Determine the dust source and address it? Or just isolate your gear from the dust source.
Alternatively, box out an area for the lab that's mostly air tight, then use an air filter to pump filtered air into the mostly-sealed space. Positive pressure with filtered air, essentially.
But I don't really think that's necessary unless you're down there kicking up dust all the time.
Higher humidity helps keep dust down, too. As someone else mentioned, about 65% is kind of a general number to target for max.
