Minimizing exposure to hexavalent chromium in Swedish workplaces

Exposure to hexavalent chromium (Cr(VI)) increases the risk of cancer, especially lung cancer. Minimizing this risk requires accurate, current information on Cr(VI) exposure and its health effects, as well as an understanding of how workers and managers perceive and implement risk management measures. However, our knowledge regarding the work processes and industries where Cr(VI) exposure occurs, exposure levels, occurrence of signs of carcinogenic exposure in exposed populations, and how managers perceive and manage risk, remains limited and not updated to current working conditions. Furthermore, we lack knowledge on how best to monitor Cr(VI) exposure in relation to toxicity, such as early risk markers for cancer. The proposed study, which will be conducted by a Swedish and Nordic network on Cr(VI) exposure, toxicity, and risk, aims to fill these knowledge gaps. We will measure markers of short-term and long-term Cr(VI) exposure, i.e. Cr(VI) in air (inhalable fraction) and Cr(IV) in red blood cells, in 100 potentially exposed workers at workplaces in and around Umeå, Örebro, Stockholm, Uppsala, Gothenburg, and Lund and 50 (matched for age, gender and education) controls, all non-smokers. Exposure data will be supplemented with early biological effect data: we will measure sensitive markers for Cr(VI)-related toxicity, i.e. chromosome damage (micronuclei in reticulocytes), oxidative stress (8-oxodG), DNA modifications (telomere shortening and epigenetic modifications), in blood and urine samples. Exposure data and some biological effect data will be compared with a Danish Cr(VI) exposed cohort (N=100). We will also investigate risk perception in the participating companies and interview managers for their views on the current Cr(VI) occupational exposure limit and other applicable regulations before and after measurements. This project thus lays the foundation for guidelines and best practices on how to work safely with Cr(VI) to minimize exposure and disease.