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An urgent investigation is under way into whether one of the country's largest P labs caused extensive health problems for neighbours.

Shanelle Borlase has spent more than a year visiting doctors to establish the cause of her deteriorating health.

After numerous tests, she was told migraines could be the cause, then Hamilton police busted a Newcastle Rd rental property in August and found a P lab operating metres from the 18-year-old's bedroom window. At least one other neighbour also suffered headaches and nausea that he attributes to the clandestine laboratory.

The Waikato District Health Board and police have launched an inquiry into Borlase's claims. "The Medical Officer of Health is taking this very seriously," a spokeswoman for the DHB said.

The Herald on Sunday understands police wanted to issue a public health warning about the lab, but did not for fear of interfering with court proceedings and the medical investigations.

Cold comfort for Borlase, whose condition has prevented her from moving to Australia to attend a prestigious dance school.

"When mum told me about the P lab I burst into tears," Borlase said. "I was angry that someone had taken my health away from me [through] no fault of my own."

Borlase now wants people to know that chemicals used to manufacture methamphetamine may have endangered her life.

Her medical records show that from last year she complained about migraine headaches, dilated pupils, vision impairment, loss of balance, collapsing, shaking, eye seizures, heart palpitations and fatigue.

She had never suffered from these symptoms before. Medical professionals were stumped over her condition and repeatedly asked whether she was on drugs.

But the aspiring dancer - who was forced to give up her cafe job and dance classes because of her sickness - denies taking drugs, besides occasional cigarettes and alcohol.

A blood test confirmed she was not taking methamphetamine. "I started complaining of being sick within two months of living at the Newcastle Rd house," Borlase said.

"Every second week, a new symptom would occur. At the beginning I suffered from absence of time, where I'd black out but my eyes would be open and I'd still function.

"Then I started getting blurred vision and walked into objects and people. In the end, I had migraines every day."

Borlase's parents, Denise and Cedrick, and younger brother, Caleb, complained of migraines during the time they lived in Newcastle Rd. The family believe Shanelle was more severely affected because her immune system was weakened after she contracted glandular fever in 2005.

"My room was closest to the lab's kitchen," Borlase said.

Her health has improved since the family was forced to leave the house in March, when the landlord's daughter moved in.

The family relocated before the P lab was busted, and continued to think Borlase was critically ill.

"Doctors thought I might have a tumour," she said. "They sent me to hospital in June for an MRI scan but the results came back negative. Then they thought I had epilepsy, but my ECG came back normal. I've had my vision checked but my examination was normal."

It got to the point where she could not complete a full dance lesson without falling over, shaking or going momentarily blind.

Another neighbour, Alan Watkins, believes his health was also affected by the P lab chemicals.

"I used to get quite a lot of headaches and nausea," he said. "I definitely am of the opinion it was from the lab. Since the clean-up I've been fine."

Borlase said even the family washing was tainted with chemicals from the house.

"The washing on our line always had a strange, chemical smell. Mum would have to rewash the clothes."

Borlase has applied to ACC but has been told by her doctor she has "a slim chance" of getting compensation.

Fumes from deadly labs

Dr Wayne Temple, director of the National Poisons Centre, says a number of harmful solvents are used to make methamphetamine.

"There are a lot of solvent emissions and acid mists because it's not like a lab situation where they have fume hoods," he said.

"The cooks are venting chemicals outside the house, so if washing is nearby it could be covered in those things.

"If you have a low immune system, you may be sensitive to low-level exposure to those sorts of things. You certainly could not discount that."

Without wanting to give away the recipe, Temple said P cooks mixed pills and chemicals, including hydrochloric acid and sulphuric acid, used in car batteries.

"When people are doing some of these operations, they can form things like phosphine gas, which is extremely toxic," he said.

An American study by the police and the National Jewish Medical and Research Centre found mock labs in hotels and houses left chemical residues.

"Amphetamine itself was tracked right through the house," Temple said.

"It was found on the carpet and walls, people got it on their clothes, and it was tracked outside. A teddy bear with a jersey was put beside one of the cooks, and the jersey ended up with an extraordinarily large amount of amphetamine on it.

"There have been instances where cooks have been found dead at the scene."

Temple said the solvents found in meth labs affected the central nervous system, and were flammable. "That's why the police and forensic people go in suited up. It looks like overkill, but they don't know what they're going to find."