Depending on how much mold, it might not be a big deal to live around it unless there's a lot of air movement. If it's just sitting there under the cabinets, it's not flying around.
Back in the 80's when they began tightening up homes to save energy, moisture sometimes collected between the walls. Someone invented the term toxic mold, ie: black mold. Everyone since then thinks all mold is black mold and toxic. I worked for a guy that does remediation. He said tho it's always good to remove the mold, the vast majority isn't the scary "black death" kind.
Some people are very sensitive to it, just like allergy's.
I'd hook up a shop vac, put it outside, then using a long enough hose with a brush attachment....... suck up the mold anywhere you can reach it. Toss the filter, clean the hose and inside of the vac and you'll be fine till any mold remediation company comes and does whatever they do. Harbor Freight as a nice 6 gallon vac for $59, but you'd want more hose.