I participated in a conference call a few weeks ago sponsored by the Environmental Bankers Association (EBA) that discussed “Chinese Drywall”.  An attorney and a consultant both provided presentations and their perspective on the issues and how they are dealing with it. 

A quick summary:

• Chinese drywall was generally used in the southeast U.S. after the hurricanes/storms in the early to mid 2000’s in response to repair/rebuild of structures.  At the time, the U.S. did not have adequate inventory of drywall, could not manufacture it fast enough and the cost of Chinese drywall was much less expensive.  There are some case studies that have shown it present as far north as Virginia (coastal areas). 
• Chinese drywall contains elevated levels of sulfur and strontium (potential radiation that may be cancer-causing).  Sulfur can off-gas into a variety of substances such hydrogen sulfide, carbon sulfide, etc.  These off gases can cause health issues with residents/tenants/occupants and also may cause significant corrosive damage to HVAC and plumbing systems (particularly copper components). 
• There are subjective procedures in-place for the assessment/evaluation of potential Chinese drywall systems and include visual observations (keying on specific components, looking for drywall markings, etc.), on-site sampling (intrusive), analytical testing and reporting.  Full and comprehensive evaluation can be fairly intrusive (need to often open up walls, cavities and chases to access/observe systems). 
• Generally, evaluation/testing is a fairly expensive option (compared to asbestos/lead testing).  Analytical parameters are building material and site-specific. 

I would estimate that we will see more data and information upcoming.  More to follow.