FREEPORT - Long Islanders whose homes were flooded during Sandy could be dealing with a silent after-effect: mold.

The New York Committee for Occupational Safety and Health, an independent safety group, warns that mold is still a big problem in many homes affected by the 2012 storm.

Many people just use bleach to get rid of mold, but NYCOSH says that won't work on porous surfaces like wood and sheet rock. The group says the only way to get rid of mold is to completely remove the materials saturated with water.

NYCOSH warns that mold can cause serious health problems if left untreated.