Microplastics, long associated with ocean pollution and food, are now taking a new concern. According to a study recently published in Nature Medicinetraces of these particles have been found in samples of human brain tissue taken from people who died in New Mexico. This revelation relaunches concerns about the capacity of microplastics to cross physiological barriers renowned impermeable, such as the blood-brain barrier.
An animal experiment that alerts without certainty
Work carried out on mice by a team of researchers led by Matthew Campen, toxicologist at theNew Mexico Universityhighlighted The potential effects of these particles on the brain. The results indicate that tiny plastic fragments could cause the formation of rare blood clots By obstructing certain cells. The quantities injected roughly corresponded to the equivalent of a plastic spoonwhich offers a concrete point of comparison but which remains very far from real exposure levels in humans.
However, the authors of the study themselves recognize the limits of this extrapolation. The human organism, more complex and more resilient than that of a rodent, could react differently to chronic exposure to these particles. Animal experimentation remains an indicator, not direct evidence of danger for humans.
Scientists call for caution
Several experts not involved in the study reacted with caution. They insist on the need to reproduce these results independently and on a wider scale. Current conclusions are deemed speculative By some, due in particular to the limited size of the human sample and the lack of data on actual environmental exposure.
This debate highlights the importance of rigorous and reproducible approaches in an emerging field of research. L’World Health Organization (WHO) has already expressed similar concerns in its previous reports on microplastics in drinking water, while calling for more research before drawing definitive conclusions on health effects.
A presence now confirmed in several organs
This is not the first time that microplastics have been detected in the human body. Previous studies have revealed their presence in lungsthe heartthe sang or the placenta. The crossing of the blood-brain barrier, however, represents a symbolically and biologically significant step, due to the crucial protective function of this barrier against toxic substances.
The now raised question concerns daily exhibition: inhalation, ingestion via diet or drinks, or dermal contact. These different entry routes make it difficult to assess the impact of microplastics on long -term human health.
Towards a more structured scientific supervision?
While global plastic production continues to increase – with more than 400 million tonnes produced each year -, research on the effects of microplastics on human health remains late. Several programs are underway, notably in European Union, To assess toxicological risks, but the protocols vary largely from one country to another.
The subject also arouses growing interest in the medical community, where we are starting to consider new environmental surveillance criteria. If studies like that of Nature Medicine Place important milestones, they are for the moment only begin in the understanding of a global and potentially insidious phenomenon.
Additional work will be necessary to confirm whether microplastics represent a real neurological risk, or if they are only silent witnesses of a massive exhibition still too little documented.