Shock as scientists find plastics in human blood


Test-tube with blood sample. Scientists have found plastics in human blood.

Photo credit: Shutterstock

Global researchers say they found plastics in 17 out of 22 healthy study participants.

The researchers took blood samples from anonymous, healthy adults and found that 77 per cent of them had between 700 and 500,000 nanometers (nm) of plastic.

The amount of plastic traces found is about 140 times smaller than the width of a human hair.

The study, which was published in Environmental International, a global journal, points out that polyethylene terephthalate (PET), which is commonly used in disposable water bottles, was the most widely encountered plastic polymer. It was found in about 50 per cent of the donors.

The second most widely encountered polymer was polystyrene (PS), which is used in food packaging and polystyrene foam, was found in about 36 per cent of the samples.

The authors are of the view that the participants could have been exposed to microplastics through air, water and food.

Dental polymers

They further point out that they could have accidentally ingested the plastic through personal care products such as toothpaste or lip gloss, dental polymers or through implants and tattoo ink residues.

Earlier this month, a group of scientists found 39 microplastics of 12 different types in 11 out of 13 lung tissue samples.

The peer-reviewed findings of this study were published in the Science of the Total Environment journal by the University of Hull and Hull York Medical School assessed the presence of microplastics in human lung tissue samples collected through lung reduction surgery or lung cancer surgery.

The researchers noted that exposure to microplastics is inevitable given that traces are present in the air people breathe, the water they drink, the items they touch and the food they eat.

“Airborne microplastics (MPs) have been sampled globally, and their concentration is known to increase in areas of high human population and activity, especially indoors.

 “Respiratory symptoms and disease following exposure to occupational levels of MPs within industry settings have also been reported. It remains to be seen whether MPs from the environment can be inhaled, deposited and accumulated within the human lungs.


“The study demonstrates the highest level of contamination control and reports unadjusted values alongside different contamination adjustment techniques.

These results support inhalation as a route of exposure for environmental MPs, and this characterisation of types and levels can now inform realistic conditions for laboratory exposure experiments, with the aim of determining health impacts,” the researchers note.

The researchers disclosed that 45 per cent of the study participants were female, with an average age of 63 years.

The researchers added that they used strict control measures to avoid and adjust for contamination.

They then used tissue samples taken from different lung areas after surgical procedures of 11 study participants at Castle Hill Hospital and Hull University Teaching Hospitals with two participants contributing two tissue samples from distinct lung areas.

“The four microplastics present in the most considerable quantities included polypropylene, which is found in carpets, clothing, automotive plastics; polyethylene terephthalate (PET): present in clothing, beverage, and food containers and resin; a constituent of protective coating and paints as well as polyethylene (PE); a component of food wrappers, milk containers, toys and detergent bottles,” they said.

In an exclusive interview with the Nation, Kenyan Youth Biodiversity Network co-founder Kevin Lunzalu and an Aspen New Voices 2022 Fellow explained that the presence of microplastics in human blood, though unfortunate, is not shocking.

“As early as 1998, scientists had already established the presence of microplastics in human lungs – which should have served as a serious warning on the foreseen health dangers of plastic consumption.

“Microplastics are also found in the air we breathe, catalysing the health risks associated with the plastic crisis. Research points to the fact that humans ingest 11 microplastic fibers per hour, with 33 per cent of that coming from indoor settings, such as household dust from synthetic clothes.

“Residents of big cities like Nairobi are at a greater risk of the health impacts of microplastics, including damage to lung tissues, coughing, breathing complications, cancer, asthma and blood-related complications.

Health hazards

“Kenya’s rapidly expanding middle class points to a country whose purchasing power is steadily rising. This means that the use of plastics has not reached its optimum levels, with related health hazards expected to rise. Increased purchasing power has a direct impact on plastic consumption, with items such as water bottles, plastic straws, synthetic clothing and plastic packaging heightening the risks associated with plastic use,” he  explained.

Roads, Mr Lunzalu further pointed out, have also contributed to the microplastic crisis.

“Cars emit little fragments of plastics through tyres and braking pedals, which are deposited on the roads and eventually end up in our waterways (rivers, streams and drainage systems), and eventually in our oceans, causing serious health risks to humans and aquatic life.

“Some of the particles accumulate in the air that Kenyans breathe in. These particles, which are carried by the wind, can easily be swayed beyond urban zones. Without going into the mathematics of car tyre diameter and surface area, it is clear that the bigger the car the higher the amounts of plastic particles spewed into the air.

“With the country registering in excess of 350,000 additional cars each year, the contribution from the automobile sector is significant and made worse by the poor state of most roads,” he further noted. 

Washing machines, he added, are another factor, with a single wash producing thousands of plastic fibers from clothes.

“Making people aware of the harmful impacts of plastic and how their lifestyle choices put everyone else at risk is essential to attaining the collective behavioural change that is needed to drive Kenya towards a plastic-free economy.

“The government should ensure that alternatives to single-use plastics are subsidised to make them affordable and to encourage businesses to embrace reusable packaging. A policy to ensure all washing machines have microplastic filters would be ideal,” he told the Nation. 

“If world leaders don’t take radical and urgent steps to cut our evident addiction to plastics, countries in the Southern hemisphere, such as Kenya, will bear the brunt of ecological and health-related impacts, since we lack enough resources and capacity to timely monitor, avert and treat complications arising from plastic pollution.

“Even though Kenya has banned plastic bags and single-use plastics, pockets of plastic carrier bags still linger in our markets.

 “If well embraced and executed, a global deal could drastically reduce single-use plastics in favour of biodegradable and reusable alternatives.

“It remains our collective and differentiated responsibility to minimise our consumption and exposure to plastics,” he offered.