The sorption and vector effect of microplastics on the transfer of pesticides and polycyclic aromatic hydrocarbons (PAHs), as well as its impact on agriculture remain largely unexplored. This comparative study is first to investigate the sorption behavior of different pesticides and PAHs at environmentally realistic concentrations by model microplastics and microplastics derived from polyethylene mulch films. Sorption was found to be up to 90% higher in the case of microplastics derived from mulch films as opposed to pure polyethylene microspheres. For microplastics from mulch films, the sorption percentages for pesticides in media containing CaCl₂ were reported to be: pyridate (75.68% and 52.44%), fenazaquin (48.54% and 32.02%), pyridaben (45.04% and 56.70%), bifenthrin (74.27% and 25.88%), etofenprox (82.16% and 54.16%) and pyridalyl (97.00% and 29.74%) at 5 μg/L and 200 μg/L pesticide concentration levels respectively. For PAHs, the sorption amounts were: naphthalene (22.03% and 48.00%), fluorene (38.99% and 39.00%), anthracene (64.62% and 68.02%) and pyrene (75.65% and 86.38%) at 5 μg/L and 200 μg/L PAH concentration levels respectively. Sorption was influenced by the octanol-water partition coefficient (log K_ow) and ionic strength. Kinetics of the process in the case of sorption of pesticides were best explained by pseudo-first order kinetic model (R² between 0.90 and 0.98) while the best fitting isotherm model was Dubinin-Radushkevich (R² between 0.92 and 0.99). Results suggest the presence of surface level physi-sorption through a micropore volume filling mechanism and the role of hydrophobic and electrostatic forces. Pesticide desorption data in polyethylene mulch films indicate that pesticides with high log K_ow were almost completely retained in mulch films, while those with lower log K_ow were desorbed rapidly into the surrounding media. Our study highlights the role of microplastics from plastic mulch films as vectors for pesticide and PAH transport at environmentally realistic concentrations and the factors that influence it.

Microplastics from mulch films can be a source of chemical contamination to agricultural soils. In this context, biodegradable films have been widely positioned as a greener choice. However, their sorption/desorption capabilities, in contrast to the conventional plastic types remain understudied. It is for this reason that objective evaluation of their interactions with residual agricultural contaminants becomes important. Our findings reveal that polyethylene (PE) mulch films retained lower amounts of pesticide residues and demonstrated a higher desorption/release [median desorption = 71.86 μg/L or about 50%], while polybutylene adipate terephthalate (PBAT) mulch films retained higher amounts of pesticide residues onto their surface and demonstrated a much lower desorption [median desorption = 24.27 μg/L or about 17%] after a spraying event. A higher ambient temperature had no significant effect on final desorption amounts in both PE [median = 65.27 μg/L at 20 °C and 74.23 μg/L at 40 °C] and PBAT [median = 24.26 μg/L at 20 °C and 24.78 μg/L at 40 °C] mulch films. However, it did favour a faster desorption pace in PE films. Desorption in PBAT and PE plastic types was correlated with the log K_ow value [Spearman's correlation: 0.857 and 0.837 respectively, p < 0.05]. However, only a moderate correlation with pKa was observed in PBAT [Spearman's correlation: 0.478, p < 0.05], while none for PE plastic type. Sorption of pesticides onto biodegradable PBAT microplastics were best explained by Elovich [R²: 0.937-0.959] and pseudo-second order kinetics [R²: 0.942-0.987], suggesting the presence of chemisorption. Furthermore, Weber Morris plots suggested the presence of a multi-step process and Boyd plots indicated that film diffusion or chemical bond formation was the rate-limiting step governing this phenomenon.

This study critically evaluates an analytical approach combining enzymatic extraction and single particle ICP-MS (spICP-MS) for quantifying europium-doped polystyrene nanoplastics (Eu-PS-NPs) bioaccumulated in tomato tissues. Optimization of extraction parameters identified citrate buffer at pH 6.5 and a digestion temperature of 37 °C as the most effective extraction conditions, while maintaining particle stability. Experiments with spiked tomato tissues demonstrated that extraction efficiency is highly tissue-specific, with optimal digestion of 24 h for stem, leaf, and fruit, and 36 h for root tissues, and enzyme concentrations ranging from 10 to 100 mg per sample. Under optimized conditions, good extraction recoveries (85 - 116 %) were achieved for particle number and mass concentrations, particle size and mass, and total Eu mass, with the majority of extracted Eu associated with NPs and around 10 % as ionic Eu. In contrast, analysis of tomato samples exposed to Eu-PS-NPs during their growth revealed substantially lower and tissue-dependent extraction recoveries. Root and stem tissues yielded only 18 - 32 % of total Eu mass concentration, while leaves showed recoveries ≤ 21 % under most extraction conditions. Fruit samples exhibited higher apparent recoveries (66 - 80 % after 24 h digestion), likely due to the acidic environment promoting Eu leaching from NPs. Across all exposed tissues, ionic Eu fraction dominates (reaching up to 97 % in fruits), indicating extensive leaching from Eu-PS-NPs in the tomato plants. These findings underscore the importance of accounting for matrix effects, metal leaching, and the limitation of extrapolating recoveries from spiked controls to exposed samples when interpreting spICP-MS data from plant exposure studies with metal-doped NPs.

Airborne microplastics (MPs) are emerging contaminants of concern in school environments, where children may experience prolonged exposure. This study assessed airborne MPs at three Spanish schools located in contrasting settings: a dense urban area in Madrid (A), a residential area in Almería (B), and an agricultural peri-urban area in Almería surrounded by greenhouses (C). An additional simultaneous indoor–outdoor comparison was performed at School B. Air samples were collected using active samplers with 25 µm stainless-steel meshes, and particles were characterised by stereomicroscopy, µ-FTIR spectroscopy, FESEM, and FTIR. Fibres were the predominant morphology, and polyethylene terephthalate (PET) was the most abundant synthetic polymer. School A showed the highest abundance of synthetic fibres, while polymer composition differed significantly among schools (χ² (12) =41.77, p < 0.0001). Indoor samples contained more particles than outdoor samples, although natural-to-synthetic proportions were similar; PP, PA, and PE contributed relatively more indoors, whereas PET predominated outdoors. Only 0.45% and 0.13% of particles fell within the <10 µm and <4 µm estimated aerodynamic-size ranges, respectively, all being fibres. Overall, airborne MP occurrence varied with location and indoor–outdoor setting, while selected PET and PP fibres showed polymer-dependent surface and chemical alteration.

Respiratory exposure to microplastics (MPs) remains poorly quantified because most tissue-based studies neither report extraction recovery efficiency nor assess whole-organ burden. Using lamb lungs as a model, we validated a method for determining MP burden in lung tissue by comparing three digestion oxidants and three sample masses against four spiked reference polymers:polypropylene(PP),polystyrene (PS),low-density polyethylene (LDPE) and polyethylene terephthalate (PET). Sodium persulfate (Na₂S₂O₈) digestion of 10 g freeze-dried tissue (~25% of the lamb lung) gave the best recovery (~70%) and was applied to lung tissue from captive-held Saharan ungulates (two adult gazelles, a pregnant gazelle with two fetuses, and a neonatal aoudad). Across the adult gazelles, fibres dominated the internal burden, with PP enriched among fragments and PET dominant among fibres, confirmed by micro-Fourier- transform infrared spectroscopy (µFTIR). Particles were overwhelmingly coarse (mostly 30 to ≥100 µm), with essentially none meeting respirable (<10 µm) or alveolar-like (<4 µm) size criteria, consistent with retention in conducting airways rather than alveolar deposition. No MPs were detected in either fetus or in the neonatal aoudad, suggesting postnatal rather than prenatal accumulation of pulmonary burden. This is, to our knowledge, the first recovery-characterized, whole-lung (one animal) and per-gram tissue-level (two animals) burdens in captive-held ungulates, providing a transferable framework for assessing respiratory MP exposure in captive-held life and livestock.