National Coordinator of NADMO, Mr Kofi Portuphy, told the Daily Graphic on Monday, that the emission was not a new phenomenon.
A seemingly harmless gas that emits from the ground may be slowly and negatively affecting the health of people who live at Dunkonaa and its environs in the Ga-South municipality in the Greater Accra Region.
Known as radon gas, the fume, which is colourless, odourless and tasteless, is known to be a major cause of respiratory infections, blood poisoning and lung cancer where it is highly concentrated.
The National Coordinator of the National Disaster Management Organisation (NADMO), Mr Kofi Portuphy, told the Daily Graphic on Monday, that the emission was not a new phenomenon.
In 2000, studies conducted by a team of scientists, including scientists from the Ghana Atomic Energy Commission, indicated that the gas coming out of the Dunkonaa area was highly concentrated.
The study found that the potency of the Dunkonaa radon gas measured 2,000 Becquerel per square metre.
Internationally, the allowable amount of radon gas for residential areas is 200 Becquerel per square metre.
The United States of America (USA) has pegged 200 Becquerel per square metre as the permitted amount of emission for residential areas and even with that the structures must have enough ventilation.
In the United Kingdom, the allowable amount is 150 Becquerel per square metre.
Mr Portuphy revealed that following that study, NADMO discouraged the Ghana Real Estate Developers Association (GREDA), from building its estates in the area, although the association had laid infrastructure, including roads and drains.
He said NADMO became curious when some residents of the area started reporting about the emission of smoke some years ago.
He further stated that after the 1939 earthquake in the then Gold Coast, scientists advised state officials that Dunkonaa was a weak zone, since it was an earthquake epicentre, a situation which allowed the poisonous gas to emit in such quantity.
According to residents of the area, the name ‘Dunkonaa’ was an adulterated one. Originally, the place was called ‘Dun ko naa’, which in Ga meant ‘the edge of smoke’, because the ground always emitted smoke.
Scientific publications explain that radon is formed as part of the normal radioactive decay chain of uranium. Uranium has been present since the earth was formed and its most common isotope has a very long half-life (4.5 billion years), which is the amount of time required for one-half of uranium to break down.
Unverified information volunteered by some residents of the area suggested that the Rlg Communications building project, the City of Hope, which was earmarked for the area, might no longer be located at Dunkonaa for health reasons.
Currently, Mr Portuphy said, NADMO was putting together its experts to undertake research again to ascertain the impact of the gas on the health of people who had been living very close to the emission zone.
He said the area was declared a reserved green zone not suitable for human habitation and that it was for that reason that former President J.J. Rawlings intervened in 1998 to halt the development of the area after he had been briefed by NADMO and shown documents indicating that the place was an earthquake epicenter emitting radon gas.
Last month, the Vice-President of the Ghana Academy of Arts and Sciences (GAAS), Professor Aba Bentil Andam, raised a red flag over the high concentration of radon in some parts of Ghana, which she indicated could cause lung cancer when inhaled over a longer period.
She called for a national radon map to help identify the geographical areas where the population was most at risk of exposure above the reference levels established by the World Health Organisation.
A visit to Dunkonaa by the Daily Graphic Thursday revealed that a large tract of land had been developed.
Parts of the area had covered drains, well laid out and tarred roads, some of which were deteriorating over time. Various types of buildings, ranging from estate houses to stores and storey buildings, had also sprung up.
A resident, Richard Lamptey, said he had been in the area for the past 15 years and claimed that the thick smoke that was emitting from the ground was from a god. He said the emissions ceased after some rituals had been performed.
Ms Roseline Amankwa, another resident, said she had never heard of any poisonous gas. Rather, she argued, stories about the emission of radon were strategies by some people to take away their land.
A former president of GREDA, Mr Torgbor Mensah, contradicted the claim that they were discouraged from putting up the estate because of the dangerous gas emission. He explained that though the gas issue was raised at the time, GREDA decided to put up houses in the area.
Government policy at the time, he indicated, stalled the efforts of GREDA to put up the houses at Dunkonaa. However, Mr Mensah said GREDA officials raised the issue at a housing exhibition in the USA for advice.
He said the estate developers were told that if they decided to go ahead with the project, then the developers would have to construct big manholes in each house to trap the gas so that it will not cause harm to occupants of the estates.
However, other sources say that even the trapped gas in the manholes could still find its way into the buildings and become injurious to the health of occupants.