Microplastics, the tiny synthetic particles now found in our air, food, and water, may be silently harming human health, researchers at the University of California, San Francisco (UCSF) warn. These minuscule pollutants have become ubiquitous in modern life. They are suspected of causing serious health issues. These include fertility problems, colon cancer, and respiratory dysfunction.
UCSF researchers conducted a “rapid” review of studies published between 2018 and 2024 to assess the potential health risks posed by microplastics. This analysis was not a full systematic review. It focused on the most compelling evidence regarding microplastics’ effects on humans and animals.
ANIMAL RESEARCH: FERTILITY AND GUT HEALTH AT RISK
The review included 31 studies, primarily conducted on rodents, with just three involving human subjects. The majority of animal experiments focused on mice, conducted mostly at research institutions in China. The researchers found strong evidence that links microplastics to reduced sperm quality in animals. They also discovered that microplastics can alter gut immune responses in animals. The researchers rated these findings as “high” quality.
LIMITED HUMAN STUDIES SHOW TROUBLING RESULTS
Although animal models give the first glimpse into microplastics’ potential effects, human research is still in its early stages. The three human studies included in the UCSF review were conducted between 2022 and 2024 in Turkey, Iran, and China. These studies measured microplastics in maternal amniotic fluid, placenta, and nasal fluid. The results reveal that plastic particles are indeed making their way into the human body.
MODERATE EVIDENCE FOR RESPIRATORY ISSUES
The evidence for respiratory issues, including lung injury, pulmonary function impairments, and oxidative stress, was rated as “moderate” in quality. Researchers suggest that microplastics could be contributing to lung damage. Nevertheless, the evidence is less conclusive compared to the stronger findings on fertility and gut health.
CONCERNS FOR THE FUTURE: MICROPLASTICS IN THE BODY
Microplastics are now found in various human tissues, including breast milk, brain tissue, blood, and even placental tissue. Despite these alarming findings, research on the health consequences of microplastic accumulation remains in its infancy. The review notes that plastic production will triple by 2060. It is critical to better understand the potential long-term effects on human health.
DIGESTIVE HEALTH: COLON ALTERATIONS LINKED TO PLASTIC EXPOSURE
No human study in the review investigated digestive issues. Nevertheless, several animal studies revealed significant changes to the colon following exposure to microplastics. Rodents exhibited a decrease in mucosal surface area, correlating with the level of plastic exposure. This suggests that microplastics may contribute to digestive problems, including chronic inflammation and altered gut function.
SPERM HEALTH: MICROPLASTICS DAMAGE REPRODUCTIVE FUNCTION
Five animal studies examined the effects of microplastics on sperm, revealing a worrying decline in sperm quality. The research found reductions in living sperm, sperm concentration, and sperm motility. Some studies reported an increase in sperm malformations.
URGENT ACTION NEEDED: A CALL FOR PREVENTION AND MITIGATION
Given the growing body of evidence, UCSF researchers strongly urge regulatory bodies and decision-makers to take immediate action, even in the face of limited evidence. The potential long-term consequences of microplastics on human health demand swift intervention to reduce exposure and mitigate risks.
