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Exposure of firefighting instructors to polycyclic aromatic hydrocarbons (PAHs) such as naphthalene is unavoidable during live fire training. The study aimed to investigate naphthalene uptake by measuring the urinary excretion of the naphthalene metabolite 1,2-dihydroxynaphthalene (DHN), to describe the DHN elimination kinetics and to evaluate the results by comparison to further biomarkers of PAH exposure. N = 6 male non-smoking firefighting instructors completed five training sessions each in a residential fire simulation unit under respiratory protection. All participants provided two urine samples before and another seven samples within an 18-h-interval after each session. DHN was detected by gas chromatography/tandem mass spectrometry (GC-MS/MS) in all samples (n = 237) with median concentrations ranging from 3.3 µg/g crea. (range 0.9-10.2) before exposure to 134.2 µg/g crea. (43.4-380.4) post exposure. Maximum elimination found 3.3 h (median) after onset of exposure decreased with a mean half-life of 6.6 h to 27.1 µg/g crea. (15.7-139.5) 18 h after training. DHN sensitively indicated a presumed dermal naphthalene intake during training, showing similar elimination kinetics like other naphthalene metabolites. Internal exposure of the participants transiently exceeded exposures determined for non-smokers in the general population, but was lower than at other workplaces with PAH exposure. Despite limited uptake, accumulation is possible with daily exposure., (© 2024. The Author(s).)

Firefighting instructors in live fire training are inevitably exposed to emissions containing, carcinogenic PAH. The study investigated PAH uptake in a group of firefighting instructors during short-term exposure in live fire training by urinary biomonitoring. Six firefighting instructors (non-smokers) completed five 2 h-training sessions each in a carbonaceous-fired simulation unit using self-containing breathing apparatuses (SCBA). Complying with a minimum time interval of six days between the individual training sessions, the participants provided urine samples before and immediately after, as well as 1, 3, 6, 9, 11, and 18 h after each training session. Samples were analyzed for 10 mono-hydroxylated metabolites of the PAH naphthalene, fluorene, phenanthrene and pyrene using gas chromatography/tandem mass spectrometry. A significant effect of the training sessions on the time course of internal exposure was found (p < 0.0001). The concentration of all parameters clearly increased at the latest 3 h after end of training. After peaking, the concentrations dropped with half-lives between 3.5 and 9.3 h but did not reach the initial levels within 18 h again. Compared to pre-training levels, the increase in metabolite excretion was between 546-933 %. During peak excretion reference values for hydroxynaphthalene (35 μg/L, sum of 1- and 2-isomer) and 1-hydroxypyrene (0.30 μg/L) were exceeded in 64 % (maximum: 381.3 μg/L) and 73 % of the samples (maximum: 1.88 μg/g crea.), respectively. Live fire training is associated with an additional uptake of PAH. Due to the consequent use of SCBA, dermal absorption is assumed as major exposure route. Further measures to reduce PAH exposure should be considered, in particular since higher internal loads caused by accumulation effects are to be expected with daily or more frequent training., Competing Interests: Declaration of competing interest Bernd Rossbach, Daniel Wollschläger, Stephan Letzel are employees of the University Medical Center of the Johannes Gutenberg-University of Mainz, Germany. Axel Muttray has retired; he is a former employee of the University Medical Center of the Johannes Gutenberg-University of Mainz, Germany. The above institution received funding to conduct the study from the magistrate of the City of Frankfurt/Main, Germany. Wolfgang Gottschalk is employee of the City of Frankfurt/Main, Germany. The authors declare the following financial interests/personal relationships which may be considered as potential competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Tropenol ester is a highly toxic anticholinergic substance and an intermediate used in industrial production of the bronchodilator tiotropium bromide. The aim of this study was to systematically test workers involved in its production for tropenol ester in urine to identify any exposure pathways and define additional preventive measures. Twelve workers performing tasks involving potential exposure to tropenol ester were repeatedly monitored at the end of each production cycle. Medical exams revealed no symptoms of acute poisoning with tropenol ester, but biological monitoring of urine showed 36 positive findings in 79 samples, with tropenol ester concentrations ranging between the detection limit of 54 pg/mL and 2160 pg/mL. We managed to establish the cause of only one positive finding, which was a hole in a protective glove, whereas the rest most likely occurred due to human error. Because of this, the plant decided to modify the production process by replacing tropenol ester with a safer intermediate. While it is the safest course of action, there where it cannot be taken, biological monitoring can be very helpful in raising awareness about exposure to toxic substances, including the new ones that have not been studied for their adverse potential.

Purpose: This study aims at experimentally determining the incidence and extent of liquid releases onto the operator's hands and into the work environment during common nursing operations involving infusions., Methods: A sequence of operations related to the preparation and administration of infusions was conducted by three subjects for 15 times each using fluorescein marked infusion solutions and two different infusion sets (standard set vs. safety-optimized set). Unintended release of liquid was quantified by glove and surface wipe sampling and HPLC/FD analysis of the samples. Operations concerning the disposal of infusions were also part of the study., Results: In over 90% of the simulations, a release of infusion solution was observed in a standard workflow, comprising priming and decapping the infusion set, connecting it to a peripheral intravenous (IV) cannula, and detaching it again. Based on median values (229 vs. 26 μl), the release of infusion solution was about ninefold higher when using the non-optimized standard infusion set. During decapping, a hand contamination was found in a majority of cases., Conclusions: The handling of infusions may involve a risk of nurses' exposure to active agents by release of infusion solution into the work environment. According to our results with different infusion sets, exposure risks can be reduced technically and by appropriate handling. Nevertheless, hand contaminations found for both sets emphasize the necessity for additional measures such as more consistent use of protective gloves.

Purpose: Human biomonitoring (HBM) implies the assessment of internal exposure to hazardous substances by measuring the substances, their metabolites or reaction products, as well as effect parameters in human body fluids. Along with blood, plasma and urine, saliva is of increasing interest as an alternative matrix for HBM., Methods: This paper reviews studies that measure salivary background levels of hazardous substances, elevated levels after environmental or occupational exposure, as well as references which deal with physiological and toxicokinetic behaviour of saliva and salivary parameters, respectively., Results: The studies revealed that the determination of biomarkers in saliva is a promising approach for HBM, even if only few substances showed a satisfying correlation with exposure data or established biomonitoring matrices such as blood, plasma and urine. Saliva has been proven to be particularly suitable for substances of low molecular weight such as organic solvents, selected pesticides, cotinine, and for some specific trace elements. Besides several advantages, serious problems and limitations were identified. Above all, the complex interactions between substance properties, sampling procedure, sample preparation, measurement techniques or individual factors, and the salivary analyte level are discussed., Conclusions: A major conclusion of the review is that more scientific studies are needed in order to systematically collect data on parameters, influencing salivary analyte levels. Crucially required is a harmonisation of the sampling as well as the sample preparation techniques and procedures, which is indispensable to achieve an overall comparability and interpretability of salivary biomarker levels.

Objectives: To analyse differences in uptake of the insecticide permethrin in wearers of non-impregnated and permethrin impregnated battle dress uniforms (BDU) in Afghanistan and Germany., Methods: In two separate studies, in April 2003-January 2004 (study I, n=549) and in February-April 2005 (study II, n=195), healthy female and male members of the German Federal Armed Forces were equipped with permethrin impregnated BDU (two sub-cohorts in Germany and one in Afghanistan) while members equipped with non-impregnated uniforms served as a control group. Human biomonitoring was conducted before, during and after wearing the uniforms by measuring permethrin metabolites in urine samples via GC-MS., Results: Subjects of the Afghan and German control groups had permethrin levels in the range of the German general population. In contrast, subjects wearing impregnated BDU had about 200-fold higher exposure levels. Within this group, subjects located in Afghanistan and smokers had significantly higher exposure levels. Internal exposure decreased with increasing duration of use of impregnated BDU., Conclusions: There is no evidence for a higher background permethrin contamination in military bases located in Afghanistan compared to Germany. Daily use of permethrin impregnated BDU is associated with significantly higher permethrin uptake compared to the general population. Hand-mouth contact by smoking can increase uptake which also seems to be influenced by the duration of use of impregnated BDU.

In order to examine exposure and health risks which can arise from permethrin-impregnated clothing, a controlled trial was conducted. In a study group consisting of 187 volunteers in total, a subgroup of 86 persons was equipped with permethrin-impregnated battle dress uniforms (BDU) for 28 days. One hundred and one persons served as a control group, wearing non-impregnated BDUs throughout the entire study period of 56 days. Internal exposure of all participants was assessed by determination of urinary permethrin metabolites (cis-DCCA, trans-DCCA and 3-PBA) on day 0, 14 and 28 of the wearing period and 28 days after termination of wearing. Exposure levels in the control group ranged within background exposure of the general German population at all four dates of sampling (medians Sigma DCCA+3-PBA were 0.09, 0.13, 0.23 and 0.10mug/l, respectively). For the group equipped with impregnated BDUs this applied to day 0 (0.31mug/l) only, while the following measurements revealed considerably higher metabolite concentrations (31.39, 22.01 and 1.44mug/l, respectively), especially while wearing impregnated clothing. Due to these results a substantial uptake of permethrin from impregnated BDUs has to be assumed. However, since calculations reveal a maximum permethrin uptake clearly below the acceptable daily intake (ADI), health impairments are rather unlikely., (Copyright 2009 Elsevier Ireland Ltd. All rights reserved.)

Objectives: This is the second of two parallel longitudinal studies investigating Al exposure and neurobehavioral health of Al welders over 4 years. While the first published study in the trail and truck construction industry examined the neurobehavioral development of Al welders from age 41-45 in the group mean (Kiesswetter et al. in Int Arch Occup Environ Health 81:41-67, 2007), the present study in the automobile industry followed the development from 35 to 39. Although no conspicuous neurobehavioral developments were detected in the first study, which furthermore exhibited the higher exposure, it cannot be excluded that exposure effects appear in earlier life and exposure stages., Methods: The longitudinal study is based on a repeated measurement design comprising 4 years with three measurements in 2 years intervals. 92 male Al welders in the automobile industry were compared with 50 non-exposed construction workers of the same industry and of similar age. The repeated measurements included total dust in air, and Al pre- and post-shift plasma and urine samples. Neurobehavioral methods comprised symptoms, verbal intelligence, logic thinking, psychomotor behavior, memory, and attention. The computer aided tests came from the Motor Performance Series and the European Neurobehavioral Evaluation System. The courses of neurobehavioral changes were analyzed with multivariate covariance-analytical methods considering the covariates age, indicators of 'a priori' intelligence differences (education or markers of 'premorbid' intelligence), and alcohol consumption (carbohydrate-deficient transferrin in plasma). Additionally, the interrelationship, reliability and validity of biomonitoring measures were examined., Results: The mean environmental dust load during welding, 0.5-0.8 mg/m(3), and the mean internal load of the welders (pre-shift: 23-43 microg Al/g creatinine in urine; 5-9 microg Al/l plasma) were significantly lower than in the parallel study. Under low exposure, the stability of biomonitoring measures was reduced, but the Al load differed significantly between Al welders and referents. It could not be shown that the development of neurobehavioral performances over the 4-year period differed between both groups. Mainly, markers of premorbid intelligence and age were related to neurobehavioral performance differences but not Al exposure., Conclusions: The biomonitoring and neurobehavioral results are in line with the results of the first published study. The repeated measurement models of both studies showed no adverse neurobehavioral effects of Al welding. A modular lifetime-oriented research concept is outlined aiming at the investigation of sequential periods of exposure life with special focus on the biologically most sensitive phases like first exposure and old age.

Exposure to polycyclic aromatic hydrocarbons (PAH) and DNA damage were analyzed in coke oven (n = 37), refractory (n = 96), graphite electrode (n = 26), and converter workers (n = 12), whereas construction workers (n = 48) served as referents. PAH exposure was assessed by personal air sampling during shift and biological monitoring in urine post shift (1-hydroxypyrene, 1-OHP and 1-, 2 + 9-, 3-, 4-hydroxyphenanthrenes, SigmaOHPHE). DNA damage was measured by 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and DNA strand breaks in blood post shift. Median 1-OHP and SigmaOHPHE were highest in converter workers (13.5 and 37.2 microg/g crea). The industrial setting contributed to the metabolite concentrations rather than the air-borne concentration alone. Other routes of uptake, probably dermal, influenced associations between air-borne concentrations and levels of PAH metabolites in urine making biomonitoring results preferred parameters to assess exposure to PAH. DNA damage in terms of 8-oxo-dGuo and DNA strand breaks was higher in exposed workers compared to referents ranking highest for graphite-electrode production. The type of industry contributed to genotoxic DNA damage and DNA damage was not unequivocally associated to PAH on the individual level most likely due to potential contributions of co-exposures.

Objectives: This study was conducted to assess external and internal exposure of workers to polycyclic aromatic hydrocarbons (PAHs). In this context, the analytical and diagnostical reliability of 3-hydroxybenzo[a]pyrene (3OH-BaP) as a biomarker of internal exposure to PAHs was established., Methods: Ambient and biological monitoring was carried out of 225 PAH-exposed employees of different industries. External exposure was determined by personal air sampling and analysis of 16 EPA-PAH. Internal exposure was examined by the urinary metabolites 3OH-BaP, 1-hydroxypyrene (OH-Pyr) and monohydroxylated phenanthrenes (OH-Phens)., Results: Benzo[a]pyrene (BaP) was detected at all workplaces. Concentrations in the breathing zone of the workers ranged from below the limit of detection up to 44.3 mug/m(3). In biological monitoring, urinary 3OH-BaP was found in median concentrations of 0.8 ng/g creatinine (crea) and the 95th percentile of 6.7 ng/g crea. The results ranged from the limit of detection up to 19.5 ng/g crea. Only 1% of the analysed samples showed concentrations below the limit of detection (0.05 ng/l). Regarding median concentrations, workers in coking plants showed lower 3OH-BaP concentrations (0.5 ng/g crea) than those employed in the production of fireproof material in refractories (1.1 ng/g crea), converter infeed (1.2 ng/g crea) and graphite electrode production (1.3 ng/g crea). Strong correlations of 3OH-BaP with OH-Pyr and the sum of OH-Phens were found for the workplaces converter infeed, coking plants and graphite electrode production (r(Pearson) ranging from 0.618 to 0.867, p<0.001). The poor correlation of BaP in the air and 3OH-BaP in urine is most probably caused by routes of uptake other than via air-for example, dermal uptake., Conclusion: 3OH-BaP as a metabolite of the carcinogenic BaP could be shown to be a diagnostically specific and sensitive biomarker for determining the internal exposure of workers in different industries. Using this method, the estimation of health risks for workers can be fundamentally improved, because the 3OH-BaP represents the group of carcinogenic PAHs. The procedure for analysing 3OH-BaP is complex, but it is robust and produces reliable results.

In an age when vector-borne diseases are emerging worldwide, personal protective measures are essential for shielding soldiers and other exposed persons from arthropod attack. The development of permethrin-impregnated clothing has been one recent advance in protecting persons at-risk. However, to date risk assessment has not been performed related to wearing permethrin-impregnated clothing over longer time periods. Therefore, this paper describes relevant toxicological aspects of permethrin and estimates the extent of dermal permethrin uptake by soldiers wearing impregnated uniforms by determining urine metabolites of permethrin. The exposure monitoring conducted in wearers of untreated uniforms did not show any signs of increased permethrin uptake and was similar to that of the general population in Germany. By contrast, studies involving the soldiers wearing permethrin-impregnated uniforms identified far higher internal exposure, the amounts of urine metabolites clearly above the reference value for the background exposure of the German population at large. Comparing the median excretion values, an approximately 200 times higher exposure can be assumed. The excretion levels of the subject with the maximum amount of metabolites correspond to an internal exposure of around 5-6microg/kg body weight and day thereby considering that biomonitoring could not take all urine metabolites and other elimination routes into account. Based on an oral absorption rate of 50%, the internal dose of 5-6microg/kg body weight and day would correspond to an oral uptake of permethrin which is around 20% of the ADI value of 50microg/kg body weight and day. In addition, based on these data and using a dermal absorption rate of 2% the permethrin dose reaching the skin was estimated to be 250microg/kg body weight and day. Considering a standard body weight and the area covered by the uniform, an exposure level of about 1.25microg permethrin/cm(2) skin and day can be calculated. Clinical subjective symptoms were recorded by means of a self-reporting questionnaire which has been developed and used for this specific purpose in environmental outpatient departments in both groups (wearers of impregnated versus non-impregnated uniforms). Only minor sensory impairments were identified in one of the studies (Kabul/Afghanistan) which may represent skin paraesthesiae. Based on these results, it can be assumed that the normal use of permethrin-treated uniforms does not affect human health to a clinical relevant extent. We recommend that the release rate of permethrin from the textile material should be strictly monitored by means of a quality assurance method. It should comply with standards to which the results of this study may contribute.

Objectives: The aim of our study was to assess individual polycyclic aromatic hydrocarbon (PAH) exposure of workers coming from three different industrial branches by several parameters of external and internal exposure. By analysing the relationships between those markers the suitability of individual parameters [e.g. monohydroxylated phenanthrene (Phe) metabolites] for exposure surveillance should be evaluated., Methods: The total study population consisted of 255 male workers (age: 19-62, mean: 39.61 years), who were employed in coke production (n=40), production of graphite electrodes and special carbon products (92), or production of refractory materials (123), respectively. For each worker external PAH exposure was determined by personal air sampling of 16 PAH, including Phe, pyrene (Pyr) and benzo[a]pyrene (BaP). For determination of internal PAH exposure the excretion of the PAH metabolites 1-, 2 + 9-, 3-, 4-hydroxyphenanthrene and 1-hydroxypyrene was measured in post-shift urine samples of all workers., Results: In the total study population median total PAH exposure and exposure to BaP were 30.62 and 0.27 microg/m(3), respectively. A calculation of PAH profiles resulted in substantial branch-related variations with Phe being a major component. Considering all branches the median excretions of 1-hydroxypyrene and hydroxyphenanthrenes (sum) were 6.68 and 11.22 microg/g creatinine. A correlation analysis yielded a good correlation between total ambient PAH exposure and excretion of hydroxyphenanthrenes in urine (r=0.662; P<0.01), but no significant correlation between Phe metabolites and the carcinogenic BaP. For 1-hydroxypyrene and BaP a weak but significant association was found (r=0.235; P<0.01)., Conclusions: Considering the results of the correlation analysis hydroxyphenanthrenes in urine should reflect an uptake of lowly condensed volatile PAH rather than an incorporation of highly condensed PAH like BaP which should be reflected better by 1-hydroxypyrene. Therefore, the determination of hydroxyphenanthrenes in addition to the well-established marker 1-hydroxypyrene could offer some further information about the exposure situation at a particular work place.

Objectives: Previous cross sectional studies on potential neurotoxic effects of long-term aluminium exposures by aluminium welders lack clear interpretable results for methodological reasons. The present longitudinal study examined on the one hand the reliability and representativity of Al-biomonitoring as indicator of individual long-term exposure and on the other hand the long-term changes of neurobehavioural performance in Al welders in relation to Al exposure and neurobehavioural performance changes of a non-exposed control group., Methods: The longitudinal study compared repeatedly measured exposure data and neurobehavioural data of 20, initially 44, male Al welders in the train and truck construction industry with data of a control group of similar age on the basis of three investigations over a period of 4 years. The repeated measurements of exposure included total dust in air as well as Al in pre- and post-shift plasma and urine samples. Neurobehavioural methods comprised symptoms, verbal intelligence, logic thinking, psychomotor behaviour, memory, and attention. Computer-aided tests from the Motor Performance Series (MLS) and the European Neurobehavioural Evaluation System (EURO-NES) were used. The characteristics of the biomonitoring data and the relationship to neurobehavioural data were examined with methods of correlation and regression analysis. The courses of neurobehavioural changes were analysed with multivariate covariance-analytical methods (MANCOVA) considering the covariates age, indicators of 'a priori' intelligence differences (education or 'premorbid' intelligence), and alcohol consumption (carbohydrate-deficient transferrin in plasma, CDT)., Results: The mean total dust load during welding, near to the routinely worn ventilated helmets, was in the range of 5-8 mg/m(3). The biomonitoring data of the welders (pre-shift: 88-140 microg Al/g creatinine in urine; 13-16 microg Al/l plasma) showed a high long-term stability but also sensitivity to acute shift dependent exposure changes. The Al welders who had been working in this profession at an average of 15 years showed no significantly increased symptom levels compared with the control group. Explorative regression and covariance analyses revealed neither a correlation between biomonitoring and performance variables nor a significant difference between Al-exposed and controls in the performance courses during the 4 years period. Explorative modelling indicated that the structure of neurobehavioural outcomes could be determined by possible indicators of intellectual 'a priori' (premorbid) differences between subjects but not by their exposure information., Conclusions: Compared to studies in the literature this study is characterized by relatively high and non-confounded Al exposure of the welders, a repeated-measurement design, and multivariate analyses. However, the long-term stable interindividual differences of internal Al exposure were not related to interindividual differences in neurobehavioural performances. Additionally, the lack of processual changes of neurobehavioural performances during the observation phase and the insignificant group differences do not make it very probable that degenerative processes caused by Al had happened before study onset or stopped just at this time point.

In regulatory toxicology, the dose-response relationship between occupational exposure and biomarkers is of importance in setting threshold values. We analyzed the relationships between occupational exposure to polycyclic aromatic hydrocarbons (PAH) and various biomarkers of internal exposure and DNA damage with data from 284 highly exposed male workers. Personal exposure to phenanthrene and other PAHs was measured during shift and correlated with the sum of 1-, 2+9-, 3-, and 4-hydroxyphenanthrenes in post-shift urine. PAHs and hydroxyphenanthrenes were associated with DNA damage assessed in WBC as 8-oxo-7,8-dihydro-2'-deoxyguanosine/10(6) dGuo and strand breaks by Comet assay as Olive tail moment. Hydroxyphenanthrenes correlated with phenanthrene (Spearman r(s) = 0.70; P < 0.0001). No correlations could be found between strand breaks and exposure (r(s) = 0.01, P < 0.0001 for PAHs; r(s) = -0.03, P = 0.68 for hydroxyphenanthrenes). Correlations with 8-oxo-7,8-dihydro-2'-deoxyguanosine/10(6) dGuo were weakly negative (r(s) = -0.22, P = 0.004 for PAHs) or flat (r(s) = -0.08, P = 0.31 for hydroxyphenanthrenes). Linear splines were applied to assess the relationships between the log-transformed variables. All regression models were adjusted for smoking and type of industry. For hydroxyphenanthrenes, 51.7% of the variance could be explained by phenanthrene and other predictors. Up to 0.77 microg/m(3) phenanthrene, no association could be found with hydroxyphenanthrenes. Above that point, hydroxyphenanthrenes increased by a factor of 1.47 under a doubling of phenanthrene exposure (slope, 0.56; 95% confidence interval, 0.47-0.64). Hydroxyphenanthrenes may be recommended as biomarker of occupational PAH exposure, whereas biomarkers of DNA damage in blood did not show a dose-response relation to PAH exposure.

In 1999, we introduced the German polycyclic aromatic hydrocarbons (PAH) study. The study was designed as a nation-wide investigation on workers exposed to PAH. One aim of the study was to establish biological monitoring guidance values (BMGVs) for different branches. Here, we report on the production of fire-proof materials. This branch of industry is typically confronted with high exposure to PAH and with PAH-induced occupational (cancer) diseases. One hundred and thirty-five employees participated in the course of seven sampling dates in four different plants in Germany. External exposure was determined by personal air monitoring of the 16 EPA-PAH. Human biological monitoring was accomplished by the determination of 1-hydroxypyrene and monohydroxyphenanthrenes in post-shift spot urine samples. Concentrations of PAH in the air of the workplaces ranged up to 1102.6microg/m(3). Maximum benzo[a]pyrene concentration was 38.2microg/m(3). The internal PAH exposure of workers was much higher compared with that of the general population. Median concentration for 1-hydroxypyrene was 6.4microg/g creatinine (maximum 279.6, 90th percentile 23.9microg/g creatinine) and for the sum of monohydroxyphenanthrene metabolites 13.3microg/g creatinine (maximum 313.4, 90th percentile 70.8microg/g creatinine). The following BMGVs for the non-smokers of this branch of industry are proposed: for 1-hydroxypyrene 18microg/g creatinine and for the sum of hydroxyphenanthrenes 77microg/g creatinine in urine measured at the end of the shift.

To evaluate an adequate strategy for biological monitoring of aluminium (Al), a group of 62 Al welders (age in 1999: 23-51 years, median 35 years) was surveyed annually from 1999 to 2003 by determination of pre- and post-shift Al in urine and plasma. Biomonitoring was supplemented by personal air measurements of the total dust concentration. The welders' internal exposure was compared to the exposure of 60 non-exposed assembly workers (age in 1999: 21-51 years, median: 36 years) who were surveyed in 1999, 2001 and 2003. Having a nearly constant dust exposure, median concentrations of Al in urine (Al in plasma) of the welders decreased from 40.1 microg/g to 19.8 microg/g creatinine (8.7 to 4.6 microg/l). For the control group the median levels of Al in urine (plasma) ranged from 4.8 microg/g to 5.2 microg/g creatinine (2.4-4.3 microg/l) indicating a higher sensitivity for the marker Al in urine. No systematic differences have been found between pre- and post-shift internal exposure. This might be caused by the slow elimination kinetics and low systemic bioavailability of Al. A correlation analysis did not yield close relationships between dust exposure, Al in plasma and Al in urine underlining the importance of biomonitoring for assessment of Al exposure.

A cross-sectional study was conducted in 170 German workers exposed to polycyclic aromatic hydrocarbons (PAH) to investigate the role of 11 polymorphisms of CYP1A1, CYP1A2, CYP1B1, CYP3A4, EPHX1, GSTM1, GSTT1, and GSTP1 in the association between occupational exposure to PAH and urinary PAH metabolites. Polymorphisms were genotyped with real-time PCR. Exposure to 16 PAH was measured by personal air sampling. Urinary concentrations of 1-hydroxypyrene (1-OHP) and the sum of 1-, 2+9-, 3-, and 4-hydroxyphenanthrenes (OHPhe) were determined post-shift. Urinary 1-OHP and OHPhe correlated significantly with exogenous pyrene (Spearman r=0.52, p<0.0001) and phenanthrene (Spearman r=0.72, p<0.0001), respectively. ANCOVA was applied to investigate potential predictors of the metabolite levels. Current smoking and type of industry turned out to be predictors of 1-OHP but not of OHPhe. CYP1A1 3801TC carriers showed 1.6-fold higher OHPhe levels than 3801TT carriers (p=0.03). EPHX1 113HH was associated with higher and 139RR with lower metabolite levels when compared with the corresponding reference genotypes (113YY; 139HH). In comparison to GSTP1 114AA, carriers of the V allele had 1.5-fold higher 1-OHP (p=0.03) and 2-fold higher OHPhe concentrations (p=0.001). OHPhe turned out to be also a suitable biomarker of occupational PAH exposure. The association with ambient PAH exposure and the influence of polymorphisms was more pronounced for OHPhe.

Objectives: The aims of this study were to determine external and internal polycyclic aromatic hydrocarbon (PAH) exposure in a coke plant and to contribute to the evaluation of biological limit values., Methods: Personal air sampling was carried out on a study population of 24 coke plant workers. In detail, 16 PAHs were determined, among them phenanthrene, pyrene and benzo[ a]pyrene. For the determination of internal exposure, post-shift urine samples from the workers were examined for hydroxylated metabolites of pyrene (1-hydroxypyrene, 1-OHP) and phenanthrene (1-, 2+9-, 3-, 4-hydroxyphenanthrene, 1-, 2+9-, 3-, 4-OHPhe). In both cases, approved HPLC methods were used., Results: The workers were classified into three groups. The group most exposed was that on the top side of the coke oven, with a mean value of 491.2 microg/m(3) for the sum of all sixteen PAHs. The mean value at the bench side was 26.61 microg/m(3), while it was 76.18 microg/m(3) in the group of workers with no dedicated location (=complete area). Both the excretion of 1-OHP and the sum of hydroxyphenanthrenes had the highest mean levels in the top side group of workers (mean: 19.70 microg/g creatinine (crea.) and 39.18 microg/g crea.), followed by the bench-side workers (mean: 7.01 microg/g crea. and 12.95 microg/g crea.) and the whole-area workers (mean: 3.57 microg/g crea. and 8.70 micorg/g crea.). The concentrations of all urinary metabolites correlated significantly with benzo[ a]pyrene (BaP) in the air., Conclusions: According to these correlations, urinary concentrations of 8 and 11 microg 1-OHP/g crea., respectively 16 and 23 microg/g crea. for the sum of hydroxyphenanthrenes, correspond to BaP concentrations in air of 2 and 5 micorg/m(3), the German technical guiding concentration (TRK value). Our results are in line with others reported in the literature. That means that it should be possible today to define a standard of occupational hygiene and medicine in coke plants using the elimination of hydroxyphenanthrenes and hydroxypyrene in urine as markers for internal PAH exposure.

The relationship between biomarkers of effect (8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo, HPLC system) and tail extent moment (comet assay)), markers of external and internal exposure, and biomarkers of susceptibility was evaluated for coke-oven and graphite-electrode-producing plant workers exposed to polycyclic aromatic hydrocarbons (PAHs). Mean 8-oxodGuo levels in white blood cells (WBC) of exposed workers were between 1.38 times (coke-oven, n = 20; P < 0.01) and 2.15 times (graphite-electrode-producing plant, n = 30; P < 0.01) higher than levels found in control samples (mean +/- SD 0.52 +/- 0.16 8-oxodGuo/10(5) dGuo, n = 47). The mean tail extent moment in lymphocytes was 1.38 times higher for coke-oven workers (n = 19; P = 0.09) and 3.13 times higher for graphite-electrode-producing plant workers (n = 29; P < 0.01) when compared with controls (mean plus minus SD 2.54 +/- 0.68, n = 32). Elevated tail extent moments (>3.73) were found in the majority (84%) of PAH-exposed workers showing increased DNA adduct levels (>0.78 8-oxodGuo/10(5) dGuo). However, no association (P > 0.05) was found between DNA damage (8-oxodGuo/10(5) dGuo or tail extent moment) in WBC of all PAH-exposed workers and either benzo[a]pyrene levels or the sum of 16 PAH levels in the air at work place. Furthermore, no relation (P > 0.05) could be established between DNA damage in WBC and biomarkers of internal exposure (1-hydroxypyrene (1-OHP) and sum of five hydroxyphenanthrenes (OHPHs)). Higher exposure to airborne pyrene and phenanthrene led to increasing concentrations of the metabolites 1-OHP (P < 0.01) and the sum of five OHPHs (P < 0.01) in the urine of PAH-exposed workers. The polymorphisms of genes CYP1A1, GSTM1, GSTT1 and GSTP1 (biomarkers of susceptibility) showed no association with biomarkers of effect. In conclusion, both biomarkers of effect may be appropriate for further surveillance studies of workers under PAH exposure.