"It is a good sign, however ... [as we] become busier leading up to Christmas and the holiday seasons, unfortunately, the trends in the past see the positive rates also rise."
The number of non-negative pre-employment tests in the Bay of Plenty grew from 5.4 per cent in 2016 to 7.09 per cent this year to date - a 31.2 per cent increase.
Te Utuhina Manaakitanga general manager Donna Blair said she supported drug testing in the workplace when it was done from a supportive background and not one of punishment.
"If you have an addiction, you can be treated. But if you are going to use it as punishment to fire them, I don't support that. Employment for a lot of people is a protective factor," she said.
"We've had referrals from the forestry industry.
"They are very supportive in assisting their crew over the years. They've brought people in for support and to understand the effects of drinking and drugs.
"The mills themselves, they have been very responsible employers also."
Ms Blair said she had seen many success stories of workers failing tests, being supported to get help and heading back to work.
Lakes District Health Board portfolio manager for mental health and addictions Marita Ranclaud said there had been increases in the demand for drug and alcohol services over time, but it was difficult to attribute that increase solely to people seeking support following positive drug screening.
"From a system perspective, the cost of treatment for alcohol and drug issues is much less than the cost of having people 'out of work'," she said.
"Where possible, people should be supported as much as possible to address their drug use and return to work."
New Zealand Council of Trade Unions president Richard Wagstaff said drug testing was appropriate when people worked in transport or heavy machinery but felt money could be better spent on other health and safety issues "with greater effect and less impact on worker's privacy".
"We are worried that over-zealous drug testing may result in people switching from cannabis (which stays in the system longer) to less detectable but more serious drugs like methamphetamine."
Mr Wagstaff said drug use in the workplace was an issue but the council felt it received disproportionate attention compared to other sources of harm such long working hours.
"Many of the industries which religiously drug test workers (such as agriculture, horticulture and forestry) also work some of the longest hours in New Zealand.
"We call for industries to look carefully at all causes of impairment."
Mr Wagstaff said, in his view, companies like the agency greatly exaggerated the workplace risks of drug use and the benefits of testing.
He encouraged employers thinking about introducing such policies to seek independent legal advice on their implementation.
The number of workplace serious harm notifications in the Bay of Plenty has gradually dropped in recent years from 458 in 2011 to 213 in 2015 and 95 for the first four months of 2016, in the latest figures from Worksafe New Zealand.
