Beryllium is known to cause chronic beryllium disease damaging the heart and lungs with symptoms like pneumonia and bronchitis. According to the National Institute for Occupational Safety and Health, 1.7 million U.S. workers have a potential exposure to the substance.

In the Paz case the workers sued for creation of a medical monitoring trust fund, claiming they were exposed to beryllium dust, fumes and particulate matter.

U.S. District Court Judge Louis Guirola Jr. in Gulfport, Miss., granted the defendant businesses a summary judgment motion to dismiss the case in Jan. 2005. He found that Mississippi law would most likely not permit a claim for medical monitoring absent a physical injury.

The plaintiffs appealed to the Fifth U.S. Circuit Court of Appeals in New Orleans, which found that Mississippi law was unclear and sent the question concerning the statute to the Mississippi Supreme Court for clarification. The Mississippi Supreme Court must now rule on its application.

Among the trade groups who are part of the amicus brief opposing the workers' request are the National Association of Mutual Insurance Companies, the Property Casualty Insurers Association of America, the Chamber of Commerce, the National Association of Manufacturers, and the Pharmaceutical Research and Manufacturers of America.

“For more than 200 years, a fundamental tort law principle has been that a plaintiff must have a present, actual injury to obtain a recovery,” their brief states.

According to Mark A. Behrens, a partner in Shook, Hardy & Bacon L.L.P., who represents defendants in asbestos and similar cases filed under state laws, the Paz case is important, because the question of whether medical monitoring claims are recognized under state law has reached a number of state supreme courts as well as the U.S. Supreme Court under a law governing railroad worker claims.

According to Mr. Behrens, once the Mississippi high court decides the question, the case will most likely go back to the federal court to decide the case consistent with the law as decided by the Mississippi Supreme Court.

The amicus brief argues that courts have established the principle that plaintiffs must have an actual injury to recover “as a filter to prevent a flood of claims, provide faster access to courts for those with reliable and serious claims, and ensure that defendants are held liable only for genuine harm.”

“Medical monitoring claims brought by asymptomatic plaintiffs conflict with the traditional rule,” the brief says.