Clean Air Quality is a major focus in the USA. For more that 30 years manufacturers have been supplying outlets and distributors inadequate soffit vents used for venting a bathroom exhaust fan to the exterior under the requirements of the International Code Council that governors the USA Building Code.
These vents instead of solving long-standing are actually contributing the cause of attic mold and moisture damage in the home.
Once the problem was realized instead of solving it the International Code Council came out with steps to remediate the damage. This only increased the creation of more Remediation Companies that is a billion dollar industry. Most of all it has increased the costs of medical treatments from mold contamination.
In the end it is left to the homeowners to cover the billions of dollars required to address the effects.