Phytoremediation for Air Quality: A Sustainable Solution for Urban Resilience and Post-Covid Green Recovery

Urban air pollution remains a critical environmental challenge in rapidly developing countries such as India, with severe implications for public health, ecosystem stability, and progress toward the United Nations Sustainable Development Goals (SDGs 3, 11, and 13). While mechanical air-purification systems offer some relief, their high costs and operational limitations underscore the need for sustainable, nature-based solutions. This review highlights phytoremediation as a cost-effective, eco-friendly, and scalable approach that uses plants to capture, absorb, and degrade pollutants including CO2, NO2, particulate matter, carbon monoxide, and volatile organic compounds (VOCs). The mechanisms underlying phytoremediation—such as surface deposition, stomatal uptake, biochemical transformation, and carbon sequestration—are discussed to illustrate how plants improve air quality in diverse environments. A global assessment, supported by case studies across Asia, Europe, the Americas, and Africa, demonstrates increasing post-COVID interest in plant-based strategies as part of green recovery initiatives. Several outdoor species, including Magnolia grandiflora L., Ficus benghalensis L., Buxus sempervirens L., Pinus sylvestris L., Tilia platyphyllos Scop., Quercus ilex L., and Picea abies (L.) H. Karst., effectively remove Polycyclic aromatic hydrocarbon (PAHs), particulate matter, and heavy metals. Indoor plants such as Spathiphyllum wallisii Regel, Epipremnum aureum (Linden & André) G.S. Bunting, Syngonium podophyllum Schott, and Crassula ovata (Miller) Druce efficiently eliminate VOCs, ozone, formaldehyde, and other pollutants. Additionally, the model species Arabidopsis thaliana (L.) Heynh. offers valuable insights into the molecular basis of heavy-metal tolerance. Together, these species underscore the versatility and promise of phytoremediation in promoting cleaner air. The review also explores India’s urban air-pollution landscape—particularly in Delhi, Kolkata, and Mumbai—and evaluates national programmes such as Swachh Bharat Mission, the National Clean Air Programme, and the National Mission for a Green India. A Strengths–Weaknesses–Opportunities–Challenges (SWOC) analysis further outlines the practical potential and limitations of large-scale phytoremediation initiatives. Overall, the study demonstrates that integrating phytoremediation with strategic urban planning and green audits can significantly advance efforts toward healthier, more resilient, and sustainable urban ecosystems.