Setting up a collaborative European human biological monitoring study on occupational exposure to hexavalent chromium.

The EU human biomonitoring initiative, HBM4EU, aims to co-ordinate and advance human biomonitoring (HBM) across Europe. Within its remit, the project is gathering new, policy relevant, EU-wide data on occupational exposure to relevant priority chemicals and developing new approaches for occupational biomonitoring. In this manuscript, the hexavalent chromium [Cr(VI)] study design is presented as the first example of this HBM4EU approach. This study involves eight European countries and plans to recruit 400 workers performing Cr(VI) surface treatment e.g. electroplating or stainless steel welding activities. The aim is to collect new data on current occupational exposure to Cr(VI) in Europe and to test new methods for Cr biomonitoring, specifically the analysis of Cr(VI) in exhaled breath condensate (EBC) and Cr in red blood cells (RBC) in addition to traditional urinary total Cr analyses. Furthermore, exposure data will be complemented with early biological effects data, including genetic and epigenetic effects. Personal air samples and wipe samples are collected in parallel to help informing the biomonitoring results. We present standard operational procedures (SOPs) to support the harmonized methodologies for the collection of occupational hygiene and HBM samples in different countries.

Occupational exposure to metals among battery recyclers in France: Biomonitoring and external dose measurements.

In battery-recycling facilities, exposure to trace elements may occur through inhalation of contaminated dust or vapor emanating from the treatment processes. Exposure of battery-recycling workers to lead has been quite well covered in the literature. In contrast, we lack data on exposure to other elements contained in batteries. The aim of this study was to characterize the exposure of French battery recyclers to multiple elements using biomonitoring and airborne measurements. Eighty-six workers participated in the study. Inhalable metal concentrations were determined for personal airborne samples, and total exposure was determined from pre-shift and post-shift urine samples collected during the working week. In both types of sample, a total of 33 trace elements were measured using inductively coupled plasma mass spectrometry. Results showed battery recyclers to be mostly exposed to Cd, Co, Cr, Li, Mn, Ni, and Pb. Administrative and sorting workers were exposed at lower levels than maintenance, treatment, and dismantling workers. Cd, Co, Li, Mn, and Ni were detected at high levels in air samples, especially near the treatment facilities, with airborne cadmium levels of up to 79.4 µg/m3. Urinary sample analysis indicated exposure to Cd and Co, with levels measured at up to 27.6 and 3.34 µg/g of creatinine, respectively. Concentrations were compared to data reported for e-waste recycling companies. The data presented provide valuable information on exposure to trace elements for workers involved in battery-recycling. They also highlight the need to improve both collective and individual protective measures, which were not sufficient in the participating companies.

Simultaneous determination of aromatic and chlorinated compounds in urine of exposed workers by dynamic headspace and gas chromatography coupled to mass spectrometry (dHS-GC-MS).

Mixed exposure to chemical products is a topical issue for occupational health and often includes exposure to volatile organic compounds (VOCs). As very few methods are available for evaluating these mixed exposures, the aim of this work was to develop a simple biomonitoring method to assess simultaneous occupational exposures to chlorinated and aromatic VOCs by analyzing the unmetabolized fraction of the VOCs in the urine of workers. Volatile organic compounds were analyzed using dynamic headspace gas chromatography coupled to mass spectrometry (dHS-GC-MS), and 11 unmetabolized urinary VOCs were measured into headspace phase, without any time-consuming pretreatment. Simultaneously, a standardized collection protocol was designed to avoid VOC losses or the contamination of urinary samples. The calibration samples were real urines, spiked with known amounts of the VOC mixtures studied. Test investigations were performed on potentially exposed workers in three factories in order to assess the effectiveness of both the collection protocol and analytical method. A satisfactory level of sensitivity was achieved, with limits of quantification (LOQ) between 10 and 15 ng/L obtained for all VOCs (except for styrene at 50 ng/L). Calibration curves were linear in the 0-20 µg/L range tested, with R2 correlation coefficients of 0.991 to 0.998. At the lowest concentration tested (0.08 µg/L), within-day precision varied from 2.1 to 5.5% and between-day precision ranged from 2.7 to 8.5%. Sample stability at -20 °C required that urinary samples be analyzed within 3 months. Even though the urinary concentrations of VOCs used in the plants were mostly quite low, significant differences between post-shift and pre-shift were observed. In conclusion, a fast, sensitive, specific and easy-to-use method has been developed for extracting VOCs from human urine using dHS-GC-MS. The method described has proven to be reliable for assessing current occupational exposure to chlorinated and aromatic VOCs in France.

Evolution of dissolved organic matter during abiotic oxidation of coal tar--comparison with contaminated soils under natural attenuation.

In former coal transformation plants (coking and gas ones), the major organic contamination of soils is coal tar, mainly composed of polycyclic aromatic compounds (PACs). Air oxidation of a fresh coal tar was chosen to simulate the abiotic natural attenuation impact on PAC-contaminated soils. Water-leaching experiments were subsequently performed on fresh and oxidized coal tars to study the influence of oxidation on dissolved organic matter (DOM) quality and quantity. The characterization of the DOM was performed using a combination of molecular and spectroscopic techniques (high-performance liquid chromatography-size-exclusion chromatography (HPLC-SEC), 3D fluorescence, and gas chromatography coupled with mass spectrometry (GC-MS)) and compared with the DOM from contaminated soils sampled on the field exposed to natural attenuation for several decades. An increase in the oxygenated polycyclic aromatic compound concentrations was observed with abiotic oxidation both in the coal tar and the associated DOM. Polycyclic aromatic hydrocarbon concentrations in the leachates exceeded pure water solubility limits, suggesting that co-solvation with other soluble organic compounds occurred. Furthermore, emission excitation matrix analysis combined with synchronous fluorescence spectra interpretation and size-exclusion chromatography suggests that oxidation induced condensation reactions which were responsible for the formation of higher-molecular weight compounds and potentially mobilized by water. Thus, the current composition of the DOM in aged soils may at least partly result from (1) a depletion in lower-molecular weight compounds of the initial contamination stock and (2) an oxidative condensation leading to the formation of a higher-molecular weight fraction. Abiotic oxidation and water leaching may therefore be a significant combination contributing to the evolution of coal tar-contaminated soils under natural attenuation.