But the new study of health outcomes for residents living near the site in Mapua, near Nelson, has also highlighted the importance of consulting fully with the community and maintaining public trust when such remediation projects were undertaken, study officials said.
Study principal investigator David McBride, of the Otago preventive and social medicine department, said the study did strongly suggest there had been significant social health effects linked to the remediation process.
Other members of Associate Prof McBride's team were
departmental colleague Kirsten Lovelock, Kim Dirks and David Welch, both of Auckland University, and Daniel Shepherd, of AUT University.
This had been the first multidisciplinary investigation into health effects induced by exposure to chemicals in New Zealand.
The former Fruitgrowers Chemical Company site had been classified as New Zealand's ''most contaminated'' and soil remediation was undertaken there between 2004 and 2008.
Several organisations and agencies had been involved in this complex remediation exercise, much of the overall supervision having been undertaken by the Ministry for the Environment.
The ministry had faced a ''very difficult'' and challenging task in consulting over the matter, but any bodies undertaking such work in future would clearly require a ''really good plan'' for such consultation, Prof McBride said in an interview.
Previous testing had indicated dioxins were released into the environment during the remediation work, although an environmental model predicted the associated risk to public health would be low.
The latest study, which compared health outcomes for Mapua residents with their counterparts in a similar area of Nelson, involved a survey and blood testing of a small number of residents, particularly those closest to the clean-up site.
Researchers shared findings from the study and answered questions at a community meeting in Nelson last night. Of those people surveyed in Mapua, more than 60% of residents reported not being consulted about the remediation.
Prof McBride felt some satisfaction in having taken part in the research, which he believed would help some Mapua residents who had been concerned about possible ill effects from toxic chemical exposure.
''I just hope that we can put people's minds at rest,'' he said.
