With all the work being done to maintain the appearance and integrity of the 50-year-old Tappan Zee Bridge, a new potential safety threat has emerged.

Evidence of shipworms was discovered on wooden test panels left hanging in the Hudson River under the bridge. Shipworms are a type of clam, which bores into wood and chews it up once inside. Thruway officials say there is no evidence that the worms have set their sights on the wood pilings that support the bridge and no immediate danger is posed.

However, the Westchester Business Council has long pushed for a new bridge and rail system to be constructed. The council say this new environmental concern drives that point home. The council adds that the Tappan Zee was designed to carry 100,000 cars a day. The fact that it now carries 140,000 cars a day indicates the bridge's structure may not last for the next 100 years.