Abstract  The tetrahydronaphthalene-benzoxazine glucocorticoid receptor (GR) partial agonist 4b was optimized to produce potent full agonists of GR. Aromatic ring substitution of the tetrahydronaphthalene leads to weak GR antagonists. Discovery of an "agonist trigger" substituent on the saturated ring of the tetrahydronaphthalene leads to increased potency and efficacious GR agonism. These compounds are efficacy selective in an NFkB GR agonist assay ( representing transrepression effects) over an MMTV GR agonist assay ( representing transactivation effects). 52 and 60 have NFkB pIC(50) = 8.92 (105%) and 8.69 (92%) and MMTV pEC(50) = 8.20 (47%) and 7.75 (39%), respectively. The impact of the trigger substituent on agonism is modeled within GR and discussed. 36, 52, and 60 have anti-inflammatory activity in a mouse model of inflammation after topical dosing with 52 and 60, having an effect similar to that of dexamethasone. The original lead was discovered by a manual agreement docking method, and automation of this method is also described.

Abstract  TLV Recommendation Exposure of animals to chlorinated naphthalenes has produced severe liverinjury and skin absorption has been suggested. In oral administration experiments with animals, octachloronaphthalene has caused hyperkeratosis; on the skin of human volunteers itwas entirely nonacneigenic. Sikes et al.(3> concluded from ingestion experiments in cattle that, for chlorinated naphthalenes, the greater the degree of chlorination, the more toxic the compound. Accordingly, by analogy with hexachloro naphthalene (TLV-TWA 0.2 mg/m3, skin), a TLV-TWA of 0.1 mg/m3 and a STEL of 0.3 mg/m3, with a skin notation, are recommended for octachloronaphthalene. These values should minimize the risk of liver injury and the potential for percutaneous absorption and skin toxic ity. Deletion of the STEL is being considered by the TLV Committee.

Abstract  Fish have been taken from the main major rivers in Carinthia and their muscles examined for their contents of about 50 different volatile hydrocarbons. The analyses have allowed the establishment of an ecological survey with respect to those components.

Abstract  Naphthazarin (5,8-dihydroxy-1,4-naphthoquinone; Naph) is proposed as a chromogenic reagent for the spectrophotometric determination of copper(II). The polynuclear complex has a mole ratio of Cu:Naph=4:6 in a 50% v/v ethanol/water medium containing 0.1 M ammonium acetate and 1.5% (w/v) sodium dodecyl sulfate. The copper-naphthazarin complex shows an absorption maximum at 330 nm with a molar absorptivity of 1.84x10(4) l mol(-1) cm(-1). Beer's law is obeyed up to 4.5 ppm of copper(II). The method was applied for copper determination in alloy samples with satisfactory results.

Abstract  In a population-based case-referent study, the occupational experience of 86 men with oral or oropharyngeal cancer and 373 referents was analyzed with respect to employment in 41 occupations and 40 industries, as well as to exposure to 16 chemicals, as estimated via a job-exposure matrix. Among the occupations and industries at higher risk were machinery operator (odds ratio [OR] 2.0; 95% confidence interval [95% CI] 1.0-4.0), plumber (OR 5.0, 95% CI 1.2-21.5), building industry (OR 2.5; 95% CI 1.3-4.5), textile industry (OR 2.5; 95% CI 0.6-4.6), and electricity production (OR 2.8; 95% CI 0.7-12.1). All the OR estimates were adjusted for age, education, area of birth, tobacco smoking, and alcohol consumption. An association between formaldehyde exposure and oral cancer was suggested (OR for any exposure 1.6, 95% CI 0.9-2.8; OR for probable or definite exposure 1.8, 95% CI 0.6-5.5). No other chemical included in the matrix showed any risk pattern. The evidence of an association between formaldehyde exposure and oral or oropharyngeal cancer is strengthened by the results of this study.

Abstract  Bis-selenides (LL), such as 8-[MeSe(X)]-1-[MeSe(Z)]C10H6 (1 (LL)), 8-[EtSe(X)]-1-[EtSe(Z)]C10H6 (2(LL)), 8-[p-YC6H4Se(X)]-1-[MeSe(Z)] C10H6 (3(LL)) and 8-[p-YC6H4Se(X)]-1-[p-YC6H4Se(Z)]C10H6 (4(LL)) were oxidized with ozone at 0 degrees C, where (X, Z) = (lone pair, lone pair) for LL. Bis-selenoxides, 1(OO), 3(OO) and 4(OO) where (X, Z) = (oxygen, oxygen), were obtained in the oxidation of 1(LL), 3(LL) and 4(LL), respectively, via corresponding selenide-selenoxides, 1(LO), 3(LO) and 4(LO), respectively. A facile Se-C bond cleavage was observed in 2 (LL). The structures of 1(LO) and 1 (OO) were determined by the X-ray analysis. Three Se center dot center dot center dot Se=O atoms in 1(LO) and four O=Se center dot center dot center dot Se=O atoms in 1(OO) align linearly. While the non-covalent Se center dot center dot center dot Se=O 3c-4e interaction operates to stabilize 1(LO), the non-covalent O=Se center dot center dot center dot Se=O 4c-4e interaction would not stabilize 1(OO). The 3c-4e interaction must play an important role to control the stereochemistry of selenoxides. The 8-G-1-[MeSe(OH) 2]C10H6 (n(OH center dot OH)) are the key intermediates in the racemization of 8-G-1-[MeSe(O)]C10H6 (n(O)) in solutions, where G = SeMe (1), H (5), F (6), Cl (7) and Br (8). Energies of n(OH center dot OH), relative to n(O), are evaluated based on the theoretical calculations. G of SeMe is demonstrated to operate most effectively to protect from racemization of selenoxides among n = 1 and 5-8, since the relative energies for G of cis- and trans-SeMe are largest.

Abstract  The mass transfer of naphthalene vapor to water droplets in air was studied in the presence of ozone (O3) in the gas phase. A falling droplet reactor with water droplets of diameters 55, 91, and 182 µm was used for the study. O3 reacted with naphthalene at the air--water interface, thereby decreasing the mass transfer resistance and increasing the rate of uptake of naphthalene into the droplet. A Langmuir-Hinshelwood reaction mechanism at the air--water interface satisfactorily described the surface reaction. The first-order surface reaction rate constant, ks, increased with decreasing droplet size. Three organic intermediates were identified in the aqueous phase as a result of ozonation of naphthalene at the surface of the droplet indicating both peroxidic and nonperoxidic routes for ozonation. The presence of an organic carbon surrogate (fulvic acid) increased both the partition constant of naphthalene and the surface reaction rate of O3. The heterogeneous oxidation of naphthalene by O3 on the droplet was 15 times faster than the homogeneous oxidation by O3 in the bulk air phase, whereas it was only 0.08 times the homogeneous gas-phase oxidation by hydroxyl radicals under atmospheric conditions. [ABSTRACT FROM AUTHOR] Copyright of Journal of the Air & Waste Management Association (1995) is the property of Air & Waste Management Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract  Sulfonated aromatic pollutants such as Armstrong’s acid, or 1,5-naphthalenedisulfonic acid (NDS), are recalcitrant to environmental breakdown and microbial treatment. This study investigated the effects of H2O2 concentration, pH, microwave (MW) power and irradiation time on the oxidative degradation of NDS in aqueous solutions. The formation of hydroxyl radicals as the active oxidant was confirmed by electron paramagnetic resonance spin trapping. A combination of both H2O2 and MW heating proved essential for NDS degradation. Degradation factors of f ⩾70% were obtained after about 20min of irradiation at [H2O2]:[NDS] ratios=10. Acidic conditions were found to be more favorable to the degradation of NDS, and the process follows pseudo-first-order kinetics. Attempts to scale-up the process using a conventional MW reactor provided less striking results. [Copyright 2009 Elsevier] Copyright of Chemosphere is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)

Abstract  Electrokinetic soil remediation has been proven to remove heavy metals and polar organics from low hydraulic conductivity subsurface environment. In this study, carboxymethyl-beta-cyclodextrin (CMCD) was used as a carrier to assist electrokinetic treatment for removal of low polarity organic contaminants from soils (2.2% organic carbon content). Naphthalene and 2,4-dinitrotoluene (2,4-DNT) were selected as the test compounds. The results from columns experiments showed that 46 and 43% of naphthalene and 2,4-DNT, respectively, were removed using 0.01 N NaNO(3) flushing solution with 40 V electrical potential while 70 and 72% of naphthalene and 2,4-DNT were removed using 2 g/L CMCD solution. Naphthalene and 2,4-DNT removal was enhanced to 83 and 89%, respectively, by using 2 g/L CMCD with 40 V electrical potential. Findings from this study also demonstrated that cyclodextrin assisted electrokinetics can enhance the removal rate of naphthalene and 2,4-DNT. Electric potential applied has more influence on the contaminant removal than the amount of CMCD used. Higher voltage application caused increase in the removal rate of naphthalene and 2,4-DNT, and appeared to be one of the critical factors in obtaining higher contaminant removal while increasing CMCD solution concentration above 2 g/L appeared to have little effect on the contaminant removal.

Abstract  The pathways for 2,4-dinitrotoluene (2,4-DNT) and nitrobenzene offer fine illustrations of how the ability to assimilate new carbon sources evolves in bacteria. Studies of the degradation pathways provide insight about two principal strategies for overcoming the metabolic block imposed by nitro- substituents on aromatic compounds. The 2,4-DNT pathway uses novel oxygenases for oxidative denitration and subsequent ring-fission. The nitrobenzene pathway links facile reduction of the nitro- substituent, a novel mutase enzyme, and a conserved operon encoding aminophenol degradation for mineralization of nitrobenzene. Molecular genetic analysis with comparative biochemistry reveals how the pathways were assembled in response to the recent appearance of the two synthetic chemicals in the biosphere.

Abstract  This work reports a genetic analysis of the expression of nitrobenzene dioxygenase (NBDO) in Comamonas sp. strain JS765 and 2-nitrotoluene dioxygenase (2NTDO) in Acidovorax sp. strain JS42. Strains JS765 and JS42 possess identical LysR-type regulatory proteins, NbzR and NtdR, respectively. NbzR/NtdR is homologous to NahR, the positive salicylate-responsive transcriptional activator of the naphthalene degradation genes in Pseudomonas putida G7. The genes encoding NBDO and 2NTDO in each strain are cotranscribed, and transcription starts at the same site within identical promoter regions for each operon. Results from a lacZ reporter gene fusion demonstrated that expression of NBDO and 2NTDO is induced by multiple aromatic compounds, including an array of nitroaromatic compounds (nitrobenzene, 2-, 3-, and 4-nitrotoluene, 2,4- and 2,6-dinitrotoluene, and aminodinitrotoluenes), as well as salicylate and anthranilate. The nitroaromatic compounds appear to be the actual effector molecules. Analysis of beta-galactosidase and 2NTDO activities with strain JS42 demonstrated that NtdR was required for induction by all of the inducing compounds, high basal-level expression of 2NTDO, and complementation of a JS42 ntdR null mutant. Complementation with the closely related regulators NagR (from Ralstonia sp. strain U2) and NahR restored only induction by the archetype inducers, salicylate or salicylate and anthranilate, respectively, and did not restore the high basal level of expression of 2NTDO. The mechanism of 2NTDO gene regulation in JS42, and presumably that of NBDO gene regulation in JS765, appear similar to that of NahR-regulated genes in Pseudomonas putida G7. However, NbzR and NtdR appear to have evolved a broader specificity in JS42 and JS765, allowing for recognition of nitroaromatic compounds while retaining the ability to respond to salicylate and anthranilate. NtdR is also the first example of a nitroarene-responsive LysR-type transcriptional activator.

Abstract  Aminonitrotoluenes form rapidly from the reduction of dinitrotoluenes (DNTs) which are priority pollutants and animal carcinogens. For example, 4-amino-2-nitrotoluene (4A2NT) and 2A4NT accumulate from the reduction of 2,4-DNT during its aerobic biodegradation. Here, we show that 2,4-DNT dioxygenase (DDO) from Burkholderia sp. strain DNT oxidizes the aminonitrotoluenes 2A3NT, 2A6NT, 4A3NT, and 5A2NT to 2-amino-3-nitrobenzylalcohol, 2-amino-4-nitro-m-cresol and 3-amino-5-nitro-p-cresol, 4-amino-3-nitrobenzylalcohol and aminonitrocresol, and 2-amino-5-nitro-o-cresol, respectively. 2A5NT and 3A4NT are oxidized to aminonitrocresols and/or aminonitrobenzylalcohols, and 4A2NT is oxidized to aminonitrocresol. Only 2A4NT, a reduced compound derived from 2,4-DNT, was not oxidized by DDO or its three variants. The alpha subunit mutation I204Y resulted in two to fourfold faster oxidization of the aminonitrotoluenes. Though these enzymes are dioxygenases, they acted like monooxygenases by adding a single hydroxyl group, which did not result in the release of nitrite.

Abstract  Abstract: Three homochiral metal–organic frameworks (MOFs) based on enantiopure chiral ligand: (R)-2,2’-dimethoxy-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-3,3′-dicarboxylic acid (H2L), namely Cd(L)(Py)3 1, Cu(L)(Py)3 2, Na[Cd(L)(LH)]·2.5H2O 3 (Py=pyridine), were firstly synthesized, under solvothermal reactions. X-ray single-crystal diffraction studies reveal that 1 and 2 adopt one-dimensional (1D) infinite helical structures, while 3 possesses 2D chiral framework structure adopting ABAB offset stacking modes along the a-axis. Thermogravimetric analyses (TGA) display that 3 is thermally stable to 330°C which is rare for homochiral MOFs. [Copyright 2008 Elsevier] Copyright of Inorganic Chemistry Communications is the property of Elsevier Science Publishing Company, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)

Abstract  Samples of mother's milk were collected from Bayonne, NJ; Jersey City, NJ; Pittsburgh, PA; Baton Rouge, LA; and Charleston, WV, and analyzed for volatile (purgeables) and semivolatile (extractable) organics using glass capillary gas chromatography/mass spectrometry/computer. In the volatile fraction, 26 halogenated hydrocarbons, 17 aldehydes, 20 ketones, 11 alcohols, 2 acids, 3 ethers, 1 epoxide, 14 furans, 26 other oxygenated compounds, 4 sulfur-containing compounds, 7 nitrogen-containing compounds, 13 alkanes, 12 alkenes, 7 alkynes, 11 cyclic hydrocarbons, and 15 aromatics were found, including major peaks for hexanal, limonene, dichlorobenzene, and some esters. The levels of dichlorobenzene appeared to be significantly higher in the samples from Jersey City and Bayonne than in samples from other sites. Jersey City samples also appeared to have significantly higher levels of tetrachloroethylene. Charleston and Jersey City samples appeared to have significantly higher levels of chloroform; however, chloroform was observed in the blanks at about 20% of that in the samples. Due to the small sample size and lack of control over the solicitation of sample donors, the data cannot be used to extrapolate to the general population. Fewer semivolatile compounds of interest were found. Polychlorinated naphthalenes, polybrominated biphenyls, chlorinated phenols, and other compounds were specifically sought and not detected (limit of detection about 20-100 ng/mL milk). Polychlorinated biphenyls (PCBs) and DDE were found.

Abstract  A diffusion limited physiologically based pharmacokinetic model for rats and mice was developed to characterize the absorption, distribution, metabolism, and elimination of naphthalene after inhalation exposure. This model includes compartments for arterial and venous blood, lung, liver, kidney, fat, and other organs. Primary sites for naphthalene metabolism to naphthalene oxide are the lung and the liver. The data used to create this model were generated from National Toxicology Program inhalation and iv studies on naphthalene and consisted of blood time-course data of the parent compound in both rats and mice. To examine the basis for possible interspecies differences in response to naphthalene, the model was extended to describe the distribution and metabolism of naphthalene oxide and the depletion and resynthesis of glutathione. After testing several alternative models, the one presented in this paper shows the best fit to the data with the fewest assumptions possible. The model indicates that tissue dosimetry of the parent compound alone does not explain why this chemical was carcinogenic to the female mouse lung but not to the rat lung. The species difference may be due to a combination of higher levels of naphthalene oxide in the mouse lung and a greater susceptibility of the mouse lung to epoxide-induced carcinogenesis. However, conclusions regarding which metabolite(s) may be responsible for the lung toxicity could not be reached.

Abstract  Chlorobenzenes having 1-6 chlorine substituents are the dominant products of combustion of a chlorine-containing polymer (Saran plastic wrap). The effects of high-sulfur Illinois coals, designated IBC-102 (high in inorganic pyrite S and low in organic S), and IBC-108 (high in organic S and low in inorganic content), pyrite (the predominant form of inorganic sulfur in coals), and unbleached paper, a polymeric precursor common in municipal solid waste (MSW) on the formation of the mono- through trichlorinated benzenes, the most abundant of these chlorobenzenes, were investigated. At 500ˆC the addition of IBC- 108 in a 30:1 weight ratio to the Saran was shown to diminish the production of the chlorinated benzenes the most (77%). Co-combustion with paper was not effective in reducing the organochlorine species, but rather enhanced their production.

Abstract  The application of sewage sludges to agricultural land may increase the concentrations of many toxic organic chemicals in soils which could have adverse effects on wildlife and human health if these compounds enter foodchains. Chlorobenzenes (CBs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and furans (PCDDs) are amongst those compounds currently receiving most attention. The 'form' in which these, and other organic chemicals, are present in soils and their potential to be lost by various processes including leaching, volatilisation and (bio)degradation is shown to be dependent on the physicochemical characteristics of the soil and sewage sludge, environmental conditions and the properties of the chemicals themselves. The distinction is made between those compounds that are labile, reversibly sorbed and irreversibly sorbed by sewage sludge-amended soils.

Abstract  A bacterial bioassay, suitable for rapid screening to assess the relative toxicity of xenobiotic contaminated groundwater has been developed. The quantitative bioassay utilizes a decline in luminescence of the lux marked soil bacterium Pseudomonas fluorescens on exposure to contaminated groundwaters from which effective concentration (EC) values can be assessed and compared. P. fluorescens was most sensitive to semivolatile organics in groundwaters but there was no correlation between EC value and chemical content. The sensitivity and reproducibility of the P. fluorescens bioassay was compared with that of Microtox and results showed that mean EC50 values for diluted ground water replicate samples were 20% and 18% respectively. This suggested that the P. fluorescens bioassay was as applicable to groundwater screening as the widely used Microtox bioassay.

Abstract  The occurrence of organic priority pollutants originating from leachate at a landfill adjacent to wetlands in Orange County, Florida was studied and compared to a prior one-year study. Volatile organic compounds were detected in groundwater at total concentrations of less than 150 μg/L. Few base/neutral and acid extractable compounds were detected in surface water and groundwater. Both studies suggested that organic priority pollutants present in the solid waste were likely metabolized by microorganisms or degraded, sorbed on particulate matter, or diluted to non-detectable levels.

Abstract  The kinetics of bio-oxidation by a microbial ensemble of a model mixture of contaminants that mimicked the ground-water pollution plume at an existing contaminated site was investigated. Phenol at 50 mg/l and a mixture of ten organic contaminants (MOC) (benzene, tetrachloromethane, trichloroethylene, toluene, o-xylene, 1,4-dichlorobenzene, o-cresol, nitrobenzene, naphthalene and 2,6-dichlorophenol) at individual concentrations ranging from 150 mug/l to 600 mug/l were the components of the model mixture. The microbial ensemble consisted of at least three Pseudomonas spp. isolated from the polluted site. Patterns of oxygen uptake rate (OUR) for the oxidation of phenol alone and with added MOC were treated mathematically. The values for kinetic parameters that gave the best fit to the data were respectively 11.29 and 15.03 ml O2 h-1 (mg protein)-1 for the OUR maximum (OURmax), 75.89 mg/l and 33.66 mg/l for the saturation constant (Ks), 105.92 mg/l and 36.44 mg/l for the i

Abstract  Results of C-6-C-12 hydrocarbon measurements at three sites in the southern part of The Netherlands, a polluted region in Western Europe, are presented. The measurements were carried out over the period March 1991-February 1997. The concentrations at the sites, with 100-150 km distance between them, are quite similar and they are predominantly determined by large-scale transport. The concentrations in this part of the country are substantially higher than those observed at a coastal site in the north of The Netherlands, but much lower compared to the concentrations in cities and near streets. A distinct difference between the trends of aromatics and aliphatics was observed. The concentrations of the aromatic components display trends that are systematically 4-5% yr(-1) lower than the trends of the aliphatics, which is possibly related to the increased use of catalysts in cars and, partly, to an enhanced atmospheric chemical activity. For the chlorinated species the trends are highly significant. The trend of 1,1,1-trichloroethane is in the order of 8-12% yr(-1) downward while for tetrachloromethane an annual downward trend of 4-6% is found. These downward trends suggest that measures have been taken to fulfil the requirements of the Montreal Protocol to ban the production of these species in a few years time from now. (C) 1999 Elsevier Science Ltd. All rights reserved.

Abstract  Biosis copyright: biol abs. rrm review groundwater pollution soil pollution water pollution control drinking water analysis hazardous waste humic acids polychlorinated biphenyls pesticide contamination

Abstract  Ozonation by‐products were analyzed for two surface water sources in Southern California—Los Angeles Aqueduct Water (LAAW) and State Project Water (SPW). Included are data obtained when LAAW was being treated at the Los Angeles Aqueduct Filtration Plant and similar data obtained during a two‐day experiment in which the plant was treating SPW. Some batch‐scale ozonation studies are also reported. Ozonation by‐products were monitored using three methods: closed‐loop stripping analysis, nonionic resin accumulation, and a direct aqueous derivatization method for low‐molecular‐weight aldehydes, each followed by gas chromatography–mass spectrometry analysis of the extracts. The major neutral by‐products appear to be aliphatic aldehydes, but the levels are unexpectedly low in SPW compared with LAAW treated under similar conditions. Low levels of several other compounds were found in ozonated water, including bromoform and some compounds tentatively identified as ketones.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. The kinetics of organics purging in the purge-and-trap gas chromatography/mass spectrometry technique for the concentraton of volatile compounds in water using primary fragment ions in modified method 524.2 is revealed to be first order with respect to purging time. This kinetic model is applicable from a concentration of 200 ppb for ketones and nitrogen compounds to the sub-ppb levels for more readily purgeable volatile compounds. The purging ratios of the compounds, as well as their first-order purging rate constants, are obtained. The rate constant can be used as an alternative guide to gas chromatographic retention time for the selection of internal standards for quantitation purposes and/or replacement of surrogates for performance and quality assurance.

Abstract  Human and environmental exposures to toxic substances may be evaluated by direct measurement (i.e., monitoring data), or by using surrogate measures (i.e., release data). The usefulness of surrogate measures is dependant upon their reliability as indicators of actual human exposure. The release of toxic substances into the environment may result in human and environmental exposures. Therefore, the recent creation of the Toxic Release Inventory (TRI) data base may provide suitable surrogate measures of regional human and environmental exposure. However, the reliability of these data as indicators of regional exposure has not been adequately tested. Previous studies using existing national monitoring data from the National Human Adipose Tissue Survey (NHATS) and the Environmental Protection Agency (EPA) STORET data base have demonstrated that regional differences in human and environmental exposures exist (Phillips and Birchard 1991a, 1991b). Regional correlations between NHATS and STORET data have a/so been observed (Phillips, 1991 ). In this study, regional relationships between the quantity of toxic substances released into the environment, and the magnitude of human and environmental exposures were evaluated using TRI data in conjunction with NHATS and STORET data. The results of this study provide: 1) a comprehensive assessment of regional correlations between the amount of toxics released via various emission pathways, and the levels of human exposure and environmental contamination; and 2) an evaluation of the reliability of toxic release data for predicting exposures.