Microplastics have become an increasing concern in recent years as more research reveals their ubiquity and potential impacts.
These tiny plastic particles less than 5mm in size are found throughout the environment, from oceans and waterways to agricultural soils.
In 2024, the issue of microplastics continues to grow as a threat to personal health and the environment.
Below, we have compiled the latest research and statistics for microplastics (MPs).
Microplastic Detection and Levels
One study tested various animals and consumer products for microplastic levels using advanced techniques that pave the way for future research.
Here’s an overview of the key findings:
- Bivalves like mussels and clams had the highest microplastic contamination of the food items tested, with levels ranging from 0.2 to 4.35 particles/gram across multiple studies. This suggests bivalves are effective indicators of microplastic pollution in marine environments.
- Other seafood like fish and crustaceans had lower but still measurable levels of microplastics.
- Honey, sugar, salt, beer, bottled water, and tap water all contained detectable levels of microplastics based on the reviewed studies. This indicates microplastics have permeated many components of the human diet and food production system.
- There is variability in contamination levels across different studies and sample locations. More research is still needed to understand microplastic prevalence in foods, drinks and the environment.
- The use of spectroscopy and staining techniques allows reliable detection and quantification of microplastics down to the particle level in food and water samples.
Microplastics and Inflammation
Recent research highlights that exposure to microplastics can activate the inflammation process in the body.
Plastic fibres are extremely durable in synthetic lung fluid (Law, Bunn, & Hesterberg, 1990). Stemmer, Bingham, & Barkley (1975) found that inhaled polyurethane foam dust caused inflammation and eventually tissue scarring in guinea pigs.
Scientific evidence for the inflammatory effects of aerial microplastics currently only exists in non-human animal research.
It’s still unclear whether humans are impacted in the same way.
Overall, this finding underscores the potential health risks associated with microplastic exposure.
Textile Microplastics in Homes
Studies have found a high presence of textile microplastics in homes, which are a primary source of these particles in human respiratory and digestive systems.
In indoor environments, 67% of the fibers are natural, like cotton, while 33% are from oil-based materials, mainly polypropylene.
These fibers, also found in ocean and land microplastic studies, are typically too large to breathe in but can be ingested through dust, posing a risk especially to young children.
Impact of Microplastics on Behavior and Immune System
This study suggests that even short-term exposure to microplastics can lead to changes in behavior and affect immune markers in liver and brain tissues, indicating a broader impact on health.
qPCR analysis showed a ~2x increase in mRNA expression of the inflammatory cytokine TNF-α in the liver of both young and old mice exposed to microplastics.
In simple terms, the study found that when both young and old mice were exposed to microplastics, there was about a two-fold (or double) increase in the activity of a specific gene in their liver.
The gene is responsible for producing TNF-α, a protein that plays a key role in causing inflammation.
This suggests that exposure to microplastics can lead to increased inflammation in the liver.
Microplastics’ Effects on Intestinal Health
Evidence from animal studies indicates that nano- and microplastics can disrupt the balance of oxidative and inflammatory processes in the intestines, as well as the permeability of the gut lining.
Mice were exposed to water containing microplastic particles at concentrations of 100 to 1,000 micrograms per liter (μg/L).
This corresponds to a range of approximately 15,000 to 14.5 billion particles per liter, depending on the particle size.
Microplastics and Inflammatory Bowel Disease
A study found a correlation between the presence of microplastics in feces and inflammatory bowel disease (IBD).
While a direct relation has yet to be established, this data implies that microplastic exposure might be linked to the development or aggravation of IBD.
Microplastic in Soil
Another study provides detailed insights into the various sources and distribution patterns of microplastics.
Soils are probably major holders of tiny plastic particles, even more than rivers or oceans, though we don’t have exact data yet.
Nanoparticles and Brain Accessibility
A notable study has shown that very small particles, specifically nanometer-sized ones, can reach the brain within a few hours after entering the body, highlighting their potential to bypass biological barriers.
The researchers defined nanomaterials as “materials with at least one dimension less than 100 nanometers.”
According to the researchers, breathing in tiny silica microplastics can damage brain cells, causing stress and affecting brain defense cells.
This can lead to memory problems and changes in brain connections, similar to those seen in brain diseases.
While these particles disrupt brain cell signals, they don’t seem to alter genes or behavior.
Primary and Secondary Microplastic Sources
Research differentiates between primary sources, like synthetic clothing and tires, and secondary sources, such as degrading plastic objects, in the distribution of microplastics.
These microplastics could contribute up to 30% of the plastic pollution in the ocean.
Microplastics in Placenta
A study identified the presence of microplastics in a human placenta.
In this study, six human placentas from healthy pregnancies were examined.
Using a technique called Raman Microspectroscopy, researchers found 12 microplastic fragments, ranging from 5 to 10 μm, in four placentas.
These were present on both the fetal and maternal sides and in the membranes.
All fragments were colored; three were identified as polypropylene, a common plastic, while the others were linked to pigments used in products like paints, adhesives, and cosmetics.