International Journal of Environmental Medicine doi: 10.3390/ijem1020007

Authors: Akira Onodera

Environmental exposure to particulate matter, including PM2.5 and engineered nanomaterials, is a major global health concern. Although acute toxic effects have been widely documented, new evidence suggests that the retained particle burden arising from incomplete clearance, tissue retention, and redistribution plays a key role in long-term health outcomes. This review synthesizes knowledge on particle accumulation at multiple biological levels. It examines how particles are retained in pulmonary and lymphoid tissues, their uptake by immune cells, and their sequestration within organelles, particularly the endo-lysosomal system. The mechanisms by which lysosomal dysfunction can cause mitochondrial stress, redox and metabolic disturbances, and impaired autophagy are also discussed. These disruptions can alter the status of immune cells and disturb immune homeostasis. This review also examines how immune perturbation from accumulation may contribute to chronic lung diseases. Understanding these mechanisms explains the persistent health effects associated with low-dose exposure and supports more effective risk assessment and prevention.

International Journal of Environmental Medicine doi: 10.3390/ijem1020006

Authors: Nicole Montes Pérez Tia Warrick

Flooding is an increasingly frequent climate hazard with the potential to mobilize environmental contaminants and elevate human health risks. In this study, we assessed heavy metals and metalloids across five sites arranged along a flood-risk gradient from low to high. Six replicate samples per site (n = 30 per contaminant) were collected in a single sampling event. Contaminants were evaluated using the US Environmental Protection Agency (EPA) risk assessment framework to calculate chronic daily intake (CDI), hazard quotients (HQs), and lifetime cancer risk. Arsenic, chromium, and nickel emerged as the most concerning cancer drivers, with nickel cancer risk consistently exceeding 1 × 10−3 (equivalent to one additional cancer case per 1000 exposed individuals) and arsenic at 4.4 × 10−4 (about 1 in 2250). Lead posed non-cancer risks (HQ = 0.912, near the threshold of concern), while cobalt demonstrated a significant decreasing gradient with increasing flood-risk (p = 0.018). Arsenic and thallium more than doubled in concentration at high-flood sites relative to low-flood sites, while cadmium, cobalt, and nickel decreased. These findings suggest flooding may mobilize arsenic, lead, and thallium, while diluting or displacing other metals such as cadmium, cobalt, and nickel. Organs of concern include the liver and kidneys for arsenic, cadmium, nickel, and cobalt, the brain and bones for lead, and the lungs and liver for chromium. Although statistical significance was limited by the small sample size, effect sizes and fold-changes indicate meaningful flood-related differences. This study highlights the importance of considering flood-risk in contaminant hazard assessments and the need for flood-adaptive risk management strategies in vulnerable communities.

International Journal of Environmental Medicine doi: 10.3390/ijem1010005

Authors: Dristi Sapkota Dinesh Phuyal

Contamination of agricultural water poses significant health risks that are often underrecognized in clinical practice. This review synthesizes peer-reviewed literature from biomedical and environmental sciences. It examines the pathways by which nitrates and zoonotic pathogens contaminate rural drinking water and delineates the resulting spectrum of acute and chronic health risks relevant to primary care. Agricultural practices are a primary source of nitrates and pathogens (e.g., Escherichia coli, Cryptosporidium, Giardia) in rural water supplies. Nitrate nitrogen exposure is linked not only to acute infant methemoglobinemia but also to chronic conditions like colorectal and thyroid cancers and adverse birth outcomes. These risks are observed at concentrations below the current United States Environmental Protection Agency regulatory limit of 10 mg L−1 NO3−–N. Pathogen exposure leads to acute gastrointestinal illness and can trigger long-term sequelae, including irritable bowel syndrome. Agricultural communities are uniquely vulnerable because they rely heavily on unregulated private wells, which are more prone to contamination than public systems. Evidence suggests a substantial and often underrecognized burden of waterborne disease in agricultural communities. The findings highlight a critical need for clinical vigilance regarding low-level nitrate nitrogen exposure and long-term post-infectious syndromes. By identifying these patterns, family physicians serve as essential sentinels for both individual patient safety and community public health.

International Journal of Environmental Medicine doi: 10.3390/ijem1010004

Authors: Ravi Shankar Aaron Goh Qian Xu

The transition to environmentally sustainable healthcare is gaining urgency, yet public discourse shaping this shift remains underexamined. This study employs natural language processing (NLP) to analyze 15,976 English-language tweets (2006–2024) related to sustainable healthcare. Using Latent Dirichlet Allocation (LDA), eight dominant topics were identified, including eco-friendly access, net-zero implementation, climate impact, emissions, cost and waste, education, infrastructure, and green technologies. Sentiment analysis (VADER) of 9433 tweets showed 59.1% positive, 31.1% neutral, and 9.8% negative sentiment, with AI and technology topics receiving the highest positivity (73.5%) and climate-related topics the most negativity. Thematic analysis of 800 tweets revealed six cross-cutting themes, including healthcare’s environmental responsibility, co-benefits for health, urgency of climate action, and optimism in technological solutions. These findings offer a nuanced understanding of public perceptions, informing targeted strategies and communication for healthcare sustainability. The study also demonstrates the value of mixed-method NLP in examining enablers and barriers to health system transformation.

International Journal of Environmental Medicine doi: 10.3390/ijem1010003

Authors: Pedro Henrique Campello Torres Sandra Momm Beatriz Milz Thais Tartalha Lombardi Gabriel Machado Araujo Bruna Bauer Dorcas Nthoki Nyamai

The COVID-19 pandemic has underscored and intensified existing structural inequalities, particularly in urban centers of the Global South. This paper revisits the Sustainable Livelihoods Framework (SLF), originally designed for rural contexts, proposing its adaptation to centralize mobility as a critical analytical axis in urban contexts. Through an examination of São Paulo, Brazil, we explore how mobility restrictions, access to natural capital, and health outcomes intersected during the pandemic, disproportionately affecting vulnerable populations. To explore the application of the adapted framework, we analyze two contrasting neighborhoods in São Paulo, highlighting how different urban contexts mediate the impacts of systemic crises. By integrating mobility into the SLF, we aim to provide a more nuanced tool for analyzing and addressing urban vulnerabilities in times of systemic crises.

International Journal of Environmental Medicine doi: 10.3390/ijem1010002

Authors: Alessandro Miani Jing Shang

Contemporary global society is confronting unprecedented health challenges [...]

International Journal of Environmental Medicine doi: 10.3390/ijem1010001

Authors: Giulia Stefenelli

We are delighted to announce the launch of the International Journal of Environmental Medicine (ISSN: 3042-7681) [...]