The Toxic Chemicals Hiding in Our Homes
Most indoor toxins are airborne, which makes indoor air quality a major health concern. While some pollutants drift in from outdoors, many are generated inside – from things like combustion (solid-fuel fireplaces and stoves), cleaning products, and building materials that release harmful gases and fine particles into the air.
Some toxins, such as lead, asbestos, and chemicals in older building materials, usually remain locked in solid form or cling to indoor surfaces until they’re disturbed or damaged. When this happens – for example, during renovations or general wear and tear – these substances can become airborne. Once in the air, they can settle back onto household surfaces, where they might be picked up by touch or even ingested if they land on uncovered food.
Indoor environmental toxins are typically grouped into organic, inorganic, biological, or radioactive categories. Common examples include volatile organic compounds (VOCs), particulate matter (PM), biological agents like mould and bacteria, and radioactive gases such as radon. Another useful way to think about them is by source – whether they come from combustion, building materials, household products, or outdoor pollutants that seep inside.
"The Air That I Breathe"
We think a lot about the food we eat and the water we drink, but rarely do we stop to consider the air we breathe – especially indoors, where most of us spend around 90 percent of our lives. Breathing is essential to survival: we can live weeks without food, days without water, but only minutes without air.
Every breath draws in not only oxygen but also invisible pollutants – dust, fungal spores, pathogens, chemicals, particulates, and carcinogens – that can harm our health and even affect our focus and productivity. Studies show that clean indoor air reduces illness, improves cognitive function, and helps prevent the spread of respiratory infections. The challenge is that air is invisible, undervalued, and still largely missing from building codes and public health policies.
"The Invisible Killer"
The COVID-19 pandemic briefly pushed indoor air quality into public conversation, but once the masks came off, the momentum for change quickly faded. Unlike water or food contamination, poor air quality usually can’t be seen, smelled, or tasted. While food- and water-borne illnesses often cause sudden, dramatic symptoms, poor indoor air quality tends to harm us quietly over time.
Many people tolerate stuffy rooms or recurring symptoms – headaches, irritated eyes or nose, worsening asthma – without realizing these may be a sign of poor air quality. There’s still a widespread assumption that air is naturally “clean” unless there’s a visible cue like smoke or a bad odour. In reality, viruses, bacteria, and pollutants are continuously circulating indoors. This invisibility makes indoor air quality easy to overlook in public health discussions, where issues with obvious, immediate effects tend to get priority.
There are many sources of indoor air pollution – everything from building materials and household cleaners to biological pollutants such as mould spores, dust mites and pet dander. However, indoor sources that release gases or particles into the air – a process called “off-gassing” – are often the primary cause of indoor air quality problems. According to the United Nations, nine out of ten people breathe air containing levels of pollutants that exceed World Health Organization limits, and around seven million people die each year from diseases and infections related to air quality issues.
Unlike food and water safety, indoor air quality isn’t regulated or consistently monitored. Building codes focus mainly on energy efficiency, often ignoring fresh-air circulation, which allows pollutants to become trapped indoors. Public health frameworks often treat clean air as a personal responsibility – “open a window” or “wear a mask” – rather than a systemic infrastructure issue. The result? Schools, workplaces, public buildings, and public transport rely on individual budgets and decision-making. Without clear standards, improvements tend to happen only in wealthier institutions or after major health crises.
Where Toxins Hide Indoors: The Main Sources
When it comes to harmful substances in our homes, it’s not just about what’s in the air and elsewhere – it’s also about where those toxins come from. Many of them are hiding in plain sight: in the walls, floors, furniture, and even the products we use every day. Let’s take a closer look at the most common sources.
A. Building and Furnishing Materials
The materials that make up our homes – and the things we fill them with – can release a surprising number of chemicals into the air. New carpets, furniture, and paints often emit volatile organic compounds (VOCs), which are gases that “off-gas” slowly over time, giving that “new home” or “new car” smell. Unfortunately, that scent is often a mix of irritants that can affect your eyes, nose, throat, and lungs.
Another common indoor toxin is formaldehyde, found in pressed-wood products, plywood, and insulation. It can cause irritation and has been linked to long-term health risks with repeated exposure.
Older homes may still contain asbestos (in insulation, floor tiles, or roofing) and lead paint – both harmless when undisturbed, but dangerous when damaged or sanded.
Quick Tip: When renovating or redecorating, choose low-VOC paints and finishes, ventilate well, and let new carpets and furniture air out before bringing them indoors. If you suspect lead or asbestos, have a professional handle it – don’t DIY.
B. Household and Cleaning Products
Ironically, some of the products we use to make our homes “smell clean” are among the worst offenders. Cleaning sprays, air fresheners, and disinfectants can release chemicals that irritate the lungs and disrupt hormones with frequent use.
Common culprits include ammonia, chlorine bleach, and quaternary ammonium compounds (quats) found in disinfectant wipes and sprays. Many products are also loaded with synthetic fragrances, which may contain phthalates – chemicals linked to hormonal and reproductive issues. Aerosol sprays and scented candles can release fine soot-like particles (PM) and VOCs that linger long after the scent fades.
Quick Tip: You don’t need a chemistry degree to clean safely. Vinegar, baking soda, and fragrance-free detergents often work just as well (or better). You can even add a few drops of your favourite natural essential oil if you like. Look for eco-certified cleaning products, and skip the air fresheners – fresh air is the best deodorizer.
C. Kitchen and Food Contact Materials
The kitchen can be another hotspot for hidden toxins. Non-stick cookware coated with PFAS (so-called “forever chemicals”) can release fumes when heated. These chemicals are also used in grease-proof food packaging like takeout containers and microwave popcorn bags – and once they enter the body, they tend to stay there.
Plastics are another concern. Many plastic containers and water bottles contain bisphenol A (BPA) or phthalates, which can leach into food or drinks, especially when heated.
Old plumbing can also be a source of lead or copper contamination in drinking water. PVC water pipes aren’t much better – especially not for hot water – though safer alternatives such as PEX or polypropylene are now available. Add in pesticide residues on fruits and vegetables, and it’s easy to see how even “healthy eating” can become an unintended exposure route.
Quick Tip: Opt for stainless steel, ceramic, or cast-iron cookware; use glass or stainless-steel containers for food storage; and run tap water through a good-quality filter if you’re unsure about your plumbing or water supply. Washing produce thoroughly (or buying organic when possible) can help reduce pesticide intake.
D. Indoor Air Contaminants
Many indoor pollutants come from things that burn – gas stoves, fireplaces, candles, and smoking. These sources can release carbon monoxide (CO), nitrogen dioxide (NO₂), and fine particulate matter (PM) – microscopic particles that can penetrate deep into the lungs.
Then there’s radon, a naturally occurring radioactive gas that seeps into homes (especially basements) from the ground. You can’t see or smell it, but in many parts of the world, long-term exposure is the second leading cause of lung cancer after smoking.
Quick Tip: Ensure proper ventilation when cooking or heating your home. Use range hoods or exhaust fans, and service heating appliances regularly. If you live in an area where radon is common, inexpensive test kits are available to check your home’s levels.
E. Biological Toxins and Mould
Not all indoor toxins are chemical – some are living. Mould, bacteria, and fungal spores thrive in damp, poorly ventilated areas like basements, bathrooms, or around leaky pipes. They can trigger allergic reactions, asthma, and chronic fatigue.
Dust mites, pet dander, and even certain houseplants can also contribute to poor indoor air quality. And while a bit of dust is inevitable, it can act as a carrier for other toxins, binding with chemicals that settle from the air.
Quick Tip: Keep humidity between 30–50%. Fix leaks promptly, use dehumidifiers where needed, and clean or replace HVAC filters regularly. Regular vacuuming with a HEPA filter and wiping surfaces with a damp cloth can also help keep dust and spores under control.
F. Personal Care Products
Our homes aren’t the only places toxins hide – many of them come straight from the bathroom cabinet or makeup bag. Every day, most of us use a small army of personal care products – from moisturizers and makeup to toothpaste, deodorant, hair colour, and perfume. The average adult uses around nine to fifteen different products daily – and each one can contain dozens of chemical ingredients.
Over time, these ingredients can add up. While the amounts in a single product might be low, repeated use and the combination of multiple products can increase what’s called your “dermal load” – the amount of chemicals absorbed through your skin.
Some of the most common culprits include:
- Parabens: preservatives used to prevent mould growth – they mimic estrogen and may interfere with hormone balance.
- Phthalates: found in fragrances, nail polish, and hair sprays – linked to reproductive and developmental issues.
- Triclosan: an antibacterial agent once common in toothpaste and soaps – it can disrupt hormones and contribute to antibiotic resistance.
- Formaldehyde releasers: preservatives that slowly release formaldehyde to prevent bacterial growth in shampoos, lotions, and cosmetics.
- Synthetic fragrances and dyes: often complex chemical mixtures that can trigger allergies or irritation.
Manufacturers aren’t required to list every ingredient in fragrances, which means the word “fragrance“ on a label can hide dozens of undisclosed chemicals.
Quick Tip: Choose products labeled fragrance-free rather than unscented (which may still contain masking agents). Look for those marked paraben-free, phthalate-free, and triclosan-free. Your skin is your largest organ – if you wouldn’t eat it, think twice before putting it on your body. The fewer ingredients, the better.
G. The "Antibacterial" Trap
For years, we’ve been told that “antibacterial“ means “better“. Advertisements promised that special soaps, wipes, and sprays would keep our homes germ-free and our families safer. But research tells a very different story – and it’s not a particularly clean one – in reality, many of these products are doing much more harm than good.
Many antibacterial handwashes, sprays, and even toothpaste brands once contained triclosan or triclocarban, both of which have been linked to hormone disruption and antibiotic resistance. In most Western countries, these ingredients have now been banned from over-the-counter soaps, but there is a chance that they can still appear in various imported or specialty products.
The irony? Studies show that plain soap and water work just as well for removing germs. Routine use of antibacterial products offers “no added benefit“ and may actually backfire by disturbing your skin’s natural microbiome – the healthy bacteria which acts as a first line of defense against pathogens.
Quick Tip: Stick with simple handwashing using ordinary soap and warm water for at least 20 seconds. Reserve strong disinfectants for times when they’re genuinely needed – such as cleaning surfaces during illness. Our immune systems actually benefit from some microbial exposure – that’s how they stay resilient.
The Compounding Effect: Everyday Exposure Adds Up
A single whiff of paint fumes or a spritz of cleaner won’t usually cause harm – but the concern is for long-term, low-level exposure to many different substances at once. Over time, these small doses can build up in the body, increasing what’s known as your “toxic load” or body burden.
This cumulative exposure can strain the liver, kidneys, and immune system – especially in older adults, children, or anyone with existing health issues. Being aware of “Environmental Toxins” is not about panic – it’s about empowerment. Once you know where these toxins hide out, you can make small changes that can make a big difference to your long-term health.
Part 3 will explore some practical ways to reduce exposure, support the body’s detox systems naturally, and create a healthier environment for lifelong wellness.