Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Polycyclic Compounds”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,081 records · Page 60Linked to original sources
PubMed1992

Gomisin A inhibits tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin.

Gomisin A, isolated from the fruits of Schisandra chinensis, is one of the dibenzocyclooctadiene lignans. Application of 12-O-tetradecanoylphorbol-13-acetate (TPA, 1 microgram/ear), a tumor-promoting agent, to the ears of mice induces inflammation. Among seven dibenzocyclooctadiene lignans assayed, gomisin A, gomisin J, and wuweizisu C inhibited the inflammatory activity induced by TPA in mice. The ED50 of these compounds for TPA-induced inflammation was 1.4-4.4 mumol. Gomisin A, with an ED50 of 1.4 mumol, showed the strongest inhibitory effect. Furthermore, at 5 mumol/mouse, it markedly suppressed the promotion effect of TPA (2.5 micrograms/mouse) on skin tumor formation in mice following initiation with 7,12-dimethylbenz[a]anthracene (50 micrograms/mouse). It is assumed that the inhibition of tumor promotion by gomisin A is due to its anti-inflammatory activity.

Animals↗
PubMed2004

Tumor prevalence and biomarkers of exposure and response in brown bullhead (Ameiurus nebulosus) from the Anacostia River, Washington, DC and Tuckahoe River, Maryland, USA.

We evaluated liver and skin tumor prevalence and biomarkers of exposure and response in brown bullhead (Ameiurus nebulosus) from three locations in the Anacostia River (Washington, DC, USA), a Chesapeake Bay region of concern. The Tuckahoe River (Maryland, USA) served as a reference. Each river was sampled in fall 2000 and spring 2001. In the Anacostia, prevalence of liver tumors was 50 to 68%, and prevalence of skin tumors was 13 to 23% in large (> or = 260 mm, age > or = 3 years) bullheads. Liver and skin tumor prevalence was 10 to 17% and 0%, respectively, in small (150-225 mm, age 1-2 years) bullheads. Tuckahoe bullhead liver tumor prevalence was 0 to 3% (large) and 0% (small); none had skin tumors. Biliary polynuclear aromatic hydrocarbon (PAH)-like fluorescent metabolites and liver DNA adduct concentrations were elevated in large and small Anacostia bullheads. Mean adduct concentrations were 16 to 28 times higher than those in Tuckahoe fish. Chromatograms revealed a diagonal radioactive zone, indicating polycyclic aromatic compound (PAC)-DNA adducts. The biomarker data and the 10 to 17% liver tumor prevalence at ages 1 to 2 suggest that these year classes are likely to have a high prevalence as they reach age 3 and older. This study provides the strongest evidence to date of the role of PAHs in tumor development in Anacostia bullheads.

Analysis of Variance↗
PubMed1994

Separation of lipophilic compounds by micellar electrokinetic chromatography with organic modifiers.

Separation of lipophilic compounds such as polyaromatic hydrocarbons (PAH) by micellar electrokinetic chromatography (MEKC) with organic modifiers was investigated. Dimethyl sulfoxide (DMSO) and acetone were used as organic modifiers, and sodium dodecyl sulfate (SDS) as a surfactant or a micelle forming reagent. By using 25 mM SDS (pH 7.0), containing 50% v/v DMSO, 8 PAHs were separated. Similarly, with 25 mM SDS, containing 30% acetone, 13 PAHs were successfully separated. For the calculation of thermodynamic quantities, critical micelle concentrations of SDS in buffers containing DMSO or acetone were measured.

Acetone↗
PubMed2005

A low-molecular-weight compound discovered through virtual database screening inhibits Stat3 function in breast cancer cells.

This study focused on the screening of small-molecule inhibitors that target signal transducers and activators of transcription 3 (Stat3) in human breast carcinoma. The constitutive activation of Stat3 is frequently detected in human breast cancer cell lines as well as clinical breast cancer specimens and may play an important role in the oncogenesis of breast carcinoma. Activated Stat3 may participate in oncogenesis by stimulating cell proliferation, promoting tumor angiogenesis, and resisting apoptosis. Because a variety of human cancers are associated with constitutively active Stat3, Stat3 represents an attractive target for cancer therapy. In this study, of the nearly 429,000 compounds screened by virtual database screening, chemical samples of top 100 compounds identified as candidate small-molecule inhibitors of Stat3 were evaluated by using Stat3-dependent luciferase reporter as well as other cell-based assays. Through serial functional evaluation based on our established cell-based assays, one compound, termed STA-21, was identified as the best match for our selection criteria. Further investigation demonstrated that STA-21 inhibits Stat3 DNA binding activity, Stat3 dimerization, and Stat3-dependent luciferase activity. Moreover, STA-21 reduces the survival of breast carcinoma cells with constitutive Stat3 signaling but has minimal effect on the cells in which constitutive Stat3 signaling is absent. Together, these results demonstrate that STA-21 inhibits breast cancer cells that express constitutively active Stat3.

Breast Neoplasms↗
PubMed1976

Multicomponent analysis in clinical chemistry by use of rapid scanning fluorescence spectroscopy.

To be useful in the clinical laboratory, multicomponent fluorescence analysis requires both the rapid measurement of the fluorescence intensity at a variety of excitation and emission wavelengths and the unambiguous reduction of the data by efficient algorithms. The Video Fluorometer, which exploits the multi-channel capability of a low-light-level television sensor to simultaneously acquire excitation and emission spectra, can meet the first requirement. For example, a complete set of emission and excitation spectra for perylene can be obtained in less than 2 s at concentrations of 10(-10) mol/liter. To meet the second need, we present two types of data-reduction strategies: (a)a least-squares fit to the data, with use of the spectra of previously determined compounds likely to be present; and (b)a determination of the eigenvalues and eigenvectors fo the fluorescence matrix, from which the number of components and the possible spectra of each can be estimated. Computer simulations of the least-squares fitting algorithms show that five strongly overlapping components can be determined in the presence of noise with an accuracy of better than 5%. Also, a fluorescent sample containing two species with very similar but unknown spectral properties can be resolved to obtain the spectrum of each.

Anthracenes↗
PubMed2002

Distribution of PACs in surficial sediments and bioavailability to mussels, Mytilus edulis of Halifax Harbour.

Surficial sediments and blue mussels were collected around the perimeter of Halifax Harbour. Samples were analysed for the levels and fingerprint of polycyclic aromatic compounds (PACs). The objective was to explore the relationship between contaminant profiles in sediments and in mussels and to explore the possibility of deducing their sources, pattern of deposition and circulation in the harbour. Combustion derived compounds predominated in both sets of samples, with more variability observed in the level of petroleum derived hydrocarbons in mussel samples. Biota-sediment accumulation factors (BSAF, dry/dry wt.) varied throughout the harbour, ranging from means of 0.006 to 1.26, where generally fluoranthene displayed the highest BSAF. Sediments and mussels give complementary views of the geographical distribution of contaminants, they reflect the state of benthic and pelagic habitats. Results observed for Halifax Harbour are discussed from the perspective of published data.

Animals↗
PubMed1983

[Effect of heliomycin on the respiration and oxidative phosphorylation of the liver mitochondria of the rat].

The effect of heliomycin and known uncouplers of oxidative phosphorylation on respiration and oxidative phosphorylation was studied comparatively. Heliomycin, as well as 2,4-dinitrophenol, valinomycin and gramicidin S inhibited the mitochondrial synthesis of ATP. This process was inhibited completely by heliomycin at a concentration of 1.5 x 10(-5) M. The synthesis of inorganic pyrophosphate, the other macroergic compound, was also inhibited by heliomycin, ATPase and pyrophosphatase of uncoupled mitochondria being not inhibited by the antibiotic. Like 2,4-dinitrophenol, heliomycin stimulated the synthesis of ATPase and respiration in intact mitochondria. Probably, heliomycin inhibited the synthesis of ATP and pyrophosphate by uncoupling the processes of respiration and oxidative phosphorylation. It was shown earlier that heliomycin, a specific inhibitor of bacterial RNA synthesis, also affected energy metabolism of bacterial cells by inhibiting the synthesis of ATP and active transport.

Adenosine Triphosphate↗
PubMed1992

Regulation by phorbol ester and protein kinase C inhibitors, and by a protein phosphatase inhibitor (okadaic acid), of P-glycoprotein phosphorylation and relationship to drug accumulation in multidrug-resistant human KB cells.

Covalent modification by phosphorylation is a characteristic of the P-glycoproteins expressed in multidrug-resistant cells. This report describes analysis of P-glycoprotein phosphorylation in multidrug-resistant human KB-V1 cells and a study of the relationship of phosphorylation and drug accumulation. In isolated membranes, phosphorylation of P-glycoprotein by purified protein kinase C (PKC) was rapid, and time-dependent dephosphorylation was inhibited by okadaic acid, an inhibitor of type 1 and type 2A protein phosphatases. In 32P-labeled intact KB-V1 cells, P-glycoprotein phosphorylation was stimulated by both 12-O-tetradecanoylphorbol-13-acetate (TPA), an activator of PKC, and okadaic acid. Two-dimensional thin layer tryptic phosphopeptide maps indicated that the sites of phosphorylation were similar in control, TPA-treated, and okadaic acid-treated cells and that they corresponded to those phosphorylated by PKC in vitro. The protein kinase inhibitor staurosporine, and the PKC-selective inhibitors calphostin C and the alkyl-lysophospholipid 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine, inhibited P-glycoprotein phosphorylation in vitro and in intact cells. Drug accumulation assays demonstrated that in KB-V1 cells TPA caused a decrease, whereas staurosporine and calphostin C caused an increase, in accumulation of [3H]vinblastine. These compounds did not significantly alter [3H]vinblastine levels in drug-sensitive KB-3 cells. These results suggest that PKC is chiefly responsible for P-glycoprotein phosphorylation in KB-V1 cells, that membrane-associated protein phosphatases 1 and 2A are active in dephosphorylation of P-glycoprotein, and that phosphorylation of P-glycoprotein may be an important mechanism for modulation of drug-pumping activity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

Mussel-based monitoring of trace metal and organic contaminants along the east coast of China using Perna viridis and Mytilus edulis.

Green lipped mussels, Perna viridis, and blue mussels, Mytilus edulis, were collected from seven locations along the east coast of China in September and October 2001. The mussel tissues were analyzed for metals (Ag, As, Cd, Cr, Ni, Pb, Se, Zn, Cu, Fe and Hg), and trace organic contaminants including organochlorine compounds (OCs), polycyclic aromatic hydrocarbons (PAHs; based on 24 individual PAHs), polychlorinated biphenyls (PCBs) and petroleum hydrocarbons (PHCs). Maximum concentrations of Ag, As, Cd, Cr, Ni, Pb, Se, Zn, Cu, Fe and Hg in the mussel tissues were 0.14, 26.76, 5.31, 15.72, 4.78, 2.93, 7.40, 231.0, 54.17, 1002 and 317.3 microg/g dry weight respectively. Levels of DDTs, PAHs, PCBs and PHCs in the mussel samples were 14-640, 456-3495, 1-13 ng/g and 621-2863 microg/g dry weight, respectively. Results of this study indicated that contaminant levels were, in general, higher or at least comparable to those reported in other local or regional studies. Mussel samples collected in Chongming Dao in Shanghai and Jiao Zhou Wan in Qingdao had significantly higher levels of metal and trace organic contaminants among the seven sampling stations. Examination of the contaminant profiles suggests that PHCs originated from petrogenic sources, while both petrogenic and pyrolytic sources were important for PAHs. The generally high levels of metals and organochlorine compounds are probably the result of increasingly intense industrial activities along the east coast of China. An assessment of potential risks to human health due to consumption of the mussels was undertaken for the metals, PCBs, DDTs and chlordanes, and the results indicated that all metals, except Ni, could pose a health risk to heavy seafood consumers, while Hg appears to be of concern even for low level consumers.

Animals↗
PubMed1989

Investigations on the use of EDTA-permeabilized E. coli cells in liquid suspension and animal-mediated genotoxicity assays.

The potential use of EDTA-permeabilized E. coli cells for the investigation of genotoxic effects of compounds with a large molecular configuration in vitro and in animal-mediated differential DNA-repair assays was studied. The indicator for the induction of (repairable) DNA damage was a pair of E. coli K-12 strains (343/765 and 343/753) differing vastly in DNA-repair capacity (uvr+/rec+ vs. uvrB/recA). Investigations on the influence of EDTA treatment on the viability of these strains show that during short-term exposure (3 min), the EDTA level should not exceed 0.5 mmole/l in the pretreatment mix, since at higher concentrations a marginal titer reduction of the repair-deficient strain occurs, thus indicating a weak genotoxic activity of this chelating agent. Comparisons of the results gained in vitro with permeabilized and untreated cells demonstrate that EDTA exposure leads to a substantial enhancement of the sensitivity of the indicator bacteria towards DNA damage induced by B(a)P and N-Ac-2AAF which is essential for the detection of genotoxic activities of these polycyclic aromatic compounds. Experiments to elucidate the possibility of employing EDTA-treated cells in vivo show that following intravenous and oral administration the recovery rates of permeabilized indicator strains from various mouse organs are substantially lower than those found under identical conditions (exposure time 150 min) with untreated strains. Nevertheless enough viable cells can be recovered from liver, spleen, kidneys, lungs and stomach to allow the investigation of organ-specific genotoxicity. It is furthermore noteworthy that exposure of permeabilized indicator cells in control animals (for 150 min) resulted in a marginal reduction of the relative survival of the repair-deficient strain in all organs investigated, whereas with non-treated strains such effects are only detectable after extended exposure periods. The observation of a slightly elevated genotoxic background under in vivo conditions does not prevent the assessment of the organ distribution of genotoxic effects induced by mutagens and/or carcinogens: in the case of B(a)P, intraperitoneal administration to mice in the dose range of 10-50 mg/kg body weight resulted in a pronounced dose-dependent inactivation of the uvrB/recA cells in the liver. Also in the lungs differential killing effects occurred at the highest dose tested, whereas no genotoxic activities were detectable in stomach, kidneys and spleen of the host animals.

Acetoxyacetylaminofluorene↗
PubMed1995

Transport of organic environmental contaminants to animal products.

A large number of chemical contaminants potentially may be present in agricultural environments, leading to exposure of animals and potential residues in animal products. The contamination may be either widespread, as a result of aerial transport of industrial emissions, or localized, as a result of accidental emissions and spills, improper waste disposal, contaminants in useful products, and areas of past use of products now banned. The halogenated hydrocarbons, including the polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and persistent organochlorine insecticides remaining from past use, are the contaminants of most concern. Depending on the degree and pattern of chlorine substitution, these compounds are resistant to degradation and tend to accumulate in the fat of animals and their products. Other classes of environmental contaminants as exemplified by the PAHs, phthalate esters, acid phenolics, and nitrosamines also may occur widely in the environment. These compounds are unlikely to be transported to animal products because the compounds are water-soluble or can be metabolized to water-soluble products, which are excreted in the urine and thus do not bioaccumulate in products such as milk and meat. The points of entry of environmental contaminants into agricultural environments usually are plants and soils. Lipophilic compounds such as the halogenated hydrocarbons are not taken up and translocated by plants. Contamination of plants is mainly a surface phenomenon resulting from aerial deposition of emissions or deposition of compounds volatilized from the surface of contaminated soil. Thus, fibrous roughages used primarily in feeding cattle and other ruminants will be the most important pathway of animal exposure and transport to human foods. The second pathway of animal exposure is by ingestion of contaminated soil while grazing or when confined to unpaved facilities. As in the case of feed sources, cattle is the species most vulnerable to exposure by the soil ingestion pathway under most commercial management systems, but poultry and swine are more vulnerable in those infrequent situations in which these species have access to contaminated soil.

Animal Feed↗
PubMed1979

In vitro mutagenicity assays of chemical carcinogens and related compounds with Salmonella typhimurium.

The mutagenic activity of 101 chemicals was studied with the use of the Salmonella typhimurium-microsome system described by Ames. The tester strains were TA1535, TA1536, TA1537, TA1538, TA98, and TA100. Assays were conducted in the presence and absence of a metabolic activation system prepared from the livers of randomly bred Sprague-Dawley rats that had been pretreated with Aroclor 1254. The test chemicals were incorporated into the agar with bacteria and the metabolic activation system. Mutagens were defined as chemicals that induced a reproducible dose-related increase in the number of histidine-independent revertants. With the use of these procedures, 65% of the organic carcinogens and 25% of the noncarcinogens were found to be mutagenic.

Alkylating Agents↗
PubMed1994

Induction of in vivo DNA adducts by 4 industrial by-products in the rat-lung-cell system.

Benz[a]anthracene (BA), dibenz[a,h]anthracene (DBA), dibenzo[a,i]pyrene (DBP), and dibenz[a,h]acridine (DBAC) are by-products found in many industrial wastes and emissions. Workers in the related occupational settings are potentially exposed to these substances through inhalation. In the present study, induction of DNA adducts in vivo by these chemicals was investigated using 32P-postlabeling analysis in the rat-lung-cell system. The potency of DNA-adduct inducing activity was also compared to that of two cytogenetic endpoints i.e., sister-chromatid exchange (SCE) and micronucleus formation. Via intratracheal instillation, male CD rats (6/group) were dosed 3 times with BA, DBA, DBP or DBAC in a 24-h interval. Lung cells were enzymatically separated and used to determine the frequency of DNA adducts, SCE and micronuclei. Results show that all 4 test compounds induced DNA adducts, SCEs, and micronuclei in the rat-lung cell in vivo and that the postlabeling DNA adduct assay detected genotoxic activity at lower dose levels than the two cytogenetic assays. These findings suggest that BA, DBA, DBP or DBAC are rat pulmonary genotoxicants and the DNA-adduct assay is more sensitive than SCE or micronucleus assays for detecting the pulmonary genotoxicity of these industrial PAHs in the in vivo rat-lung-cell system.

Acridines↗
PubMed1983

Quantitative analysis of multiple PAH's in the coal conversion atmosphere.

The development of synfuel technology has focused attention on the determination and control of polynuclear aromatic hydrocarbons (PAH) in the work and general environments. As a group, PAH are perhaps the most important family of compounds of concern to the industrial hygienist in the synfuel industry. The resolution and detection of PAH present in an environmental sample remain challenging analytical tasks. This paper describes refinements in the analytical scheme and detection of multiple PAH by a combined HPLC and GC/MS approach in samples collected over several months in various areas of a coal conversion facility. The method has been proven to be a rapid, more sensitive, and less expensive approach than GC/MS alone, and has been applied successfully to a large number of samples collected in the real coal conversion environment.

Air Pollutants, Occupational↗
PubMed2005

Determination of single particle mass spectral signatures from light-duty vehicle emissions.

In this study, 28 light-duty gasoline vehicles (LDV) were operated on a chassis dynamometer at the California Air Resources Board Haagen-Smit Facility in El Monte, CA. The mass spectra of individual particles emitted from these vehicles were measured using aerosol time-of-flight mass spectrometry (ATOFMS). A primary goal of this study involves determining representative size-resolved single particle mass spectral signatures that can be used in future ambient particulate matter source apportionment studies. Different cycles were used to simulate urban driving conditions including the federal testing procedure (FTP), unified cycle (UC), and the correction cycle (CC). The vehicles were selected to span a range of catalytic converter (three-way, oxidation, and no catalysts) and engine technologies (vehicles models from 1953 to 2003). Exhaust particles were sampled directly from a dilution and residence chamber system using particle sizing instruments and an ATOFMS equipped with an aerodynamic lens (UF-ATOFMS) analyzing particles between 50 and 300 nm. On the basis of chemical composition, 10 unique chemical types describe the majority of the particles with distinct size and temporal characteristics. In the ultrafine size range (between 50 and 100 nm), three elemental carbon (EC) particle types dominated, all showing distinct EC signatures combined with Ca, phosphate, sulfate, and a lower abundance of organic carbon (OC). The relative fraction of EC particle types decreased as particle size increased with OC particles becoming more prevalent above 100 nm. Depending on the vehicle and cycle, several distinct OC particle types produced distinct ion patterns, including substituted aromatic compounds and polycyclic aromatic hydrocarbons (PAH), coupled with other chemical species including ammonium, EC, nitrate, sulfate, phosphate, V, and Ca. The most likely source of the Ca and phosphate in the particles is attributed to the lubricating oil. Significant variability was observed in the chemical composition of particles emitted within the different car categories as well as for the same car operating under different driving conditions. Two-minute temporal resolution measurements provide information on the chemical classes as they evolved during the FTP cycle. The first two minutes of the cold start produced more than 5 times the number of particles than any other portion of the cycle, with one class of ultrafine particles (EC coupled with Ca, OC, and phosphate) preferentially produced. By number, the three EC with Ca classes (which also contained OC, phosphate, and sulfate) were the most abundant classes produced by the nonsmoking vehicles. The smoker category produced the highest number of particles, with the dominant classes being OC comprised of substituted monoaromatic compounds and PAHs, coupled with Ca and phosphate, thus suggesting used lubricating oil was associated with many of these particles. These studies show, by number, EC particles dominate gasoline emissions in the ultrafine size range particularlyforthe lowest emitting newer vehicles, suggesting the EC signature alone cannot be used as a unique tracer for diesels. This represents the first report of high time- and size-resolved chemical composition data showing the mixing state of nonrefractory elements in particles such as EC for vehicle emissions during dynamometer source testing.

Automobiles↗
PubMed1983

Identificatin of polynuclear aromatic hydrocarbons in diesel particulate emissions.

Following collection of diesel particulate samples on high efficiency glass fibre papers, and Soxhlet extraction with cyclohexane, a two-stage clean-up involving DMF/H2O partition and silica gel thin-layer chromatography is required in order to simplify the extract. Individual compound identification can then be achieved by high resolution gas chromatography using WCOT quartz capillary columns with flame ionisation or computer-assisted electron impact mass spectrometry detection systems. The technique provides a relatively quick and simple enrichment step, whilst the high separating power of the capillary column is able to resolve the many chromatographically similar isomers and substituted PAH members that are present. Investigations indicate that presence of a vast range of PAH species, comprising both substituted and unsubstituted two- to seven-membered ring systems, many of which are known carcinogens and mutagens.

Chromatography, Gas↗
PubMed2002

Chiral recognition in the binding of helicenediamine to double strand DNA: interactions between low molecular weight helical compounds and a helical polymer.

Binding of a helicene, 5,8-bis(aminomethyl)-1,12-dimethylbenzo[c]phenanthrene, to calf thymus DNA was studied using UV, CD, and fluorescence spectroscopy as well as calorimetry. The enantiomeric helicenes strongly bound to the double strand DNA possessing the right-handed helical structure. In addition, chiral recognition was observed in the binding, where the (P)-helicene with the right-handed helicity formed more stable complex than the (M)-helicene with the left-handed helicity. The binding studies of the helicenes and natural nucleosides by 1H NMR spectroscopy also revealed the higher affinity to the (P)-helicene. Both monomeric and polymeric nucleic acids thus turned out to favor the (P)-helicity.

Calorimetry↗
PubMed1988

Photolysis primes biodegradation of benzo[a]pyrene.

14C-labeled benzo[a]pyrene (BaP) was used as a model-compound for polycyclic aromatic hydrocarbons (PAH) in order to assess the effect of photolytic pretreatment on the subsequent fate of BaP in sewage sludge and soil test systems. Photolysis was performed in methanolic solution with or without 0.1 M H2O2, under either UV light (300 nm) or natural sunlight. The presence of H2O2 greatly enhanced the rate of photolysis both with UV and with natural sunlight. Intact BaP resisted biodegradation in both test systems. Photolysis transformed BaP to polar materials that were subject to increased mineralization and binding in both biological test systems. As shown by the Ames assay, photolysis decreased the mutagenicity of BaP to test strains TA98 and TA104 only moderately. The photolysate had an increased acute toxicity and lost its need for activation by S-9 enzymes. However, during subsequent incubation in soil or sewage sludge, mutagenicity decreased rapidly by one to two orders of magnitude and acute toxicity disappeared due to the mineralization and binding of photoproducts to humic materials. Photolysis of BaP and similar PAH compounds represents a useful treatment option that could be applied to certain PAH-containing petroleum refinery sludge and to coal tar residues in order to facilitate their detoxification and environmentally safe disposal.

Benzo(a)pyrene↗