WORKERS are being put at risk of contracting lung cancer or other respiratory diseases because of a failure by watchdogs to bring in adequate safeguards against a toxic workplace dust.

Academics at a Scottish university have strongly criticised the Health and Safety Executive (HSE) over its recommended safe level of exposure to the substance crystalline silica, a powder created when working with bricks, concrete and plaster.

Experts now say the current standard of 0.1 mg/m³ is too low.

Silica is second only to asbestos as a cause of occupational cancer deaths and exposure can cause a range of other illnesses including silicosis, tuberculosis, kidney disease, chronic obstructive pulmonary disease and arthritis.

The HSE claims that technological limitations mean it is impractical to monitor for its presence below the exposure standard, while some industry bodies have argued that the cost of implementing these new controls would be prohibitive.

But Professor Rory O'Neill, Stirling University's Occupational and Environmental Health and Safety Research Group and author of a new report on the substance, said: "The HSE says monitoring technology isn't good enough yet to measure lower levels of silica dust, so we must stick with the same deadly, higher but measurable standard. It is wrong on both counts. The increasingly toothless safety watchdog is regurgitating the line promoted by the industry lobby, placing vested interests above workers' health.

"Modern science can obtain and analyse dust on Mars. If HSE's science can't obtain and analyse adequately one of the most commonly encountered and deadly workplace dust exposures here on Earth, you have to ask who on Earth is the watchdog protecting?"

He called on the HSE to follow the lead of the American Occupational Safety and Health Administration (OSHA), and implement a rule change that would cut the recommended safety level in half.

Researcher Professor Andrew Watterson said: "OSHA says a tighter standard is perfectly possible, can be monitored in the workplace and would save hundreds of lives and billions each year.

"The current lax legal occupational exposure standard in the UK guarantees another generation will be blighted by entirely preventable, deadly and disabling conditions. Yet the HSE is actively promoting an industry-supported but unsustainable argument that the current standard must stay."

The call for tighter controls has been backed by workplace safety campaigners.

Michelle Aldous, Chief Executive of the recently-established Constructing Better Health Scotland, said: "If it is indeed technically possible to measure silica at lower levels than we currently are.

"However, there is also much more we could be doing at a practical level to protect construction workers from exposure to this risk. Walk down any high street and you will see construction workers generating dust while working on-site, equipped with a hard hat, gloves and high visibility vest but often without a dust mask or water suppression to protect themselves against silica exposure.

"These are the sort of simple, common-sense measures the industry ought to be applying as standard which would help to manage exposure to occupational health risks."

A spokeswoman for the HSE said: "Health and Safety law requires employers to assess the risk of exposure to silica dust in their workplace and prevent it, when prevention is not possible exposure must be controlled.

"There is a UK workplace exposure limit for silica of 0.1 mg m-3, and employers must reduce exposure to below this level.

"With the required exposure controls in place silica dust is usually reduced to significantly below 0.1 mg m-3."