Frustrated residents living near the new Suvarnabhumi airport have threatened to launch balloons in the sky to disturb air traffic if the airport authority does not comply with its demands over noise pollution.

The Airports of Thailand (AoT) has tried several methods to silence the protesters but to no avail.

First, the AoT gave the villagers earplugs, then sleeping pills and later when some complained of respiratory problems they suggested wearing a face-mask, according to a villager living near the airport.

Residents living nearby the airport have complained of extreme noise pollution from planes taking off and landing and are calling for the AoT to buy their houses so they can resettle in quieter areas.

The residents said they would submit a petition to the AoT, calling on the airport operator to adopt a runway management scenario that reduces the impact of noise on local communities and speeds up compensation payments to eligible recipients under an agreement signed by the AoT, affected villagers, and the Treasury Department.

The villagers also called on the AoT to look into the noise impact on communities living outside the official noise-hazard zone and come up with proper assistance, as they are also suffering from severe noise pollution from aircraft.

``We will cancel the balloon operation if the AoT shows their sincerity in solving the problem. Solve the problem, and you will see no balloons in the sky this Friday,'' Prasert Boonkaeo, spokesman of the alliance of 32 communities affected by aircraft noise, told a press conference.

The plan to launch balloons into the sky is worrying the authorities, who fear the balloons could cause an accident or, at the very least, damage the reputation of Suvarnabhumi airport.

Deputy Transport Minister Sansern Wongcha-um warned the residents that they would be breaking the law if they went ahead with the action.

Prasert said the villagers were upset because the AoT had quietly redrawn the map of the official noise-hazard zone. Reducing the size of the area, was the last straw.

Under the new mapping of the noise-hazard zone, approved by the cabinet on May 29, a number of households would be excluded from the compensation list, he said.

The May 29 cabinet resolution also states that the AoT will buy back only houses suffering from noise of over 40 on the Noise Exposure Forecast (NEF) scale, or over 75 decibels. This is contrary to the Nov 21, 2006 resolution, under which the buy-back scheme covers houses affected by 35-40 on the NEF.

NEF is the official method used for aircraft noise assessment.

For most Thai people, acquiring sleeping pills or stress-relief drugs legally is not simple, as the medicines can't be bought over the counter.

But for villagers living near Suvarnabhumi airport, the drugs were delivered directly to their homes by AoT in the agency's latest attempt to silence residents' complaints about aircraft noise.

Thanatos Preeprem is among the neighbours who received dozens of sleeping pills from the AoT's mobile medical unit this year.

"I did not expect that the doctor would prescribe controlled medications that easily," said the 35-year-old artist whose house is in Keha Nakhon 2 housing estate, around 400m from the north of the western runway.

The AoT's medical unit visited his community twice after the airport opened on September 28 last year.

On the first visit, the doctor gave him drugs that "help ease sleeping disorders" right after he complained that he had problems sleeping.

However, after finishing them, his insomnia problem still had not eased. So he met the medical unit again. This time they gave him yellow-white capsules clearly described as sleeping pills, after a quick check of his physical and mental condition.

"It seems that sleeping pills and stress relief drugs have become the airport's key measure to tackle the Suvarnabhumi noise problem," said Thanatos.

He said the villagers' struggle had become fruitless since the AoT had failed to come up with any measures to mitigate aircraft noise. "First they gave us earplugs, then sleeping pills. And now that some of us have developed respiratory problems, possibly caused by oil vapour from the aircraft, AoT suggested that we should buy a face-mask," he said.

"Superficial solutions are all we can expect from the agency."

A public relations official working for the AoT's environmental department admitted that the agency's mobile medical unit had prescribed sleeping pills and anti-stress drugs to villagers who suffered from insomnia and stress.

However, the prescriptions were written only after a thorough examination of the patients' mental health by state doctors who joined AoT's mobile unit.

Most drug recipients were the elderly, said the official.