Silicosis risks not real for residents but dust management required

Posted on 29 January 2018

Fears about people living near quarries being exposed to dust that can cause the dangerous lung disease of silicosis have been dismissed by the National Health and Safety Council for the mining and quarrying sector, MinEx.

MinEx CEO Wayne Scott says testing to date in Canterbury quarries, which have been at the centre of silicosis claims, have shown no evidence that the active cause of silicosis – Respirable Crystalline Silica – is present at levels that would cause any harm.

“New Zealand’s limit on RCS is 0.01mg per cubic metre. If any risk of RCS exposure is to quarry workers, not neighbours who most often are hundreds of metres from a quarry face with a huge amount of air space between them. MinEx is currently working with WorkSafe to continue reducing any risk to quarry workers.”

Wayne Scott says some people are talking up RCS risks while authorities are trying to calm any fears about RCS exposure.

‘We’ve seen a toxicology professor being at pains to emphasise the low chances of developing silicosis from quarry dust and medical authorities saying testing to date at those Canterbury quarries at the centre of dust concerns shows no RCS level which is remotely likely to cause silicosis.”

 “We need to dispel some of the myths that are emerging which suggest quarry dust is laden with RCS. Another round of monitoring is underway at some Canterbury quarries which by mid-year is expected to confirm that RCS is virtually undetectable and no serious health risks arise.

“Meantime, while acknowledging many quarries have good dust management in place, some quarries have to continue to lift their game because any dust that emerges from a quarry – as from any farming or earthmoving operation – is annoying to close neighbours.”

The Aggregate and Quarry Association represents about 85% of New Zealand’s production of the crushed rock, stone and limestone. AQA president Brian Roche says most of his members are actively managing dust through practices such as watering quarry roads and stockpiles, and washing the wheels and bodies of departing trucks.

“All quarries have to meet dust limits set by councils as part of a resource consent. Most modern quarrying operations also minimise noise and traffic movements, working in with neighbours and councils.  

“Most of our members work to meet those requirements while operating a lot of heavy machinery. What we’d like communities, councils and Government to acknowledge is that quarries provide the foundation material for every New Zealand home, road and building.’’

“Too often, we face residents who want all of these benefits but say quarries should go into remote areas. That comes at a huge cost as DoC has just acknowledged in their recently approved application for a quarrying concession on DoC conservation land for its Franz Josef walking track because carting it from the nearest established quarry would more than quadruple the price.”

Mr Roche says if quarries cannot continue to operate close to where the aggregate they provide is needed for every road and building – with appropriate controls in place - then New Zealand’s economic momentum will be done and dusted.