Search

The concentrations of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in total suspended particulates (TSP) and soil were measured at a traffic site in Hanoi, a typical motorcycle city of Vietnam. TSP was collected using high-volume air sampler on Pallflex 2500QAT-UP membrane filters. PAHs and NPAHs were analyzed by high-performance liquid chromatography (HPLC) using fluorescence and chemiluminescence detectors, respectively. The average concentrations of total 10 PAHs and 10 NPAHs in soil varied from 3.4–43.7 ng g−1 and from 112–780 pg g−1 dry weight, respectively, which were much lower than those in TSP. The results showed that large part of the higher molecular weight PAHs in soil, especially benzo[ghi]perylene and benzo[b]fluoranthene came from the atmosphere. However, NPAHs profile showed a different pattern. 3-nitroperylene and 6-nitrochrysene were the most abundant NPAHs in soil, followed by 1-nitropyrene and 6-nitrobenzo[a]pyrene. The fate of NPAHs in soil...

The formation of hydroxynitrofluoranthene (OHNF) via photochemical reactions of 2-nitrofluoranthene (2-NF) was demonstrated using a UV irradiation system. The photoreaction of 2-NF in acetonitrile/water (3/1, v/v) gave a product that was hydroxynitro-substituted. Moreover, we detected an OHNF isomer, which was found in the 2-NF photoreaction products, in soluble organic fractions of ambient airborne particles collected in Kanazawa, Japan. The atmospheric concentration of the OHNF isomer was estimated to be less than 2 fmol m−3, which was comparable to that of 1-hydroxy-3-nitropyrene, but lower than that of 1-hydroxy-6-nitropyrene by a factor of 10. The results suggests that atmospheric OHNF is partly formed via secondary formation processes, i.e., photochemical reactions of 2-NF appear to have a significant effect on the occurrence of OHNF in the atmosphere.

We investigated polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in airborne particulates collected at two sites (I and T) in Hanoi city, a typical city where traffic jams were caused by many motorbikes. The mean total concentration of 10 PAHs having 4–6 rings at sites I and T ranged from 9.6–63.7 pmol m−3 and from 24.8–41.9 pmol m−3, respectively. The predominant PAHs determined were 6-ring PAHs: benzo[ghi]perylene (BghiPe), indeno[1,2,3-cd]pyrene (IDP) and 5-ring PAHs: benzo[b]fluoranthene (BbF), benzo[a]pyrene (BaP). The NPAHs with the highest mean concentrations were 9-nitroanthracene (9-NA) (297 ± 134 fmol m−3) at site I and 1-nitropyrene (1-NP) (331 ± 103 fmol m−3) at site T. Both PAH and NPAH concentrations were higher in winter at site I but higher in summer at site T. Diagnostic markers indicated that motorbikes strongly contributed to atmospheric PAHs and NPAHs in Hanoi city. The contribution of PAHs having 6 rings and 7-NBaA in Hanoi city was larger and ...

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, and generate various types of PAH derivatives, such as nitrated PAHs, hydroxylated PAHs, and PAH quinones through chemical reactions in the atmosphere. PAHs are well known to activate the aryl hydrocarbon receptor (AhR), followed by the induction of metabolizing enzymes mainly in the liver, while biological responses to PAH derivatives are not understood well. In this study, we investigated the induction patterns of gene expression of CYP1 family and Phase II metabolizing enzymes in rat H4IIE cells exposed to PAH quinones and their parent PAHs for 24 h. Dibenz[a,h]anthracene and benzo[a]pyrene dramatically induced mRNA expression of CYP1 family, such as cytochrome P450 (Cyp) 1a1, Cyp1a2, and Cyp1b1, and PAH quinones, especially 1,4-chrysenequinone, possess a high potential to induce CYP1 family. As for Phase II enzymes, PAHs induced NAD(P)H: quinone oxidoreductase 1 (Nqo1) and UDP-glucuronosyltransferase (Ugt)1a6, and their i...

Binding activities and estrogenic/antiestrogenic activities of polycyclic aromatic hydrocarbons (PAHs) and hydroxylated PAHs (OHPAHs) having 2 to 6 rings were evaluated by competition assay and yeast two-hybrid assay expressing human estrogen receptor (hER), respectively. PAHs did not bind to hER and did not show any activity. On the other hand, OHPAHs bound to hER and several OHPAHs showed estrogenic or antiestrogenic activity. Relative estrogenic activity (REP E ) and antiestrogenic activity (REP AE ) were calculated from the values of E 2 and 4-hydroxytamoxyfen as positive controls, respectively. Several OHPAHs having 4 rings showed strongly estrogenic activity. 4-Hydroxybenzo[a]anthracene exhibited the strongest estrogenic activity (REP E = 7.5 × 10−3 ) followed by 3-hydroxybenzo[a]anthracene and 2-hydroxychrysene (REP E = 4.2 × 10−3 ). Several other 4-ring OHPAHs showed strongly antiestrogenic activity. 3-Hydroxybenzo[c]phenanthrene exhibited the strongest antiestrogenic activity (REP AE = 190) follo...

We examined endocrine disruptors in diesel exhaust particulates (DEP) emitted from a diesel engine under different engine loads. The antiandrogenic and aryl hydrocarbon receptor (AhR) agonistic activity of DEP extracts (DEPE) were evaluated using PC-3/AR human prostate cancer cells transiently transfected with androgen- or AhR agonist-regulated luciferase reporter plasmids, respectively. The antiandrogenic and AhR agonistic activities were enhanced by higher engine load. The AhR antagonist α-naphthoflavone reversed the antiandrogenic activity of DEPE as seen through a reduction in AhR agonistic activity. The concentrations of polycyclic aromatic hydrocarbons (PAHs) with four or more rings, which are AhR agonists in DEPE, increased with higher engine load. Therefore, the enhanced antiandrogenic activity of DEPE is due in part to the increase in AhR agonists such as PAHs with higher engine load.

2-Hydroxyfluorene (2-OHF) and 1-hydroxypyrene (1-OHP) in urine samples of smokers and nonsmokers were determined separately by using two high-performance liquid chromatography (HPLC) systems with fluorescence detection. Urine samples were collected from the subjects who lived in Japan and Thailand, and were not occupationally exposed to polycyclic aromatic hydrocarbons (PAHs). The mean concentrations of 2-OHF and 1-OHP of Thai smokers (0.75 and 3.03 μmol/mol creatinine) and nonsmokers (0.22 and 0.91 μmol/mol creatinine) were both higher than those of Japanese smokers (0.26 and 0.12 μmol/mol creatinine) and nonsmokers (0.04 and 0.06 μmol/mol creatinine), respectively. The difference between smokers and nonsmokers was more significant for 2-OHF than for 1-OHP, reflecting the higher intake of fluorene in the vapor phase by the smoking. Moreover, the higher urinary levels of both 2-OHF and 1-OHP were observed in Thai nonsmokers than those in Japanese nonsmokers, suggesting the higher background exposure to PA...

Diesel exhaust particulate matter (DEP) was collected from three commercial diesel engine vehicles and DEP extracts (DEPEs) were prepared from each. The estrogenic and antiestrogenic activities of the DEPE samples were examined using an estrogen response element (ERE)-driven luciferase reporter gene assay in MCF-7 human breast cancer cells. While DEPE samples did not exhibit significant estrogen agonist activity alone, they suppressed 17 g -estradiol (E 2 )-induced luciferase activity without decreasing cell viability. Several polycyclic aromatic hydrocarbons (PAHs) acting as aryl hydrocarbon receptor (AhR) agonists were detected in the DEPEs and their concentrations were higher in DEPE samples with higher antiestrogenic activity. DEPE samples elevated cytochrome P450 (CYP) 1A1 activity. f -Naphthoflavone, an AhR antagonist, and SKF-525A, a nonselective CYP inhibitor, reversed and enhanced the antiestrogenic activity of DEPE samples, respectively. These results demonstrate that DEPE has antiestrogenic act...