Although the fates of microplastics (0.1–5 mm in size) and nanoplastics (<100 nm) in marine environments are being increasingly well studied^1,2, little is known about the behaviour of nanoplastics in terrestrial environments^3,4,5,6, especially agricultural soils⁷. Previous studies have evaluated the consequences of nanoplastic accumulation in aquatic plants, but there is no direct evidence for the internalization of nanoplastics in terrestrial plants. Here, we show that both positively and negatively charged nanoplastics can accumulate in Arabidopsis thaliana. The aggregation promoted by the growth medium and root exudates limited the uptake of amino-modified polystyrene nanoplastics with positive surface charges. Thus, positively charged nanoplastics accumulated at relatively low levels in the root tips, but these nanoplastics induced a higher accumulation of reactive oxygen species and inhibited plant growth and seedling development more strongly than negatively charged sulfonic-acid-modified nanoplastics. By contrast, the negatively charged nanoplastics were observed frequently in the apoplast and xylem. Our findings provide direct evidence that nanoplastics can accumulate in plants, depending on their surface charge. Plant accumulation of nanoplastics can have both direct ecological effects and implications for agricultural sustainability and food safety.

This study focused on the distribution, combined pollution, potential source and risk assessment of 17 antibiotics in an aquaculture ecosystem surrounding the Yellow sea, North China. Antibiotics were detected in various matrices (seawater, sediment/biofilm, organism and feed) in different aquaculture modes (greenhouse and outdoor aquaculture) during the wet and dry seasons in coastal areas of Shandong province. The innovation points of the study were as follows: (1) To the best of our knowledge, this study was one of the few to investigate the occurrence and distribution of antibiotics in mariculture environments along the Yellow Sea coast; (2) Biofilms, a focus of the study, might act as a sink for antibiotics in the aquaculture ecosystem; and (3) The correlation of heavy metals and antibiotic concentrations was proved, which could correspondingly be used as an indicator for antibiotic concentrations in the studied area. The levels of antibiotics in water were observed to be relatively low, at the ng/L level. Trimethoprim was the most prevalent antibiotic, and was detected in all water samples. Oxytetracycline was detected at high concentrations in biofilms (up to 1478.29 ng/g). Moreover, biofilms exhibited a higher antibiotic accumulation capacity compared to sediments. Concentrations of oxytetracycline and doxycycline were high in feed, while other antibiotics were almost undetected. Tetracycline was widely detected and the concentration of enrofloxacin was highest in organisms. Correlation analysis demonstrated that environmental parameters and other coexisting contaminants (e.g. heavy metals) significantly affected antibiotic concentrations. In addition, the concentration of Zn was significantly correlated with the total antibiotic concentration and was proportional to several antibiotics in water and sediment (biofilm) samples (p < 0.01). High Mn concentrations were closely related to total and individual (e.g. sulfadiazine, sulfamethazine and enrofloxacin) antibiotic levels, which may result in the combined contamination of the environment. Antibiotics in estuaries and groundwater generally originated from aquaculture wastewater and untreated/treated domestic sewage. Most of the detected antibiotics posed no risk to the environment. Ciprofloxacin and enrofloxacin found in water may present high ecological and resistance risks, while the two antibiotics observed to accumulate in fish may pose a considerable risk to human health through diet consumption. All antibiotics detected in seafood were lower than the respective maximum residue limits. This study can act as a reference for the government for the determination of antibiotic discharge standards in aquaculture wastewater and the establishment of a standardized antibiotic monitoring and management system.