How to stop pollution from ruining your hair

High levels of pollution are seriously detrimental to both the planet and your skin, but a lesser-known threat until now is the adverse effect smog and exhaust fumes have on your hair. And yet, it's just as much a cause for concern. Hair actually picks up more pollution than your skin because it covers a larger area on your head and toxic particles can get trapped between the strands when you move.

To make matters worse, pollution levels rise in winter due to a phenomenon known as surface inversion. "The air directly above the ground cools down much faster than the air above it, explains aesthetic doctor Dr Barbara Sturm. "The warmth builds up a wall and traps pollutants in the cold air we're exposed to." So what can be done?

First, a bit of good news: pollutants sit on the outside of the hair cuticle so can easily be washed off. In the same way that you diligently cleanse your skin, the importance of washing your hair at least every other day can't be overstated. It's even advisable to use the same micellar technology in your lather as you would to remove makeup, SPF and daily grime.

Given pollution particles are positively charged, negatively-charged micelles will attract impurities with magnet-like precision. Maria Nila's Eco Therapy Revive Shampoo is laced with micelles that detox strands without stripping them of moisture or colour. Designed for damaged and brittle hair, Kristin Ess Scalp Purifying Micellar Shampoo lifts away build-up while smoothing damaged cuticles. Likewise, Nanoil Keratin Micellar Shampoo deploys a triple threat of purifying micelles, plus nourishing keratin proteins and castor bean oil.

What makes pollution so detrimental to skin and hair is that it sets off a cascade of free radicals, something made worse on sunny days when airborne pollution joins forces with UV rays. "Free radicals can break down the hair's lipid and protein structure," explains trichologist Anabel Kingsley. "When those become damaged, strands are weaker, more porous and lack flexibility."

Conditioners with antioxidant-rich botanicals are your best line of defence. Bjorn Axen leans on Nordic sugar beet in the Organic Moisturising Conditioner to soften strands and calm an irritated scalp. Dr Barbara Sturm's entire Super Anti-Ageing Collection is designed to protect against heat, pollution and UV. The Hydrating Conditioner is powered by purslane extract and sunflower sprouts – two potent antioxidants. Löwengrip The Cure Hair Mask is packed with antioxidant sunflower oil to repair and regenerate lack-lustre strands.

The most common type of air pollution is particulate matter (PM), which is made up of minuscule soot and chemical particles. PM measures a mere 2.5 micrometers. To put that into perspective, that's 20 times smaller than the diameter of a pore, so toxins can easily accumulate inside it, making your once healthy scalp flaky, irritated and congested.

Exfoliating the skin on your scalp will lift away any PM build-up. Turn to the Sachajuan Scalp Scrub, with gently exfoliating sugar, to clear away stubborn dirt. The gritty bits in Davines Solu Sea Salt Scrub Cleanser are natural sea salt and deep clean without being abrasive. Finally Ceremonia Papaya Scalp Scrub invigorates both the scalp and the senses with its luxurious botanical blend.

City dwellers may need an extra layer of protection against environmental impurities. Oribe’s Power Drops Hydration & Anti-Pollution Booster is oil-based and forms a defensive shield around hair strands. Similarly, the purifying benefits from Klorane Aquatic Mint Conditioner aren't simply washed down the plughole. An invisible, protective barrier remains on the cuticles to prevent pollutants from binding to the hair.

Pollution also takes the form of potentially damaging minerals in tap water. Living Proof’s Perfect Hair Day Triple Detox Shampoo contains charcoal powder to hoover up airborne pollution as well as heavy metals such as calcium and copper that latch onto wet hair, causing it to look dull and feel brittle.