Meth house myth cost millions

A bombshell report shows there is no risk to humans from third hand exposure to houses where methamphetamine has been consumed.

This means tens of thousands of homes have been needlessly tested and cleaned at the cost of millions, with some demolished and left empty.

The study by the Prime Minister’s Chief Science Adviser Peter Gluckman found that New Zealand had made a ‘‘leap in logic’’ setting standards, and set a standard used overseas to clean ‘‘clan labs’’ was now being used to test and clean houses where meth had only been smoked.

‘‘In the absence of clear scientific and health information, there has been an assumption among the general public that the presence of even trace levels of methamphetamine residue poses a health risk,’’ Gluckman said.

‘‘There is absolutely no evidence in the medical literature of anyone being harmed from passive use, at any level. We can’t find one case.’’

Gluckman said testing and cleaning still made sense when there was suspicion that methamphetamine had been produced on a property – but this was more to do with reassurance.

He said a ‘‘moral panic’’ around cleaning and remediation had occurred only in New Zealand. If science had been involved earlier in the policy-making process this could have been avoided.

Mould was a much larger health risk to tenants than meth residue.

In response to the recommendations, Housing Minister Phil Twyford has announced new standards will be set for houses within the next year, with Housing NZ immediately changing their policy.

The current level of 1.5 micrograms per 100cm2 was useful as a barometer of where to clean for after manufacturing had taken place, but not as an alert level for residue, the report said. A measure of 15 micrograms per 100cm2 – 10 times higher – would make more sense.

Gluckman said he wouldn’t be worried about ‘‘toddlers crawling around on the floor’’ until the meth residue reached the level of several hundred micrograms per 100cm2 – not the current standard 1.5 – and this was based on a 300-fold safety buffer.

Gluckman stressed their recommendation was still very far below a level where it could become dangerous. ‘‘We’re looking at a 1000-fold safety factor minimum in our recommendations, for a naked toddler crawling around the floor licking every bit of the floor up to several hours a day,’’ Gluckman said.

Several hundred state homes sitting needlessly empty would be put back into use within weeks, and Housing New Zealand would save up to $30m a year on testing, Twyford said.

‘‘The great majority is testing and remediation was completely unnecessary,’’ Twyford said.

A review into how the standards were set would also be carried out by Consumer Affairs Minister Kris Faafoi.

‘‘Very significant sums of money have been spent on testing and decontamination of houses that are thought to have been contaminated by methamphetamine. Housing New Zealand alone in the last fours years has spent $100m on testing and remediation,’’ Twyford said. ‘‘Large numbers of homes thought to have been contaminated were left empty in the middle of a housing crisis.’’

Twyford commissioned the report soon after coming into Government, but Gluckman stressed it was totally independent.