Your environment and your health: what the evidence shows

Start with the big picture: what researchers mean by your environment, and why the same substance can be harmless in one situation and a concern in another.

Your exposome is everything around you, for life#

Researchers use the word exposome for everything you meet over a lifetime that is not in your genes, from air, food and chemicals to noise, heat and stress, and for how your body responds to it.¹

The idea was conceived in 2005 as a counterpart to the genome: a way to capture the non-genetic drivers of health and disease. It now spans synthetic chemicals, what you eat, psychosocial stress and physical factors such as noise and temperature, and researchers see these non-genetic factors as playing a dominant role in disease.¹

There is a humbling side to it. Most single factors in the exposome probably have small effects, which is why very large studies are needed to find them.¹ For you, that means two things: no one exposure is likely to explain everything, and the well-studied ones are the sensible place to start.

• I feel better when I’m away from home
• Is my flat making me ill?
• Chemicals are in everything
• The traffic wakes me at night
• I can’t switch off from the news
• Summer nights are unbearable

Hazard is not risk: amount and duration count#

A substance can be hazardous without being a risk to you. What counts is how much of it reaches your body, for how long, and at what stage of life.²³

The Federal Office of Public Health puts it simply: a lion is dangerous, yet a zoo visitor behind the glass runs no risk. A chemical classed as hazardous becomes a risk only when people are actually exposed to it, and limiting contact limits the risk.²

Duration matters as much as amount. With radon, a natural radioactive gas found in indoor air, the risk of lung cancer rises with both the concentration and the length of exposure.³ Timing matters too: for hormone-disrupting chemicals, the Endocrine Society singles out exposure during development as a particular concern.¹¹

With that lens, the exposures with the strongest evidence come into focus, and outdoor air is the best studied of all.

With that lens, here are the exposures researchers have studied most, beginning with the air you breathe outside and inside, then the chemicals and damp that share your home.

Fine particles in the air affect the heart and lungs#

Fine particles and gases from traffic, heating, industry and farming are linked with heart disease, stroke, lung disease and lung cancer.¹²¹³ In Switzerland, air pollution is estimated to cause around 2,000 premature deaths a year.⁵

A systematic review prepared for the WHO pooled 107 studies. Long-term exposure to fine particles (PM2.5) was linked with higher mortality from every cause examined, about 8 percent more deaths from natural causes per 10 µg/m³, and the links held at low levels, below the guideline the WHO used until 2021.⁴ The studies are observational, but the evidence for PM2.5 was rated high certainty for almost every outcome.

In 2021 the WHO lowered almost all its air quality guideline levels, because harm appears at lower concentrations than previously understood; heart disease and stroke are the most common causes of premature death from outdoor air pollution.¹³ Swiss legal limits largely reflect the older 2005 values, and in 2023 the Federal Commission for Air Hygiene recommended aligning them with the WHO.¹⁴

There is encouraging news too. Swiss air has kept improving since 2000, although ozone still exceeds the limits over large areas in summer, and fine particles do at several locations.¹² Health improves relatively quickly when pollution falls.⁵

Indoor air depends on airing, materials and radon#

Indoor air depends mostly on how you air, on chemicals released by furniture, paints and household products, on damp and on radon.⁹³

Plastics, glues, varnishes, paints and flame retardants release substances into the air and into house dust. Volatile compounds build up indoors, and regular airing lowers them considerably; new or renovated rooms release the most during the first two to four weeks.⁹ The WHO air quality guidelines apply indoors as well as outdoors.¹³

Radon, a natural radioactive gas, causes 200 to 300 lung cancer deaths a year in Switzerland, which makes it the main cause of lung cancer after smoking; the risk grows with the amount in the air and the years spent breathing it.³ Our guide on feeling worse in a new home covers radon, carbon dioxide and what is worth measuring.

Everyday chemicals are worth reducing, not fearing#

PFAS and hormone-disrupting chemicals such as bisphenols and phthalates are found almost everywhere, and food is one of the main ways they reach you.¹⁵²¹⁶ Swiss and EU limits aim to keep exposure low, and a few habits lower it further.

PFAS, the so-called forever chemicals, break down extremely slowly and build up in the body. In a Swiss pilot study, every one of more than 700 blood samples contained three common PFAS, at levels similar to those found in Europe and Canada. Authorities have linked PFAS in blood with a weaker antibody response to vaccination in children. Yet in a 2025 survey only 0.8 percent of animal foods sold in Switzerland broke the legal limits, and Swiss drinking water is considered safe.¹⁵

Endocrine disruptors interfere with hormones by mimicking, blocking or altering them, and turn up in packaging, toys, clothing and care products.² A 2020 review found human evidence linking PFAS, bisphenols and phthalates with outcomes such as impaired glucose tolerance and lower semen quality, while noting that the strength of these links still needs systematic evaluation.¹⁶ In 2023, EFSA concluded that bisphenol A in food is a health concern for all age groups.¹⁷

Because nearly everyone carries some PFAS,¹⁵ a blood test mainly confirms exposure; what a result means for you is a conversation with your doctor. Our guides on PFAS and on endocrine disruptors explain what such tests can and cannot say, and which habits make a difference.

Damp and mould mainly affect the airways#

Damp and mould at home act mainly on the airways, bringing more respiratory symptoms, allergies and asthma.¹⁸ A chronic illness caused by mycotoxins from indoor mould has not been established.¹⁹

The Federal Office of Public Health estimates that about one home in four or five is affected, with irritated eyes, skin and airways the usual complaints; the larger the mouldy area, the greater the risk.²⁰ The most important protection, according to the WHO, is preventing persistent damp in the first place.¹⁸

Urine mycotoxin tests do not help here. The German medical guideline on indoor mould advises against them, because mycotoxins from indoor sources cannot be validly measured or interpreted this way.¹⁹ Our guides on damp and mould at home and on mycotoxins explain what to do, step by step.

Some of what surrounds you is not a substance at all. Sound, light, temperature and a steady stream of news act on your sleep and your stress.

Noise and light at night reach you while you sleep#

Traffic noise disturbs sleep, and years of exposure are linked with heart disease; in Switzerland, around 500 deaths a year are statistically attributed to it.²¹ Room light in the evening delays melatonin, the hormone of the night.²²

Noise works through the stress response: adrenaline and cortisol rise, with heart rate and blood pressure, even during sleep, sometimes without your noticing. Night-time levels of 40 to 50 decibels outside the building can already affect sleep.²¹ Around 740,000 people in Switzerland live with road traffic noise above the legal limits.²³

In studies that recorded sleep in people's own bedrooms, each 10-decibel rise in the loudest traffic noise inside the bedroom raised the odds of waking by about 35 percent.⁶ Among 4.1 million Swiss adults followed for 15 years, road and rail noise was linked with death from heart and circulation disease independently of air pollution, with effects starting below current limits.⁷ The WHO advises keeping road traffic noise below 53 dB on average and 45 dB at night.²⁴

Light acts in the same hours. In laboratory studies of young adults, ordinary room light before bedtime delayed the evening rise of melatonin and shortened its release by about 90 minutes.²² Our guide on noise, light and information overload covers both in more detail.

Heat waves strain the heart and disturb sleep#

Heat puts a strain on the heart and circulation and disturbs sleep. People over 75, people with chronic illness or on certain medicines, and people who live alone are among the most vulnerable.⁸²⁵

To shed heat, the body sweats and loses fluid and salts, while widened blood vessels lower blood pressure; heat exhaustion or heat stroke can follow.⁸ Heat in the bedroom increases wakefulness and reduces deep and REM sleep.²⁵

In the summer of 2022, the hottest on record in Europe, an estimated 61,672 people died from heat across 35 countries, and Switzerland's summer was among the furthest above normal, by 2.3 °C.²⁶ The FOPH notes that Switzerland is seeing more hot days and heat waves with climate change, and that several risk factors together raise the risk further.⁸

Constant input can keep stress switched on#

Your stress response does not only answer to events in your own life. Noise sets it off even during sleep,²¹ and hours of distressing news can raise stress in people far from the scene.²⁷

After the 2013 Boston Marathon bombings, a survey of more than 4,600 Americans found that six or more hours a day of bombing-related media in the following week went with higher acute stress than having been there in person. The authors suggest that engaging with such coverage for hours each day may prolong acute stress.²⁷

That study concerned a single traumatic event. We found far less solid research on the ordinary daily stream of notifications and news, so treat it as a load worth managing rather than a proven harm. Our guide on noise, light and information overload looks at it in more depth.

Across all these families, some of what helps is in your hands and some is not. The next part separates the two.

Knowing what matters most makes the next step simpler. This last part covers what you can do at home, what sits with policy, when to see a doctor, and where our work fits.

Small home habits help; the big levers sit with policy#

At home, the useful habits are ordinary: airing, dealing with damp, dusting, using food containers as intended, and protecting your nights and your summers.⁹⁸ The biggest levers, such as traffic and industry, are beyond any one household.¹⁰

Much of the rest is not yours to fix alone. The WHO notes that most sources of outdoor air pollution are well beyond the control of individuals.¹⁰ Measures at the source work: a 30 km/h limit lowers road noise by about three decibels compared with 50 km/h, the equivalent of halving the traffic.²³ For PFAS, the FSVO's advice to consumers is a balanced, varied diet.¹⁵

Cleanse products are not the answer. A critical review found no randomised controlled trials showing that commercial cleanse diets remove anything from the body in people.²⁸ Our guide on what your liver already does explains the work your body does every day.

Some symptoms need a doctor, not a home fix#

Severe breathlessness, chest pain, signs of heat stroke or possible carbon monoxide poisoning need help straight away.⁸²⁹ Worsening asthma, a cough that returns at home, or symptoms that clearly follow a building need a doctor soon.

Carbon monoxide has no colour or smell, and poisoning shows up as headache, dizziness and nausea that are easily mistaken for a virus.²⁹ In the heat, if someone does not feel better soon after cooling down and drinking, the FOPH advises calling a doctor or 144.⁸ For a household chemical that has been swallowed or inhaled, Tox Info Suisse answers on 145, day and night.³⁰

We work on your daily habits, alongside your doctor#

Our work runs alongside medical care, never instead of it. Your doctor looks after symptoms and tests; we work with you on the daily habits that shape how you live with your surroundings: sleep, nutrition, movement, stress and digestion.

Much of what this guide describes sits with authorities, landlords and building specialists. What sits with you is daily life: airing and light at home, a bedroom that lets you sleep, a varied diet, time outdoors, regular movement, and a stress load you can carry, including how much news you take in.

We do not test your home or your blood for pollutants, and we do not diagnose. If you would like to sort out which changes matter most for you, talk it through with our care team on a free call. It is a coaching conversation, not a medical consultation, coordinated with your doctor whenever medical care is needed.