Legal Question in Landlord & Tenant Law in California

No. Rent abatement is only available after public health authorities have deemed the condition to make the premises not legally habitable AND the landlord has failed to remediate. In addition, not all mold is the landlord's responsibility. Unless there is a defect in the structure that is causing the mold, there is at least a 50/50 chance that mold in a unit is caused by the tenant. In that case it is the tenant's responsibility to clean it up.