Pulmonary black carbon accumulation: mechanisms, health impacts, and environmental sources

INTRODUCTION: Black carbon (BC), a major component of combustion-derived particulate matter, contributes substantially to air pollution and climate change and is increasingly recognized as a biologically active particle capable of crossing biological barriers and accumulating in human tissues. This review examines the evolution of BC exposure and its emerging relevance as a biomarker of cumulative internal dose. AREAS COVERED: We review the historical sources, physicochemical properties, atmospheric behavior, exposure assessment, biodistribution, tissue retention, detection methods, and health effects of BC. Particular emphasis is placed on tissue-based biomonitoring, label-free optical detection, and evidence linking BC exposure to respiratory, cardiovascular, neurological, developmental, metabolic, gastrointestinal, and immunological effects. PubMed, Web of Science, Google Scholar, and Scopus were searched for studies published through June 2026, including epidemiological, experimental, mechanistic, and biomonitoring investigations. EXPERT OPINION: Tissue-based BC biomonitoring may bridge external exposure assessment and biologically effective internal dose. Its integration with exposome research and precision environmental health could improve individual exposure characterization, identify susceptible populations, and strengthen environmental prevention strategies.