@Lacy Tilley agreed, you need an environmental company (who doesn’t do the remediation themselves) test for unsafe levels of mold.

Plus, I have a 40-hour W-2 job (environmental engineer) and a partner of an Amazon store. 

You would need to make sure in the lease they are liable for any environmental issues if they ever to decide to vacate the property or shut down the business.

There is an environmental / moral dimension to this, however, I can't understate the housing crisis in California.  

Our side of the street is still industrial though, and our neighbor, the gas company, has had ongoing environmental issues for decades.

Build socially, economically, and environmentally sustainable products.

@Stacy Davis I'll offer my .02 based on my experience of owning an environmental remediation company: 1) Mold is not the main concern.

We had to close down the recycling business because of settlements with various environmental agencies.

You'll need a complete lender package: Tax returns on property, personal tax returns, property appraisal, maybe an environmental, rent roll, personal financial statement, schedule of real estate owned, decent FICO.

Crime Prevention Through Environmental Design... look up the principles on the internet and employ them.