MICROSCOPIC particles of silica dust that hang around in the air long after work has finished pose a major risk to workers, delegates were warned.
Nigel Strickland, marketing manager for Brandon Hire, stressed that the risk was not in the dust they could see on site but in 'invisible' particles, which measure less than 3 microns.
He said: 'The dust you can see is the dust you can cough out, but these very small particles, referred to as PM10, become embedded in your lungs, ' he said.
The deadly cloud can remain suspended in the air for up to eight hours and this can lead to a range of illnesses, from minor lung irritation to silicosis and even lung cancer.
Mr Strickland said this means the dust needs to be removed at source rather than simply relying on workers to wear appropriate PPE.
He said: 'What about the people coming into the room after the drilling or sawing has finished? They can't see any dust because it's invisible, yet they're still at risk.' The extent of this secondary exposure is revealed by figures from the Health & Safety Executive, which estimates 140,000 workers in the UK are regularly exposed to silica dust, of which around 100,000 are in construction.
The HSE estimates current exposure levels still mean 20 per cent of workers are at risk of silicosis. As a result, the HSE is now consulting on plans to reduce this risk to 2.5 per cent or less than 1 per cent.
Mr Strickland stressed that, since dust is inevitable in construction, preventing it at source would be a future requirement.
'A dust mask is too late. Control measures are required, such as water suppression and local exhaust ventilation, which is where the equipment is connected to an industrial vacuum cleaner.'