A pilot study on the feasibility of European harmonized human biomonitoring: Strategies towards a common approach, challenges and opportunities.

In 2004 the European Commission and Member States initiated activities towards a harmonized approach for Human Biomonitoring surveys throughout Europe. The main objective was to sustain environmental health policy by building a coherent and sustainable framework and by increasing the comparability of data across countries. A pilot study to test common guidelines for setting up surveys was considered a key step in this process. Through a bottom-up approach that included all stakeholders, a joint study protocol was elaborated. From September 2011 till February 2012, 17 European countries collected data from 1844 mother-child pairs in the frame of DEMOnstration of a study to COordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES).(1) Mercury in hair and urinary cadmium and cotinine were selected as biomarkers of exposure covered by sufficient analytical experience. Phthalate metabolites and Bisphenol A in urine were added to take into account increasing public and political awareness for emerging types of contaminants and to test less advanced markers/markers covered by less analytical experience. Extensive efforts towards chemo-analytical comparability were included. The pilot study showed that common approaches can be found in a context of considerable differences with respect to experience and expertize, socio-cultural background, economic situation and national priorities. It also evidenced that comparable Human Biomonitoring results can be obtained in such context. A European network was built, exchanging information, expertize and experiences, and providing training on all aspects of a survey. A key challenge was finding the right balance between a rigid structure allowing maximal comparability and a flexible approach increasing feasibility and capacity building. Next steps in European harmonization in Human Biomonitoring surveys include the establishment of a joint process for prioritization of substances to cover and biomarkers to develop, linking biomonitoring surveys with health examination surveys and with research, and coping with the diverse implementations of EU regulations and international guidelines with respect to ethics and privacy.

Interpreting biomarker data from the COPHES/DEMOCOPHES twin projects: Using external exposure data to understand biomarker differences among countries.

In 2011 and 2012, the COPHES/DEMOCOPHES twin projects performed the first ever harmonized human biomonitoring survey in 17 European countries. In more than 1800 mother-child pairs, individual lifestyle data were collected and cadmium, cotinine and certain phthalate metabolites were measured in urine. Total mercury was determined in hair samples. While the main goal of the COPHES/DEMOCOPHES twin projects was to develop and test harmonized protocols and procedures, the goal of the current paper is to investigate whether the observed differences in biomarker values among the countries implementing DEMOCOPHES can be interpreted using information from external databases on environmental quality and lifestyle. In general, 13 countries having implemented DEMOCOPHES provided high-quality data from external sources that were relevant for interpretation purposes. However, some data were not available for reporting or were not in line with predefined specifications. Therefore, only part of the external information could be included in the statistical analyses. Nonetheless, there was a highly significant correlation between national levels of fish consumption and mercury in hair, the strength of antismoking legislation was significantly related to urinary cotinine levels, and we were able to show indications that also urinary cadmium levels were associated with environmental quality and food quality. These results again show the potential of biomonitoring data to provide added value for (the evaluation of) evidence-informed policy making.

Gender differences in cadmium and cotinine levels in prepubertal children.

Susceptibility to environmental stressors has been described for fetal and early childhood development. However, the possible susceptibility of the prepubertal period, characterized by the orchestration of the organism towards sexual maturation and adulthood has been poorly investigated and exposure data are scarce. In the current study levels of cadmium (Cd), cotinine and creatinine in urine were analyzed in a subsample 216 children from 12 European countries within the DEMOCOPHES project. The children were divided into six age-sex groups: boys (6-8 years, 9-10 years and 11 years old), and girls (6-7 years, 8-9 years, 10-11 years). The number of subjects per group was between 23 and 53. The cut off values were set at 0.1 µg/L for Cd, and 0.8 µg/L for cotinine defined according to the highest limit of quantification. The levels of Cd and cotinine were adjusted for creatinine level. In the total subsample group, the median level of Cd was 0.180 µg/L (range 0.10-0.69 µg/L), and for cotinine the median wet weight value was 1.50 µg/L (range 0.80-39.91 µg/L). There was no significant difference in creatinine and cotinine levels between genders and age groups. There was a significant correlation between levels of cadmium and creatinine in all children of both genders. This shows that even at such low levels the possible effect of cadmium on kidney function was present and measurable. An increase in Cd levels was evident with age. Cadmium levels were significantly different between 6-7 year old girls, 11 year old boys and 10-11 year old girls. As there was a balanced distribution in the number of subjects from countries included in the study, bias due to data clustering was not probable. The impact of low Cd levels on kidney function and gender differences in Cd levels needs further investigation.

Occupational, life stress and family functioning: does it affect semen quality?

BACKGROUND AND AIMS: Although psychological stress has been implicated as a cause of idiopathic infertility in both men and women, it has received little scientific attention among males as compared to females. The aim of the study was to examine the association between occupational, life stress, family functioning and semen quality. METHODS AND RESULTS: The study population consisted of 327 men who were attending an infertility clinic for diagnostic purposes. Psychological stress was assessed based on two questionnaires: The Subjective Work Characteristics Questionnaire and the Perceived Stress Scale. The level of satisfaction with family functioning and support was evaluated by means of the APGAR Family Scale. The findings suggest that, on the one hand, exposure to occupational stressors can be negatively associated with semen quality (there was a positive association between stress and the percentage of sperm with DNA damage (p = 0.03) and atypical sperm (p = 0.05)); on the other hand, there was no correlation between the level of life stress and semen quality indicators. Negative associations were found between satisfaction with family functioning and the percentage of motile sperm cells (p = 0.02), VAP (p = 0.05), VSL (p = 0.05) and VCL (p = 0.04). CONCLUSION: The study indicates that occupational stress can affect male semen quality; however, due to limited data on this issue, the obtained results should be confirmed in longitudinal studies.

Quantitative determination of 5-hydroxy-N-methylpyrrolidone in urine for biological monitoring of N-methylpyrrolidone exposure.

The aim of this work was to validate a sensitive method for quantitative analysis of 5-hydroxy-N-methylpyrrolidone (5-HNMP) in urine. This compound has been recommended as a marker for biological monitoring of N-methylpyrrolidone (NMP) exposure. Different solvents and alternative methods of extraction including liquid-liquid extraction (LLE) on Chem Elut and solid-phase extraction (SPE) on Oasis HLB columns were tested. The most efficient extraction of 5-HNMP in urine was LLE with Chem Elut columns and dichloromethane as a solvent (consistently 22% of recovery). The urinary extracts were derivatized by bis(trimethylsilyl)trifluoroacetamide and analysed by gas chromatography-mass spectrometry (GC-MS) with tetradeutered 5-HNMP as an internal standard. The detection limit of this method is 0.017 mg/l urine with an intraassay precision of 1.6-2.6%. The proposed method of extraction is simple and reproducible. Four different m/z signal ratios of TMS-5-HNMP and tetralabelled TMS-5-HNMP have been validated and could be indifferently used in case of unexpected impurities from urine matrix.

The disposition and metabolism of durene (1,2,4,5-tetramethylbenzene) in rats.

The organ and tissue distribution, excretion and metabolism of [3H]1,2,4,5-tetramethylbenzene ([3H]durene) in male Wistar albino rats were investigated following a single i.p. administration (40 mg/kg) and within 9 days after five daily repeated administrations. Urine proved to be the main route of tritium excretion. Within the first 24 h after a single administration 69% of the radioactivity was excreted in the urine and only 9% in the feces. The highest level of tritium binding was found in the fat tissue, liver, kidneys and adrenal glands. The accumulation of tritium in the plasma proceeded with a kinetic constant of 0.49 h(-1), whereas the half-life of radioactivity decay amounted to about 6.3 h. In erythrocytes, the tritium level was found to be about three times lower than in blood plasma. The total amount eliminated during the 9 days following repeated administration was about 94% of the five doses given. The highest level of tritium was found in fat tissue and adrenal glands, followed by the liver, kidneys, sciatic nerve and muscle. A gradual decline in tritium levels was observed during the following 4 days in most tissues to reach about 2% of the dose given. The main urinary metabolites resulting from the administration of durene were 2,4,5-trimethylbenzyl alcohol (about 22%), 4,5-dimethyl-1,2-benzdialdehyde (about 19%), 2,4,5-trimethylbenzaldehyde (about 19%) and 2,4,5-trimethylbenzoic acid (about 16%). The oxygen-containing metabolites accounted for almost 80%, whereas sulphur-containing metabolites accounted for approximately 10% of the products of biotransformation. In conclusion, most of the durene administered has a relatively rapid turnover rate, with minor levels retained in the tissues for longer time periods.

The disposition and metabolism of 1,3,5-[U-14C]trioxane in male Wistar albino rats.

The present study was designed to investigate 1,3,5-[U-14C]trioxane (TOX) distribution, excretion and metabolism. The experiments were performed on male Wistar albino rats after a single administration of TOX at doses of 40 mg/kg and 400 mg/kg. The exhaled air proved to be the main route of 14C elimination, mainly as 14CO2. During the first 12 h following the administration of 40 mg/kg of TOX the exhalation of 14CO2 was monophasic, with a half-life of 3.5 h. After the administration of 400 mg/kg, TOX was eliminated mainly as 14CO2 with the exhaled air (77%) and unchanged TOX (8%). About 3% of 14C was excreted in the urine as unchanged 1,3,5-trioxane. With regards to TOX elimination from blood plasma for the lower dose, a biphasic process was observed, with half-lives of 4.5 and 72 h. The amount of 14C bound by the erythrocytes was minute compared with the amount in blood plasma. When the higher dose of TOX was administered the efficiency of 14C binding to the erythrocytes was found to be 10 times higher than the respective value for blood plasma. Among the examined tissues the highest concentration of TOX-derived radioactivity was detected in the liver while the lowest was in fat tissue and brain. A subsequent decay of radioactivity occurred in the tissues. The results of the present study indicate that TOX belongs to the group of compounds, which are rapidly eliminated from the organism; hence TOX should not be expected to accumulate within the tissues. The data obtained confirm the assumed pattern of metabolic transformation, according to which 1,3,5-trioxane undergoes enzymatic transformation to formaldehyde, with carbon dioxide and water being the final products.

Occupational exposure to coal tar pitch volatiles, benzo/a/pyrene and dust in tyre production.

Occupational exposure to coal tar pitch volatiles (CTPVs), benzo/a/pyrene (BaP) and dust was evaluated by means of individual measurements carried out in 80 workers and by stationary measurements on 16 work-posts in two divisions of the tyre producing plant. Dust and coal tar pitch volatiles concentrations in the air were determinated by the gravimetric method, measured, in the case of CPTVs, benzene-soluble fraction (BSF) with ultrasonic extraction. Benzo/a/pyrene analysis was performed using high performance liquid chromato-graphy (HPLC) with a spectrofluorimetric detector. It was found that nearly all personal sampling results for BaP were within the range < 4 divided by 142 ng/m3, except for the exposure of workers employed at weighing the raw materials (3,470-6,060 ng/m3) in the Semiproducts Division. Attention should be paid to the recorded CTPVs concentrations (benzene solubles). About 56% of the Vulcanizing Division workers and about 90% of the Semiproducts Division workers were exposed to these substances at concentrations of over 0.2 mg/m3 (hygienic standard for benzene solubles in USA). Exposure to dust (of high respirable fraction percentage > 90%) which exceeded the admissible value (4 mg/m3) was found mainly only in the workers of the Semiproducts Division at some work-posts.

Hygienic characteristics of carbon black used in tyre production.

Seven types of carbon black used in type production were subjected to hygienic evaluation. The coal tar pitch volatiles (CTPVs), toluene solubles, were determined by the gravimetric method and benzo/a/pyrene by HPLC with a spectrophotometric detector. Toluene solubles were found to amount to 0.12-0.25% (by weight). Benzo/a/pyrene (1.44-3.07 ppm) was detected in five out of the seven carbon blacks examined.