Dust in the Wind: creeping quarries closer to engulfing Christchurch residents

In March 2017, residents of Yaldhurst, Christchurch took their concerns to health officials over the possible negative health effects of quarry dust emanating from a site 200m from their homes that had been operating since 1988 with a significant expansion in 2014. Dust samples analysed in an Australian lab detected that it consisted of 30% crystalline silica.

Crystalline Silica

Crystalline silica itself is a common material that comes in several different forms, the most common being quartz. All forms of crystalline silica can be reduced to respirable dust particles. The main hazard that comes from quarry dust with high amounts of crystalline silica is the risk of developing silicosis, according to the US Occupational Safety and Health Administration, who classify the substance as a human lung carcinogen.

Silicosis

If inhaled over time, crystalline silica can lead to silicosis. Silicosis comes with a number of occupation-related nicknames that point to the people that the disease has traditionally affected, such as: miner’s phthisis, grinder’s asthma and potter’s rot. The dust causes scarring and inflammation in the upper lung. The lesions caused by crystalline silica dust causes shortness of breath, fever, coughs and cyanosis in affected individuals. This irreversible disease also makes victims more susceptible to other lung infections, such as tuberculosis.

Yaldhurst

In Yaldhurst, the local council submitted that the effects of the long-time quarry’s expansion would be “minor or less than minor”. The successful application for that resource consent back in 2014 has been followed by a lengthy list of health problems among nearby residents consistent with the presence of crystalline silica and the silicosis it can cause. In July 2017, University of Canterbury microbiologist Dr Kevin Duncan remarked that residents suffered from, among other symptoms, general weakness, problems with blood chemistry, bleeding from the eyes and nose, and lung inflammation.

In applying for the resource consent, the company’s dust experts and the council’s town planner admitted that, in accordance with Victorian standards, a safe distance between quarry activities and residences is 250 metres. The same standards note that the majority of impacts would occur within 100 metres and suggest that, at a concentration of 30% crystalline silica, the safe distance between the source of quarry dust and residences should be 500 metres.

Knowing that the most dangerous impacts occur within 100 metres of quarry activity have made it all the more confounding for residents when, in May 2018, ECan and the local council gave permission for a quarry operator to enlarge its area of activity to within 100 metres of local properties. Notably, during the hearing, the opinion of the Canterbury District Health Board was not taken into account on an official basis, being buried within the residents’ submissions.

Quarry activity centred on Miner’s Road

Government Response

As a response to the residents’ concerns around quarry activities, Environment Canterbury (ECan) pledged to increase mitigation efforts in the area, which included, by July 2017, a monitoring regime for residents and reminders to quarry operators that no visible dust should appear beyond the boundary of the consented activity area. Meanwhile, Alister Humphrey, a Medical Officer of Health in the Canterbury region, reiterated concerns that long-term exposure to the crystalline silica dust could be extremely hazardous to the health of residents.

In May of this year, Christchurch Mayor Lianne Dalziel asked that central government involve itself in the issue and pass legislation to help create an obligatory buffer zone of at least 500 metres between quarry activities and local houses. Discussions are still continuing on the issue.

Legal Action

Yaldhurst residents have already taken action and won cases against some quarry operators that have applied for consents in the area. In October 2017, residents won a revocation of the consent given to Harewood Gravels to create a quarry from the Environment Court. On appeal to the High Court, in December 2018, the finding was confirmed by the judge.