HBM4EU Chromates Study: Determinants of Exposure to Hexavalent Chromium in Plating, Welding and Other Occupational Settings

Abstract

Work-related exposures in industrial processing of chromate (chrome plating, surface treatment and welding) raise concern regarding the health risk of hexavalent chromium (Cr(VI)). In this study, performed under the HBM4EU project, we focused on better understanding the determinants of exposure and recognising how risk management measures (RMMs) contribute to a reduction in exposure. HBM and occupational hygiene data were collected from 399 workers and 203 controls recruited in nine European countries. Urinary total chromium (U-Cr), personal inhalable and respirable dust of Cr and Cr(VI) and Cr from hand wipes were collected. Data on the RMMs were collected by questionnaires. We studied the association between different exposure parameters and the use of RMMs. The relationship between exposure by inhalation and U-Cr in different worker groups was analysed using regression analysis and found a strong association. Automatisation of Cr electroplating dipping explained lower exposure levels in platers. The use of personal protective equipment resulted in lower U-Cr levels in welding, bath plating and painting. An effect of wearing gloves was observed in machining. An effect of local exhaust ventilation and training was observed in welding. Regression analyses showed that in platers, exposure to air level of 5 µg/m3 corresponds to U-Cr level of 7 µg/g creatinine. In welders, the same inhalation exposure resulted in lower U-Cr levels reflecting toxicokinetic differences of different chromium species.

HBM4EU chromates study – the measurement of hexavalent and trivalent chromium in exhaled breath condensate samples from occupationally exposed workers across Europe

“…The mean Cr(VI) air level for chrome platers were 1.2 µg/m 3 with only 16% of chrome platers wearing respiratory protective equipment (RPE) during plating bath operations. Whereas, the mean Cr(VI) air level was 1.6 µg/m 3 for welders, who wore RPE over 50% of the time and surface treatment workers such as paint sprayers always wore RPE and their mean Cr(VI) air level was 12.5 µg/m 3 ( HBM4EU chromates study team, 2022 , Viegas et al, 2022 ). This may indicate that the combination of the more soluble (and therefore more bioavailable) Cr(VI) the platers were exposed to and the lack of protection from RPE resulted in greater uptake, giving rise to the highest exposure as observed in biological sample results.…”

HBM4EU Chromates Study—Genotoxicity and Oxidative Stress Biomarkers in Workers Exposed to Hexavalent Chromium

“…On the other hand, welders had the highest frequency of MN RET despite the lower U-Cr levels. It is known that similar Cr exposures through inhalation lead to approximately two-fold lower U-Cr levels in welders compared to Cr platers, suggesting a decreased Cr bioavailability that is present in welding fumes, which might explain the apparent discrepancy that was observed [32,72]. Due to the limited life-span of reticulocytes, the suitability of the MN RET assay for the detection of low-dose chronic exposures in occupational settings must be studied further.…”

Developing human biomonitoring as a 21st century toolbox within the European exposure science strategy 2020–2030

“…In addition, the capability and validity of different biomarkers for the assessment of Cr(VI) exposure were evaluated (Santonen et al, 2022). This study has enabled us to recognise HBM as an important exposure assessment tool, to identify which exposure scenario implies higher exposure (plating, welding or other surface treatments), and which risk management measures are more effective in controlling workers' exposure (Viegas et al, 2022).…”