Cancer research. Petri dishes and tubes containing cell cultures. These are being used in cancer and toxins research. The cell cultures can be examined for the effects of various cancer-causing agents and toxins. Photographed in the Health and Pollutants Laboratory of the INRS (the French National Institute of Research and Safety), Nancy, France. Tests are carried out here to establish the toxicity and cancer-causing properties of different materials, chemicals and pollutants.