Journal of Toxicology & Environmental Health Part A: Current Issues

Fidan, Fatma; Guven, Hulya; Eminoglu, Ozlem; Kalkan, Sule; Ergor, Gul; Cimrin, Arif

doi: 10.1080/15287390590956489pmid: 16009651

This study was undertaken to investigate the extent of environmental tobacco smoke (ETS) exposure in coffeehouses, as these are commonly frequented public places in Turkey. From 86 coffeehouses in the 3 districts, 59 coffeehouse workers and 35 hospital staff members (as a control group) were evaluated. Participants answered a questionnaire about demographics, working characteristics, smoking behavior, and ETS exposure during their daily life lives. The amount of nicotine in hair was determined by using gas chromatography/mass spectrometry (GC/MS). The mean hair nicotine level of the nonsmoker and smoker coffeehouse workers were 23.2 ± 12.3 µg/g and 62.5 ± 49.8 µg/g, respectively. Among the hospital staff, mean hair nicotine levels were 4.5 ± 6 µg/g in nonsmokers and 30.6 ± 14 µg/g in smokers. Working in coffeehouses has a marked effect on hair nicotine levels and potential adverse health effects. The project was funded by Dokuz Eylul University, Research Fund grant 0909 99 02 09, awarded to Prof. Arif Cimrin, MD. The authors thank Peyton Jacob III for the internal standard (nicotine-d4) and pharmacist Ayse Sezgin for technical support.

Jung Koo, Hyun; Mu Lee, Byung

doi: 10.1080/15287390590956506pmid: 16009652

Some phthalates, such as di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP), and their metabolites are suspected of producing teratogenic and endocrino-disrupting effects. In this study, urinary levels of phthalates (DEHP, DBP, diethyl phthalate (DEP), butylbenzyl phthalate BBP), and monoethylhexyl phthalate (MEHP, a major metabolite of DEHP) were measured by high performance liquid chromatography (HPLC) in human populations (women [hospital visitors], n = 150, and children, n = 150). Daily exposure level of DEHP in children was estimated to be 12.4 µg/kg body weight/d (male 9.9 µg/kg body weight/d, female 17.8 µg/kg body weight/d), but, in women was estimated to be 41.7 µg/kg body weight/d, which exceeded the tolerable daily intake (TDI, 37 µg/kg body weight/day) level established by the European Union (EU) Scientific Committee for Toxicity, Ecotoxicity, and the Environment (SCTEE) based on reproductive toxicity. Based on these data, hazard indices (HIs) were calculated to be 1.12 (41.7/37 TDI) for women and 0.33 (12.4/37 TDI) for children, respectively. These data suggest that Koreans (women and children) were exposed to significant levels of phthalates, which should be reduced to as low a level as technologically feasible to protect Koreans from the exposure to toxic phthalates.

Emond, Claude; Charbonneau, Michel; Krishnan, Kannan

doi: 10.1080/15287390590956551pmid: 16009653

This study aimed to develop a physiologically based model for simulating the concentrations of polychlorinated biphenyls (PCBs) in tissue and plasma lipids of rats exposed to PCB mixtures. The model was based on the assumption that the neutral lipid fraction is the only critical determinant of the tissue distribution of PCBs, and that the solubility/retention in other tissue components is negligible. The volumes of the model compartments reflected the volumes of neutral lipids, whereas the flow rates corresponded to those of the neutral lipids in blood. Since the equilibrium ratio of PCB concentrations in neutral lipids of tissues and plasma equals 1, the present modeling approach does not require the use of tissue:blood partition coefficients. Metabolism rates were derived from the best visual fit of the model to the PCB concentrations in hepatic lipids determined on d 41 and 90 in rats exposed to a mixture containing 5, 50, or 500 μg PCBs (118, 138, 153, 170, 180 and 187) per kilogram body weight according to various protocols: (a) every-day dosing, (b) once-a-week dosing, (c) consecutive dosing for 13 d with no further treatment, and (d) 13 irregularly spaced doses. The resulting model consistently simulated the concentrations of PCBs in adipose tissue and plasma lipids of rats exposed according to the four described protocols. The physiologically based pharmacokinetic (PBPK) model developed in this study should be useful as a basis for interpretating blood or plasma lipid concentration data on PCBs collected during biomonitoring studies.

Stamler, Christopher J.; Basu, Niladri; Man Chan, Hing

doi: 10.1080/15287390590956560pmid: 16009654

Disruption of neurochemical parameters in blood and brain tissues can be used as early biomarkers of neurotoxicity in human and wildlife epidemiological studies. To investigate the feasibility of biomarker measurements in field samples obtained from remote locations, tissue storage limits were determined with human blood and mink cortex tissue using efficient and cost-effective microplate assays. Results show that isolated blood platelets and plasma can be stored at 4°C for 4 wk before measurement of monoamine oxidase (MAO) and cholinesterase (ChE) activities, while human lymphocytes can be stored at 4°C for up to 2 d before muscarinic acetylcholine (mACh) receptor binding analysis. Blood cells stored frozen resulted in decreased MAO activity and mACh receptor function. These data suggest that mink brain tissue obtained from field samples can be stored at various temperatures without affecting dopamine (D2) and mACh receptor densities; however, MAO and ChE activities were most stable in samples stored in a −20°C domestic freezer or at 4°C. Multiple freeze/thaw cycles alter mACh and D2 receptors and MAO activity in mink cortex samples and should therefore be minimized. In conclusion, these neurochemical biomarkers can efficiently be measured in large human and wildlife neurotoxicity studies, provided proper storage conditions are maintained. This study was financially supported by the Collaborative Mercury Research Network (COMERN) and the Natural Science and Engineering Research Council (NSERC) of Canada. C. J. Stamler and N. Basu are both recipients of NSERC postgraduate fellowships. We also thank Mary Gamberg (Gamberg Consulting, Whitehorse, Yukon Territory) and Dr. Steven J. Bursian (Michigan State University, East Lansing) for kind donation of mink tissues. Assistance by Donna Leggee, Leah Tivoli, Kovana M. Loua, and Stephanie Bailey is greatly appreciated.

Kuno, Nayumi; Mizutani, Takaharu

doi: 10.1080/15287390590956588pmid: 16009655

Synthetic or natural food dyes are typical xenobiotics, as are drugs and pollutants. After ingestion, part of these dyes may be absorbed and metabolized by phase I and II drug-metabolizing enzymes and excreted by transporters of phase III enzymes. However, there is little information regarding the metabolism of these dyes. It was investigated whether these dyes are substrates for CYP2A6 and UDP-glucuronosyltransferase (UGT). The in vitro inhibition of drug-metabolizing enzymes by these dyes was also examined. The synthetic food dyes studied were amaranth (food red no. 2), erythrosine B (food red no. 3), allura red (food red no. 40), new coccine (food red no. 102), acid red (food red no. 106), tartrazine (food Yellow no. 4), sunset yellow FCF (food yellow no. 5), brilliant blue FCF (food blue no. 1), and indigo carmine (food blue no. 2). The natural additive dyes studied were extracts from purple sweet potato, purple corn, cochineal, monascus, grape skin, elderberry, red beet, gardenia, and curthamus. Data confirmed that these dyes were not substrates for CYP2A6, UGT1A6, and UGT2B7. Only indigo carmine inhibited CYP2A6 in a noncompetitive manner, while erythrosine B inhibited UGT1A6 (glucuronidation of p-nitrophenol) and UGT2B7 (glucuronidation of androsterone). In the natural additive dyes just listed, only monascus inhibited UGT1A6 and UGT2B7. This work was supported in part by a grant (to Mizutani) from the Japan Food Chemical Research Foundation.