The Green Party says 18 councils are spraying a highly toxic insecticide on sports fields throughout New Zealand.
MP Sue Kedgley says endosulfan is linked to a raft of diseases, including breast cancer, birth defects, cerebral palsy, Parkinson's and autism.
Ms Kedgley says she understands New Zealand is the only country in the world to use the insecticide on sports fields.
She says the chemical can accumulate in the environment for up to six years and any human contact can do harm. It has been banned in more than 50 countries.
Though some of the councils have now decided to stop using endosulfan, others say they will continue using the chemical because it is cost-effective and provides good results.
The Environmental Risk Management Authority says a formal reassessment of the insecticide started in June and it expects to make a final decision by Christmas.