The potential dangers of Chinese drywall are back in the news again.

The federal government just released a study that was commissioned to figure out why so many homes are being damaged and so many homeowners are getting sick.

The results raise even more questions about what's in the walls in thousands of homes.

This could affect as many as 100,000 homes across the country, including some here in Washington. After all the complaints and lawsuits filed earlier this year, the Consumer Product Safety Commission ordered an indoor air investigation of dozens of homes.

The key questions: What's causing the stink and corrosion, and how bad is the safety risk?

Federal regulators hired independent technicians from an environmental health and engineering firm to test for emissions in the walls and ceilings of 51 homes.

Homeowners claim chemical emissions in Chinese-made drywall are corroding electrical wiring and causing health problems, including headaches, bloody noses, and asthma attacks.

The results released this week confirm a clear problem with the drywall, but only solve part of the problem.

The Consumer Product Safety Commission says the source of the corrosion is Hydrogen Sulfide gas, a byproduct of many industrial processes.

And the study uncovered other factors: formaldehyde, air contaminants and air exchange rates in home heating and cooling systems.

But the study does not answer the key question about the health risk. Long-term health effects are still under investigation.

In the meantime, regulators are contacting state governors to make sure all homes that have Chinese drywall problems have been reported to the CPSC.

Regulators are now working to develop a quick, affordable way to confirm the problem in homes, then find a cost-effective way to correct the problem.

Meantime, members of congress are urging the IRS to allow homeowners to deduct the resulting loss in property value on their tax returns.

A bill currently in Congress would hold foreign manufacturers fully accountable when their products prove defective.