What is it?
Microplastics are plastic particles smaller than 5mm, ranging down to nanoplastics invisible to the naked eye. They originate from the breakdown of larger plastic items, from synthetic textile fibres shed during washing, from tyre dust, and from the degradation of plastic packaging. They are now found everywhere: deep ocean sediment, mountain air, Arctic snow, and inside the human body. A 2024 study found microplastics in every human heart tissue sample examined.
What it does to your body
Inflammation
Plastic particles trigger immune responses and chronic inflammation in tissues where they accumulate.
Chemical cargo
Microplastics adsorb and carry toxic chemicals including PFAS, PCBs and heavy metals directly into cells.
Cardiovascular risk
A 2024 NEJM study found people with microplastics in their arterial plaque had a 4.5x higher risk of heart attack, stroke or death.
Gut disruption
Microplastics alter the gut microbiome, intestinal barrier integrity and absorption of nutrients.
Hormonal disruption
Plastic particles and their chemical additives disrupt oestrogen and androgen signalling.
Reproductive harm
Microplastics found in human placenta, colostrum and testicular tissue, with links to reduced sperm concentration.
How widespread is the problem?
A 2022 study found microplastics in the blood of 77% of healthy adults tested. Research published in 2024 found them in human heart tissue, lung tissue, liver, kidney, and most alarmingly in the brains of people who died. Average intake is estimated at a credit card worth of plastic per week through food, water and air.
Where it hides in your home
Key research
Microplastics in Human Blood
Published in Environment International: found microplastics in 77% of blood donors, demonstrating systemic human exposure.
Microplastics and Cardiovascular Events (NEJM)
Landmark New England Journal of Medicine study: patients with microplastics in arterial plaque had 4.5x higher risk of major cardiovascular events.
Microplastics in Human Heart Tissue
Published in Environmental Science and Technology: microplastics found in all 15 types of cardiac tissue sampled from heart surgery patients.
The body has limited ability to break down or excrete plastic particles, particularly nanoplastics which can cross cell membranes and the blood-brain barrier. Current research suggests they may accumulate in organs over decades. Reducing ongoing ingestion and inhalation is the primary strategy as clearance mechanisms are not yet understood.