The high quantity of nanoplastics found in bottled water has the potential to disrupt the body’s cellular functions, according to a newly published study.
“As a demonstration, micro-nano plastics in bottled water are analyzed with multidimensional profiling of individual plastic particles,” the Proceedings of the National Academy of Sciences study reported. “Quantification suggests more than 10⁵ particles in each liter of bottled water, the majority of which are nanoplastics.”
Nanoplastics have become increasingly more concerning to researchers as their pervasiveness in all aspects of life brings into question the impacts on humans and the natural environment.
“Post-consumer plastic waste disposal leading to plastic pollution in landfills, waterways, and oceans represents a worldwide environmental challenge,” according to a report from the American Institute of Mathematical Sciences (AIMS). “Accumulation and continued material fragmentation from micro- to nanoplastics has identified concerns pertaining to the environmental and human exposures and toxicity. While many studies have focused on particle fate and identification, the toxicological considerations must focus on the biological relevance of particle deposition within a particular organism, compartment, organ, and tissue.”
Because of their smaller size, they can be more harmful due to their ability to permeate cell walls, the study reported.
“With engineered plastic particles with fluorescent dyes or metal labels, researchers have shown the possibility of nanoplastics crossing biological barriers and entering the biological systems, raising public concern on its potential toxicity,” the report said.
Microplastics are measured at a millionth of a meter and are easier to observe under a microscope; however, nanoplastics are measured at a billionth of a meter, making them more traversable on a cellular level.
In the study, scientists used “hyperspectral stimulated Raman scattering (SRS) microscopy” to observe the nanoplastics.
“With this platform established, we moved on to apply the utility to micro-nano plastics from real-life samples,” the study said. “Microplastics have been widely found in human foods, drinks, and product packaging, among which bottled water is of particular interest for being an important source of microplastics to be ingested in daily life.”
The AIMS report sized microplastics as pieces of plastic less than 5 millimeters, while nanoplastics are materials less than 1,000 nanometers.
Because of their small size, their quantity in the environment is immeasurable but hypothesized to exceed microplastics, the report said.
Nanoplastics in the Food Chain
Studies show they’ve been ingested “by a wide range of aquatic biota.”“Ingestion of microplastics represents an environmental concern for the health of the individual as well as for the trophic transfer of plastic contaminants to larger predators as in the case of transfer from algae to zooplankton and fish,” the AIMS report said. “Small nanoplastics were found to directly absorb through the intestinal walls of mussels and bioaccumulate in barnacles. Evidence of plastic particles in the terrestrial environment confirms nanoplastic uptake by plants, earthworms, and in air pollution or aerosolized particulate matter.”
According to the AIMS report, people can be exposed to nanoplastics in several ways.
Among those are the use of consumer products such as bottled water and synthetic clothing, the inhalation of air polluted with nanoparticles, and the ingestion of food, in addition to “dermal application and intentional injection” of medical and hygiene products.
A separate study reported microplastic contamination in 16 “commonly-consumed protein products” such as seafood, meats, and plant-based proteins.
“There were no significant differences among the same product from different brands of store types,” the report stated. “Integrating these results with protein consumption data from the American public, we estimate that the mean annual exposure of adults to MPs [microplastics] in these proteins is 11,000 ± 29,000 particles, with a maximum estimated exposure of 3.8 million MPs/year.”
An analysis determined that people are exposed to an average of 258 to 312 microplastics a day, the AIMS report stated.
“Given the size disparity between micro- and nanoplastic particles, the estimate of nanoparticle exposure would be exponential,” the report stated.
Effects on Health
Though the adverse effects of nanoplastics on health aren’t currently known, a December Lancet report said exposure can lead to “oxidative stress, inflammation, immune dysfunction, altered biochemical and energy metabolism, impaired cell proliferation, disrupted microbial metabolic pathways, abnormal organ development, and carcinogenicity.”“There is limited human data on the health effects of MNPs [micro-nanoplastics], despite evidence from animal and cellular studies,” The Lancet Report stated. “Most of the published research has focused on specific types of MNPs to assess their toxicity, while other types of plastic particles commonly found in the environment remain unstudied.”
Still, The Lancet Report states that because of frequent exposure, evidence is mounting suggesting that organ systems are compromised by the infiltration of nanoplastics that could lead to more pronounced health problems.
“Although numerous animal and cell culture studies indicated the adverse biological effects of MNPs on human health, the underlying mechanisms are still unclear,” the report stated. “Furthermore, whether long-term exposure to MNPs is associated with disease susceptibility needs to be investigated.”
