Some Christchurch residents are being asked to wear 'personal exposure meters' to monitor levels of exposure to quarry dust. Residents in the Yaldhurst area have been concerned about the nearby quarry and pollution for years.
And now Environment Canterbury is asking them to wear the units to understand their exposure.
Dr Kelvin Duncan is an ecological physiologist and has taught environmental science for a number of years. And he says some residents are showing symptoms of silicosis.