UC researchers urge caution in using Red Zone for food production
University of Canterbury environmental chemists are urging caution after the recently released “Land Use Assessment
Report – Productive Land Use” by Regenerate Christchurch identified livestock grazing and fodder production as options
for Red Zoned land in Christchurch.
This has the potential to endanger New Zealand’s food safety record and potentially jeopardise exports, according to
Professor Brett Robinson and Associate Professor Sally Gaw, environmental chemists in UC’s College of Science.
Urban soils frequently contain unacceptable concentrations of contaminants, including of lead (from paint, leaded fuel,
lead arsenate pesticides), arsenic (treated timber, pesticides), DDT and other persistent organochlorine pesticides from
over-zealous historic use, as well as Polycyclic Aromatic Hydrocarbons (vehicle emissions, historic burning of coal,
wastes), they say.
Recent investigations have shown that many Christchurch soils, including those in the Red Zone, were above regulatory
limits for these contaminants.
If any of these contaminants were detected in our export products, there would be repercussions for New Zealand’s
agricultural exports, the scientists say.
“Vegetables, particularly root crops and leafy greens, are also at risk from these contaminants,” says Associate
Professor Gaw.
“We recommend that the land not be used for grazing, fodder production or vegetable crops as a precautionary measure,”
Professor Robinson says.
While cut-and-carry fodder reduces the likelihood of contaminant transfer to the food-chain, these toxins can
nonetheless enter fodder or other foods from local contaminant ‘hot spots’ which occur frequently in urban environments
but are difficult to locate.