After Monday’s bombshell news from the World Health Organisation that bacon, ham and sausages are carcinogenic, you can be forgiven for wondering just what exactly is safe for you to come into contact with – let alone eat. Handily, the International Agency for Research on Cancer – a body that collects and publishes cancer figures worldwide – has a list of the 116 substances and activities (for some of them are more verb than noun) that are now considered to cause cancer. Processed meats rank alongside smoking as cancer causes – WHO Read more Red meat isn’t on the list – that only probably causes cancer. This is the IARC’s group 1 list – the stuff it says definitely is carcinogenic. The IARC splits the list into three categories, which it calls “exposure circumstances”, “mixtures” and “agents”. Carcinogenic exposure circumstances 1 Tobacco smoking: The most common exposure to the stimulant, prepared from the leaves of the tobacco plant, is through burning it and smoking it from a cigarette or hookah pipe into the mouth and then releasing it. Smoking’s history dates back to as early as 5000–3000BC when the agricultural product began to be cultivated in South America. 2 Sunlamps and sunbeds: A tanning bed, a device that emits ultraviolet radiation for a cosmetic tan, can give humans overexposure to UV radiation, which can cause skin cancer, cataracts, and premature skin ageing. 3 Aluminium production: Increased lung and bladder cancer risks have been reported in workers in aluminium reduction plants. The fumes of chemicals the workers may inhale, and exposure to coal-tar pitch volatiles for long periods during the process, can cause cancer.