos insecticide emul- sifiable concentrate. Report No. HS-1264. Sacramento, CA: Worker Health and Safety Unit, C.4 Departmenf of Food and Agriculture, 1985. INFANT EXPOSURE TO PESTICIDES IN HOMES 25. NaUzigcr DH.Sprcnkel RJ,Maiiler M P Indoor environmental monitoring of Dunban L.O. following broadcast application. In: Down IO Earth, No. 41. Midland, MI. Dow Chemical Company, 1985. 26. Maddy KT, Edmiston S. Fredrickson AS: Monitoring Residues of DDVP in room air and on an horizontal surface following use of a mom fogger. Rerotl No. HS-897. Sacramento, C A Worker Health and Safety Unit, CA Deparlmcnt of Food and Agriculture, 1981. 27. Maddy KT, Edrniston S, Ochi E: Dissipation of DDVP and propoxur followingthe releaseof an indoorfogger-a preliminarystudy. Report No. HS-1259. Sacramento, CA: Worker HealIh and Safety Unit, CA Department of Food and Agriculture. 1%. 28. KreigerR. Ross J. ThongsinthusakT. Fong H: Measuringpotentialdermal transfer of surface pesticide residue generated from indoor fogger use. Worker Health and Safety Branch Report. Sacramento, CA: California Department of Food and Agriculture, 1988. 29. Health and Welfare Canada: Guidelines for Indoor Occupant Exposum Assecsment following Pesticide Applications in Indoor Environments. Ottawa. Ontario: Pesticides Division, Department of Health and Welfare, 1989. 30. Occupational Safety and Health Administration: Sampling for surface contamination. In: Industrial Hygiene Technical Manual, Chapter VIII. US Department of Labor. Washington. DC: US Government Ptinting Office. 1984. 31. National Academy of Sciences: An assessment of health risks of seven pesticides used for terminatc control. National Research Council Committee on Toxicology. Washington. DC: National Academy hcss, 1982. 32. National Center for Health Stntistics: NCHS Growth Charts. MontMy Vital SI:ilistics Rcport. 233). Suppl (HRA) 76.1 120. Rockvillc, MD: Health Resources Administration, 1976. 33. US Environmental Protection Agency Owce of Health and Environmental Assessment: Development of statistical distributions or ranges of standard factors used in exposure assessments. Springfield,V A National Technical Information Service PB85-242667lAS. 1985. 34. Nolan RJ. Rick DL, Freshour NL, Saunders JH: Chlorpyrifos: pharmacokinetics in human volunteers. Toxicol Appl Pharmscol 1984; 738-15. 35. Fenske RA, Leffingwell JT, Spear RC: A video imaging technique for assessing dermal exposure-I. instrument design and te Assoc J 1986;47:764-770. 36. Fenske RA, Wong SM, Letlingwell JT. Spear RC: technique for assessing dermal exposure-11. fluorescent tracer testing. Am Ind Hyg Assoc J 1986; 47:771-775. 37. Feldmann RJ, Maibach HI: Percutaneous penetration of some pesticides and herbicides in man. Toxicol Appl Pharmacol 1974: 28:126-132. 38. Noonan PK. Wester R C Percuraneous absorption of nitroglycerin. J Pharm Sci 1980; 69365-366. 39. Wester RC, Maibach HI: In vivo percutaneous absorption. In: Manulli FN, Maibach HI (eds): Dcrmatotoxicology, Third Edition. Washington, D E Hemisphere, 1987. 40. Shah PV, Fisher HL, Sumler MR, Monroe RJ, Chernoff N, Hall L L Comparison of the penetration of 14 pesticides through the skin of young and adult rats. J Toxicol Environ Health 1987; 21:353-366. 41. FAOM'HO: 1972 evaluations of some pesticide residues in foods. WHO Pesbcide Residue Series No. 2. Geneva: World Health Organization. 1973. 42. US Environmental Protection Agency: Integrated risk information system data base (IRIS). Washington. DC. USEPA. 1988. I 1`Late Breaker' Session on Injury Control Invites Abstracts The Injury Control and Emergency Health Services special primary interest group ofthe American Public Health Association has announced it will again feature a "late breaker" session during the APHA upcoming 118th annual meeting in New York City. `The session will be held on Tuesday. October 2, $30 am-10:00 am, and will feature work completed within the last few months-after the deadline for consideration in the regular symposia of the APHA annual meeting. Abstracts of 250 words or less will be accepted by the Injury Control SPIG until August 15, 1990. Please send the abstract, title of the paper, authors' name, address and telephone number to: Richad Waxweiler, Division of Injury Control, Centers for Disease Control, Mail Stop F-36, Atlanta. GA 30333. Tel: 404/488-4695.