Answer first
During haze, fine particles and pollutants settle on hair and scalp, where they mix with oil and sweat and can make the scalp itchy, dull and flaky. On haze days, wash your hair in the evening with a mild shampoo, keep hair covered outdoors when the air is bad, and avoid heavy styling products that trap dust.
What happens
Particles stick to oily scalps and may add to irritation and oxidative stress on the skin.
On haze days
Wear a cap outside, wash at night, and rinse well.
Indoor air
An air purifier and closed windows during bad readings help skin and breathing alike.
Questions
Should I wash every day in the haze?
If your scalp tolerates it, a gentle daily wash is fine.
Can a scalp treatment help after haze?
A deep but gentle cleanse can remove build-up.