Way OT. But they aren’t airtight. Can’t be. They have to allow for rapid de-pressurization of the cabin. Look at the lids then next time you are on an aircraft–there are always gaps all around. That’s not to say they are ventilated. Clearly they aren’t. There may be training/process problems here. Failure to train cabin crew that the overheads are airtight isn’t one of them.
