By:
Jürgen Mahlknecht, Leader of the Climate and Sustainability
Research Center;
and Cristina Chuck, Leader of the Health
and Food Safety Research Center
School of Engineering and Sciences, Tecnologico
de Monterrey, Mexico
Plastic has transformed modern life, but its
residues are transforming our health. From bottled water to seafood and even
table salt, microplastics have infiltrated the global food chain. It is
estimated that humans could ingest between 11,000 and 193,000 particles
annually through beverages, with bottled
water consumption being a risk factor that considerably increases exposure.
These tiny particles—less than 5 mm in size—result
from the degradation of plastic through physical, chemical, and biological
processes. Today, microplastics are not just an environmental concern: they
represent an emerging public health challenge that requires urgent action and
coordinated global policies.
Contaminants
in Food: Infiltration into the Trophic Chain
Various international studies have confirmed the
presence of microplastics in virtually all analyzed water and food sources:
●
Marine Food Chains:
Microplastics primarily affect filter feeders and small fish, which are then
ingested by larger predators. This accumulation allows microplastics to transfer
along the trophic chain and ultimately reach humans.
●
Direct Consumption Risk: The most
robust evidence comes from the marine environment: multiple studies have
revealed the presence of the endocrine disruptor bisphenol A (BPA) and the
plasticizer DEHP (a phthalate) in a high percentage of seafood samples, with
variations depending on the species and region. These findings imply a direct
and relevant exposure for the consumer.
●
Other Food Sources: In
addition to seafood, microplastics have been detected in table salt, honey, and
beer, confirming the omnipresence of these
particles in the everyday diet.
Although water is a primary route of exposure, especially
bottled water (which can contain from less than one particle up to more than
6,000 per liter), other foods contribute significantly to the total ingestion.
Ingestion is the predominant route of exposure, followed by inhalation and, to
a lesser extent, dermal contact.
Vectors
of Toxicity and Mechanisms of Cellular Damage
Microplastics represent a dual risk: physical
and chemical.
- Physical Damage and Cellular Stress (Direct
Risk): Due to their size and shape, they can interact directly with cells
and tissues, causing oxidative stress, inflammation, and cellular damage.
The evidence is especially solid for nanoplastics, which have been shown
to cross biological barriers. For larger microplastics, the evidence is
emerging but still limited.
○
Oxidative Stress and Inflammation: Exposure
to microplastics, including nanoparticles, induces oxidative stress and chronic
inflammatory processes, which are associated with neurological disorders,
cardiovascular diseases, and certain
types of cancer.
○
Cellular and Mitochondrial Damage: In vitro
experiments with intestinal cell lines (Caco-2) and dermal cell lines (HaCaT)
have shown reduced cell viability, mitochondrial damage, and increased
pro-inflammatory cytokines. Mitochondrial damage is particularly critical,
given the essential role of mitochondria in cellular energy generation.
○
Barrier Disruption and Translocation:
Nanoplastics ($<1 \mu m$) can cross biological barriers, reaching the liver,
kidneys, and lymphatic system, leading to hepatotoxic and systemic effects.
These findings underscore the importance of differentially evaluating micro-
and nanoplastics.
- Vector
Effect (Chemichal risk): Microplastics also act as vectors for
toxic additives, such as BPA, phthalates, and other components, transferring persistent, bioaccumulative, and toxic
substances to the food web.
○
Endocrine Disruption: BPA,
phthalates, and other components can mimic or block natural hormones, affecting
the cardiovascular, renal, gastrointestinal, neurological, and reproductive
systems.
○
Carcinogenicity Risks: Some
plastic compounds—such as styrene and certain phthalates—are classified as
probable carcinogens or are linked to genotoxicity
after prolonged exposure.
These discoveries suggest the imperative need to apply the precautionary
principle: it is crucial to reduce exposure to microplastics and their
additives immediately, without needing to wait for conclusive epidemiological
evidence.
The Water Paradox
and Methodological Challenges
Paradoxically, the infrastructure designed to
protect us, such as wastewater treatment plants, can become microplastic
redistribution points. Although they capture some
of the particles, they discharge significant quantities into rivers and coasts,
while residual sludge—used as fertilizer—reintroduces microplastics into the
agricultural environment.
The metropolitan area of Monterrey, Mexico,
exemplifies this paradox: a high dependence on bottled water, water scarcity,
and increasing accumulation of plastic waste elevate the risk of exposure.
To face this global challenge, the scientific community and health
authorities must close three critical gaps:
- Standardize
methods for sampling, treatment, capture, and identification using methods
such as FT-IR or Raman, in addition to AI-assisted analysis.
- Strengthen
health surveillance, integrating exposure data in water and food, with
attention to vulnerable populations.
- Implement
preventive policies, reducing single-use plastics, improving filtration in
treatment plants, and reinforcing extended producer responsibility.
The future of public health depends on how quickly we act with the
evidence already available. The cost of inaction is not theoretical: it
accumulates, particle by particle.
Key
figures on the microplastics issue:
●
< 5 mm: Definition of microplastics;
nanoparticles (< 1 µm) represent an emerging risk.
●
6,000+ particles/L: Maximum
levels detected in bottled water worldwide.
●
42 particles/L: Average
found in tap water and dispensers in Mexico City.
●
193,000 particles/year: Estimated
maximum ingestion by an adult through water consumption.
●
70–80%: Proportion of seafood samples containing BPA
and phthalates.
●
50x: Some studies report that bottled water can
contain up to 50 times more microplastics than tap water.
●
100–300 particles/kg: Average
levels found in commercial table salt.
●
2,400–9,400 particles/kg: Abundance
reported in certain edible seaweeds.
(Figures
can vary widely depending on analytical methods and minimum detectable sizes.)
References:
●
AINIA. (2022). Riesgos
alimentarios: Presencia de microplásticos en alimentos. https://www.ainia.com/ainia-news/riesgos-alimentarios-microplasticos-efecto-salud-caraterizacion/
●
CIEL. (2023). El
plástico y la salud. Center for International Environmental Law. https://www.ciel.org/wp-content/uploads/2019/03/Plastic-Health-Spanish.pdf
●
Ciencia.
(2023). Contaminación
por microplásticos. Revista Ciencia. https://www.revistaciencia.amc.edu.mx/index.php/vol-74-num-4/252-contaminacion-por-microplasticos.
●
Greenpeace
España. (2023). Plásticos en el
pescado y el marisco. https://es.greenpeace.org/es/trabajamos-en/plasticos/plasticos-en-el-pescado-y-el-marisco/
●
Hoang, H. G.,
Nguyen, N. S. H., Zhang, T., Tran, H.-T., Mukherjee, S., & Naidu, R.
(2025). A review of microplastic pollution and human health risk assessment:
Current knowledge and future outlook. Frontiers in Environmental
Science, 13, 1606332. https://doi.org/10.3389/fenvs.2025.1606332
●
INS. (2023). Perfil
de riesgo: Identificación y caracterización toxicológica de microplásticos como
peligro por vía alimentaria. Instituto Nacional de Salud.https://www.ins.gov.co/Direcciones/RedesDeLaboratorios/LABSALUD/RiesgosQu%C3%ADmicos/Perfil%20de%20Riesgo%20Micropl%C3%A1sticos%20en%20Alimentos.pdf
●
IPEN. (2022). Plásticos,
salud y perturbadores endocrinos. International Pollutants Elimination
Network. https://ipen.org/sites/default/files/documents/edc_guide_2020_v1_6bw-es.pdf
●
Mesquita, D. P.,
Quintelas, C., & Ferreira, E. C. (2023). Fate and occurrence of
microplastics in wastewater treatment plants. Environmental Science:
Advances, 2, 1616–1628. https://doi.org/10.1039/d3va00167a
●
Montero, V.,
Chinchilla, Y., Gómez, L., Flores, A., Medaglia, A., Guillén, R., &
Montero, E. (2023). Human health risk assessment for consumption of
microplastics and plasticizing substances through marine species. Environmental
Research, 237, 116843. https://doi.org/10.1016/j.envres.2023.116843
●
NutritionFacts.org.
(2023). Los microplásticos en el marisco y su riesgo de cáncer.https://nutritionfacts.org/es/video/los-microplasticos-en-el-marisco-y-su-riesgo-de-cancer/.
●
SciELO México.
(2024). Estudio de los efectos toxicológicos de los nanoplásticos en células
de colon. https://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S2448-56912023000200202
●
UN News. (2022). Los
microplásticos en el pescado y los mariscos, ¿deberíamos preocuparnos?
Naciones Unidas. https://news.un.org/es/story/2022/02/1505372.
●
Universidad de
Guadalajara. (2024). Microplásticos: Amenaza para los ecosistemas y la salud
humana. Centro Universitario de la Costa.https://www.cuc.udg.mx/noticias/microplasticos-amenaza-para-los-ecosistemas-y-la-salud-humana.
●
Valverde
Arámbula, F. A. (2025). Assessment of the presence and potential toxicity of
microplastics in bottled and tap water from the metropolitan area of Monterrey
using human intestinal and dermal cell lines. Qualifying Exam Proposal, PhD in Biotechnology, Tecnológico de
Monterrey.
●
Zuri, G.,
Karanasiou, A., & Lacorte, S. (2023). Microplastics: Human exposure
assessment through air, water, and food. Environment International, 179,
108150. https://doi.org/10.1016/j.envint.2023.108150
●
D.A. Syamsu, D.
Deswati, S. Syafrizayanti, A. Putra, Y. Suteja. (2024). Presence of
microplastics contamination in table salt and estimated exposure in humans.
Global Journal of Environmental Science and Management (GJESM). https://www.gjesm.net/article_707785_285503fd22e49b04fa945bda724c3ae2.pdf
●
Gurusamy
Kutralam-Muniasamy, V. C. Shruti, Fermín Pérez-Guevara (2024). Microplastic
contamination in commercially packaged edible seaweeds and exposure of the
ethnic minority and local population in Mexico. (PubMed). https://pubmed.ncbi.nlm.nih.gov/38163691/
# # #
About
Tecnológico de Monterrey
Tecnológico
de Monterrey (http://www.tec.mx)
is a private, non-profit university recognized for its academic excellence,
educational innovation, and global vision. It was founded in 1943 and currently
has a presence in 33 municipalities across 20 states of Mexico, with an
enrollment of 60,000 undergraduate and graduate students, as well as more than
27,000 high school students. Accredited by SACSCOC since 1950. It is ranked
#187 in the QS World University Rankings 2026 and #7 in Latin America according
to the THE Latin America University Rankings 2024. It also stands out in global
employability and entrepreneurship programs, and is part of international
networks such as APRU and U21.
About
the School of Engineering and Sciences of Tecnológico de Monterrey
The
School of Engineering and Sciences (EIC) of Tecnológico de Monterrey is a
leading institution in the training of engineers and scientists in Mexico and
Latin America. With a focus on academic excellence, cutting-edge research, and
engagement with industry, the EIC prepares its students to face the challenges
of the 21st century and to become agents of change in their communities.
Its
research strategy is focused on applied science and centers on three main
research cores: Health (Application of biotechnology, nanotechnology,
informatics, and electronics to improve human health), Climate and
Sustainability (Addressing environmental issues such as climate change and the
transition to renewable energies), and Industrial Transformation
(Implementation of digital technologies, artificial intelligence, and
innovative processes in manufacturing and supply chains). These cores are interconnected
with three strategic initiatives: the first dedicated to artificial
intelligence, the second to nanotechnology, and the third to semiconductors. To
learn more, visit: https://eic.tec.mx/es
