At Coab, a hamlet overlooking Quendale Bay, Nanette Johnson, who keeps the general store, has not felt any discomfort or nausea. 'People don't like the smell but nobody has told me that it makes them feel sick.'
At the primary school in Dunrossness, three miles from Quendale Bay, the children are doing projects on the wrecked tanker. Two of the children in primary seven, a class of about 12, complained of headaches.
David Williamson, 11, who has been staying with his grandmother a mile or two from the bay, was also affected.
'I had a sore head,' he said. 'It starts when I'm working outside feeding the cows and gets better when I come inside.'
Jamie Leslie, who lives in Coab, said the smell was at its worst after chemicals had been sprayed from the air to disperse the oil, perhaps because it allows the oil to be more readily dispersed by the wind.
However, primary seven's class teacher, Ann Black, was sceptical about reports of sickness. 'None of the children I know have been off sick and nobody I know has been ill,' she said. Audrey Mullay, headmistress of the school, said that she had been advised to keep the children inside. Children come to the school from the whole of south Mainland and Mrs Mullay has had no reports of sickness resulting from the oil spill.
'The children are full of it,' Mrs Mullay said. 'It has completely taken over from the project work we had planned. They have to talk it out. But really they are much more worried about the effect on wildlife. Most of them have not really thought about effects on themselves.
'We have been advised there could only be a danger if the wind had dropped, the temperature went up and a toxic layer developed underneath,' she said.
This phenomenon is familiar to most people who frequent Britain's inner cities in summer when temperature inversion causes intense air pollution. But with the present gale force winds in Shetland there is no danger of that. Despite the smell of oil, the air in Shetland is fresh and much better than the pungent polluted air of cities which are full of toxic burnt hydrocarbon from exhaust fumes. Dr Gerald Forbes, an environmental expert with the Scottish Home and Health Department, said that doctors had been visiting homes near Quendale Bay and could find no signs of sickness among people living there.
Tests on the water supply coming from a loch near the bay had also failed to find any significant pollution.
However, Dr Forbes said that the Home and Health Department was considering mounting a medical study of the islanders' health to see if there might be any long-term effect. He emphasised that there was no long-term danger of cancer.
The dispersants sprayed on the oil had been approved by the Government for spraying at sea, said David Bedborough, land co-ordinator for the Department of Transport oil pollution control unit. However, he had no detailed knowledge of what, if any, effect the dispersants might have on human health.
The dispersants are surfactants which cause the oil to break up into small particles and form an aerosol which can be breathed into the lungs. The surfactants would assist any penetration of the oil through the membrane of the lungs.
Mr Bedborough said that several makes of approved dispersants were being used. But he did not have the brand names and was not prepared to supply them as a matter of priority because, he said, the information would not be useful. At least one brand of dispersant formerly used in Norway has been discontinued by the Norwegian government because of health fears.
Dr Forbes said that they could not detect any oil pollution in the air in Shetland following the disaster with equipment which measured down to parts per million.
'The human nose is much more efficient in detecting chemicals and can go down to two parts per billion.'
Lung testing equipment donated by a Buckingham firm is to be sent to Shetland. A spirometer, used for measuring lung volume, will be dispatched to Levenwick Health Centre, close to the disaster, early next week. It will be used to test those taking part in the clean-up, who could become overexposed to oil particles.
The Vitalograph Alpha can perform nine lung function tests and the company's marketing manager, Steve Fletcher, said yesterday: 'The spirometer can assist in diagnosing anyone immediately at risk from respiratory problems. It will also be useful to measure any long-term effects.'