Environment Canterbury is advising dust-sensitive Christchurch residents to wear dust masks as demolitions pick up in the city.
ECan's regional manager RMA monitoring and compliance Brett Aldridge said dust may increase in the spring and summer months as Christchurch moves into the deconstruction and rebuilding phase, especially with the northwest winds that sweep across the city.
Dust mitigation plans form part of demolition contracts, with methods such as sprinklers systems and compacting and covering dust used to reduce the amount of dust blown around.
Truck washes have been set up to water down trucks leaving the CBD red zone, while streets are also swept and dampened.
"While many dust-control measures are in place at these sites, the sheer size and number of the sites means realistically there will be dust - it is part of the environment in which we will be living in for the next few years. People who may find they react to dusty conditions should consider taking extra precautions such as wearing masks," Mr Aldridge said.
Medical officer of health for Canterbury, Dr Alistair Humphrey, said although Canterbury has not seen an increase in respiratory problems since the earthquakes, it is still important for people to reduce their exposure to liquefaction dust wherever possible and seek medical advice if they feel unwell.
"At this stage we have seen no cases of dust-related lung disease that we can attribute to liquefaction dust."
According to a paper written by Department of Labour medical practitioner Dr Andrew Hilliard said the risk of health effects from dust, contaminated silt, mould or fungi to residents and to workers involved in deconstruction and reconstruction of Christchurch is likely to be low.