Plant biomonitoring in urban ecosystems: a comprehensive review in Sao Paulo

Air, water, and soil pollution pose significant threats to environmental and human health, particularly in rapidly urbanising regions. This comprehensive review evaluates the scientific literature on plant biomonitoring in the State of São Paulo, Brazil, from 2009 to 2019, aiming to compile data for future research, assess the distribution of biomonitoring studies, and analyse their relationship to human health outcomes. To the extent of our knowledge, a review according to the criteria of this article has not yet been carried out. The review followed the ENTREQ protocol and employed a systematic search methodology, with thematic synthesis and descriptive statistics (percentage). Of the 656 studies identified, only 56 met the inclusion criteria. Air pollution was the most researched (91% of studies), and the city of São Paulo was the most frequent (40.2%). Leaves were the most analysed plant part (48.5%), and Tibouchina tipu was the most studied species (8.6%). Only five studies included here related the data to human health, focusing on respiratory diseases. The review presents an integrative framework illustrating the interplay between urbanisation, pollution, biomonitoring, and health outcomes. Despite limitations, plant biomonitoring offers valuable insights into the environmental and health impacts of pollution in São Paulo and can also serve as a guide for students and researchers on plant biomonitoring and its relationship with the diversity of pollutants and contaminants present in the biosphere, serving as support for the development of public policies regarding the improvement of environmental quality.