Though not used in new construction anymore, asbestos is still present in more than 500,000 public buildings. It is a known and deadly threat that still claims in the region of 4500 lives each year (over half of all occupational cancer deaths) of people who were exposed around 35 to 40 years ago. Despite the risk being well known, inspectors still find workers cutting, drilling, sawing and breaking up materials that contain this hidden killer. If inhaled, these airborne fibres can lead to fatal illnesses. HSE prosecutes a number of employers and contractors each year for not taking adequate precautions when removing asbestos. There are stringent rules on asbestos removal for good reason, including restricting who can do the work. Some jobs must only be carried out by licensed, specialist firms.