Anthropogenic-vegetation dual controls on the hotspots of microplastic pollution in urban green space soil

Urban green spaces are critical determinants of the urban environmental quality. However, their contamination by emerging pollutants remains poorly known. This study investigated the co-occurrence patterns and pollution drivers of microplastics (MPs) and phthalate esters (PAEs) in urban green space soils spanning diverse vegetations, streets, and residential areas in Guangzhou, a representative megacity in China undergoing rapid urbanization. Soil analysis revealed MP abundances averaging 2117 items/kg (medium contamination level), with significant spatial heterogeneity reflecting the anthropogenic pressures. Street and residential green spaces exhibited 2.1/2.3 times higher MP loads than parks. Moreover, vegetation-mediated distribution patterns emerged: the grassland MP levels were 56.2 %/66.0 % lower than woody vegetation (trees/shrubs). Polymer composition analysis identified the predominance of polyethylene terephthalate and polyacrylonitrile, implicating that textile industry emissions were a major urban MP source in green spaces. The simultaneously detected PAEs reached concerning levels (∑5PAEs = 8086 ng/g), which were dominated by dioctyl phthalate and dibutyl phthalate. The risk assessment indicated limited direct health risks, but these may be underestimated because both multi-pathway and MP-facilitated PAEs exposure may increase the health risks of PAEs. Correlation analysis showed that the correlations between MPs and PAEs across all soil samples were influenced by the gradient changes of both pollutants in urban green space. The suitability of PAEs as indicators of MP pollution should be further validated in diverse urban green spaces. These findings establish an empirical basis for the coordinated management of emerging contaminants in urban ecosystems.