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PubMedDate not supplied

Development of a flow-injection fluorescence method for estimation of total polycyclic aromatic compounds in asphalt fumes.

Traditionally, measurements of specific polycyclic aromatic compounds (PACs) have been attempted as an estimate of asphalt fume exposure. However, asphalt fumes contain numerous alkyl substituted PACs, including PACs containing heteroatoms of nitrogen, oxygen, and sulfur. Many of these compounds coelute precluding the resolution of the individual compounds resulting in ambiguous data. Moreover, many researchers believe that some observed health hazards are associated with PACs overall and not just a few select PACs. Therefore, NIOSH method 5800 was developed to evaluate total PACs as a chemical class in asphalt fumes. Asphalt fume samples were collected on a poly(tetrafluoroethylene) filter backed by an XAD-2 sorbent tube. The samples were extracted with hexane; then, a cyano-solid-phase-extraction column was used to remove the polar compounds while the aliphatic and aromatic compounds were eluted with hexane. An equal volume of dimethyl sulfoxide (DMSO) was added to the hexane extract, causing the aromatic compounds to partition into the DMSO, thus isolating the PACs. The PACs were then analyzed for fluorescence using a flow-injection method with two fluorescence detectors. Wavelength settings for the first detector (254-nm excitation, 370-nm emission) emphasized the 2- to 4-ring PACs that may cause eye and respiratory tract irritation. Wavelength settings of the second detector (254-nm excitation, 400-nm emission) emphasized the 4- and higher-ring PACs that are often mutagenic and possibly carcinogenic.

Air Pollutants, Occupational↗
PubMed1990

Evaluation of the carcinogenic potency of 4 environmental polycyclic aromatic compounds following intrapulmonary application in rats.

The carcinogenic potential of 4 highly purified polycyclic aromatic compounds (PAC) was studied in the respiratory tract of rats. Using a beeswax/trioctanoin mixture as vehicle, 10, 3 and 1 mg phenanthrene (PHE), 3 and 1 mg chrysene (CHR), 0.1 mg dibenz(a,h)anthracene (DBahA) and 6, 3 and 1 mg benzo(b)naphto(2,1-d)thiophene (BNT) were injected into the lungs of 35 female Osborne-Mendel rats per group. Benzo(a)pyrene (BaP, 0.3, 0.1 and 0.03 mg) was used as the reference substance. Whereas only one squamous cell carcinoma developed at the highest PHE dose, a dose-dependent tumor incidence was found for CHR. BNT showed a carcinogenic effect similar to CHR, but an increasing incidence of neoplasms was not seen between the median and high dose. DBahA induced carcinomas in even more than half of the animals at the dose level of 0.1 mg and, therefore, has to be classified as the most potent PAC under investigation. BaP resulted in a clear dose-response relationship. According to probit analysis of the results, the carcinogenic potencies of the PAC relative to BaP (1.00) rank as follows: DBahA, 1.91; CHR, 0.03; BNT, 0.02; and PHE, 0.001. The estimated ED10- values were 0.031 mg for BaP, 0.016 mg for DBahA, 1.02 mg for CHR, 1.65 mg for BNT and 22.84 mg for PHE.

Animals↗
PubMed2001

Microwave-assisted extraction of polycyclic aromatic compounds from coal.

Microwave-assisted extraction (MAE) of polycyclic aromatic compounds (PACs) from coal is shown to give the same pattern of compounds as Soxhlet extraction. MAE requires only 10 mL solvent and 10 min extraction time whereas Soxhlet uses 200 mL and takes 24 h. Although the yields were lower, dichloromethane (DCM) was preferred to pyridine, N-methyl-2-pyrrolidone (NMP), and NMP with CS2 because the pattern of the PACs is shown to be independent of solvent and DCM is a much more convenient solvent to work with.

Chromatography, Gas↗
PubMed2003

A critical evaluation of DNA adducts as biological markers for human exposure to polycyclic aromatic compounds.

The causative role of polycyclic aromatic hydrocarbons (PAH) in human carcinogenesis is undisputed. Measurements of PAH-DNA adduct levels in easily accessible white blood cells therefore represent useful early endpoints in exposure intervention or chemoprevention studies. The successful applicability of DNA adducts as early endpoints depends on several criteria: i. adduct levels in easily accessible surrogate tissues should reflect adduct levels in target-tissues, ii. toxicokinetics and the temporal relevance should be properly defined. iii. sources of interand intra-individual variability must be known and controllable, and finally iv. adduct analyses must have advantages as compared to other markers of PAHexposure. In general, higher DNA adduct levels or a higher proportion of subjects with detectable DNA adduct levels were found in exposed individuals as compared with nonexposed subjects, but saturation may occur at high exposures. Furthermore, DNA adduct levels varied according to changes in exposure, for example smoking cessation resulted in lower DNA adduct levels and adduct levels paralleled seasonal variations of air-pollution. Intraindividual variation during continuous exposure was low over a short period of time (weeks), but varied significantly when longer time periods (months) were investigated. Inter-individual variation is currently only partly explained by genetic polymorphisms in genes involved in PAH-metabolism and deserves further investigation. DNA adduct measurements may have three advantages over traditional exposure assessment: i. they can smooth the extreme variability in exposure which is typical for environmental toxicants and may integrate exposure over a longer period of time. Therefore, DNA adduct assessment may reduce the monitoring effort. ii. biological monitoring of DNA adducts accounts for all exposure routes. iii. DNA adducts may account for inter-individual differences in uptake, elimination, distribution, metabolism and repair amongst exposed individuals. In conclusion, there is now a sufficiently large scientific basis to justify the application of DNA adduct measurements as biomarkers in exposure assessment and intervention studies. Their use in risk-assessment, however, requires further investigation.

Animals↗
PubMed2000

Solubilization of Polycyclic Aromatic Compounds into n-Decyltrimethylammonium Perfluorocarboxylate Micelles.

Solubilization of polycyclic aromatic compounds in aqueous dilute solutions of three cationic amphiphiles was studied. The maximum additive concentrations (MACs) of the aromatic compounds were constant below their critical micelle concentrations (cmcs) and monotonically increased above the cmcs. The first stepwise association constants (K(1)) between a solubilizate monomer and a vacant micelle were evaluated from the MACs for the solubilizates using the mass action model for solubilization into micelles in the dilute solution. The standard Gibbs energy changes of solubilization (DeltaG degrees ) were calculated from K(1), and the enthalpy and entropy changes of solubilization were estimated from the temperature dependence. MACs of each surfactant at the same surfactant concentration above the cmc were different depending on the cmc, but there was little difference in the DeltaG degrees values. Some differences appeared in the enthalpy and entropy values in accordance with their micellar size or degrees of counterion binding to micelles. DeltaG degrees for solubilization decreased linearly with carbon number of aromatic solubilizate for each micellar solution. Copyright 2000 Academic Press.

Journal Article↗
PubMed2001

Separation and characterization of gall bladder bile metabolites from speckled trout, Salvelinus fontinalis, exposed to individual polycyclic aromatic compounds.

Speckled trout, Salvelinus fontinalis, were orally exposed to individual polycyclic aromatic compounds (PACs) represented by benzo[a]pyrene, carbazole, chrysene, dibenzofuran, dibenzothiophene, fluorene, phenanthrene, and pyrene. Fish were sacrificed 7 d after exposure and the gall bladder removed for bile analysis. High pressure liquid chromatography (HPLC) with fluorescence (F) and ultraviolet (UV) detection was used to determine the presence of PAC derivatives in the bile without pretreatment. Glucuronide conjugates were predominant in all exposures with variable amounts (0-53%) of phenols and starting material. Identification of compounds was confirmed by selective extraction of less polar nonconjugated PACs and enzymatic hydrolysis of water-soluble material. This was followed by HPLC and/or gas chromatography-mass spectrometry (GCMS) characterization of the produced phenols. Total metabolite levels varied widely among compounds.

Animals↗
PubMed2002

Accumulation and elimination of 16 polycyclic aromatic compounds in the earthworm (Eisenia fetida).

Accumulation and elimination of different polycyclic aromatic compounds (PACs) were studied in earthworms (Eisenia fetida) exposed to contaminated soil from an old gasworks site. In total, 12 polycyclic aromatic hydrocarbons (PAHs), two N- and S-heterocyclic PACs, and two PAC-quinones were included in the study. Peak-shaped accumulation curves were found for many of the compounds. After 19 d of exposure, the ratio between concentrations in worm lipids and soil organic matter was 0.02 on average. The half-lives of the PACs were relatively long, between 2 and 11 d. The elimination rate constants, k2, correlated both with literature-derived octanol-water partition coefficients (Kow) for PAHs (r2 = 0.93) and the computed polarizability (r2 = 0.88) of all the compounds. The elimination rate constants of PAHs are comparable to those of PCBs found in earlier studies, and the linear regression coefficient, r2, of k2 against Kow for PAHs and PCBs together was 0.93.

Animals↗
PubMed2000

Laser-induced dispersed fluorescence detection of polycyclic aromatic compounds in soil extracts separated by capillary electrochromatography.

Polycyclic aromatic hydrocarbons (PAHs) and nitrogen containing aromatic compounds (NCACs) are characterized in soil extracts and laboratory standards by capillary electrochromatography (CEC) with laser-induced dispersed fluorescence (LIDF) detection using a liquid-nitrogen cooled charge-coupled device detector. The LIDF detection technique provides information on compound identity and, when coupled with the high separation efficiencies of the CEC technique, proves useful in the analysis of complex mixtures. Differences in fluorescence spectra also provide a means of identifying co-eluting compounds by using deconvolution algorithms. Detection limits range from 0.5 to 96x10(-10) M for selected PAHs and 0.9-3.7x10(-10) M for selected NCACs. Soil extracts are also injected onto the CEC column to evaluate chromatographic method performance with respect to complex samples and the ability to withstand exposure to environmental samples.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed1982

The Ah regulatory gene product. Survey of nineteen polycyclic aromatic compounds' and fifteen benzo[a]pyrene metabolites' capacity to bind to the cytosolic receptor.

The capacity of 19 polycyclic aromatic compounds and 15 benzo[a]pyrene metabolites to displace [1,6-3H]2,3,7,8-tetrachlorodibenzo-p-dioxine ([3H]TCDD) from the mouse liver cytosolic Ah receptor was examined. We compared our data with various parameters taken from previously published results: the capacity of seven polycyclic hydrocarbons to induce aryl hydrocarbon hydroxylase (AHH) activity in human cell cultures, the capacity of 10 polycyclic hydrocarbons to induce azo dye N-demethylase activity in rat liver, the capacity of 6 polycyclic hydrocarbons to shorten zoxazolamine paralysis times in the intact rat, and the capacity of 15 benzo[a]pyrene metabolites to induce AHH activity in rat hepatoma H-4-II-E cultures. An excellent correlation is seen between the capacity to displace the radioligand from the Ah receptor and the capacity to induce these monooxygenase activities. differences in the rate of cellular uptake and formation of alkali-extractable metabolites of dibenzo[a,h]anthracene, 3-methylcholanthrene, and benzo[a]anthracene in Hepa-1 mouse hepatoma cell cultures do not account for differences in the capacity of these three polycyclic hydrocarbons to displace [3H]TCDD from the Ah receptor.

Animals↗
PubMed1985

Identification of polycyclic aromatic compounds in mutagenic emissions from steel casting.

Workers in ferrous foundries show increased risk of lung cancer. In the steel casting process hot metal is poured into sand moulds solidified with organic binders, producing a plume of smoke containing a variety of organic compounds and showing strong mutagenicity in the Salmonella/S9 assay. We have collected the emissions produced when steel is poured into an experimental sand mould solidified with oil, clay and cereal, a widely used binder system. The organic constituents of these emissions have been fractionated by preparative reverse-phase high performance liquid chromatography (HPLC) and mutagenic fractions have been analysed by capillary column gas chromatography/mass spectrometry (GC/MS). Of the 65 compounds for which mass spectra are reported, 54 have been tentatively identified as alkyl derivatives of polycyclic aromatic compounds. Many compounds of this class are known to be carcinogenic and mutagenic. In addition, several unsubstituted polycyclic aromatic hydrocarbons, including the carcinogenic benz[a]anthracene and benzo[a]pyrene, were found to be present.

Air Pollutants, Occupational↗
PubMed1984

N-nitroso compounds and polycyclic aromatic hydrocarbons in Icelandic smoked cured mutton.

Five samples of Icelandic smoked cured mutton were analysed for volatile N-nitrosamines, N- nitrosoamino acids, total N-nitroso content and several polycyclic aromatic hydrocarbons. Levels varied considerably from sample to sample but generally the levels of polycyclic aromatic hydrocarbons and N-nitrosamines (as judged by N- nitrosoproline , N- nitrosohydroxyproline and total N-nitroso content) varied in the same way. It is suggested that in this product the smoking procedure is responsible for both groups of contaminants and that the curing process is relatively unimportant.

Animals↗
PubMed2000

[Pigment molecules linked to polymer support: blue rayon, blue chitin, and green chitosan-synthesis and applications].

The fact that hemin can inhibit the mutagenic activity of compounds bearing polycyclic structures is ascribable to the ability of the porphyrin structure to complex with the planar surface of the mutagens. The elucidation of this mechanism has led to the discovery of copper phthalocyanine trisulfonate (cpt) as an efficient ligand to trap polycyclic compounds on polymeric supports that bear cpt through covalent bond linkages. In blue cotton, the support for cpt is cotton, in blue rayon, it is amorphous rayon, and in blue chitin it is poly-N-acetylglucosamine. Using these blue materials, we have successfully isolated mutagens of polycyclic structures, e.g., heterocyclic amines, from environmental complex mixtures such as food, urine, feces, and river water. Preparation and properties of these adsorbents are described. Chlorophyllin linked to Sepharose and chitosan is also described. The use of these green materials is discussed.

Adsorption↗
PubMed1988

Determination of polycyclic aromatic compounds by high-performance liquid chromatography with simultaneous mass spectrometry and ultraviolet diode array detection.

A major problem in the determination of polycyclic aromatic compounds (PACs) in environmental samples is the extreme complexity of the extracts, even after extensive fractionation. The combination of high-performance liquid chromatography (HPLC) with simultaneous mass spectrometry (MS) and ultraviolet diode array detection (DAD) is a powerful tool for the identification and quantitation of such species with a high degree of confidence. HPLC allows the selective separation of a wide variety of PACs, including thermally labile and high molecular weight compounds. Electron ionization MS with the moving belt interface provides high sensitivity and selectivity, as well as structural information such as molecular weight, functional groups, and elemental composition. The diode array detector helps to differentiate isomeric structures and confirm compound identity.

Chromatography, High Pressure Liquid↗
PubMed1993

Mortality from lung cancer and cardiovascular diseases among stainless-steel producing workers.

The mortality pattern of workers involved in the production of stainless steel (SS) was studied from 1968 to 1984 in order to investigate a possible risk of lung cancer in relation to exposure to chromium compounds, polycyclic aromatic hydrocarbons, and silica. The role of heat exposure in mortality from cardiovascular diseases also was examined. The cohort was comprised of 4,227 workers. Complete individual job histories were provided by the company (UGINE SA). The smoking habits of 24 percent of the cohort members were known from the interview of workers still active during the data collection. The observed numbers of deaths were compared with the expected ones based on national rates with adjustment for age, sex, and calendar time (standardized mortality ratio, SMR). No significant excesses of lung cancer were observed among workers employed in the manufacture of ferroalloys (SMR = 0.68) and in the melting and casting of SS (SMR = 1.04), whereas a significant excess appeared among SS foundry workers (SMR = 2.29). This excess was higher and remained significant among workers with more than 30 years since first employment in the foundry area (SMR = 3.34). Among subjects exposed to heat, no excess was observed for all cardiovascular diseases or for ischemic heart diseases.

Cardiovascular Diseases↗
PubMed2003

Comparison of the mutagenic activity of XAD4 and blue rayon extracts of surface water and related drinking water samples.

The combination of mutagenicity tests and selective extraction methodologies can be useful to indicate the possible classes of genotoxic organic contaminants in water samples. Treated and source water samples from two sites were analyzed: a river under the influence of an azo dye-processing plant discharge and a reservoir not directly impacted with industrial discharges, but contaminated with untreated domestic sewage. Organic extraction was performed in columns packed with XAD4 resin, that adsorbs a broad class of mutagenic compounds like polycyclic aromatic hydrocarbons (PAHs), arylamines, nitrocompounds, quinolines, antraquinones, etc., including the halogenated disinfection by-products; and with blue rayon that selectively adsorbs polycyclic planar structures. The organic extracts were tested for mutagenicity with the Salmonella assay using TA98 and TA100 strains and the potencies were compared. A protocol for cleaning the blue rayon fibers was developed and the efficiency of the reused fibers was analyzed with spiked samples. For the river water samples under the influence of the azo-type dye-processing plant, the mutagenicity was much higher for both blue rayon and XAD4 extracts when compared to the water from the reservoir not directly impacted with industrial discharges. For the drinking water samples, although both sites showed mutagenic responses with XAD4, only samples from the site under the influence of the industrial discharge showed mutagenic activity with the blue rayon extraction, suggesting the presence of polycyclic compounds in those samples. As expected, negative results were found with the blue rayon extracts of the drinking water collected from the reservoir not contaminated with industrial discharges. In this case, it appears that using the blue rayon to extract drinking water samples and comparing the results with the XAD resin extracts we were able to distinguish the mutagenicity caused by industrial contaminants from the halogenated disinfection by-products generated during water treatment.

Cellulose↗