A large number of specialists are sounding the alarm about the effects of microplastics that have been found in almost all organs of the human body, from the lungs to the kidneys to the blood, while scientists are not yet certain about their impact on health.
Microplastic particles (less than 5 mm) have been detected in air, water, food, packaging, synthetic textiles, tires and cosmetics. Every day, humans swallow, inhale, or come into contact with these substances.
Fabienne Lagarde, a researcher at the Le Mans Institute for Molecules and Materials, said during a recent session of the French Parliament, “The person of 2024 contains plastic materials in almost all of his body parts (…), and it is likely to be worse for children who will be born in 2040.”
In recent years, scientists have found microplastics in the lungs, heart, liver, kidneys, and even in the placenta and blood.
Many studies have found links between microplastics and even nanoplastics (a thousand times smaller) and their effects on health.
One of the most recent of these researches is a study published last March in the New England Journal of Medicine, which showed a link between the accumulation of these molecules in blood vessels and an increased risk of heart attacks, strokes, and even death in some people with atherosclerosis.
Unknown and dangerous
Speaking to Agence France-Presse, Professor Tracey Woodruff from the University of California said, “Research on microplastic particles is increasing and is finding very worrying health effects,” adding that “a recent analysis of 2,000 studies on animals conducted with a group of colleagues showed that microplastic particles “It affects fertility, is associated with an increased risk of cancer and harms the respiratory system.”
Woodruff, who heads the Reproductive and Environmental Health Program, believes that these data, in addition to “finding microplastics in many organs of the body, including the brain, testicles, and even the fetus through the placenta,” constitute a “warning indicator.”
To date, no causal link has been found with human exposure to this complex mixture of polymers and chemical additives, combined with contaminants such as bacteria and even viruses.
The troubling studies were often conducted in laboratories, sometimes on human cells or animal models.
But the animal research reviewed concerns “biological systems that are very similar to those of humans,” and “animal data have been used for decades to identify carcinogens or toxic substances that affect the reproductive system,” Woodruff said.
Regarding the impact of microplastics, many details are still unknown regarding the importance of shape, size, and type of plastic or additive.
Preventive approach
Of the more than 16,000 chemicals used or found in plastics sold on the market, more than a quarter pose known risks, according to the Alliance of Scientists for an Effective Treaty on Plastics.
These risks include “infertility, obesity, non-communicable diseases, such as diabetes, cardiovascular disease, and many types of cancer,” according to a memorandum published by the coalition this year.
The level of exposure to microplastics remains uncertain.
In 2019, a shocking report by the non-governmental organization Worldwide Fund for Nature indicated that humans swallow and inhale up to 5 grams of plastic per week, the equivalent of a credit card. The results and methodology were reconsidered, and several subsequent studies pointed to lower estimates, or very variable estimates depending on the countries.
Research on microplastics and human health should continue, studies that began in the early 2000s and are already urging action in this regard, according to a large number of experts.
“Despite the novelty of the topic and the limits that have been identified, the risks associated with oral or inhalation exposure exist,” said Muriel Mercier Bonan, director of research at the French National Institute for Research in Agriculture, Food and Environment, during a session of the French Parliament.
Governments, regulators and manufacturers have a key role to play, because “the most important aspect is tightening measures to reduce plastic production and the rate of pollution associated with it,” says Woodruff.
A large number of specialists consider reducing exposure to plastic at the individual level to be a “preventive approach.”
Among the advice they give people is to avoid plastic containers, not to heat food in plastic containers, to prefer clothes made from natural materials, and to ventilate the house.