Received same kind of phone call re: accent (sounded Indian to me) stating a survey for air quality by Micro Solutions. He asked a few simple questions about air quality, whether we had allergies and used air filters, or smoked, and then abruptly stated something about might win a drawing and hung up on me before I could ask any further questions. I am concerned this is a scam, as he threw in a couple questions about whether I worked full time or others lived in the house, whether we had pets - seems like trying to see if house would be empty during work day and no dog to worry about.
Called our home phone and they hung up when answering machine came on. Tried to return the call and got a message stating that "the party has do not disturb activated and to please try my call later".