U.S. postal workers will be offered potassium iodide pills to protect against thyroid cancer in the event of a radiological emergency.

"Employees are out there in all of these communities nationwide and we wanted to err on the side of caution,'' Postal Service spokeswoman Sue Brennan said.

The USPS said Monday it was buying nearly 1.6 million pills from Tampa-based Anbex, Inc. for distribution to workers who want to have the tablets if a radiological emergency occurs.

Potassium iodide is the only medication for internal radiation exposure. It has just one use — to prevent thyroid cancer by blocking the thyroid from taking up radioactive iodine.

The pills are generally kept on hand in areas where there is a threat of a nuclear accident, but in recent years concerns have also increased that an enemy might include a form of iodine in a nuclear weapon.

The Food and Drug Administration-approved tablets will be available for all 750,000 postal workers nationwide.

Employees will be given counseling in advance to understand the use of the pills, which will be kept on hand for distribution if needed.

"It's a proactive approach regarding the safety, health and well-being of employees nationwide,'' Brennan said.

Brennan said the pills are being offered much like free flu shots were offered in the wake of the anthrax scares after the Sept. 11 attacks.

The recommendation came up in meetings of the mail security task force, comprised of representatives of postal unions, management associations and the Office of the Inspector General, along with safety and medical specialists and members of the mailing industry.

In January, the Nuclear Regulatory Commission announced it would provide free potassium iodide to 33 states that had residents living within a 10-mile radius of each of the nation's 102 nuclear reactors.

Brennan said the post office was paying 18.3 cents per pill, well below the average price of 71.4 cents.

Like any medication, overdoses of potassium iodide can be dangerous. Some people may experience allergic reactions, including nausea or rashes.

Phone calls to the American Postal Workers Union and National Association of Letter Carriers were not immediately returned.