Gas Chromatography-high Resolution Mass Spectrometry Research Articles

HRGC/HRMS analysis of mirex in soil of Liyang and preliminary assessment of mirex pollution in China

China is a country with the most severe termite damage in the world. Mirex is one of the two effective orgochlorine pesticides used in China for termite control. A high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) was employed for mirex analysis in soil samples from Liyang city, which once was an important mirex production base in China. The detected mirex levels in soil in Liyang were 2.9–4300 pg g −1 dw (dry weight), with the geometric mean 26.83 pg g −1 dw and the geometric standard deviation 5.02. The highest level occurred at the site near the Liyang Guanghua Chemical Factory. It implies the contribution of industrial activities to the mirex pollution in the surrounding environment. However, the factory only influenced very limited adjacent areas. A Level III fugacity model was developed to study the mirex pollution in Chinese provinces. The results show that the highest concentration occurred in Jiangxi Province, which has the largest consumption of mirex among Chinese provinces. On a regional scale, the calculated concentrations of mirex in the environment are generally so low that it indicates no harm to human and organisms. The total amount of mirex in the environment in China was estimated to be about 25.12 tons, most of which exists in soil.

Characterization of persistent-bioaccumulative-toxic (PBTs) substances in hazardous waste: Integration of chemical analysis and in vitro fish cells response

High-resolution gas chromatography mass spectrometry (HRGC/MS) is the standard method for analyzing dioxin, furan, and polybrominated retardants in hazardous waste. Methods based on biological interactions (ligand–receptor recognition) have begun only recently to be investigated in the context of environmental applications. We have compared dioxin, furan, and polybrominated diphenyl ethers toxicity levels by two analytical approaches: HRGC/MS analysis and a battery of in vitro bioassays with the fish cell line rainbow trout gonad cell line-2 (RTG-2), in nine (liquid and solid) hazardous waste samples. The battery assays included a cytotoxicity neutral red bioassay, a Kenacid blue protein content bioassay, an ethoxyresorufin O-deethylase bioassay, and a β-galactosidase bioassay. A dose-dependent stimulation of enzymatic activities was observed in four of the nine samples, associated to high levels of octachlorodibenzo-p-dioxin (OCDD) and/or polychlorinated biphenyls (PCB) 77 congener. The enzymatic values of the whole samples were higher than the extracts’ values, which indicated that there had to be other effective compounds in the waste samples that could be lost in the extraction-purification process. The outcome of both approaches makes the bioassay useful as a rough estimate for the synergistic or antagonistic effects of polychlorinated dibenzo-p-dioxins (PCDDs)/Fs and dl-PCBs in extracts from the samples, and it can provide preliminary information regarding the characterization procedure in ecological risk.

Toxicity comparison of chlorinated and brominated dibenzo- p-dioxins and dibenzofurans in industrial source samples by HRGC/HRMS and enzyme immunoassay

Limited information is available on the applicability of polychlorinated dibenzo- p-dioxin/furan (PCDD/F) toxicity assays to their brominated counterparts: polybrominated dibenzo- p-dioxins/furans (PBDDs/Fs). We estimated the toxicity of mixtures of chlorinated, brominated, and mixed bromochloro-dioxins and -furan (PBCDDs/Fs) laboratory standards using a chemically-activated luciferase gene expression cell bioassay (CALUX). The relative effects potency (REP) values obtained were comparable to the World Health Organization (WHO) toxic equivalency factors (TEFs) and in agreement with the concept of additive congener toxicity of mixtures of dioxins and furans. Enzyme immunoassay (EIA)-based toxic equivalents (TEQs), however, showed overestimation for PCDDs/Fs (0–4 orders of magnitudes higher) and underestimation for PBDDs/Fs (0–1 orders of magnitude lower) when compared to high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS)-based TEQ calculation (using WHO TEFs) in samples from an industrial source line. No correlation was found between the EIA and the HRGC/HRMS data, which could be attributed to differences in homologue-specific cross-reactivity responses, sample matrix type, and presence of other compounds competing for antibody binding in the immunoassay.

Detection of benzotriazole UV stabilizers in the blubber of marine mammals by gas chromatography-high resolution mass spectrometry (GC-HRMS)

Benzotriazole UV stabilizers (BUVSs), such as UV-328 and UV-327, were identified in the blubbers of finless porpoises (Neophocaena phocaenoides) collected from the Ariake Sea, western Japan, by gas chromatography-high resolution mass spectrometry (GC-HRMS). The mean concentrations and standard deviations of UV-328 and UV-327 in five blubber samples were 38 ± 28 ng g(-1) (lipid wt) and 19 ± 19 ng g(-1), respectively. The bioconcentration factor (BCF) of UV-327 between water and finless porpoises was estimated to be 33 300, which is approximately one order of magnitude higher than that found for small fish inhabiting the same regions. The BCF of UV-327 in finless porpoises was similar to that of persistent organochlorine pesticide, hexachlorocyclohexane (HCH: 37 000) in marine mammals from the western North Pacific Ocean. These results suggest that BUVSs appear to be persistent and bioaccumulative in the aquatic food chain. Further investigations on temporal trends, and regional and global monitoring of BUVSs are needed to understand their environmental profiles and potential risks to wildlife and human.

Compounds Structurally Related to Dechlorane Plus in Sediment and Biota from Lake Ontario (Canada)

The historical occurrence of Dechlorane Plus (DP) and detection of novel compounds structurally related to DP is described in a dated Lake Ontario sediment core. Our core was collected near the mouth of the Niagara River, which is known to be a major source of DP to the lake. Maximum DP concentrations (920 ng g(-1), dry weight) were observed between 1976 and 1980, the highest reported to date. Following that time, we observed a dramatic decrease in DP concentration which coincided with the enactment of United States federal and state laws to mitigate free release of chemicals into the Niagara River and installation of an industrial wastewater treatment facility. During the course of our research, four new substances structurally related to DP were also identified. These compounds were thought to arise from the Diels-Alder reactions resulting from impurities present in 1,5-cyclooctadiene, a feedstock used in production of DP. To confirm our hypothesis, Diels-Alder reactions were performed on the individual impurities. Using different stationary-phase capillary gas chromatography columns and high-resolution mass spectrometry, we were able to positively identify some of these novel compounds in the core. Interestingly, we also were able to identify a monoadduct compound, formed by addition of 1 mol of hexachlorocyclopentadiene to 2 mol of 1,3-cyclooctadiene, in lake trout. The concentration of this monoadduct was approximately 2 orders of magnitude greater than that of DP, suggesting that it is more bioaccumulative.

Liquid chromatography–atmospheric pressure photoionization tandem mass spectrometry for analysis of 36 halogenated flame retardants in fish

A comprehensive, sensitive and high-throughput liquid chromatography–atmospheric pressure photoionization tandem mass spectrometry (LC–APPI-MS/MS) method has been developed for analysis of 36 halogenated flame retardants (HFRs). Under the optimized LC conditions, all of the HFRs eluted from the LC column within 14 min, while maintaining good chromatographic separation for the isomers. Introduction of the pre-heated dopant to the APPI source decreased the background noise fivefold, which enhanced sensitivity. An empirical equation was proposed to describe the relation between the ion intensity and dopant flow. The excellent on-column instrument detection limits averaged 4.7 pg, which was similar to the sensitivity offered by gas chromatography–high-resolution mass spectrometry (GC–HRMS). This method was used to analyze a series of fish samples. Good agreement was found between the results for PBDEs from LC–APPI-MS/MS and GC–HRMS.

Determination of 43 polycyclic aromatic hydrocarbons in air particulate matter by use of direct elution and isotope dilution gas chromatography/mass spectrometry

We are reporting a method for measuring 43 polycyclic aromatic hydrocarbons (PAH) and their methylated derivatives (Me-PAHs) in air particulate matter (PM) samples using isotope dilution gas chromatography/high-resolution mass spectrometry (GC/HRMS). In this method, PM samples were spiked with internal standards, loaded into solid phase extraction cartridges, and eluted by dichloromethane. The extracts were concentrated, spiked with a recovery standard, and analyzed by GC/HRMS at 10,000 resolution. Sixteen (13)C-labeled PAHs and two deuterated Me-PAHs were used as internal standards to account for instrument variability and losses during sample preparation. Recovery of labeled internal standards was in the range of 86-115%. The proposed method is less time-consuming than commonly used extraction methods, such as sonication and accelerated solvent extraction (ASE), and it eliminates the need for a filtration step required after the sonication extraction method. Limits of detection ranged from 41 to 332 pg/sample for the 43 analytes. This method was used to analyze reference materials from the National Institute of Standards and Technology. The results were consistent with those from ASE and sonication extraction, and these results were also in good agreement with the certified or reference concentrations. The proposed method was then used to measure PAHs on PM(2.5) samples collected at three sites (urban, suburban, and rural) in Atlanta, GA. The results showed distinct seasonal and spatial variation and were consistent with an earlier study measuring PM(2.5) samples using an ASE method, further demonstrating the compatibility of this method and the commonly used ASE method.

Influence of the solvent quality on the AhR mediated Procept® assay measurement of dioxin and dioxin-like compounds

Polychlorodibenzo-p-dioxins, polychorodibenzofurans and "dioxin-like" polychlorinated biphenyls are widespread persistent organic pollutants sharing a similar toxicological pathway mediated by the aryl-hydrocarbon receptor (AhR). Since the confirmatory method for their measurement at trace levels in complex matrices (using isotopic dilution and gas chromatography-high resolution mass spectrometry) remains time and cost-consuming, growing efforts of the scientific community have been focused on the development of screening approaches, including AhR mediated assays. Unfortunately, AhR ligands are highly diverse and agonistic/antagonistic effects can be observed on procedural blanks and/or sample extracts. In this study, the influence of solvent grade quality on the response of a DNA-binding AhR mediated assay used for screening dioxins has been investigated. Our results demonstrated a very critical impact of this parameter with both strong agonistic and antagonistic effects observed for any tested solvent lot. A small silver nitrate silica column removed partly these interfering compounds and then can be recommended as final purification step. Some preferable grades can be identified and selected in order to guarantee the best possible performances. However, it appears necessary to test every new lot, even if a grade appeared previously compliant.

Analysis of POPs in human samples reveal a contribution of brominated dioxin of up to 15% of the total dioxin TEQ

Polybrominated dibenzo- p-dioxins and dibenzofurans (PBDD/Fs) were analyzed in both human adipose tissue and plasma from nine individuals, from the Swedish general population, using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). In addition, several other persistent organic pollutants (POPs) were determined in the same samples, including polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated chemicals (PFCs). Polybrominated dibenzofurans were detected in all of the human adipose tissue samples confirming their presence in the Swedish population. The highest concentration was found for 2,3,7,8-TeBDF, ranging from 0.27 to 2.4 pg g −1 lipid, followed by 1,2,3,7,8-PeBDF, 0.23–0.89 pg g −1 lipid, 2,3,4,7,8-PeBDF, 0.44–0.54 pg g −1 lipid, and 2,7/2,8-DiBDF, 0.19–0.30 pg g −1 lipid. No PBDDs could be detected above the limit of detection (<0.02–<0.21 pg g −1 lipid) in any of the samples. The levels of PCDD/Fs were in the range 1.79–31.5 pg toxic equivalents (TEQ) g −1 lipid, and PBDEs were found in the 1.16–7.46 ng g −1 lipid range. The measured chlorinated dioxins indicate decreasing human concentrations in Sweden. The toxicity equivalents (TEQ) for PBDD/Fs (0.2–0.8 pg TEQ g −1 lipid) were found to contribute 1–15% of the total dioxin TEQ of the chlorinated dioxins and furans (5–18 pg TEQ g −1 lipid) depending on the individual. Also PBDEs concentrations are decreasing compared to 1997–2000, but most noteworthy a shift in BDE pattern where BDE#47 is surpassed by BDE#153. The levels of PFCs are in the same range as the highest levels of the traditional POPs (sum of 60 PCBs) based on volume. These findings illustrate the importance of continuous monitoring of brominated compounds in both human and the environment.

High-throughput screening of dioxins in sediment and soil using selective pressurized liquid extraction with immunochemical detection

A high-throughput screening method using selective pressurized liquid extraction (SPLE) and enzyme-linked immunosorbent assay (ELISA) for monitoring dioxins in sediment and soil is described. SPLE conditions were developed by extracting sediment or soil together with alumina, 10% AgNO 3 in silica, and sulfuric acid impregnated silica (acid silica) using dichloromethane (DCM) as the solvent at 100 °C and 2000 psi. Post-extraction cleanups were not required for ELISA. Two reference sediments (National Institute of Standards and Technology SRM 1944 and Wellington Laboratories WMS01) were analyzed by the SPLE–ELISA method. The ELISA utilized a polyclonal antibody and 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) as the calibrant. Recoveries of ELISA-derived TCDD equivalents (EQ) relative to the expected gas chromatography/high resolution mass spectrometry (GC/HRMS) derived dioxin toxic equivalent (TEQ) values were 116 ± 11% for SRM 1944 and 102 ± 13% for WMS01. ELISA TCDD EQs were consistent with the dioxin TEQs as measured by GC/HRMS for 25 soil/sediment samples from seven different contaminated sites. The ELISA had an approximate method detection limit of 10 pg g −1 with a precision of 2.6–29% based on the relative percentage difference (%RPD) for duplicate samples. Estimated sample throughput for the SPLE–ELISA was three times or more than that of the GC/HRMS method employing PLE with a multi-column cleanup.

Application of a Bioassay Using DR-EcoScreen Cells to the Determination of Dioxins in Ambient Air: A Comparative Study with HRGC-HRMS Analysis

There is a strong need for the development of relatively rapid and low-cost bioassays for the determination of dioxins (polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls) in environmental and food samples. In this study, we applied a bioassay system using highly sensitive DR-EcoScreen cells (DR-cell assay) to the determination of low levels of dioxins in ambient air samples. The dioxins from 80 ambient air samples were extracted, purified by cleanup procedure, and applied to both DR-cell assay and high-resolution gas chromatography/high-resolution mass spectrometry (HRGC-HRMS) analysis. Interestingly, the toxic equivalents (TEQ) values obtained from the DR-cell assay were closely correlated with those from the HRGC-HRMS analysis (r2 = 0.957). Although the cell-based TEQ values were relatively (3.66-fold) higher than the TEQ values from the HRGC-HRMS analysis, this discrepancy was thought to be due to the difference between the toxic equivalency factor (TEF) and the relative potency (DR-REP) determined for individual dioxins. Therefore, we multiplied the TEQ values from the DR-cell assay by a conversion coefficient (0.273, the reciprocal of 3.66) and could approximate the values from the HRGC-HRMS analysis. These results clearly suggest at the DR-cell assay might be a promising method for the rapid and low-cost screening of dioxins in ambient air samples.

Identification of a medicinal off-flavour in mineral water

The aim of the present study was to identify the compounds responsible for a characteristic medicinal off-odour in mineral water. 2-Dimensional high resolution gas chromatography–mass spectrometry analysis, in combination with olfactometry (HRGC–MS/O), led to the identification of 2-iodophenol and 2-iodo-4-methylphenol as the two compounds exhibiting the medicinal odour notes in mineral water. Determination of odour thresholds of these two compounds in air and water, as well as investigation of their odour characteristics in specific structure–odour activity assays, showed that 2-iodophenol and 2-iodo-4-methylphenol were both extremely potent odour substances with odour thresholds down to 0.03 and 0.0003 ng/L air and 0.313 and 0.009 μg/L water, respectively. The higher odour potency of 2-iodo-4-methylphenol suggests that this compound is primarily responsible for the medicinal off-odour. Furthermore, the same proportion of the panellists who were not able to detect the off-odour in mineral water exhibited drastically decreased sensibility to 2-iodo-4-methylphenol, but not to 2-iodophenol, which supports this hypothesis.

Method for the determination of tobacco specific nitrosamine related DNA adducts as their pentafluorobenzoyl ester in pancreatic tissue of sudden death victims

Cancer of the pancreas is the 13th most common type of cancer worldwide. Smoking causes a 70% increased risk for this cancer. The tobacco specific nitrosamine 4-(methylnitrosamino)1-(3-pyridyl)-1-butanone (NNK) is a strong carcinogen inducing pancreatic tumours in rodents. 4-(Methylnitrosamino)-1-(3pyridyl)-1-butanol (NNAL), a major NNKmetabolite, proved to be a more potent pancreatic carcinogen than NNK. Metabolic activation ofNNKandNNN lead to the formation of pyridyloxobutyl (POB) and pyridylhydroxybutyl (PHB)DNA adducts releasing 4-hydroxy-1-(3pyridyl)-1-butanone (HPB) and4-hydroxy-1-(3-pyridyl)-1-butanol (diol) after acid hydrolysis, respectively. NNK and NNAL were detected in human pancreatic juice, but metabolic activation leading to DNA adducts as necessary initial step in carcinogenesis has not yet been proven in pancreatic tissue. For analysis of pancreatic tissue, the established method for detection of HPB released after acid hydrolysiswas adopted for the detection of diol-releasing DNA adducts. After hydrolysis the diol was transferred to organic solvent and derivatized with pentafluorobenzoyl chloride (PFBC). The resulting ester was quantified by gas chromatography highresolution mass spectrometry negative chemical ionization. The derivatization product was qualified through specific mass fragmentation, showing the fragments for themolecular ion (m/z 361), the [M-HF]− ion (m/z 341) and the attached pentafluorobenzoate (m/z 167). For quantification in the single ionmode themass traces of PFBCesters fromdiol, HPBand the internal standard [3,3,4,4-D4]HPB, m/z 341, m/z 359, and m/z 363 were recorded. This method allowed for the first time the detection POB and PHB adducts in human pancreatic tissue of smoking and non-smoking sudden death victims.

Polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls levels in human breast milk from different regions of Turkey

Human breast milk offers the optimal nutrition for all infants and have been widely used in biomonitoring programs to assess human exposure to lipophylic environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB). There are no previous reports from Turkey on chemically determined levels of PCDDs, PCDFs, and PCBs in human breast milk expressed as World Health Organization (WHO) toxic equivalents (TEQ). To get an overview of the levels of these contaminants in Turkish human milk, samples from 51 Turkish women living in the Ankara, İstanbul, Antalya, Kahramanmaraş, and Afyon provinces were analyzed by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) throughout 2007. The mean concentrations of WHO PCDD/F-TEQ and WHO PCB-TEQ of all samples from the five regions were 7.5 and 3.1 pg g −1 on a lipid basis, respectively. PCDD/F concentrations ranged between 0.78 and 29.3 pg WHO-TEQ g −1 fat (1.7 and 36.2 pg WHO-TEQ g −1 fat, respectively, including PCB). Of the five studied locations, the lowest levels of ∑TEQs (PCDD/F + PCB) were found in the Afyon (6.8 pg WHO-TEQ g −1 fat) and the highest in the Antalya (15.6 pg WHO-TEQ g −1 fat) province. The results have been discussed in terms of regions and PCDD/F and PCBs for which analyses had been made. The mean levels of PCDD/Fs and PCBs in Turkish human milk are comparable to that found in other countries.

CALUX Bioassay of Dioxin-Like Compounds in Sediments from the Haihe River, China

Chemically Activated LUciferase gene eXpression (CALUX) bioassay is a rapid, effective, and cheap method to analyze dioxin-like compounds (DLCs). Using this method, total levels of DLCs, including PCDD/Fs (polychlorinated dibenzo-p-dioxin and dibenzofurans) fraction and DL-PCBs (dioxin-like polychlorinated biphenyls) fraction, in extracts of sediments from the Haihe River, China, were determined. It was found that the levels of PCDD/Fs in the sediments from the Haihe River were tens of times to hundreds of times higher than those of DL-PCBs. The DLC levels in sediments in March 2005 approximated those in November 2006. The CALUX toxic equivalents (TEQs) of DLCs were independent of the total organic carbon (TOC) of sediments. Significant correlation was observed between the PCDD/Fs TEQs and DL-PCBs TEQs. The two fractions of some samples were also analyzed by HRGC/HRMS (high-resolution gas chromatography/high-resolution mass spectrometry) method. Significant statistical correlations were observed between the CALUX TEQs and HRGC/HRMS TEQs. The difference between TEF (toxic equivalent factor) and REP (relative potency) can explain most of the discrepancy between CALUX and HRGC/HRMS analysis. A high level of DLCs was found at the sites near the influx into Bohai Bay. The dioxin pollution might be associated with industrial activities of pentachlorophenol (PCP) in the adjacent area. More attention should be paid to the increase of DLC levels and further investigation should be done for this area.

Dioxin-like chemicals in soil and sediment from residential and industrial areas in central South Africa

Persistent organic pollutants (POPs) are a global concern due to their ubiquitous presence and toxicity. Currently, there is a lack of information regarding POPs from South Africa. Here we report and interpret concentrations of polychlorinated dibenzo- p-dioxins (PCDDs), -dibenzofurans (PCDFs) and co-planar-biphenyls (PCBs) in soils and sediments collected from central South Africa. High resolution gas chromatography–high resolution mass spectrometry (HRGC/HRMS) and the H4IIE- luc bio-assay were used to identify and quantify individual PCDD/F congeners and to report the total concentration of 2,3,7,8-tetrachloro dibenzo- p-dioxin equivalents (TCDD-EQ), respectively. TCDD-EQs determined by use of the bio-assay, and concentrations of WHO 2005-TEQ (toxic equivalents) determined by chemical analysis, were similar. The limit of detection (LOD) for the bio-assay was 0.82 and 2.8 ng TCDD-EQ kg −1, dw for sediment and soil, respectively. EQ20 concentrations determined by use of the bio-assay ranged from <LOD to 70 ng TCDD-EQ kg −1, dw for soil, and from <LOD to 45 ng TCDD-EQ kg −1, dw for sediment. Concentrations of WHO 2005-TEQ in soils were generally greater than those in sediments, and soils from the industrial area of Vanderbijlpark and the residential area of Klerksdorp contained the greatest concentrations. Based on the congener-specific HRGC/HRMS analyzes, concentrations of WHO 2005-TEQ ranged from 0.12 to 32 ng WHO 2005-TEQ kg −1, dw in sediments, and between 0.34 and 20 ng WHO 2005-TEQ kg −1, dw in soils. The sources, processes and threats that govern and are associated with the lesser concentrations in sediment and greater concentrations in soils need further investigation.

Agent Orange exposure, Vietnam War veterans, and the risk of prostate cancer

BACKGROUND. It has been demonstrated that Agent Orange exposure increases the risk of developing several soft tissue malignancies. Federally funded studies, now nearly a decade old, indicated that there was only a weak association between exposure and the subsequent development of prostate cancer. Because Vietnam War veterans are now entering their 60s, the authors reexamined this association by measuring the relative risk of prostate cancer among a cohort of men who were stratified as either exposed or unexposed to Agent Orange between the years 1962 and 1971 and who were followed during the interval between 1998 and 2006. METHODS. All Vietnam War era veterans who receive their care in the Northern California Veteran Affairs Health System were stratified as either exposed (n = 6214) or unexposed (n = 6930) to Agent Orange. Strata-specific incidence rates of prostate cancer (International Classification of Diseases, 9th Revision code 185.0) were calculated. Differences in patient and disease characteristics (age, race, smoking history, family history, body mass index, finasteride exposure, prebiopsy prostate-specific antigen (PSA) level, clinical and pathologic stage, and Gleason score) were assessed with chi-square tests, t tests, a Cox proportional hazards model, and multivariate logistic regression. RESULTS. Twice as many exposed men were identified with prostate cancer (239 vs 124 unexposed men, respectively; odds ratio [OR], 2.19; 95% confidence interval [95% CI], 1.75-2.75). This increased risk also was observed in a Cox proportional hazards model from the time of exposure to diagnosis (hazards ratio [HR], 2.87; 95% CI, 2.31-3.57). The mean time from exposure to diagnosis was 407 months. Agent Orange-exposed men were diagnosed at a younger age (59.7 years; 95% CI, 58.9-60.5 years) compared with unexposed men (62.2 years; 95% CI, 60.8-63.6 years), had a 2-fold increase in the proportion of Gleason scores 8 through 10 (21.8%; 95% CI, 16.5%-27%) compared with unexposed men (10.5%; 95% CI, 5%-15.9%), and were more likely to have metastatic disease at presentation than men who were not exposed (13.4%; 95% CI, 9%-17.7%) than unexposed men (4%; 95% CI, 0.5%-7.5%). In univariate analysis, distribution by race, smoking history, body mass index, finasteride exposure, clinical stage, and mean prebiopsy PSA were not statistically different. In a multivariate logistic regression model, Agent Orange was the most important predictor not only of developing prostate cancer but also of high-grade and metastatic disease on presentation. CONCLUSIONS. Individuals who were exposed to Agent Orange had an increased incidence of prostate cancer; developed the disease at a younger age, and had a more aggressive variant than their unexposed counterparts. Consideration should be made to classify this group of individuals as ‘high risk,’ just like men of African-American heritage and men with a family history of prostate cancer. Cancer 2008. © 2008 American Cancer Society.

Characterization of benzoate degradation by newly isolated bacterium Pseudomonas sp. XP-M2

An effective benzoate-degradation strain XP-M2 belonging to the genus Pseudomonas, was newly isolated from aromatic compounds contaminated soils. The growing cells of strain XP-M2 completely degraded 10 g/L benzoate within 12 h, and the degradation efficiency was found to be higher than other reports. Catechol and cis,cis-muconic acid as the metabolic intermediates were identified by gas chromatography–high-resolution mass spectrometry, and the catA gene encoding catechol 1,2-dioxygenase in this strain was cloned and expressed in Escherichia coli, which indicated that benzoate degradation by Pseudomonas sp. XP-M2 was via the ortho-cleavage pathway. In addition, the Andrews model was used to describe the functional relationship between specific growth rate and benzoate concentrations with kinetics parameters: K S = 2.47 g/L, K I = 3.81 g/L.

PCBs and PCDD/DFs in waste oil illegally dumped and neglected for more than 20 years

Quantification of polychlorinated biphenyls (PCBs), polychlorinated-dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in waste oil by high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS), and profiling of their congeners and homologues were described. Waste oil packed in drums which were estimated to have been exposed to the weather for more than 20 years were found by the illegal dumping patrol in 2006. PCBs were detected in all of 12 waste oil samples examined, with concentrations in the range of 0.0032–22 μ g/g. The main pollution sources of the waste oil samples were presumed to be KC300, KC400 and/or KC500 by principal component analysis (PCA) and a chemical mass balance (CMB) method. The concentrations of PCDDs and PCDFs (PCDD/DFs) in the illegally dumped waste oil ranged from 1.1 to 360 pg/g and 1.3 to 110 pg/g, respectively. The ratios of toxicity equivalency quantity (TEQ) of PCDDs and PCDFs to Co-PCBs were lower than those of Yusho rice oil. Consequently, it was determined that even after 20 years of exposure to the weather, no PCB denaturation occurred. However, it was confirmed that low-chlorinated biphenyls in corroded drums would have evaporated into the atmosphere.

Mass Spectrometry

Mass Spectrometry