A Validated HPLC-MS/MS Assay for 14-O-[(4,6-Diaminopyrimidine-2-yl)thioacetyl] Mutilin in Biological Samples and Its Pharmacokinetic, Distribution and Excretion via Urine and Feces in Rats.

14-O-[(4,6-Diaminopyrimidine-2-yl)thioacetyl] mutilin (DPTM), a novel pleuromutilin candidate with a substituted pyrimidine moiety, has been confirmed to possess excellent antibacterial activity against Gram-positive bacteria. To illustrate the pharmacokinetic profile after intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) administrations with DPTM, as well as tissue distribution and excretion via urine and feces in vivo, a specific, sensitive and robust HPLC-MS/MS method was first developed to determine DPTM in rat plasma, various tissues, urine and feces. The plasma, tissues, urine and feces samples were treated by protein precipitation with acetonitrile using tiamulin fumarate as an internal standard (IS). This method which was achieved on an HPLC system detector equipped with an ESI interface, was sensitive with 5 ng/mL as the lower limit of detection and exhibited good linearity (R² > 0.9900) in the range of 5⁻4000 ng/mL for plasma, various tissues, urine and feces, as well as intra-day precision, inter-day precision and accuracy. The matrix effects ranged from 94.2 to 109.7% with RSD ≤ 9.4% and the mean extraction recoveries ranged from 95.4 to 109.5% in plasma, tissue homogenates, urine and feces (RSD ≤ 9.9). After i.v., i.m. and p.o. administrations, DPTM was rapidly absorbed and metabolized in rats with the half-life (t1/2) of 1.70⁻1.86, 3.23⁻3.49 and 4.38⁻4.70 for 10, 25 and 75 mg/kg doses, respectively. The tissue distribution showed that DPTM was diffused into all the tested tissues, especially into the intestine and lung. Excretion via urine and feces studies demonstrated that DPTM was mainly excreted by feces after administration.

[Analysis of inner or extra-exposure for worker in carbon and coal tar process industries].

Objective: To evaluate the inner or extra-exposure of workers in carbon and coal tar process industries. Methods: In May 2015, 271 exposure and 75 non-exposure workers in two of carbon and coal tar process industries in Shandong province were selected. Coal tar pitch (CTP) was detected according to the methods of GB17054-1997. The 1-OH-Nap、2-OH-Nap、1-OH-Pyr in urine were detected by high performance liquid Chromatography (HPLC) . Results: The concentration of 1-OH-Nap、2-OH-Nap、1-OH-Pyr in urine of exposure group were significant higher than that of control group (P<0.05) , respectively. The urine concentration of 1-OH-Nap、2-OH-Nap、1-OH-Py in contact group tar and asphalt were 12.20, 12.55, 7.08 and 10.62, 8.73, 3.07 µg/gCr, and the concentration of them were 7.25, 8.54, 3.00 µg/gCr in container handle workers. Significant positive correlations were found between high or median CTP exposure and the urine concentration of 1-OH-Nap、2-OH-Nap、1-OH-Pyr in exposure groups (P<0.05) . Conclusions: The inner or extra exposure level is relative and different for different type of work in these carbon and coal tar process industries.

The effects of heavy metals and their interactions with polycyclic aromatic hydrocarbons on the oxidative stress among coke-oven workers.

Heavy metals and polycyclic aromatic hydrocarbons (PAHs) are predominate toxic constituents of particulate air pollution that may be related to the increased risk of cardiopulmonary events. We aim to investigate the effects of the toxic heavy metals (arsenic, As; cadmium, Cd; chromium, Cr; nickel, Ni; and lead, Pb), and their interactions with PAHs on oxidative stress among coke-oven workers. A total of 1333 male workers were recruited in this study. We determined their urinary levels of As, Cd, Cr, Ni, Pb, twelve PAH metabolites, 8-hydroxydeoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α). Multivariate linear regression models were used to analyze the effects of these metals and their interactions with PAHs on 8-OHdG and 8-iso-PGF2α levels. It was found that only urinary As and Ni showed marginal or significant positive linear dose-dependent effects on 8-OHdG in this study population, especially among smokers (ß=0.103, P=0.073 and ß=0.110, P=0.002, respectively). After stratifying all participants by the quartiles of ΣOH-PAH, all five metals showed linear association with 8-OHdG in the highest quartile subgroup (Q4) of ΣOH-PAHs. However, these five urinary metals showed significantly consistent linear associations with 8-iso-PGF2α in all subjects and each stratum. Urinary ΣOH-PAHs can significant modify the effects of heavy metals on oxidative stress, while co-exposure to both high levels of ΣOH-PAHs and heavy metals render the workers with highest 8-OHdG and 8-iso-PGF2α (all P(interaction)≤0.005). This study showed evidence on the interaction effects of heavy metals and PAHs on increasing the oxidative stress, and these results warrant further investigation in more longitudinal studies.

Identification of metabolites of deoxyschizandrin in rats by UPLC-Q-TOF-MS/MS based on multiple mass defect filter data acquisition and multiple data processing techniques.

Deoxyschizandrin is an active lignin ingredient originating from Schisandra chinensis (Turcz.) Baill or Schisandrae Sphenantherae Fructus. In the present study, a novel and efficient strategy was developed for the in vivo screening and identification of deoxyschizandrin metabolites using ultra high performance liquid chromatography combined with triple TOF mass spectrometry (UPLC-TOF/MS/MS). This strategy was characterized by the following: a novel and unique multiple mass defect filter (MMDF) combined with an on-line data acquisition method that is dependent on dynamic background subtraction (DBS) was developed to trace all of the probable metabolites of deoxyschizandrin. The MMDF and DBS methods could trigger an IDA scan for the low-level metabolites that are masked by background noise and endogenous components. A combination of data processing methods including extracted ion chromatography (XIC), mass defect filtering (MDF), product ion filtering (PIF) and neutral loss filtering (NLF) were employed to identify the metabolites of deoxyschizandrin. Next, the structures of the metabolites were elucidated based on an accurate mass measurement, the fragmentation patterns of the parent drug and relevant drug bio-transformation knowledge. Finally, an important parameter ClogP was used to estimate the retention time of isomers. Based on the proposed strategy, 51 metabolites (including 49 phase I and 2 phase II metabolites) were identified in rats after the oral administration of deoxyschizandrin. Among these metabolites, 41 metabolites were characterized in the rat urine, and 28 metabolites were identified in the rat bile. The results indicated that oxidization was the main metabolic pathway and that the methoxy group and the biphenyl cyclooctene were the metabolic sites. Conjugation with sulfate and cysteine groups produced two phase-II metabolites. This study firstly reported the description of deoxyschizandrin metabolism in vivo. This study provided a practical strategy for rapidly screening and identifying metabolites, and this methodology can be widely applied for the structural characterization of the metabolites of other compounds.

Urinary metabolites before and after cleanup and subjective symptoms in volunteer participants in cleanup of the Hebei Spirit oil spill.

BACKGROUND: On December 7th, 2007, the Hong Kong tanker Hebei Spirit (HS) (146,848 tons) was crushed by a crane ship near the shore of Taean, Korea. More than 12,547 kl of crude oil spilled into the sea and contaminated the western coastline of the Korean peninsula. For a period of six months after the accident, approximately 1,000,000 volunteers participated in the cleanup. Our goal in this study was to examine the exposure status and acute health effects on volunteers that participated in the oil spill cleanup. METHODS: A survey questionnaire was filled out by 565 volunteers, requesting information regarding physical symptoms. Out of the total number of participants, urine samples from 105 university student volunteers were collected before and after the cleanup work, and metabolite levels of volatile organic compounds and polycyclic aromatic hydrocarbons were analyzed. RESULTS: Volunteers that participated for longer cleanup work reported an increase in physical symptoms including visual disturbance, nasal and bronchus irritation, headaches, heart palpitations, fatigue and fever, memory and cognitive disturbance, and abdominal pain. The levels of t,t-muconic acid, mandelic acid, and 1-hydroxypyrene were significantly higher in samples after cleanup than those measured before participation (p<0.05). Other than the associated risk of dermal irritation with the difference in the t,t-muconic acid level between the post- to pre-cleanup levels, no other physical symptoms demonstrated a significant association with changes observed in the levels of urinary metabolites. CONCLUSIONS: Based on the significant increase of subjective symptoms in volunteers participating in the study, monitoring of the long term health effects, focusing on those with longer exposure, is warranted.

Joint effects of XRCC1 polymorphisms and polycyclic aromatic hydrocarbons exposure on sperm DNA damage and male infertility.

X-ray repair cross-complementing group 1 (XRCC1) plays a role in repairing polycyclic aromatic hydrocarbons (PAHs)-induced DNA damage. We examined the effects of exposure to PAHs and XRCC1 polymorphism, alone or combined, on sperm DNA integrity and male fertility. A total of 620 idiopathic infertile subjects and 273 fertile controls were recruited in this study. PAHs exposure was indicated by urinary 1-hydroxypyrene level. Genotypes were determined by PCR-RFLP, and sperm DNA damage was detected by Tdt-mediated dUTP nick end labelling assay using flow cytometry. A positive correlation was found between PAHs exposure and sperm DNA damage (beta coefficients = 0.183, p < 0.001), whereas there was no significant association between the XRCC1 polymorphisms and sperm DNA damage. However, when the patients were dichotomized for PAHs exposure, higher sperm DNA damage was found among 399Gln allele carriers compared with the wild-type homozygotes (p = 0.033). Further analysis based on a case-control study revealed the joint effect of XRCC1-399 polymorphism and PAHs exposure on the risk of male infertility (p interaction = 0.041). These findings provided the first evidence about potential joint effects of PAHs exposure and DNA repair gene polymorphisms on male reproductive system and may be helpful in improving our understanding of the etiology of male infertility.

Urinary 1-hydroxypyrene as a biomarker of PAH exposure in 3-year-old Ukrainian children.

Urinary 1-hydroxypyrene (1-OHP) is a biomarker of polycyclic aromatic hydrocarbon (PAH) exposure. We measured urinary 1-OHP in 48 children 3 years of age in Mariupol, Ukraine, who lived near a steel mill and coking facility and compared these with 1-OHP concentrations measured in 42 children of the same age living in the capital city of Kiev, Ukraine. Children living in Mariupol had significantly higher urinary 1-OHP and creatinine-adjusted urinary 1-OHP than did children living in Kiev (adjusted: 0.69 vs. 0.34 micromol/mol creatinine, p < 0.001; unadjusted: 0.42 vs. 0.30 ng/mL, p = 0.002). Combined, children in both cities exposed to environmental tobacco smoke in their homes had higher 1-OHP than did children not exposed (0.61 vs. 0.42 micromol/mol creatinine; p = 0.04; p = 0.07 after adjusting for city). In addition, no significant differences were seen with sex of the children. Our sample of children in Mariupol has the highest reported mean urinary 1-OHP concentrations in children studied to date, most likely due to their proximity to a large industrial point source of PAHs.

Polyurethane foam chips combined with liquid chromatography in the determination of unmetabolized polycyclic aromatic hydrocarbons excreted in human urine.

A method suitable for the determination of unmetabolized polycyclic aromatic hydrocarbons (PAHs) excreted at trace levels (ng/L) in human urine for the monitoring of exposure of the general population to PAH contamination was developed. PAHs were determined, after enrichment by solid-phase extraction on polyurethane foam (PUF) chips, by HPLC with fluorescence detection. Different parameters affecting analyte extraction to the PUF, including urine salting-out and organic additives, and optimization of conditions for clean-up and desorption have been investigated. Optimized conditions were 40 mL acidified urine sample, added with magnesium sulfate, tetrahydrofuran and a 2 cm3 PUF chip, and extracted by shaking at 30 rpm for 1 h at ambient temperature. Desorption was performed, after a clean-up step with diluted sodium hydroxide, using a small amount of diethyl ether. The recovery of PAH congeners from spiked urines was >90% in the 2-100 ng/L range; the detection limit was 0.1-0.5 ng/L, depending on the considered PAH congener; day-to-day precision, at 50 ng/L native PAH content, was CV = 10-20%. The proposed technique provides a simple, economical and effective procedure for the determination of trace amounts of unmetabolized PAHs excreted in human urine spot samples.

Non-smoking coke oven workers show an occupational PAH exposure-related increase in urinary mutagens.

We examined the urinary mutagenicity in the YG1024 Salmonella typhimurium strain in the presence of S9 mix, of 31 male non-smoking coke oven workers and an equal number of controls matched for gender and dietary habits. Occupational PAH exposure to the workers was assessed by means of the individual urinary post-shift excretion of 1-pyrenol (mean +/- S.D.: 5.41 +/- 6.06 micromole/mol creatinine). Eleven urinary extracts of workers (35.5%) were clearly mutagenic (with at least a doubling of the number of spontaneous revertants), against only two samples in the control group (6.5%) (chi2-test; chi2 = 7.883; P < 0.01). Moreover, the mean mutagenic activity level corrected for dilution/concentration of the urine was about three times higher in coke oven workers than in matched controls (mean +/- S.D. (range) 495 +/- 407 (89.7-1603) versus 186 +/- 113 (14.2-524) net revertants/mmol creatinine; Mann-Whitney U-test, z = 3.86, P < 0.001). Simple linear regression analysis showed that the coke workers' urinary mutagenic activity is associated with the PAH occupation-related urinary excretion of 1-pyrenol (r = 0.41, P = 0.0215). This study definitely demonstrates an occupation-related exposure of coke oven workers' bladder epithelium to mutagenic PAH metabolites. This factor, mainly in the case of high exposure studied here, may account for a higher bladder cancer risk in coke oven workers.

Biomonitoring of polycyclic aromatic hydrocarbons in human urine.

Measurement of polycyclic aromatic hydrocarbons (PAH) metabolites in human urine is the method of choice to determine occupational and/or environmental exposure of an individual to PAH, in particular, when multiple routes of exposure have to be taken into account. Requirements for methods of biomonitoring PAH metabolites in urine are presented. Studies using 1-hydroxypyrene or phenanthrene metabolites including its phenols and dihydrodiols are summarized. The role of these PAH metabolites as established biomarkers and also more recent developments of PAH biomonitoring are discussed.

Determination of selected monohydroxy metabolites of 2-, 3- and 4-ring polycyclic aromatic hydrocarbons in urine by solid-phase microextraction and isotope dilution gas chromatography-mass spectrometry.

Eighteen monohydroxy polycyclic aromatic hydrocarbon metabolites (OH-PAHs) representing polycyclic aromatic hydrocarbons (PAHs) containing up to four rings in human urine have been measured. The method includes the addition of carbon-13 labeled internal standards, enzymatic hydrolysis, and solid-phase microextraction followed by gas chromatography with high-resolution mass spectrometry. By using response factors calculated with the carbon-13 labeled standards, results are presented for calibration, relative standard deviations and analyte levels from an unspiked human urine pool. The method detection limits ranged from 0.78 ng/l for hydroxyphenanthrenes to 15.8 ng/l for 1-hydroxynaphthalene, and the recoveries ranged between 6% for hydroxychrysene and 47% for 1-hydroxypyrene. The relative standard deviation was lowest for 3-hydroxyphenanthrene at 2.4% and went up to 18.7% for 6-hydroxychrysene. The method was calibrated from 10 to 1200 ng/l. Eleven of the 18 metabolites were found in background pooled urine samples. This validated method is a convenient and reliable tool for determining urinary OH-PAHs as biomarkers of exposure to eight PAHs.

Aromatic and polycyclic hydrocarbons in air and their urinary metabolites in coke plant workers.

This study describes the exposure of coke plant workers to hydrocarbons. Aromatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) in the breathing zone air and their oxygenated metabolites in the urine of coke plant workers are qualitatively and quantitatively determined. Concentrations of benzene, toluene, naphthalene, m + p-xylene, o-xylene and 14 different PAHs were measured at the different workplaces by personal air sampling. O-cresol, 1- and 2-naphthol, methylhippuric acid, and 1-hydroxypyrene were determined in hydrolyzed urine of workers collected after the work shift. The gas chromatography-mass spectrometry (GC/MS) method was applied to identify AHs in air and in urine samples. Time-weighted values of exposure to aromatic hydrocarbons at a coke plant were: benzene (0.06-9.82 mg/m3), toluene (0.05-4.71 mg/m3), naphthalene (0.01-3.28 mg/m3), o-xylene (0.01-1.76 mg/m3) and m + p-xylene (0.01-2.62 mg/m3). At the coke batteries, the total concentration of PAHs ranged from 7.27 to 21.92 micrograms/m3. At the sorting department, the total concentration of PAHs were about half this value. Concentration of the urinary metabolites (naphthols and methylhippuric acid) detected in workers at the tar distillation department are three times higher than those for the coke batteries and sorting department workers. A correlation between inhaled toluene, naphthalene, xylene, and urinary excretion of metabolites has been found. Time-weighted average concentrations of AHs in the breathing zone air show that exposure levels of the workers are rather low in comparison to exposure limits. The 1-hydroxypyrene concentration is below 24.75 mumol/mol creatinine. The GC/MS analysis reveals the presence of AHs, mainly benzene and naphthalene homologues. It has been found that coke plant workers are simultaneously exposed to the mixture of aromatic and polycyclic hydrocarbons present in the breathing zone air of a coke plant. Exposure levels are significantly influenced by job categories. Compounds identified in the urine appear to be the products of the hydroxylation of AHs present in the air as well as unmetabolized hydrocarbons.

Biological monitoring of environmental exposure to PAHs in the vicinity of a Söderberg aluminium reduction plant.

OBJECTIVES: To assess environmental exposure to polycyclic aromatic hydrocarbons (PAHs) in the vicinity of a Söderberg aluminium reduction plant in Shawinigan, Canada with urinary 1-hydroxypyrene (1-OHP) as a biomarker. METHODS: Urine samples were collected from 20 non-occupationally exposed subjects living less than 500 m from the plant and from 20 controls living in Trois-Rivières, another industrial town 40 km from Shawinigan. Concentrations of 1-OHP were measured by high performance liquid chromatography (HPLC). RESULTS: Among controls, geometric mean (range) 1-OHP concentrations were 0.046 (0.012-0.116) mumol/mol creatinine in non-smokers and 0.125 (0.051-0.282) mumol/mol creatinine in smokers. Among exposed subjects, values were 0.103 (0.056-0.196) mumol/mol creatinine in non-smokers and 0.250 (0.112-0.448) mumol/mol creatinine in smokers. Excretion of 1-OHP was significantly higher in exposed subjects than in controls among non-smokers and smokers (P < 0.05). CONCLUSION: Based on urinary 1-OHP as a biomarker, it seems that living near an industrial point source of PAHs is associated with higher exposure. The health significance of this finding will require further investigation.

Human exposure and dosimetry of polycyclic aromatic hydrocarbons in urine from Xuan Wei, China with high lung cancer mortality associated with exposure to unvented coal smoke.

The lung cancer mortality rate in Xuan Wei (XW) county, China, is 5-fold the national average of China; the rate for women is the highest in China. Xuan Wei residents have been exposed to unvented coal or wood smoke during cooking or heating in homes. This study investigated indoor air exposure and dosimetry of polycyclic aromatic hydrocarbons (PAHs) in XW residents using smoky coal. Indoor air particles collected during cooking in four XW homes using smoky coal were analyzed for PAHs by GC/MS. Urine samples from 16 XW non-smoking women and six XW smoking men, eight Kunming non-smoking controls and four non-smoking Chinese American controls were analyzed for PAHs and hydroxy-PAHs by GC/MS. The results showed that XW residents were exposed to PAHs at occupational levels. The potent carcinogen, dibenzo[a,l] pyrene (4.9 +/- 1.3 micrograms/m3) was found in the indoor air of the XW homes. The levels of urinary hydroxy-PAH were higher than those of the parent compounds in most subjects, indicating that most PAHs were metabolized. In urine, the mean levels of 9-hydroxy BaP (BaP) and BaP are 1.5 +/- 0.5 mumol/mol creatinine and 0.5 +/- 0.3 microns/mol for XW men, 1.9 +/- 0.9 microns/mol and 0.5 +/- 0.3 microns/mol for XW women. In general, the levels of PAH metabolites in urine were higher in the XW residents than in Kunming and Chinese American controls; however only the concentrations of 9-hydroxy BaP in XW women showed statistically significant difference from the Kunming controls (P < 0.05 by ranking test). The mean levels of 3 methylated-PAHs analyzed were 4.8-fold higher than that of the parent PAHs in XW subjects. This is consistent with previous findings that alkylated PAHs are the major mutagens in the XW indoor air and may be etiologically important in XW lung cancer.

Improved high-performance liquid chromatographic method for the determination of polycyclic aromatic hydrocarbon metabolites in human urine.

A reversed-phase HPLC method with fluorescence detection was evaluated for utility in determination of urinary metabolites of polycyclic aromatic hydrocarbons as biomarkers of environmental exposure. The method, which was developed for use in studies of high-level occupational exposure, was found to be unreliable for relatively low-level environmental exposures. The method was modified to include quantitation by standard addition in order to compensate for matrix effects at levels as low as 0.1 ng/ml. The standard addition modification increased both qualitative and quantitative performance, with recovery of 1-hydroxypyrene spikes improved from 164% to 114% at 0.36 ng/ml. The modified method was successfully applied in an environmental exposure study.

Urinary excretion of mutagens in coke oven workers.

The influence of occupational exposure to polycyclic aromatic hydrocarbons (PAHs) on urinary mutagenic activity was assessed in 75 coke oven workers, using a highly sensitive bacterial mutagen technique (extraction with C18 resin and liquid micro-preincubation test on strain TA98 of Salmonella typhimurium in the presence of metabolizing and deconjugating enzymes). Exposure to PAHs was assessed according to the urinary excretion of 1-pyrenol; the main confounding factors were checked by the number of cigarettes smoked per day and the levels of nicotine and its metabolites in urine, or by ascertaining whether recommended dietary restrictions had been followed. Of the 20 urine samples which turned out to be positive (producing at least double the number of spontaneous revertants), 19 (95%) belonged to smokers. Only one non-smoker had obvious urinary mutagenic activity, and was highly exposed occupationally to PAHs (urinary 1-pyrenol of 3.930 mumol/mol of creatinine). Of the five urine samples from subjects who had not followed the recommended diet, two (40%) were clearly mutagenic. Multiple regression analysis (n = 67) showed that the presence of samples positive for urinary mutagenic activity depended only on smoking habits, if this confounding factor was assessed according to the number of cigarettes smoked per day, while the significant influence of exposure to PAH could be shown when the confounding factor was objectively estimated according to the urinary levels of nicotine and its metabolites. Assessment of the mutagenic potency of urinary extracts (net revertants/mmol creatinine) confirmed the strong influence of smoking habits on urinary mutagenic activity (all smokers 2156 +/- 2691 versus non-smokers 939 +/- 947 net revertants/mmol creatinine; Mann-Whitney test: P < 0.01). In smokers highly exposed to PAHs, greater excretion of mutagens with respect to low-exposure smokers was revealed (3548 +/- 4009 versus 1552 +/- 1227 net revertants/mmol creatinine; Mann-Whitney test: P < 0.01). Multiple regression analysis showed that the mutagenic potency of urinary extracts of coke oven workers depended on exposure to PAHs, tobacco smoking habits, and consumption of fried, grilled or barbecued meat. Increased urinary mutagenic activity strengthens epidemiological evidence of the increased risk of renal and urinary tract tumours in these workers. The presence of mutagenic metabolites in urine as a result of occupational exposure to PAH may be demonstrated only by using highly sensitive techniques for assessing urinary mutagenic activity in studies which include careful checking of the main confounding factors.

Background urinary 1-hydroxypyrene levels in non-occupationally exposed individuals in the Province of Québec, Canada, and comparison with its excretion in workers exposed to PAH mixtures.

The urinary excretion of 1-hydroxypyrene (1-OHP) was measured in two reference groups of non-occupationally exposed individuals and in four groups of workers. Two of these groups were exposed to what were considered to be low levels of polycyclic aromatic hydrocarbons (PAH) on the basis that even post-shift 1-OHP excretion values were low (< 2 mumol/mol creatinine). Therefore, urine samples were collected from these workers after a period of > 60 h without occupational exposure which should yield values approaching background levels. Pooling these results with those of the reference groups yielded a total of 140 individuals having a mean (geometric) excretion of 0.08 mumol/mol creatinine and 5th, 50th and 95th percentiles of 0.02, 0.09 and 0.32 mumol/mol creatinine. The mean (geometric) excretion in the 95 nonsmokers and 45 smokers of this pool was 0.07 and 0.12 mumol/mol creatinine, respectively (one-tailed Student t-test, P < 0.001). Both this background excretion and the contribution of smoking appeared small in comparison with the excretion levels observed in some groups of exposed workers. Indeed, creosote workers described in this report had a geometric mean (range) excretion of 1.63 (0.18-10.47) mumol/mol creatinine during their working week. It is concluded that, for the biological monitoring of workers exposed to PAH, urinary 1-OHP appears to be a useful bioindicator for which background environmental contamination or smoking habits can be neglected in most cases.

Urinary 1-hydroxypyrene as biomarker of exposure to polycyclic aromatic hydrocarbons in workers in petrochemical industries: baseline values and dermal uptake.

The suitability of urinary 1-hydroxypyrene as a biomarker for the assessment of exposure to polycyclic aromatic hydrocarbons (PAH) in petrochemical industries was evaluated in 562 workers involved in various operations in petrochemical industries. The median 1-hydroxypyrene concentration in 121 of these workers (both smokers and non-smokers) who had had no recent occupational exposure to PAH was 0.11 mumol/mol creatinine. The upper limit of the 95% confidence interval was 0.51 mumol/mol creatinine. During activities with a low potential exposure to PAH, such as loading bitumen and the handling of clarified slurry oils and furfural extracts, 1-hydroxypyrene concentrations were only marginally increased compared with the values measured in the 121 workers with no recent occupational exposure to PAH. Despite the substantially higher potential exposure to PAH during clean-out operations of various oil refinery installations, the concentrations of 1-hydroxypyrene in the workers involved were in the same range. This suggests that personal protection equipment was generally adequate to prevent excessive exposure. However, in workers digging PAH-contaminated soil and workers engaged in the production of needle coke from ethylene cracker residue, significantly increased urinary 1-hydroxypyrene concentrations were measured. A major decrease in urinary 1-hydroxypyrene following the application of dermal protective equipment in the ground workers suggested that skin absorption plays a major role in occupational exposure to PAH. The excretion of 1-hydroxypyrene by the workers of the needle coke plant was investigated in relation to potential determinants of exposure to PAH. It was indeed found that not only inhalatory but also dermal exposure was a significant determinant of occupational exposure to PAH.

Coupled-column high-performance liquid chromatographic method for the determination of four metabolites of polycyclic aromatic hydrocarbons, 1-, 4- and 9-hydroxyphenanthrene and 1-hydroxypyrene, in urine.

A coupled-column high-performance liquid chromatographic method applying system-integrated sample processing on a copper phthalocyanine modified solid-phase material, gradient elution and fluorescence detection for the quantification of 1-, 4- and 9-hydroxyphenanthrene as well as for 1-hydroxypyrene in urine is described. The automated chromatographic system tolerates direct and repeated injection of urine samples. Validation results presented indicate quantitative and matrix-independent recoveries, low imprecisions in within-series and between-series analysis in combination with broad linear working ranges (2-400 nmol/l) and low detection limits (< 0.1 nmol/l).