You've already got your N95 face mask, the air purifiers and are not doing excessive outdoor activity. Here are more protective measures against lung damage and disease to work into your regular routine.
1. Don't ignore your snore. If snoring is a chronic problem, you are likely to be damaging your lungs as much as haze and smoking. Make an appointment to clear your airways. The doctor may prescribe a better pillow or surgery at worst.
2. Practice more aerobic activity. One hour a day of minor puffing broken up over 4 sessions has been shown to improve breathing in emphysema patients.
3. Consume more Omega-3 supplements. This fish oil supplement is an all-round anti-inflammatory.
4. Strengthen your Abs. Your abs and chest muscles help you to breathe. Work in 10-20 crunches a day to reduce lung burden. Also practicing deep abdominal breathing will help reduce muscular activity in the lungs.