I am not close to MA, but it does sound like an environmental issue as all are suffering alike. Arbs will lose a portion of their interior needles annually as new needles form each year at the tips. If the damage is directional, i.e. on the south side mainly, then soil moisture and the intensity of the sun may be a factor. While they should be established by now, summer soil moisture in general may be part of this. Consider contacting your local Extension office for a more focus response to find out what is going on with your evergreens.