Quarries under close scrutiny

A new comprehensive air monitoring programme is being set up in Yaldhurst amid concerns about the health effects of the dust coming from quarries.

Environment Canterbury senior manager service delivery Brett Aldridge said nuisance dust has been a long-standing issue in the area.

“Late last year, some Yaldhurst residents came to us with their concerns about the health effects of dust coming from the quarries,” he said. “We agreed it was important we get a good understanding about the potential for the health effects the community has concerns about, and there was a need to really understand the scale and magnitude of the risk of dust to residents. Therefore, we started a testing process, including taking dust samples from a resident’s property.”

Initial results showed there was some crystalline silica coming from the quarries.

Environment Canterbury shared these results with the Canterbury Medical Officer of Health, Alistair Humphrey, who looked at them along with a respiratory physician and a toxicologist.

Dr Humphrey said, while no resident had shown abnormal lung function tests, some had been suffering from symptoms consistent with mined silica exposure.

“These symptoms resolved when they were no longer exposed to the dust,” he said.

Dr Humphrey said he and other clinical experts agreed it was important to ensure residents were not exposed to unacceptable levels of mined silica in the long-term, which could have serious effects.

“It is important to ensure that any dangerous exposure to mined silica dust is dealt with by the quarrying companies,” Dr Humphrey said.

“If such exposure has been occurring in the past, it is important that it is ceased immediately. As long as this occurs, residents are unlikely to develop long term silica related conditions.”

Dr Humphrey said the Yaldhurst residents could be assured everyone is working together to address their concerns to reduce any chances of dust exposure and any associated health risks.

Dr Humphrey, together with staff from both Environment Canterbury and Christchurch City Council, met with quarry operators yesterday.

Brett Aldridge said Environment Canterbury will consider any dust beyond the boundary as offensive and objectionable given the new information about the potential health risk of the dust.

“We will be taking a no tolerance approach. We will take action if we see any dust outside the quarry boundaries,” he said. “The quarry operators agreed this was fair.”

To ensure that no visible dust leaves the quarry boundaries, a staff member will be assigned to monitor these boundaries regularly – this is separate to the monitoring that occurs for the resource consent conditions.

“We’ll also be setting up a new air monitoring programme to quantify what the risk is. We’ve asked an independent air quality specialist to design this for us. We expect the monitoring programme will take at least a year to get reliable data. But, results will be reviewed as they come in to see if there are any patterns.”

Dr Humphrey agreed getting more data was key to understanding what the risks were, especially as while visible dust could be monitored, crystalline silica was not visible.

“We all want to ensure that our communities are safe.”

Dr Humphrey, Brett Aldridge and a Christchurch City Council representative met with the residents today to talk about the dust and the plans for monitoring.

For further information contact  Environment Canterbury Media on 027 221 5259 or email media@ecan.govt.nz