Heavy Metal Air Pollution: Human Health Effects and Nanomaterial Strategies for Monitoring and Remediation

Heavy metal air pollution represents a critical global environmental and public health challenge due to its persistence, bioaccumulation, and diverse toxic effects. Lead, mercury, cadmium, and arsenic are among the most hazardous, disrupting biological systems through oxidative stress, chronic inflammation, and interference with cellular signaling. These mechanisms drive the onset of acute and chronic diseases, damaging multiple organ systems and reducing overall health quality. The respiratory system is highly susceptible, as inhalation of fine and ultrafine particulates induces oxidative injury, inflammation, fibrosis, and progressive loss of lung function. Cardiovascular disorders such as endothelial dysfunction, hypertension, and atherosclerosis arise from oxidative stress and calcium signaling disruption, while endocrine toxicity occurs when heavy metals displace essential elements, disturbing hormone synthesis and metabolic balance. Reproductive toxicity manifests through reduced fertility, impaired gametogenesis, and abnormal embryonic development, often mediated by epigenetic alterations. Neurological consequences include cognitive decline, behavioral changes, and neurodegenerative progression, driven by apoptosis, oxidative damage, and altered neurotransmission. Addressing these risks, recent advances in nanotechnology offer promising solutions for air quality management. Engineered nanomaterials including metal nanoparticles, carbon-based adsorbents, and metal organic frameworks demonstrate high efficiency in capturing and neutralizing airborne heavy metals. Nanostructured catalysts can transform toxic particulates into less harmful forms, while nanosensor platforms enable real-time monitoring at ultra-trace levels. This review synthesizes current evidence on the health impacts of heavy metal exposure, with particular emphasis on air pollution and emerging nanotechnology-based strategies for monitoring and remediation.