No.
Most hard drives, if you look hard enough, will have a tiny hole in them somewhere, and behind that is a very fine filter. That hole is there so the drive's internal pressure can equalize with the ambient atmospheric conditions. If it wasn't hard drives would have a nasty tendancy to bulge when shipped via air or taken up mountains.
(Without significant design changes drives would leak around the motor spindles and the points where wires enter and exit the drive case anyway, so I imagine the reason for the equalization filter is to make the air flow "predictable" and avoid air forcing its way through the bearings and drying them out/possibly loosening debris from them or the other possible egress/ingress points.)
Not to say you don't need a clean room, or close to it, if you want to put a clear plastic cover on a hard drive and expect it to function for long afterwards. People *have* done it for show by fiddling with the parts through a plastic bag or other jury-rigged expedient but I certainly wouldn't trust a drive so modified with *anything*. I'm sure you've seen the illustrations showing how large various sorts of debris are compared to the flying height of a Winchester drive head already, so there's no need for me to Google them up. Short answer is that even a drop of oil from a fingerprint, a below-average-size pollen grain, or a fleck of cigarette ash is more than enough to cause a crash.