Tiny plastic particles may increase risk of serious illness

Global levels of micro- and nanoplastics (MnPs) being absorbed by the human body are increasing, potentially increasing the risk of cancer, diabetes, cardiovascular disease and chronic lung disease, according to a new study.

Such non-communicable diseases (NCDs) are associated with inflammatory states in organs of the body, and particulates may increase the absorption of MnPs and their exudates within the digestive and respiratory systems, potentially increasing the risk and severity of NCDs in the future.

Additionally, infant fecal MnP concentrations are significantly higher than adults, likely due to the common use of plastics in preparing, serving and storing food for infants, and infant behaviors such as putting objects in their mouths may also be a contributing factor.

Publication of research results Cell Report MedicineAn international group of researchers now calls for a global, integrated, One Health approach to human health and environmental research that will elucidate the environmental mechanisms behind increased human exposure to MnPs and the link between particles and NCDs.

Lead author Professor Stefan Krauss, from the University of Birmingham, said: “Plastic pollution is increasing globally, making it important to understand the overall health risks associated with exposure to MnPs.”

“The global spread of MnP, which has already occurred, will remain a concern for centuries to come, so to reduce further emissions this pollution must be addressed at the source. This requires systematic investigation of the environmental drivers of human MnP exposure and their impact on the prevalence and severity of major NCD groups, such as cancer, diabetes, cardiovascular disease and chronic lung disease.”

The researchers emphasize that the relationship between MnPs and NCDs is similar to that between other particles, whether from natural sources such as pollen, man-made pollutants such as diesel exhaust, MnPs, or engineered nanomaterials, which all behave biologically in a similar way: the body treats them as foreign bodies and activates the same defense mechanisms. This puts the body's defense mechanisms at risk of being overwhelmed, increasing the frequency and severity of NCDs.

The incidence of NCDs is increasing worldwide, with the four main types together accounting for 71% of all annual global deaths and predicted to have an economic impact of more than $30 trillion over the next 20 years.

Co-author Semira Manaseki-Holland from the University of Birmingham said: “We need to better understand how MnPs and NCDs interact to advance global prevention and treatment efforts towards the UN Sustainable Development Goal of reducing premature mortality from NCDs and other inflammation-related diseases by 2030.”

“This need is crucial in low-income and low-middle-income countries (LMICs), where NCD rates are rising and plastic pollution levels and exposures are high. Whether indoors or outdoors, MnPs have the potential to increase global health risks.”

Global pollution trends mean that microparticles (<5 mm) and nanoplastic particles (<1 µm) are ubiquitous. MnPs have been detected in lung, blood, breast milk, placenta, and stool samples, confirming that particles can enter the human body from the environment.

Humans are exposed to MnP in outdoor and indoor environments through a variety of sources, including food, beverage ingestion, air, and cosmetic and human care products.

MnP has been found in fish, salt, beer, bottled drinks and in the air and is released from synthetic clothing, plastic bedding while sleeping, plastic carpets and furniture. Other sources include fertilizers, soil, irrigation and absorption by food crops and agricultural products.

Human exposure to MnP varies greatly depending on location and exposure mechanism, with evidence that indoor air MnP contamination hotspots contain up to 50 times more particles than those encountered outdoors.

Co-author Professor Iseult Lynch from the University of Birmingham commented: “We need to understand the human health risks associated with MnP, and to do that we need to understand the environmental controls of individual exposure. This requires environmental scientists and medical scientists to work very closely together.”