While a deep cleanse can be beneficial (especially if you use lots of products or are prone to oily roots), Sam Burnett, owner and creative director of London salon, Hare & Bone warns against overdoing it – even if the thought of pollution-logged lengths makes you want to wash your hair daily. "Despite pollution causing a build-up of dirt, over-washing will strip the scalp and hair's natural oils," adds Sam. "This will dry out your ends, which could cause hair to break and increase split ends, especially when styling." His advice? Introducing a clarifying or deep cleansing shampoo into your haircare routine alongside your usual shampoo once a week. Sam rates KMS Head Remedy Deep Cleanse Shampoo, £15, for chipping away at pollution grime and oil. Also try Klorane's Anti-Pollution Detox Shampoo, £8 (the star ingredient is aquatic mint, an active ingredient said to gently remove any build-up and prevent clogging), and TRESemme Cleanse & Renew Deep Cleansing Shampoo, £5.49 , which, like many anti-pollution skincare products, enlists vitamin C – essentially a shield against pollutants.