The U.S. Supreme Court on Monday threw out a $5 million jury verdict awarded to a former CSX Transportation Inc. (CSX) railroad worker who alleged that he had been negligently exposed to toxic chemicals and asbestos on the job, which caused him to develop brain injuries and asbestosis, a lung disease.

Among other things, Tennessee railroad worker Thurston Hensley sought monetary damages for a fear of developing cancer in the future.

CSX argued that the instructions given to the jury were too friendly to Thurston. The company wanted jurors to be instructed that Thurston needed to demonstrate that his fear of cancer was genuine and serious.

The Supreme Court, in an unsigned opinion, said it was a "clear error" for the trial judge not to give the jury instructions CSX requested.

The high court sent the case back for new court proceedings.

-By Brent Kendall, Dow Jones Newswires; 202-862-9222; brent.kendall@dowjones.com