Occupational exposure to hexavalent chromium (Cr(VI)) and its toxicity

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. However, our knowledge regarding the work processes and industries where Cr(VI) exposure occurs, exposure levels, and occurrence of signs of carcinogenic exposure in exposed populations 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. We will measure markers of short-term and long-term Cr(VI) exposure, i.e. Cr(VI) in the air (inhalable fraction) and Cr(IV) in red blood cells, in around 100 potentially exposed workers at workplaces in Umeå, Örebro, Stockholm, Uppsala, Gothenburg, and Lund, and around 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. This project thus lays the foundation for guidelines and best practices on how to work safely with Cr(VI) to minimize exposure and disease.