Otago study finds banned farm pesticides in rivers and streams

Agricultural pesticides that are banned in the United States and Europe have been detected in 36 rivers and streams in rural New Zealand.

A study by the University of Otago found traces of seven pesticides in water samples taken from streams in Canterbury, Otago, Southland in the South Island and the Waikato region in the upper North Island.

The most common were: chlorpyrifos, which is used to kill insects and worms; atrazine, a herbicide banned by the European Union in 2004; diazinon, a pesticide banned by the Environmental Protection Agency in the US; and 2-4-D, a weedkiller used in aerial spraying of crops that has been linked by some studies to an increase in cancers among farm workers in Australia and the US.