Links Between Chemical Sensitivities and Mould Toxicity

One of my earliest memories is linked to a smell. I was very young, in the basement of one of the first homes we lived, digging through old toys. The smell was pungent and unmistakable — so distinct that decades later I can still recognise it almost instantly. It is familiar because, in one form or another, it has been present in nearly every place I have lived since.

I remember being rushed to hospital in the middle of the night with severe asthma flares at the age of three. My mother later told me that I was highly sensitive to certain fabrics and clothing tags, easily irritated by even minor physical discomfort. As the years went on, new symptoms emerged: rashes on the insides of my elbows and behind my knees, increasing food sensitivities, persistent acne, various skin conditions, weight gain, hormonal imbalances, worsening asthma, hair loss, heavy and painful periods, EMF sensitivities, brain fog, chronic fatigue and even cancer — eventually progressing to full-blown multiple chemical sensitivity.

In recent years, I have likely appeared unusual to others — hurrying past perfume counters in shopping centres or holding my breath as I walk past nail salons. I have unintentionally offended family members and friends by asking them not to wear deodorant or perfume when visiting our home. At times, I have even asked visitors staying for longer periods to shower on arrival and change into clothes I have washed, because I cannot tolerate the scent of laundry detergents or fabric softeners.

For two years, I stopped using all hair products, washing only with water, because everything I tried — even products marketed as “natural” — triggered reactions or worsened my asthma. Eventually, even most essential oils began to provoke symptoms. After removing every possible trigger I could identify, daily life began to feel as though I were living in a bubble.

Over time, I came to understand that multiple chemical sensitivity (MCS) is not, in itself, the root cause, but rather a manifestation of an underlying biological process. Increasing clinical and scientific evidence suggests that, in many individuals, MCS can arise in the context of chronic exposure to water-damaged buildings and mould toxins.

Mould exposure introduces a complex mixture of mycotoxins, microbial volatile organic compounds (mVOCs), and inflammatory fragments that can activate the innate immune system, promote neuroinflammation, and alter sensory processing pathways. Research in environmental medicine has described mechanisms such as toxicant-induced loss of tolerance (TILT), central sensitisation, mast cell activation, and persistent inflammatory signalling — all of which may contribute to heightened reactivity to low-level chemical exposures.

Clinically, it is frequently observed that when the underlying drivers of mould-related illness are identified and addressed — including removal from exposure and targeted medical management — patients often report a reduction in chemical sensitivities, with some experiencing substantial improvement or resolution over time.

Understanding MCS as a symptom rather than a primary disorder shifts the focus toward identifying causes and addressing the physiological processes involved, offering a more coherent framework for both patients and clinicians navigating this complex condition.