A groundbreaking study from Brazil's Universidade do Oeste Paulista (Unoeste) has garnered international acclaim, highlighting the pervasive threat of microplastics and nanoplastics in both human lungs and regional rivers. Presented at the European Respiratory Society (ERS) Congress 2025 in Amsterdam—the world's premier pneumology event—the research was selected as one of the top works in sustainability, marking it as the sole Brazilian contribution to receive such recognition.

Led by medical student Bruno Henrique Couto under the guidance of Prof. Renata Calciolari Rossi, a pathologist in Unoeste's Medicine program, the systematic literature review analyzed over 700 studies, narrowing down to 46 key experiments primarily on rodents. The findings reveal alarming respiratory damage from these pollutants, predominantly polystyrene from everyday disposables like foam cups and food packaging. This work underscores Unoeste's rising profile in global environmental health research, positioning the institution as a key player in addressing Brazil's inland pollution challenges.

Unoeste's Research Excellence and the Team Behind the Study

Unoeste, located in Presidente Prudente in São Paulo's Oeste Paulista region, has long emphasized interdisciplinary research blending medicine, environmental science, and public health. Prof. Rossi, holding master's and doctoral degrees in Health Sciences, specializes in pathology and has previously explored contaminants' health impacts. Her mentorship of Couto exemplifies how university programs foster student-led innovation, with the duo's abstract titled 'Deleterious effects of microplastics and nanoplastics on rodent lungs' earning accolades at ERS 2025.

This isn't Unoeste's first foray into microplastics; the university hosts ongoing projects examining their presence in marine cosmetics, cardiac vascular effects, and oceanic health implications. The institution's commitment to real-world problems in agrarian regions like Oeste Paulista—rich in rivers such as the Paranapanema and Peixe—drives such initiatives, supported by programs like PROBIC for undergraduate research.

The award validates Brazil's interior universities' capacity for high-impact science, as Rossi noted: 'This shows that science from Brazil's hinterlands has international quality and relevance.' It also highlights opportunities for higher education institutions to lead in sustainability, attracting funding and talent amid Brazil's push for greener policies.

Methodology: A Rigorous Systematic Review

The study employed a systematic review approach, screening global literature for evidence on microplastics (particles <5mm) and nanoplastics (<1μm) in the respiratory tract. From 700+ papers, 46 were selected for detailed analysis, focusing on rodent inhalation exposure experiments. Outcomes measured included lung inflammation, hemorrhage, fibrosis, alveolar wall thickening, and inflammatory cell infiltration—intensifying with higher doses.

This method, akin to those in top journals like *Science of the Total Environment*, ensures robust synthesis of preclinical data. While human data is emerging—such as USP's 2021 discovery of microplastics in São Paulo lungs—the rodent models provide mechanistic insights into translocation, oxidative stress, and cytotoxicity. By mapping effects step-by-step—from particle deposition to chronic remodeling—the Unoeste team bridges environmental exposure to health risks.

Key Health Effects Uncovered in Rodent Models

Rodents exposed to polystyrene microplastics exhibited dose-dependent pulmonary pathology: acute inflammation via neutrophil influx, hemorrhage disrupting gas exchange, progressive fibrosis scarring alveoli, and structural alterations impairing function. These mimic human conditions like chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF), where particles evade mucociliary clearance due to size.

Globally, 2025 studies link inhaled microplastics to lung cancer risk via chronic inflammation and DNA damage, with humans inhaling up to 68,000 particles daily. In Brazil, USP found polyethylene and polypropylene in 65% of lung samples from autopsies, confirming inhalation as primary route. Unoeste's review amplifies calls for epidemiological surveillance in polluted areas.

The 'Invisible Cycle': From Rivers to Lungs

Central to the study is the 'ciclo invisível'—plastics discarded in urban valleys fragment via UV/weather, aerosolize in dust or wind, and deposit in lungs. In Oeste Paulista, poor sanitation transports them via rivers to treatment plants ill-equipped for nanoplastics. Rossi explains: 'Stations weren't designed for these; nanoplásticos are extremely small and hard to filter.'

This cycle echoes Brazil-wide trends: 1.3 million tons of plastic enter oceans yearly, with rivers like Rio dos Bugres (SP coast) ranking second globally at 93,000 particles/kg sediment. Inland, Meia Ponte River holds 60,169 particles, mostly in sediments. Urban discharge amplifies risks for 10 million in São Paulo basins.

Photo by CDC on Unsplash

Regional Focus: Microplastics in Oeste Paulista Rivers

Oeste Paulista's hydrology—Paranapanema, Peixe—suffers urban runoff, agriculture, and waste dumping. Though site-specific data lags, Brazilian surveys show microplastics in 69% of 1,024 beaches, with rivers as conduits. Unoeste urges prioritizing valley streams for sampling, as human activity concentrates pollutants. Local treatment upgrades are vital, as particles persist post-filtration, entering potable water.

This positions Unoeste at the forefront of regional monitoring, potentially inspiring collaborations with state agencies like CETESB for basin-wide assessments.

Global Context: Microplastics as Emerging Threat

Worldwide, microplastics pervade air, water, food; Europe reports alarming river levels. Human lungs harbor them deep, per 2022-2026 studies showing inflammation, fibrosis. Brazil's coast sees 12-1,300 particles/m² beaches; 600 ocean discharge points exacerbate. Unoeste's synthesis integrates these, stressing inhalation over ingestion in inland settings.

Public Health Implications and Vulnerable Populations

Oxidative stress, cytotoxicity, and translocation risk chronic diseases; rodents show parallels to asthma, fibrosis. Vulnerable: children, elderly, polluted-area residents. Brazil's urban poor face compounded risks from sanitation gaps. Policy needs: exposure limits, biomonitoring. For details on global reviews, see this study on lung deposition.

Environmental Ramifications and Mitigation Strategies

Rivers bioaccumulate toxins, harming aquatic life; airborne spread contaminates crops/air. Solutions: cut single-use plastics, enhance recycling (Brazil recycles 1.2%), wastewater tech upgrades, education. Rossi advocates prevention: 'Invest in research, awareness, waste reduction.' Community programs at universities like Unoeste can drive change. Explore ERS abstract here.

Future Directions: Calls for Brazilian Research

Unoeste eyes field studies in local rivers, human epidemiology. Partnerships with USP/FAPESP could scale up. As Brazil hosts 600 plastic hotspots, federal funding via CNPq/CAPES is crucial for higher ed-led solutions. This award boosts Unoeste's profile for grants, international ties.

Photo by CDC on Unsplash

Unoeste's Broader Impact on Higher Education in Brazil

Amid Brazil's 10M higher ed enrollments, Unoeste exemplifies interior unis' potential. Research output aids rankings, attracts research positions. Students like Couto gain global exposure, preparing for academia/industry. Ties to /br/ jobs highlight regional opportunities.