The notion of having a spoonful of plastic in one’s brain is alarming, and many people share this concern. Recently, a study has sparked widespread worry among scientists, revealing that microplastics can accumulate in the brain.

Researchers from the United States and Canada have authored a commentary, published on Tuesday in the journal Brain Medicine. The commentary not only discusses the recent brain study but also delves into the broader scientific understanding of the harm caused by microplastics to the environment and human health. Although more research is necessary to determine the most effective methods for removing these substances from our bodies, the scientists claim that individuals can already take steps to minimize their exposure.

Microplastics are defined as any piece of plastic smaller than 5 millimeters. In recent years, scientists have discovered them almost everywhere, from mountaintop clouds to human testicles to a baby’s feces. However, a study published last month in Nature Medicine by researchers at the University of New Mexico has raised new concerns.

The University of New Mexico researchers found microplastics in the brains of deceased individuals, as well as higher concentrations of plastic in their livers, kidneys, and other organs. Moreover, this accumulation seemed to be significantly greater in recently deceased people, suggesting that plastic exposure has worsened in recent times. They also discovered a higher concentration of plastics in the brains of individuals with dementia, potentially indicating a link to the fatal neurological condition. The researchers estimated that the brains of people today may contain an entire plastic spoon’s worth of these tiny fragments.

Nicholas Fabiano, the lead author of the new commentary, published today, warns that there is still much to be learned about the health impacts of microplastics. However, the current findings are not reassuring.

“The discovery of a spoon’s worth of microplastics in the brain was shocking. As a psychiatry resident, this is particularly relevant, given that we currently do not know the full extent of its impact on cognition or mental health,” Fabiano, a researcher at the University of Ottawa’s Department of Psychiatry, told Gizmodo. “In the Nature Medicine study, microplastic levels were 3-5 times higher in the brains of those with dementia, which raises alarms, although these findings are not causal in nature.”

The plastics themselves, as well as the chemicals that leach out of them, pose potential dangers to our bodies. Scientists have identified over a hundred chemicals in plastic that may harm humans or other animals, particularly endocrine-disrupting chemicals that can mimic and disrupt the regulation of important hormones. These chemicals have been linked to increased rates of infertility, certain cancers, and metabolic disorders like diabetes, among other health issues.

“The current evidence base (largely based on animal and cell culture studies) suggests that [microplastic] exposure can lead to adverse health impacts via oxidative stress, inflammation, immune dysfunction, altered biochemical/energy metabolism, impaired cell proliferation, abnormal organ development, disrupted metabolic pathways, and carcinogenicity,” the authors of the Brain Medicine commentary wrote.

Many unanswered questions regarding microplastics remain, according to Fabiano. In addition to the unknown long-term health risks, it is unclear how these plastics are entering the brain. Furthermore, little is known about how our bodies might eliminate microplastics, although some research has suggested that we can sweat out certain plastic-associated chemicals.

Despite these unknowns, Fabiano (and many other scientists) have called for governments and policymakers to take action to reduce our collective exposure to microplastics. In the meantime, individuals can take steps to limit their plastic intake, such as switching from bottled water to filtered tap water, eating fewer foods made with plastic (like certain tea bags, although some types are better than others), avoiding foods known to contain high levels of microplastics (such as seafood, alcohol, and highly processed foods), and storing leftovers in glass or stainless steel containers instead of plastic ones.