Eye health and hygiene on your London commute

Wednesday, 29 May 2024 by Vision Direct

Banner showing woman applying makeup on train

Contouring on your commute may save you time, but it’s not just the eyeballing from fellow passengers you need to worry about. Doing your makeup on the tube is a practice riddled with hidden risks. Everything from quick touch-ups to a full face of makeup can expose you to a host of germs and pollutants that lurk in London's underground. That’s why we swabbed all 12 tube lines and measured pollution levels to see exactly what's out there. We also teamed up with microbiologist Jason Tetro, and dermatologist Dina Keen, to further understand how doing your makeup in a contaminated environment can impact upon your skin and overall health.

The punch that pollution packs on your skin and eyes

As you step onto the escalator and descend into the underground, it’s hard not to notice a change of atmosphere. The air thickens, the temperature becomes more stifling, and the humidity leaves a film on your skin. The pollution in London's underground transportation network comes from a myriad of sources including gas fumes, particles from the wear and tear of the wheels and brakes as they run along the tracks. Combined with the CO2 exhaled by from other passengers, it’s not the ideal environment for your skin or your eyes.

When you hop on the tube, you probably already assume you’re not breathing in the freshest of air. But what exactly are we exposing ourselves to? We looked at a variety of pollution levels to get a clearer picture of what the tube environment is emitting. One factor we looked into was PM2.5 which refers to particulate matter with a diameter of 2.5 micrometres or less, but basically, you should be concerned about anything above 50 ug/m3 (micrograms per cubic metre). This is because it can irritate the skin and eyes upon impact and leave them feeling dry, uncomfortable and irritated. The Central line and Jubilee line are the two lines that you should be most concerned about as they had 125 and 124.2 ug/m3 respectively.

It’s no secret that the underground can feel muggy and close – especially during peak times with high passenger density and in the summer heat. In this regard, the Central line takes the top spot with 79% humidity on the tube. High humidity levels can lead to excess moisture on your skin’s surface, creating a damp and sticky environment, which can contribute to feelings of heaviness and discomfort. Combine this with the perspiration that usually comes hand-in-hand with high humidity levels, which can aggravate congestion and oiliness, and you’re increasing the risk of clogged pores and acne breakouts.

Data card showing information about Tube lines and levels of pollution

A smoggy outlook: How environmental factors affect eye health

Feeling less than stellar when you come off the tube is to be expected when you’ve been travelling in an environment that spews out all sorts of pollutants. The study found that many of the lines have high levels of pollutants such as PM2.5, CO2 and TVOC, all of which can negatively impact eye comfort and health.


PM, including PM2.5, can deeply penetrate the respiratory organs and enter the bloodstream. Not only does this result in cardiovascular, cerebrovascular, and respiratory effects, but toxic changes to the intraocular tissues of the eye. Here are some specific ways in which PM2.5 pollution can affect the eyes:

  • General eye irritation: Exposure to PM2.5 can also lead to general eye irritation, including increased tearing, burning, grittiness and discomfort. These sub-ocular symptoms manifest because of conjunctival changes brought about by exposure to the PM particles,
  • Conjunctivitis: PM2.5 pollution can contribute to the development of non-specific conjunctivitis, an inflammation of the mucous membrane, lining the outer part of the eye and inner surface of the eyelids. Symptoms can include redness, itching, tearing, and discharge.
  • Corneal damage: Some studies have shown that long-term exposure to PM2.5 pollution has been linked to potential damage to the cornea, the clear outer layer of the eye. This can cause changes in vision quality or increased susceptibility to corneal infections.
  • Macular degeneration: Other studies suggest that long-term exposure to air pollution, including PM2.5, may be associated with an increased risk of age-related macular degeneration (AMD), which is the leading cause of vision loss among older adults.

Banner of empty tube carriage

Total Volatile Organic Compounds (TVOCs)

High levels of Total Volatile Organic Compounds (TVOCs) can also result in some of the issues above, including eye irritation, corneal damage and dry eye.

What can be done to protect your eyes?

Travelling on the tube is a necessary evil for millions of people daily, but there are measures travellers can take to help mitigate the risks of these pollutants on their eyes.

  • Avoid rubbing your eyes: In cases where PM2.5 levels are high; your eyes may feel more irritated. While it may be uncomfortable, it’s vital that you avoid rubbing your eyes, as this would not only exacerbate the symptoms, but potentially cause the spread of bacteria and other contaminants that you encounter.
  • Use artificial tears: Before and after travelling, with clean hands, administer hydrating eye drops to keep your eyes moist by supplementing the natural tear film and providing lubrication to the surface of the eye.
  • Switch to daily contact lenses: Just as with the bacteria, some of these pollutants Including PMs can adhere to the surface of a contact lens. Switching to silicone hydrogel daily lenses, such as Everclear ELITE contact lenses , can help. These hydrophilic lenses retain water, making them an ideal choice for sufferers of dry eyes. Replacing these lenses daily ensures the pollutants are removed, reducing their direct contact with the eye, whilst enhancing compliance.

Banner of hand holding tube rail

The germiest tube lines

Time is a luxury that few can afford which often means corners get cut and multi-tasking seems like a wise move. That's why scoffing a snack or doing your makeup on your commute to work or a social function, may seem like a good way to optimise your time. But it isn’t. Seats and handrails retain bacteria introduced to the tube in a variety of ways including coughs, sneezes, food, and pets. It’s a messy situation. But let’s face it, sometimes needs must. So, in that case, which lines should you avoid multitasking on?

Well, that would be the Victoria line. The swab data revealed an exceptionally high colony-forming unit (CFU) of 16000 for E. coli. The presence of this bacterium could indicate unhygienic practices on the part of other passengers, such as travelling with dirty hands or allowing an unwashed dog to sit on the seat. No matter what it is, it’s not good news. To then be touching your face when applying makeup is a risky business.

Infographic detailing bacteria found on tube

Up next is the Metropolitan line with traces of Pseudomonas aeruginosa (400 CFU) and streptococci and enterococci (960 CFU) on the seat and the pole (80). The presence of these bacterial types indicates potential contamination from human skin. Pseudomonas aeruginosa is found in the environment and can cause havoc to your skin and eyes.

Even if you take extra care not to touch anything when you’re on the tube itself, there’s also the escalator you should look out for. For safety reasons, you should be holding on to the handrail but that leaves you open to Escalator 3, which again isn’t too concerning, but make sure you apply hand sanitiser on your way in and on your way out of the tube and you should be okay.

Eye-spy bad bacteria: The impact of tube germs on eye health

It’s fair to assume most people won’t be wiping their eyes on the seats of the London Underground. However, there are those that opt to do their makeup to save time while on their morning commute or even when they’re getting ready to go out after work.

This can mean that simply removing a mascara smudge, tautening your eyelid to apply eyeliner, or using your fingers to blend eyeshadow, can result in these lingering bacteria making their way into your eyes, causing unwanted side effects.

Our professional services optician Nimmi Mistry explains the impact these bacteria could have on eye health, and we hope will persuade on-the-go makeup artists to reconsider their place of application.

Pseudomonas aeruginosa

Pseudomonas aeruginosa is a bacterium that can cause severe eye infections, particularly in individuals who wear contact lenses or are immunocompromised. This bacterium can cause inflammation of the cornea, a condition commonly known as microbial keratitis (MK).

The impact of this type of bacteria can be sight-threatening. Some symptoms of this type of infection include:

  1. Pain and Redness: The eye will often become very painful and appear red.
  2. Discharge: There will most likely be a yellow-green discharge from the eye.
  3. Blurry Vision: Vision can become blurred due to inflammation and corneal damage.
  4. Photophobia: Eyes can become sensitive to light.
  5. Ulceration: The infection can lead to the formation of ulcers (a break in structure of the cornea). This normally begins at the site where the bacterium enters the cornea, before spreading. If not treated promptly this can lead to further complications with potential sight loss.

Photo of open tube doors

E.coli and streptococci

Streptococci is most known to cause eye infections, however, E.coli which spreads to the eye can be as equally infectious.

One eye infection that can be caused by these bacteria is bacterial conjunctivitis. Conjunctivitis is a relatively common eye infection and there are typically three types, viral, allergic, and bacterial. E.coli and streptococci, being bacteria, could cause the bacterial version of the infection, the symptoms of which include redness, irritation, discharge, and crusting of the eyelids.

Luckily, conjunctivitis is mostly self-limiting, meaning it will resolve independently. However, sufferers of bacterial conjunctivitis may need to resort to antibiotic eye drops if symptoms persist. Self-care includes cleaning the eye using a clean cotton pad dipped in tepid boiled water and wiping once in a singular motion, avoiding contact with the other eye. Always wash your hands and refrain from sharing towels to prevent the spread.

In more severe cases especially when the cornea is compromised due to injury or trauma (such as an abrasion or scratch), E.coli and streptococci can cause corneal infections including ulcers. This can result in significant pain, blurred vision, and potential scarring of the cornea. If you are experiencing these symptoms, it is important to seek immediate medical advice, to prevent any long-term complications.

Lastly there is Endophthalmitis, a rare inflammation of the intraocular structures of the eye. Most commonly present following surgical complications of the eye, or through trauma, this rare condition has the potential to cause irreversible sight loss if not seen to immediately.

Most of these issues can be avoided by being sure to follow best hygiene practices when travelling on any public transport, such as:

  • Carrying hand sanitiser: This can help eradicate lingering bacteria on the skin, ensuring it won’t make its way into your eye, especially if you accidentally rub your eyes.
  • Not doing makeup while travelling: For many, makeup application becomes a subconscious activity, and for eye makeup this can involve using fingers to wipe, pull and smudge around the eyes. Either wait until you’re at your destination to apply makeup or sacrifice a bit of your sleep and get up earlier to protect your eyes in the long run. In addition, all it takes is someone to bump into you on the tube whilst you’re applying makeup to end up with a corneal abrasion (corneal scratch).
  • Switch to daily contact lenses: Contact lens wearers are at an increased risk of spreading bacteria through inserting and removing lenses. Switching to daily contact lenses minimises this risk through replacing them daily. Be sure though to always wash your hands with mild soap thoroughly before changing your contact lenses.

It’s not all doom and germs

When you see hundreds if not thousands of fellow commuters, it can be hard to not think about all the germs being left behind. After all, humans shed millions of microbes every hour. All it takes is one grip of a pole or a hand on the seat and you may be put at risk. But our swab data reveals that the underground environment is relatively clean, with only four out of the 12 tube lines returning positive results for microbial contamination. While the presence of some germs is inevitable in densely populated environments, the low frequency of microbial contamination suggests that sanitation efforts and cleaning protocols implemented by TfL are working like a charm. However, despite this encouraging result, it’s still not clean enough to be touching your face, so being vigilant with personal hygiene practices is crucial to make sure you have a safe and hygienic commute.

What the experts have to say

We enlisted the help of Jason Tetro, a microbiologist, and Dr. Dina Keen, a dermatologist, to provide expert insights on the cleanliness standards and potential health risks associated with the tube and the impact it can have on your health.

Jason Tetro

Inline photo of microbiologist Jason Tetro

Jason “The Germ Guy” Tetro is a long-time microbiologist and immunologist focusing on human health and infection prevention in control in healthcare. He’s also recognised for translating complex information into easy-to-understand content. He has written two bestselling books, The Germ Code and The Germ Files, and is the host of the Super Awesome Science Show.

What are your thoughts on people applying makeup while on the way to work or a social engagement on the tube?

“There is little doubt that public transport is flooded with germs and if we could see them, I’m sure people would not be applying their makeup and other cosmetics. There are two risks at play. The first is contamination of the cosmetics themselves with unsafe hands. This can lead to the introduction of unwanted microbes on the skin such as bacteria that cause cellulitis, impetigo, and acne. Then there is the risk of putting unsafe hands in the mouth to aid in the application of makeup. This can lead to exposure to a variety of different pathogens including SARS-CoV-2.“

“There is an easy answer to lower this risk – application of hand sanitiser. Using 62-70% ethanol for 20 seconds of wetness will remove the majority of bacteria and other pathogens allowing you to safely administer cosmetics.”

Which bacteria is most likely to cause damage to the skin?

“That would be Staphylococcus aureus (Staph). It’s a naturally occurring bacterium found on the skin but can cause infections when it enters the skin through cuts, abrasions or through touching the eyes and mouth.”

How easy is it for bacteria to get onto your skin when doing your makeup?

“It’s important to remember that makeup cosmetics are already dirty enough as it is. They are products that you’re putting on your face, so you really don’t want to contaminate it further. You need to be safe when you apply the makeup, and you don’t know if the tube will be clean enough, but you can take the necessary precautions when you’re at home. Plus, the oils in makeup can help microbes grow and thrive, so while it may not be an issue at the time, it could be the next time you apply your makeup, once they’ve had a chance to grow and cultivate. However, your biggest concern is the dust and pollution when it comes to your skin when you’re on the tube.”

Dina Keen

Inline photo of dermatologist Dr Dina Keen

With over 20 years of experience as a dermatologist, Dr. Dina Keen has extensive experience working with various ages, ethnicities, and cultures. Skilled in acne, laser rejuvenation, body contouring, rosacea, and IPL treatments.

How does exposure to pollutants and bacteria on the tube impact skin health?

“Our skin acts as a protective barrier against various environmental hazards, such as pollutants and bacteria. However, the strength of our local skin immunity and general immune system, as well as the concentration of pollutants and bacteria in our surroundings, determine the level of protection our skin can provide. When using public transportation like the tube, the number of people travelling and the level of pollution on different lines can also affect our skin. While exposing ourselves to viruses and bacteria can help strengthen our immunity, it's important to maintain a balance and take necessary precautions, especially for individuals with sensitive skin and those who may be more susceptible to skin problems.”

Are there any specific skincare routines or products that you recommend for people who frequently commute on public transportation and may be exposed to pollutants and bacteria?

“I recommend that people who commute on public transport update their skincare routine with antioxidants. Moisturising creams or mists/sprays and supplements with antioxidants could be added to their routine at home on clean skin.”

“For your daily skincare routine, it's crucial to opt for gentle cleaning methods. Avoid wipes, as they often contain alcohol, which can irritate the skin if used regularly. Instead, consider using a mild cleanser that is suitable for your skin type.”

“High quality mineral makeup is a must-have, as minerals have antibacterial properties and naturally protect our skin. It is important that these makeup products are talc-free and do not look cakey after application. Some companies claim that their makeup products are minerals, but they are actually 50% minerals and 50% chemicals.”

Meet the bacteria

The London Underground is used by around 4 million people a day so it’s no surprise that it’s home to a whole host of bacteria. But what types of bacteria exactly and why should we be cautious around them? We swabbed for a whole host of bacteria species, including Escherichia coli (E.coli), Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Clostridium perfringens and the combination of streptococci and enterococci to see which one rules the underground

Image of Pseudomonas aeruginosa bacteria Image of E.Coli bacteria Image of streptococci and enterococci

Pseudomonas aeruginosa

The impact of Pseudomonas aeruginosa on the eyes can be significant. Symptoms can include pain and redness, blurry vision, sensitivity to light and ulceration on the cornea.


Can cause conjunctivitis (pink eye), corneal ulcers (open sores on the cornea) and systemic infections with Ocular involvement.

Streptococci and enterococci

Can cause conjunctivitis, eye infections and corneal ulcers.


We conducted an experiment on 12 tube lines and 3 escalators, that involved swabbing both the seats and the poles/handrails to ascertain what types of bacteria breeds there. The bacteria that we tested for were Escherichia coli, Clostridium perfringens, Pseudomonas aeruginosa, Salmonella, Faecal Streptococci and Enterococci, Staphylococcus aureus, Bacillus cereus.

The swabs were taken at the busiest tube stop on each line at off-peak times. Swabs were rubbed and rotated against the object for at least 30 seconds per swab to ensure accurate samples were taken. Hand sanitiser was applied before swabbing commenced at each tube line to prevent transfer or cross-contamination of bacteria.

We used a Tempcon portable monitor to measure air quality, including PM2.5, CO2, HCHO, TBOC, AQI, temperature and relative humidity levels on the tubes. We took a reading of the air quality at five stops per tube line to find the average across those stations to get a good idea of pollution levels. Readings were taken throughout the tube ride and noted down just before the doors opened.

Photo of woman sitting on Tube

So, while the London Underground isn’t as filthy as people might fear, it’s clear that even with sanitiser and good hygiene habits, the tube is contaminated. Contact lens wearers in particular should be mindful of their eye health with all the potential risks posed by microbial contamination and environmental factors on the Underground. Whether applying contact lenses before or after makeup , it’s best to do it in a clean, controlled space at home. At Vision Direct, you’ll enjoy the perks and accessibility of online contact lens shopping, and find the cheapest contact lenses in the UK with minimal fuss.

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