The Board of Health will hold an April 1 public hearing on the issue of shadow flicker from the town’s wind turbines. The board discussed the issue last week and heard statements from residents who live near the turbines and said they have recorded 30- to 40-minute sessions of flicker from a turbine. The town had expected shadow flicker to occur only rarely and for a few minutes at a time. “Flicker has really become a more significant concern than anyone in the beginning thought,” board chairman Joe Casna said. The board also agreed to approach selectmen to consider the town’s options in addressing residents’ concerns over health effects from the turbines.