2022 No https://www.sciencedirect.com/science/article/abs/pii/S0048969722014693?via%3Dihub Zhao, Bin Asia Europe North America Observational Carbon Monoxide (CO) Particulate Matter (PM) Nitrogen Dioxide (NO2) It is clear that the updated WHO AQGs of 2021 now apply to indoor air. A single measure seems challenging to help the current indoor air meet the standard. We are calling for efforts from multiple disciplines and perspectives to achieve the target. The required measures may include (but are not limited to): developing feasible indoor and outdoor source control strategies and policies, researching and developing high cost-effective indoor air cleaning technologies, and improving people's awareness of indoor air quality. Suppose each of the potential solutions is implemented through combined policy, technology, and education; we would have a cocktail treatment-like method to manage our indoor air to achieve the new ambitious AQGs.