[gizmo686]

Governments are perfectly capable of setting building codes. This isn't an instance fix, but would be effective over the long term.

Governments also have a well established mechanism to incentives faster compliance: tax refunds to offset the cost of improvement. We already offer such incentives for energy efficiency improvements (some of which actively harm ventilation).

From an engineering perspective, the clean air proposals are much easier than wastewater management. There is no centralized infastructure needed. Every building can be upgraded independently, and the people in that building will see an immediate benefit.

Further, the upgrades needed are typically not that major. Most building already have a forced air HVAC solution. These solutions already have inline air filters, and often already have the ability to actively pull in fresh air.

We can get significant improvement my simply leaving the fan on these units running regardless of if they are actively heating/cooling; and using already available high quality filters.

In that subject, a quick PSA to home owners: if you have not changed your HVACs filter recently, you probably should.