Liquefaction dust from the 2010 Canterbury earthquake has been ruled out as the reason for a subsequent jump in Legionnaire's disease cases in the region, according to an Otago University study.
Researchers tested samples for six months after the earthquake which, like the deadly second quake in February 2011, produced widespread soil disturbance in parts of Christchurch.
The aim was to see if Legionella bacteria could grow in the liquefaction-affected soil.
Thirty silt samples were collected randomly from locations within Christchurch's metropolitan area that was affected by liquefaction.
The results, published in the NZ Medical Journal, showed legionella bacteria were undetectable after day one.
The study concluded that liquefaction-affected soil could not have contributed directly to the observed increase in legionellosis cases, given that the bacteria were unable to survive in the soil.