Microplastic Content of Over-the-Counter Toothpastes – A Systematic Review

Published In: F1000Research
Publication Year: 2023

Study Design

This study is a systematic review that analyzed published research on the presence and characteristics of microplastics in over-the-counter toothpaste formulations.

Funding Sources

The study authors declared that no grants were involved in supporting this work.

PICO Framework – what was studied and how?

Population:

• Toothpaste samples from different countries.

Intervention:

• None.

Comparison:

• Toothpastes from different regions and brands were compared for microplastic content.

Outcomes:

• Presence and characteristics (shape, composition, and weight percentage) of microplastics in toothpaste.
• Environmental impact (estimated annual microplastic emissions from toothpaste).

In Paragraph Form:

This systematic review analyzed toothpaste samples from various countries to determine whether they contained microplastics and, if so, their characteristics, including shape, composition, and concentration. The study also assessed the potential environmental impact by estimating the annual release of microplastics from toothpaste usage.

Inclusion and Exclusion Criteria

Inclusion Criteria:

• Studies that analyzed the microplastic content in toothpaste.
• Studies that provided details on microplastic characteristics (size, shape, composition).
• In-vitro studies.

Exclusion Criteria:

• Studies published in languages other than English.
• Studies without available full texts or abstracts.

Demographics and Study Design

• Total number of studies reviewed: 6
• Countries included: China, Vietnam, Myanmar, UAE, Malaysia, Turkey, and India.
• Toothpaste samples tested:
  • Some studies tested multiple brands (e.g., one study analyzed 135 toothpaste samples from 23 brands).
  • Studies from China, Vietnam, Myanmar, and UAE reported no evidence of microplastics.
  • Studies from Malaysia, Turkey, and India reported the presence of microplastics.

Primary Outcome Variables and Results

Presence of Microplastics by Country

Microplastic Characteristics and Environmental Impact

• The highest percentage of microplastics in toothpaste was found in Malaysia (7.24%).
• India had the highest estimated microplastic emissions (1.4 billion grams per year).

Conclusions

• Some toothpaste formulations still contain microplastics, despite growing environmental concerns.
• The types of microplastics identified varied by country, with polyethylene being the most common in Malaysia and Turkey, while India had cellophane, polypropylene, polyvinyl chloride, and polyamide.
• Microplastics in toothpaste can contribute significantly to environmental pollution, with some countries releasing millions to billions of grams of microplastics annually.
• Stricter regulations are needed to phase out microplastics in personal care products, including toothpaste.

Discussion: Strengths and Limitations

Strengths:

• The review used multiple databases (PubMed, Scopus, Web of Science, etc.), ensuring a comprehensive search.
• The study followed PRISMA guidelines, maintaining scientific rigor.
• The study highlighted global differences in microplastic presence in toothpaste.

Limitations:

• Limited number of studies included (only six met the criteria).
• Lack of global representation – most data came from Asia and the Middle East.
• Medium risk of bias due to missing details on sample size calculations and blinding.

Citation

Chengappa KS, Rao A, Aparna KS, et al. Microplastic content of over-the-counter toothpastes – a systematic review [version 1; peer review: 2 approved]. F1000Research 2023, 12:390.
https://pubmed.ncbi.nlm.nih.gov/