Folliculitis can be caused by bacteria from soil, but Williams said the county does not know which kind of bacteria caused the outbreak.

"We may never know for sure, but it would not surprise me if this was caused by a combination of bacteria trapped in soil, mixing with water and being heated to extreme temperatures by the weather," Williams said.

Dylan Crump, 7, of Cedar Hill, woke up Thursday with clusters of small red dots on his stomach, underarms, elbows and upper lip even though his mother had taken him to see a doctor, who had prescribed an antibiotic.

Dylan and his 11-year-old brother Zach, whose rash was getting better, had gone to Mud Mania on July 29, but they won't be returning.

"I'll make my own mud pit in the backyard," said Jason Crump, the boys' father.

"Manufacturers are required to print 'not only dangerous for human consumption, but also the quantity of the residues, if any, on each label,'" said spokesman K. Tiwari.

The Press Trust of India said the state legislative assembly of the northern state of Punjab also removed soft drinks from the menu of its lawmakers beginning Friday.

"The restriction will remain in force until the controversy regarding harmful ingredients in soft drinks is cleared," said assembly Secretary Nachhattar Singh Mavi.

Federal MPs Thursday demanded a nationwide ban on Pepsi and Coke after the privately-funded Centre for Science and Environment (CSE) said 11 drinks sold by the two US companies contained unacceptable doses of pesticides.

A two-judge bench of India's Supreme Court, meanwhile, gave the two firms a month to reveal the ingredients of their products, officials said.

The court reacted to a public lawsuit which argued products sold by both the firms were deeply laced with harmful chemicals such as phosphoric acid, caffeine and aspartame.

Pepsico and Coca-Cola have rejected the CSE's report, saying customers interests were their paramount concern.

Alarming

And increasing numbers of diagnostic and therapeutic procedures, including some lung, heart and bone scans, use radioactive particles.

Given the current political climate, airport authorities are keen to detect any radioactive material being carried by passengers, and have installed sensitive alarms.

Researchers at City Hospital, Birmingham, say that having heard about the problems their 46-year-old patient encountered, they began issuing all patients with a radionuclide card explaining the risk of persisting radioactivity following such treatment and problems this might cause, including the risk of radiation alarms being triggered.

When they searched medical literature they found four similar cases.

In the first report, dated 1986, two patients were detained and later released after trying to enter the White House for a public tour four days after exercise testing with a thallium scan.

In 1988, a patient triggered a bank's security alarm, again because of an earlier thallium scan.

In 2004, a 55-year-old pilot was detained after setting off airport radiation detector alarms while travelling as a crew member to Moscow.

He was released later the same day when it transpired the radioactivity detected was the result of a heart scan he had undergone two days earlier. Experts estimate that some patients might trigger alarms up to 12 weeks after radioactive diagnostic and therapeutic procedures.

Writing in the BMJ, Dr Kalyan Kumar Gangopadhyay and colleagues said: "Airports worldwide are deploying more sensitive radiation detection systems and one would therefore expect more such cases unless we take the responsibility of forewarning our patients."

Practical advice

Dundee University experts Dr Daniel Cuthbertson and Dr John Davidson said new guidelines due on the use of radioiodine for thyroid disease should include this advice.

Patients who have received treatment involving radioactive particles are already advised to avoid public transport for two weeks so that they do not expose nearby passengers to radioactivity.

Patients with young children at home are also advised to avoid prolonged daily close contact - within less than 1 metre - with them for a time dependent on the dose of radioiodine administered.

A spokeswoman from the Royal College of Physicians, the organisation that is due to publish new guidance on radioiodine use for thyroid disease, said: "The guidelines are due for publication in November, so there will be time for this new issue to be considered."