Sustainably sourced, bundled, White sage (Salvia apiana) is antimicrobial. And has been shown to repel insects. Burning sage is thought to release negative ions which can help neutralize positive ions.
Common positive ions are allergens like: pet dander, pollution, dust, mold. If this is the case, burning sage may be a blessing for those with asthma, allergies, bronchitis, and other respiratory conditions. Just be sure to wait til the smoke clears before entering the room.