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[Display omitted] • Particles release from erasers and pen grips upon dermal contact. • Particles derived from erasers and pen grips are mainly smaller than 1 μm. • Migrated particles mediate dermal contact of plasticizers to erasers and pen grips. Dermal exposure to chemicals released from daily consumer products is a rising concern, particularly for children who are susceptible to unintentional hand-to-mouth transfer and related chemical exposure risk. However, chemical transfer induced by tiny particles of intact products has yet to be adequately addressed. The objective of the present study was to determine the potentiality of particles release from intact erasers and pen grips upon dermal contact by measuring the migration rates of the embedded plasticizers (phthalates and its alternatives). The results showed that billions of particles were released from erasers (0.6–1.2 × 109) and pen grips (0.2–1.6 × 108) upon dermal contact at ambient temperature, with sizes mainly smaller than 1 μm. The composition of eraser leachates was identical to that of the corresponding bulk eraser, as confirmed by Fourier-transform infrared spectroscopy and pyrolysis. Migrated hydrophobic plasticizers may be used as indicators of particle release from erasers and pen grips. The potentiality of particle release was negatively correlated with the total plasticizer contents (r = −0.51; p < 0.05) for both erasers and pen grips. These findings indicated that particles directly released from school supplies and accessories could be a non-negligible source of human exposure to plasticizers. [ABSTRACT FROM AUTHOR]

• Dissolved PBDEs and OPFRs were concentrated in porewater and overlying water. • Sediment is interchanged with sink and source for riverine transport of OPFRs. • Sediment-water diffusion of PBDEs and OPFRs was not significant compared to riverine transport. Despite ample evidence on spreading of e-waste derived hazardous materials, riverine transport of organic contaminants from e-waste recycling zones to surrounding areas has not been evaluated. To address this issue, passive and grab sampling methods were used to assess sediment-water diffusion and horizontal transport of polybrominated diphenyl ethers (PBDEs) and organophosphorus flame retardant (OPFRs) at upstream and downstream sites of two rivers in a typical e-waste recycling zone. Sediment acted as a source of BDE-17 with fluxes of 0.007−0.04 ng m−2 d−1 at all sampling sites. BDE-47 and BDE-99 reached equilibrium between overlying water and sediment porewater. Sediment interconverted from a sink at the upstream site to a source of OPFRs at the downstream site with a flux varying between −7.3 and 234 ng m−2 d−1. The amounts of OPFRs (11−45 g d−1) via horizontal riverine transport were greater than those of PBDEs (0.68−2 g d−1). The vertical sediment-water diffusion of PBDEs and OPFRs was not significant compared to horizontal riverine transport. The annual riverine outputs of PBDEs and OPFRs from the downstream sites were 250–330 g and 12,000–16,500 g, respectively, indicating the significance of riverine transport of organic contaminants from e-waste recycling zones to surrounding areas. [Display omitted] [ABSTRACT FROM AUTHOR]

The partition coefficient (K pew) of an analyte between low-density polyethylene (LDPE) film and water is a critical parameter for measuring freely dissolved concentrations of the analyte with PE passive sampling devices. Measuring log K pew for super hydrophobic organic chemicals (HOCs) have been proven extremely difficult. The present study developed a large volume model for measuring log K pew of super HOCs, i.e., novel halogenated flame retardants (NHFRs). Results showed that the measured log K pew values of selected PAHs and PCBs obtained by the large volume model were in line with those from the co-solvent model and the literature data within less 0.3 log units of difference, while those of NHFRs (6.27–7.34) except for hexachlorocyclopentadienyldibromocyclooctane (HCDBCO) and Decabromodiphenyl ethane (DBDPE) were significantly lower than those (6.51–8.89) from the co-solvent model. A curvilinear relationship was observed between log K pew and log K ow of all target compounds, with the turning point at log K ow = ∼8.0 in the large volume model, but that was not found for the co-solvent model. These can be attributed to the large molecular volumes (> 450 Å3) for NHFRs, which require high Gibbs free energy to penetrate into the inside structures of LDPE in the large volume model. However, the solvent swelling effects in the co-solvent model needs to be investigated. Therefore, the large volume model is robust to determine the K pew values of super HOCs for facilitating the application of aquatic passive sampling techniques. • The large volume model is feasible to measure the K pew values of super HOCs. • The K pew values of HOCs from the co-solvent model were greater than other models. • The K pew values of NHFRs decreased with increasing molecular volumes. [ABSTRACT FROM AUTHOR]