Could your home environment be affecting your thyroid and immune system?

Your thyroid and immune system are responding to more than just your diet, stress levels, and sleep. From indoor air quality and mould exposure to plastics, synthetic fragrances, PFAS, and household chemicals, this episode uncovers the environmental toxins many people are exposed to every single day, often without realizing it.

If you’ve been struggling with Hashimoto’s, autoimmune symptoms, fatigue, hormone imbalances, inflammation, brain fog, or unexplained thyroid issues, this conversation will help you better understand the connection between your environment and your health. You’ll walk away with actionable steps to support your body’s natural detoxification systems, lower your overall toxic load, and practical, realistic ways to reduce environmental exposures without becoming overwhelmed or fearful.

01:30 — Why Your Home Environment Impacts Thyroid Health & Autoimmune Disease

03:20 — The Biggest Environmental Triggers Affecting Thyroid & Immune Health

06:20 — Why Even “Clean” Homes Can Still Increase Toxic Load

08:08 — The Top 5 Changes to Reduce Environmental Toxins at Home

12:15 — What Detoxification Actually Means (And What It Doesn’t)

15:05 — Why Some People Are More Sensitive to Environmental Toxins

18:00 — Perimenopause, Stress & Autoimmune Flare-Ups

RESOURCES: Grab all the links and resources mentioned in this episode at https://www.nicolegoodehealth.com/the-goode-health-podcast/episode-127

DISCLAIMER: The content in this podcast and related website is not intended to be a substitute for medical advice. It is not intended to be used to diagnose or treat, instead it is designed to help educate and inspire. Always seek the advice of a professional medical practitioner or qualified health practitioner. Never ignore or disregard advice given to you based on information in this podcast or related website and do not delay in seeking medical advice.

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On this podcast, we talk a lot about diet, we talk about stress, we talk about sleep, and we talk about movement, and all the things you do with your body. But I want to start today by turning the camera around, because here is a number that genuinely changed how I think about health. Most of us spend somewhere around 90% of our lives indoors, which means the room you are sitting in right now, the air in it, the dust on the surfaces, the water that comes out of your taps, that's not just your background, that's part of your immune environment.

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Your thyroid and your immune system are quietly responding to your home. I'm Nicole Goode, Certified Functional Medicine Practitioner, and this is the Goode Health Podcast. And today, we're talking about the environmental drivers of autoimmunity, and specifically how your home is affecting your thyroid.

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Now, I want to be really clear about the tone of this episode right up front. This is not a fear episode. I'm not here to make you frightened of your own house.

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And this is absolutely not about you having a dirty home, you'll see that in a minute. It's almost the opposite of that. What this is, is a lever.

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Your home is one of the highest leveraged things you actually have control over. And it's the one that almost nobody is auditing. So by the end of this episode, you'll understand which exposures genuinely matter, where they're hiding in even a beautiful home, and the realistic prioritised audit, the small handful of changes that do the most work.

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And this is particularly important if you have something like an autoimmune disease or a thyroid condition. Let's start with the why. Why are we even talking about the environment in a conversation about autoimmunity and thyroid health? Here's the piece that I think makes it click.

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Rates of many autoimmune conditions have been climbing, and they've been climbing faster than our genetics could possibly explain. Your gene pool does not change meaningfully in a generation or two. So when something rises that quickly, it's telling us that something in the environment is part of the story.

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Genes load the gun, as the saying goes, but the environment pulls the trigger. And it's doing an awful lot of the pulling because of the rates that we are seeing in the increases. They don't match the changes in genetics.

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There's a word for this that I really like, and that's the exposome. Your genome is the sum of your genes, your exposome is the sum of everything you are exposed to across your whole life. Every chemical, every pollutant, every bit of air and water and dust.

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And the exposome sits right alongside your diet and your stress as a genuine input into your health. We just don't talk about it because you can't see it, and nobody sells you an easy version of it. And here's where the thyroid in particular keeps coming up in this conversation.

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Your thyroid is a gland that actively takes up and concentrates certain substances from your bloodstream. That's literally part of how it does its job, which is brilliant when the thing it's concentrating is iodine, which is exactly what it needs, for example. It's much less brilliant when there are other substances in the mix that the thyroid can mistake for iodine or that get in the way.

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So the thyroid is, in a sense, uniquely exposed. It's a gland that actually goes looking for this. So let's get specific.

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What are we actually talking about here? I'm going to give you the main categories, and I'm going to be honest with you about where the evidence is strong and where it's still emerging, because that honesty is the whole point of doing this properly. Category one, endocrine-disrupting chemicals. These are substances that can interfere with the body's hormone signalling.

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The familiar names here are things like BPA, which is associated with certain plastics, phthalates, which are in a lot of soft plastics and synthetic fragrances, parabens, and then PFAS, the so-called forever chemicals, which have been used in things like nonstick, stain-resistant, and waterproof coatings. The reason these matter for us is that endocrine-disrupting chemicals can interfere with the thyroid hormone signalling and transport. And in large population studies, PFA's exposure in particular has been associated with altered thyroid function.

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Now, associated with is doing the real work in that sentence. This is population-level data, not a simple one-to-one, but it's a consistent enough signal that it belongs in this conversation. Category two, and this is the one with the cleanest, best-established mechanism, so I really want you to hear this one.

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These are a group of substances, things like perchlorate and nitrates, they're the main ones, that can compete with iodine for uptake into the thyroid. So remember I said the thyroid actively pulls iodine in through a kind of gate? Perchlorate can essentially get in the queue at that gate and take iodine's place. So you've got a substance that can turn up in some water supplies, in some food, that directly competes with the raw material your thyroid actually needs.

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And this one isn't a vague association, this is a really well-understood mechanism. Category three is the air. We tend to think of air pollution as an outdoor traffic, big city problem.

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But indoor air is frequently more polluted than air outside, because everything off-gases indoors. And then a well-sealed home, particularly modern homes, trap those things inside. And alongside the air, we've got household dust, which is genuinely an exposure route in its own right, and every home has some dust in it.

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Things like flame retardants from furniture and electronics settle into the dust, and then we breathe those in and we touch them. And then category four is water and damp. And this is one I see so often.

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Water quality varies enormously depending on where you live and what your pipes are like. And then there's damp and mould. And here I'll be really measured.

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Damp and mould are a recognised indoor hazard, and they place a real burden on the immune system and the airways. And in functional medicine, we treat that immune burden as part of someone's total load. The science on mould driving specific autoimmune conditions is still developing, but this is adding to your immune system's workload is a really fair and reasonable thing to say.

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And the amount of mould I see in autoimmune cases in clinic is unbelievable. So now here's the part that I think surprises people. Because when I list all of that, the instinct is to think, but my home is lovely.

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My home is really clean. So this isn't really about me. It's not going to affect me.

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But this has never been a cleanliness problem. It's a modern materials problem. And modern, beautiful, high-end homes are absolutely full of modern materials.

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Think about it honestly. A gorgeous home still has plastics throughout the kitchen. It has scented candles, reed diffusers, plug-ins, synthetic fragrance.

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It's often considered a luxury, not a red flag. It has brand new furnishings and finishes that off-gas for months after they arrive. It has flame retardants in the sofa and the mattress and the electronics that are quietly settling into any dust that lands in the home.

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It very likely has non-stick cookware. And the nicer and more recently renovated the home, the more sealed and insulated it tends to be, which is wonderful for your energy bills and means the indoor air gets less of a chance to actually move and refresh. Not so wonderful for your health.

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So I want to take the guilt out of this completely. If this is landing close to home, it's not a reflection on you or your standards or how well you keep or clean your house. It's a reflection of what almost every modern home is now built and furnished with.

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The point isn't to feel caught out. The point is that once you can see it, you can do something about it. And some of these things, as much as you do it, as expensive as you buy, you can't get away from.

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There are rules in the UK and in the EU that you have to have flame retardant furniture when you buy anything new now. So these are not things that you can necessarily escape no matter how good quality you buy and put in your home. Let's do the audit.

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And I want this to feel doable and not overwhelming. So I'm going to give you this in priority order. This is the 20% that does 80% of the work.

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So number one, water. If you do one good thing from this episode, make it this. Get a good quality water filter for your drinking and cooking water.

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Water is something that you take in every single day, multiple times a day. So improving it is one of the highest value, most repeatable changes that you can make. So start there.

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Number two, the air, and especially the bedroom air. You spend about a third of your entire life in your bedroom. So it's a very logical place to invest.

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Two things here. First, ventilation. It is so easy to actually open the windows.

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You just need to do it properly every day and let in the air, even in the winter. Let the air move round. And second, consider a good air filter for the bedroom specifically, particularly if you do have problems such as autoimmune disease or thyroid conditions.

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You don't need to filter the whole house at once. Start with the room that you breathe in for eight hours at night. But the simplest way of dealing with this is just to open the windows in your home.

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Don't think about it as, is it too hot, do I need to open the windows? Think of it as airing your room and your home every single day. Number three, this one is really important. Plastics.

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And here's the specific rule because avoid all plastic is not realistic in the world that we live in. The combination to design out first is heat plus plastic plus food. So don't microwave food in plastic.

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Don't pour anything hot into plastic. Be wary of plastic that's been left in a hot car or in the sun. And then if you can, move your food storage over to glass and stainless steel over time.

You don't have to do it all in one weekend. Just replace things as they start wearing out or pick one thing to replace first. But if you just want to start somewhere with plastics, heat, plastic, food.

Don't have the combination. So do not heat food in plastic. Do not eat food out of plastic that has got warm.

Number four, fragrance. So we're specifically talking about synthetic fragrances here in so many products. And they come in everything from candles, diffusers, cleaning sprays, laundry products, personal care.

And I'm not gonna tell you that you have to strip everything nice smelling out of your home overnight. Instead, just pick one category. So let's say your laundry products or your main cleaning spray.

And when it runs out, replace it with a genuinely fragrance-free version. And then next month, do the next category. These are all things that you can do slowly.

Start to choose things with natural fragrances in. So as you replace these products, that's when you start changing over to better things than the ones that you've maybe already got in your home. And number five is dust and damp.

Regular damp dusting. And you need to dust damp so that you really make sure that you are capturing rather than just flinging all the dust back into the air, which is what happens when we just dry dust. And then next, take damp and mould seriously.

If there is a damp patch or if there's a musty smell or condensation issues, that's a health item, not a decorating item. So don't just paint over it, find the source. But one thing that I want to caveat here, and this is really important, is you can't see all mould that is causing you a problem.

So if you are at all unsure or think that you may have been exposed to mould, the best thing you can do is get a mycotoxin test done. And then outside of that top five, if I could add one more thing in, it would be nonstick pans cookware. Choosing something like stainless steel or ceramics is much better option.

And again, the reason this is outside of the top five is because this does end up being quite expensive for people. Cookware is not something that is cheap to replace, but it is very important, particularly if you have thyroid issues. So maybe it's just slowly starting to change things over, starting to buy one type of pan and buying a new stainless steel one.

You can do things slowly. This isn't about being perfect on day one. And it's really important that you remember that.

Now we've spent this episode so far looking outwards at what's in your home and at how to bring less of that in. But I'd be giving you only half a picture if we stopped there, because there is another side to all of this. There's your side, what your body actually does with everything that it meets.

And I want to start here because honestly, I think it's the reassuring part. Your body is not a passive victim in your environment. You are not a sponge just soaking things up with no defence.

You are genuinely capable of processing these things. You have a capable processing system and that system has been doing this work quietly and well for your entire life. So here's how it actually works, kept very simple.

Your body is constantly doing something we loosely call detoxification, and this is not a detox diet. And I want to take that word back from the wellness industry for just a second, because it doesn't mean doing a juice cleanse or going on a weekend retreat or a supplement. It means the ordinary continuous behind the scenes work that your body does every single day to process things it doesn't need and move them out.

And your body is very good at this, and this is true detoxification. Your liver is the main engine of that. The liver takes compounds that are difficult for the body to get rid of, and it transforms them in stages into a form that can actually be carried out of the body.

So first it changes the compound and then it packages it up for removal. And then your exit routes take over. A lot of it leaves through your bile, into your gut and out through your bowel.

Some leaves through your kidneys and your urine. You breathe a little of it out through your lungs. You release a little of it through your skin when you sweat, and your lymphatic system runs underneath all of this like a quiet drainage network.

So this is not an emergency response. This is housekeeping, and it's happening right now. While you sit here and you're listening to this, and it's been happening reliably since long before any of us had plastics or synthetic fragrances, because the natural world has always contained things that the body has to process.

So you came built for this job. If your body is built for this, why do we worry about it at all? And this is the bit that I really want to land with you. It's not a question of whether your body can do the work or not.

It's a question of balance, the balance between the two things. How much is coming in, and how much capacity does your body have to process it and clear it? Think of it like a bucket, a steady trickle coming in and the bucket draining well at the bottom. That's a body in balance, and that's completely fine.

The trouble only starts when the rate coming in is faster than the rate going out. When the bucket starts to fill faster than it can empty. And that's why this is not about being perfect.

We don't need you to not come into contact with anything. We just need to reduce the load so that your bucket doesn't overfill. And this brings me to a question I get asked all the time.

Why is it that two people can live in the same house, eat broadly the same food, breathe the same air, and one of them is completely fine while the other one develops a thyroid issue or an autoimmune flare or the run of unexplained symptoms? Same environment, completely different outcome. Why? And the honest answer is because you are not processing it with the same equipment or from the same starting point. So let's look at some of the main reasons for this.

The first is genetics. We each inherit a slightly different version of this machinery. Some people's processing enzymes simply run a little bit faster.

Some run a little bit slower. It's a bit like everyone being handed a slightly different toolkit at birth. And it's not something to be frightened of.

It's just genuinely useful to know. If you've always quietly sensed that you react to things more than the people around you do, you may well be right. Secondly, we have your nutrient status.

And this one you can have a real influence over. Remember I said that the liver packages things up for removal? That packaging step needs raw materials to do its job. Certain vitamins, certain amino acids, certain minerals.

And if you're running low on those, which a lot of people are, through stress, through a depleted modern diet, through gut issues that stop you absorbing them properly, then your processing capacity quietly drops. You've still got the machine, you've just got less of the fuel that runs it. Thirdly, we've got your gut.

Your gut is both a major exit route and a place this load can build up. If your digestion is sluggish, if you're not clearing your bowels regularly and well, then things that were meant to leave your body can simply get reabsorbed. They get a second pass through a system that was doing its best to get rid of them.

So gut health is not a separate topic from this conversation. It sits right at the heart of it. Fourth is what I'd call your total load.

Your processing capacity is not infinite and it is shared. So if you're running on very little sleep, you're under relentless stress, you're fighting off an infection, or already carrying an autoimmune process, all of that is drawing on the same account. So it leaves you with less spare capacity for everything else.

Two people, the same exposure, but the one who is depleted, stressed, and not sleeping is going to feel it while the one with some reserve in the tank may not. And fifth, and this sits quietly underneath all of the others, is simply time. Your exposome, as I mentioned earlier, is the running total of everything you have been exposed to across your whole life.

It accumulates. So part of why something can surface in your forties when it never bothered you in your twenties is just the arithmetic of a lifetime adding up. It's never only about today's exposure.

It was always about today's exposure meeting the body and the history that you are bringing to it. And that is exactly why this shifts across your life because the body you are bringing to it keeps changing. There are certain seasons where your capacity is naturally more stretched.

And at precisely those times, we need to be a little bit more deliberate. So perimenopause is a big one here. And if you've listened to me before, you'll know why.

Your hormones are in flux. Your whole system is working harder to adapt and you simply have less spare capacity than you did a decade ago. The very same environment you coasted through in your early thirties can start to make itself felt in your forties.

And that's not you failing. That's a system that's just under more strain. It's working with thinner margins.

Pregnancy as well, and the time around it. That's another more sensitive window. The body's doing extraordinary work and developmental windows in general are simply more delicate.

The same goes for early childhood and adolescence. And then there are temporary dips that catch every single one of us, a stretch of broken sleep, a period of high stress, recovering from an illness, the early postpartum months. In all of those, your capacity is genuinely lower for a while.

So the very same exposure can land harder than it would have done six months earlier or six months later. Now here is what all of that actually tells you. And it's genuinely empowering once you see it.

It tells you that you have two levers here, not just one. We've spent most of the episode on the first lever, which is reducing what comes in. That's the home audit.

That's the water, the air, the plastics. But this, your body side, is a second lever. And in many ways, it's a more empowering one because it is so much of what we've talked about on this podcast anyway.

You support your processing capacity with the unglamorous fundamentals. Nutrient-dense food, so the machinery actually has its raw materials. A gut that is working well.

A bowel that is moving so your exit routes stay open. Enough water, enough sleep. Movement, and yes, a bit of sweat.

And not letting chronic stress quietly eat all of that reserve up. None of it's exotic. It's just the foundations.

But the foundations are what give you capacity. And that reframe matters most. Your body is not a passive victim of your environment.

It's an active, capable, and intelligent system, but it can be supported. The goal here is never to live in something that is perfect or sterile or a chemical-free bubble. That doesn't exist in today's world.

And chasing it would cost you more than it would ever give you. And probably stress you out a lot more. The goal is balance.

A sensible amount coming in and a body that is well-resourced and well-supported to handle what does. And this is really important because I know that for some of you, a list of things to do like this can tip into anxiety. And anxiety is not the goal here.

Anxiety is its own kind of load on the body. So here's the mindset that I want you to hold. A completely chemical-free life is not possible.

It doesn't exist. And chasing it, trying to be perfect about this is just gonna create its own stress, which is genuinely counterproductive. The goal is not perfection.

The goal is to lower total load. Think of it like background noise. Your immune system can handle a certain amount of noise without any trouble at all.

The aim is simply to turn the volume down so that your immune system has less to manage in the background and more capacity for everything else. Small permanent swaps in the places you're exposed most often will always beat one dramatic gesture that you can't sustain. Lower the load.

Don't chase perfection. If this episode has opened something up for you, the place I'd point you next is my book, Optimal You. The environment doesn't sit on its own.

It's one input into your immune and thyroid pillars. And the book gives you the full foundational picture of how all that fits together so that this doesn't feel like a random list of swaps, but part of a coherent approach. And if you're listening to this and thinking it's not just theoretical, if you suspect this kind of load is already showing up for you in your thyroid or your immune symptoms, then the mitoimmune health assessment is designed to look at those systems as a whole.

Both are linked in the show notes below. To bring it home, you spend the vast majority of your life indoors, which makes your home part of your immune environment, whether you've ever thought of it that way or not. This isn't about fear and it isn't about a dirty house.

It's about recognising that this is a lever that you can control. Start with things like your water, your bedroom air, your pots and pans. Lower the load.

Don't chase perfection. Thank you for being with me here today and I'll see you next week on the Goode Health Podcast.