Blood testing for people in firefighting foam contamination zones is going ahead, despite the Ministry of Health downplaying that it's necessary.
Ohakea in Manawatū and other defence bases have contaminated the groundwater around them with toxic and longlasting firefighting foam chemicals.
In Australia's worst contamination zones, the concentrations in some people's blood of a now-banned foam chemical called PFOS have been more than 30 times higher than the general population.
The Ministry of Health in New Zealand initially struggled to find an accredited lab that could do the tests but AsureQuality has now begun - and in early March tested the blood of four people.
Most of those are understood to be for locals around Ohakea Air Base.
Manawatū District mayor Helen Worboys said locals knew the blood tests were not definitive but wanted them anyway.
"A doctor from the DHB visits them and takes them through the process, and reminds them that currently there is no guidelines or modelling for what the results may show or what levels are acceptable.
"But from the residents' point of view it's giving them a baseline that they have on their records for any future developments."
She backed more people getting tests for "peace of mind" and so a baseline of exposure would be available.
The Ministry of Health has been asked by Ms Worboys to ensure GPs in Rangitikei and Manawatū know that locals might want blood tests.
Firefighting foam contains hundreds of the PFAS class of chemicals - of which PFOS and PFOA are the only two banned in New Zealand.
These chemicals accumulate in the body over time, and are increasingly linked in overseas studies to environmental and health risks.
The Defence Force knew in April 2015 it had contaminated the groundwater at Ohakea. It told the public in December 2017.
Defence told the Health Ministry in October 2017 of some early results of water testing at its bases. Contamination has been confirmed at Woodbourne in Marlborough and Devonport in Auckland.
Blood testing not effective for predicting long-term health effects - Health Ministry
"The Ministry did not receive further details on the [water] test results and theoretical modelling of possible movement of groundwater contamination until November  when the need for further off-site testing was being discussed and planned," the Health Ministry told RNZ in a statement.
"Actual results off-base were only provided to the Ministry in late January ."
It was not good to rely on blood testing to try to interpret any long-term health impacts, it said.
"Everyone in New Zealand has PFAS in their body and the test does not tell us how it has come to be there, or whether it could lead to health effects later in life," it said.
It promised in February there would be a package of health support in contamination zones.