Document YDZqnEm7o9x4XMq3G2oDeVggk

f-)- JOURNALOF T@(lCOLOGY AND ENVIRONMENTAL HEAlTH Volume 18 Number 4 1986 CONTENTS i ! 503 REVIEW OF THE BlODlSTRlBUTlON AND TOXICITY OF THE INSECT REPEL- I LENT N,N-DIETHYL-m-TOLUAMINE (DEET) Philip ]. Robbins and Martin C. Cherri:*1ck 527 USE OF y-HEXACHLOROCYCLOHEXANE (LINDANE) TO DETERMINE THE ON- TOGENY OF METABOLISM IN THE DEVELOPING RAT M. E Copeland, R. W. Chadwick, N. Cooke, D. A. Whitehouse, and D. M. Hill 543 USE OF MULTIPARAMETER ANALYSIS TO QUANTITATE HEMATOLOGICAL DAMAGE FROM EXPOSURE TO A CHEMICAL (ETHYLENE OXIDE) D. M. Popp, R. A. Popp, S. Lock, R. C. Mann, and R. E. Hand, Jr. 567 BENZENE LEVELS IN AMBIENT AIR AND BREATH OF SMOKERS AND NON- SMOKERS IN URBAN AND PRISTINE ENVIRONMENTS Ronald C. Wester, Howard 1. Maibach, Larry 0. Gruenke, and John C. Craig 575 ACUTE HEPATOTOXICITY INDUCED BY HEPATOTOXINS IN S U N C U S MURlNUS Songchow tin, Hiroshi Saito, Takeshi Yohro, and Junji Shiga 589 EVALUATION OF CHICKEN EMBRYO, BRINE SHRIMP, AND BACTERIAL BIOASSAYS FOR SAXITOXIN Douglas L Park, lvette AguirreFlores, William F. Scott, and Ellen Alterrnan 595 EFFECTS OF ETHANOL ON METHYL MERCURY TOXICITY IN RATS Hidehiko Tamashiro, Mikio Arakaki, Hirokatsu Akagi, Kouji Murao, Kimiko Hirayama, and Michael H.Smolensky 607 CARCINOGENIC EFFECTS OF ANTIMONY TRIOXIDE AND ANTIMONY ORE CONCENTRATE IN RATS David H. Croth, Lloyd E. Stettler, JeAnne R. Burg, William M. Busey, George C. Grant, and Lawrence Wong The ]ournal of Toxicology and Environmental Health i s cited in Biology Digest, Biosciences Information Service, Cambridge Scientific Abstracts, Chemical Abstracts Service, Current Awareness in Biological Sciences, Environmental Periodicals Bibliography, Excerpta Medica. Index Medicus (USA), Institute for Scientific Information (ISI), Medline, and 0,icology Intormation Service (UK). Coverage is also provided by Environment Report. R O O L b 2 72837 1 BENZENE LEVELS IN AhlBIENT AIR A N D BREATH .OFSMOKERS A N D NONSMOKERS IN URBAN A N D PRISTINE ENVIRONhtENTS Ronald C.Wester, Howard I . Maibach, Larry D. Cruenke, JohnC. Craig Department of Dermatology, School of Medicine, and Department of Pharmaceutical Chemistry, School of Pharmacy, University of Caliiornia, San Francisco, California I Benzene levels in human breath and in ambient air were compared in the urban area I oi 5an flJnCfSc0 : 5 f ) dnd in 3 /,!ore emore codala/pristirie serting of Stinsorr Br.icr~. 1 C ~ l i f .ISB). Benzene ~ n ~ l y s\ivsas done by gas chromatognphy-ma>s spectro>copy (CC-MSJ. Ambient benzene levels \\ere sevenfold higher i n SF (2.6 z 7.3 ppb, n = i =25) than SB (0.38 0.39 ppb, n = 21). In SF, benzene in smokers' breath (6.8 f 3.0 I =ppb, \vas greater than in nonsmokers' breath (2.5 0.8 p p b ) and smokers' ambient I air (3.3 2 0.8 ppb). In SB the same pattern was observed: benzene in smokers' breath was higher than in nonsmokers' breath and ambient air. Benzene in SF nonsmokers' breath was greater than in SB nonsmokers' breath. hlarijuana-only smokers had ben- zene breath levels between those of smokers and nonsmokers. There was little correlafion between benzene in breath and number of cigarettes smoked, or wirh other benzene exposures such as diet. Of special interest was the finding that benzene in breath of SF nonsmokers (2.5 2 0.8 ppbJ was greater than that in nonsmokers am- bient air (7.4 f 0.1 ppb). The same was true in SB, where benzene in nonsmokers breath was greater than ambient air (7.8 2 0.2ppb versus 1.0 2 0.7 p p b on d 1 and 1.3 2 0.3 p p b versus 0.23 z 0.78 p p b on d 2). This suggests an additional source of benzene other than outdoor ambient air. INTRODUCTION -- - - Benzene is one of the most widely used chemicals, with an annual production of about 10 billion pounds (Lee et al., 1983). Concerns about the toxicity and carcinogenicity of benzene have led to continuing pressure to lower allowable occupational exposures (Snyder, 1974; Zenz, 1978; Brief et al., 1980). However, while the major risk of exposure is originally believed to be from the atmosphere in the tvorkplace, new concerns have also been raised about the possible health risk to the general population from atmospheric benzene pollution, thoughtto arise largely from automobile fuels and exhaust (Lonnerman et al., 1968; Pilar and Graydon, 1973). There is, however, little available Supported by a grant from the American Petroleum Institute. Requests for reprints should be sent to Ronald C. IVester. Department O( Dermatology. School of Medicine. and Department ofPharmaceutical Che:nistry. School of Pharmacy. University of California, San Francisco, California 91143. 567 lournil o f Toxicology .md Environmental Health. 18:567- r73. 1'186 i Copbright C 1986 by Hcmirphen. Publishing Corporation 568 ' R. C. WESTER ET AL. data on the relative importance of various routes of exposure for the nonoccupationally exposed individual. The objective was to determine background benzene concentrations in the breath of urban smokers and nonsmokers and to compare the levels found to those from subjects who live in a "pristine" environment (where atmospheric benzene levels are much less than those found in typical urban environments). METHODS Urban subiects were male volunteers age 18 and above, who were residents of the city of San Francisco and fromi whom informed consent had been obtained. Most of the subjects studied lived in the Mission District of San Francisco, an inland area somewhat sheltered from the flow of ocean air. Duplicate breath samples were obtained from 15 smokers and 15 nonsmokers on separate days at a clinic in the city. Each subject was required to fill out a questionnaire detailing his exposure during the previous 24 h and during the previous week to cigarette smoke, sol- vents (including gasoline), and dietary items known to be high in benzene. The room air at the clinic was also sampled continuously during the collection period on both study days for the determination of benzene levels in the inspired air. Smoking was not allowed in the clinic, and breath samples from smokers were generally obtained 45-85 min after the Iast cigarette smoked. Stinson Beach, California, wirs selected for the pristine environment. Subjects were selected for the pristine environment study from local residents. Breath samples were collected outdoors and were worked up on site within a few hours of collection in a mobile laboratory to avoid contamination of samples on storage in gas sample bags. Otherwise, the collection and analytical procedures used were the same as those used for the urban study. The environmental air was sampled repeatedly on both study days. Breath samples were collected by asking the subject to exhale normally into a 5-1 gas sample bag made of a plastic-metal laminate (Varian 00-996893-02) until the bag was full. The internal standard, 150 ng benzene-1,3,5-d3 (98% D, KOR Isotopes) in 25 p1 water, was injected into each bag. Bags were worked up the following day by withdrawing the sample through a silica trap (520/260 mg dual section, SKC Inc. 2 6 - 1 5 or equivalent). The upstream poftion of the trap was transferred to a 2-ml vial and water was added to desorb the benzene. Air samples were taken by drawing air directly through a silica trap using a battery-oper- ated pump. Both sections of the trap were saved in separate vials and the internal standard w a s added to each. Sample vials were heated to about 70'C, and headspace samples were taken for analysis by se- i I ! i B E N Z E N E IN S M O K E R S ' AND NONSMOKERS' BREATH iw is69 lected-ion-monitoring gas chromatography-mass spmztrometry-. Se- I lected-ion records were obtained with Tenax GC or ((,hemipack ( 3 8 I columns using an lnfotronics model 2468/2600 gas chromatograph cou- pled to a Kratos/AEI MS-12 mass spectrometer, which h a d been modi- I fied for selected-ion monitoring (Gruenke et al. 1980). Records were obtained at m/z 78 (M+of benzene) and at m/z 81 (M' of the internal Ii standard). Ion current ratios were compared to those irom calibration standards, and a number of quality control saniples were run on each day to assess the intluence of benzene contamination on the analytical I process. The limit of detection was 0.1 ppb (Gruenke et al., 1986). Sta- tistical analyses were done on an Apple computer asin9 ,':.NOVA and Stats Plus programs (Human Systems Dynamics). I 1 RESULTS Table 1 gives a summary of the atmospheric benzene levels. The I average for San Francisco was 2.6 5 1.3 ppb. The lowest levels were observed near the coast, and the highest levels were observed inland near sources of heavy auto traffic. Benzene in the air at Stinson Beach i was found to be significantly lower ( p < 0.001) than that found in the San Francisco Bay area (Table 1). This is probably not only due to the I lack of the usual urban sources of benzene pollution (such as heavy I automobile traffic) but also because of the climate, which is dominated by strong winds off the ocean, resulting in low benzene levels at the I -- lim-it of detection (0.1 ppb). On a day when there was ~ little wind, air - I TABLE 1. Summary of Atmospheric Benzene Levels San Francisco Average 2.6 1.3d ppb benzene in = ?5)J.c Range 0.8-5.2 ppb i Dates of measurement between Nov. 4 and Dec. 6, 1984, at i six different urban locations Stinson Beach I Day n' Atmospheric benzene (ppb) I lb 5 1.02 = 0.09 1 26 6 0.23 ? 0.18 36 0.13 t 0.11 1 44 0.16 2 0.12 Total 21 0.38 z 0.3gC I I i Number of samples, n. i Days when breath measurements were taken. i Significantly diiferent, p c: 0 001, between benzene in Sari Franci>coand Stinton Bedch. Standard deblation. I I 1 1 i I I ! ;-&--. ;,*3 r,. ..-rT. L ,." -e.- P ! '1 'I t -I t 1- J 8 5 i o R. C . WfSTER FT AL. TABLE 2. Benzene Concentrations in Breath of Sinokers and Nonsmokers a n d in Respective Ambient Air --- ! Environmental concentration IV' Benzene (ppbP '/ --. , Urban Smokers' breath 'I !i Smokers' ambient air I! Nonsmokers' breath IS 6.8 = 3.0 5 3.3 2 0.8 ='I 5 2.5 0.8 ii Nonsmokers' ambient air *4 1.4 c 0.7 Pristine td 1) Smokers' breath 8 12.1 =9.0 Nonsmokers' ;Ireath 6 1.8 = O . Z I Xiarijuana-only smokers' breath 3 2.5 2 1.3 Ambient air 3 1.1) = 0 . 1 Pristine (d 2) Sniokers' breath Nonsmokers' bredth Ambient air 6 4.8 = 2.: 3 1.3 z 0.3 6 0.13 2r :3.18 1N, Number of samples. b X\ean z standard deviation levels reached 1.0 ppb. Overall levels for the site averaged 0.38 c- 0.39 ppb, sevenfold less than the average for the urban site. Tables 2 summarizes the benzene levels in breath of smokers', non- smokers', and marijuana-only smokers' breath, and the respective am- bient air levels. Table 3 gives the statistical comparisons. This gives a TABLE 3. Statistical Comparison of Benzene Concentrations Environment -Comparison - -. A6 Statistic Urban Smokers' breath Smokers' breath Nonsmokers' breath >' Nonsmokers' breath > Ambient air > Ambient air p < 0.001b p = 0.0P p = 0.0? .. Pristine ( d 1) Smokers' breath > Nonsmokers' breath p = O.OP Smokers' breath > Ambient air p = 0.OP Nonsmokers' breath > Ambient dir p < 0.001~ Smokers' breath > Marijuana-only Nonsmokers' breath smokers' breath > Marijuana-onlv p = 0.13 (NS smokers' breath p = 0.18 (N5 kiarijuana-only smokers' breath 'Z Ambient air p = 0.03* Pristine ( d 2) Smokers' breath Smokers' breath , > Nonsmokers' breath > Ambient air Nonsmokers' breath ~- ~ > Ambient air >, Greater than: <, less than: >, not greater than. b Statisricallv significant difference. c Not statisticJlli ditterent (NS). p = 0.w p < O.OOlb p < 0 OOlb ~-~~ BENZENE IN SMOKERS' AND NONSX1OKERS' BREATH 5i 1 comparison of intake air (ambient) and exhaled air (breath) at a partic- ular time. In the urban environment, benzene levels in smokers and nonsmokers were higher than the respective ambient ail levels ( p = 0.021, and b e n z e n e levels in smokers' breath were ,llmo!jt threefold higher than in nonsmokers ( p < 0.001). The held true for t h e breath levels found in subjects from the pristine environment, where breath levels of benzene were again statistically higher in smokers than in nonsmokers and both were higher than b e n z e n e levels in ambient air. Marijuana-onlv smokers had benzene breath levels betsveen that of smokers 2nd nonsrnokrs. In addition to t h e t-test comparisons (Table 31, a separate analysis of variance of e n \ ironment (urban, pristine) versus b e n z e n e concentrations (smokers, nonsmokers, smokers' ambient air, nonsmokers' ambient air) was signifi,cmt for b e n z e c e concentrations ( F = 12.5, p < 0.001), and was significant for both benzene concentrations ( F = 23.1, p < 0.001) and environment (f = 14.2, p < 0.001) w h e n smokers were not included. This is because smokers had high benzene breath levels regardless of environment. There was n o statistical interaction of b e n z e n e and environment (Table 4). The data show that t h e concentration of b e n z e n e f o u n d in t h e breath of smokers is higher than that found in nonsmokers, a n d that the concentration for a smoker appears to be independent of environment. Smoking only marijuana adds benzene to the breath, just as with , TABLE 4. Analyses of Variance tor Environment and Benzene Design Environment Smokers Nonsmokers Benzene Smokers` air Urban Pristine X X X X X Y Results Source Degrees OI freedom Mean bquare I. Including smokers Environment Benzene Env x benzene Error II. Not including smokers Environment Benzene Env x benrene Error 1 3 3 76 1 1 1 35 5.4 167.0 17.7 13.1 52 8.5 0.01 0.3i NS. nonsi:-nir:c-anf. - -- Nonsmokers` air X X F P' 0.4 NS 12.8 co.001 1.3 "5 14.2 23.1 0.28 <0.001 <0.001 SS t `f $ , c;E `$. F-: 1-i "'. 572 R. C. WESTER ET AL. any amount of cigarette smoking. Urban smokers averaged 40 c 1 2 (SD) cigarettes per day; in t h e pristine study the average was 23.9 -c 8.4. There was little correlation between b e n z e n e in breath a n d number of cigarettes smoked ( r = 0.3 urban; 0.2 pristine). This may be d u e to differences in individual degree of smoker's inhalation, or to t h e interval allowed between smoking and taking the breath sample. DISCUSSION Although the prevailing flow of air from the ocean gives t h e San Francisco Bay area a unique climate. we found that atmospheric b 2nz e n e levels in t h e citv w e r e typicai ot thosz rcported !Brier e t al., 1980; Hapson, 1978) for other urban areas (1-10 ppb). The lowest levels w e r e observed near the coast, and the highest levels were observed inland near sources of heavy a u t o traffic. Atmospheric b e n z e n e may thus d e termine s o m e of the a m o u n t of b e n z e n e that gets into the body. This was consistent with o u r findings that benzene levels in breath of nonsmokers was higher in the urban environment than in t h e pristine environment. Benzene in t h e breath of nonsmokers for both urban a n d pristine environments was higher than the respective ambient air concentrations, suggesting an additional source of benzene exposure other than environmental air. O t h e r possible sources of benzene exposure include cigarette smoke, solvents (including gasoline), and diet (especially the n u m b e r of eggs eaten). The pharmacokinetics of b e n z e n e have been described as a three-compartment model (Sato et ai., 1974). It may b e that b e n z e n e is accumulated in the body in the h o m e or workplace, a n d t h e higher concentMtion s e e n is body elimination of this concentrated benzene. However, n o correlation could be f o u n d between breath levels a n d exposure to any of these sources as indicated o n t h e questionnaires filled o u t by each subject. Benzene in ind o o r air may b e an important source of exposure. However, i; is not known whether the magnitude of exposure to benzene from indoor air is sufficient to explain t h e elevation in breath levels w e have observed in o u r subjects. Thus, w e also suggest the possibility of an in vivo source of b e n z e n e production. REFERENCES Brief, R. S.,Lynch. I., Bernath, T., and Scala, R. A. 1980. Benzene in the workplace. Am. /nd. H y g . ASSOCI.. 411616-623. Cruenke, L. D., Bier, D. M., and C!aig, I. C. 1388 An improved selected ion recording system for precise ratio determination. Biomed. Mass Spectrom. 7:381-385. Gruenke, L. D.. Craig, I . C.. Wester, R. C., and hlaibach. H. 1. 1986. Quantitative analvsis of ben- zene by selected ion monitoring gas chromatography-mass spectrometry. 1. Anal. Tox~col., in press. --