Development and applications of diffusive gradients in thin films for monitoring pharmaceuticals in surface waters.

Pharmaceutical contaminants in surface water have raised significant concerns because of their potential ecological risks. In particular, coronavirus disease 2019 (COVID-19)-related pharmaceuticals can be released to surface water and reduce environmental water quality. Therefore, reliable and robust sampling tools are required for monitoring pharmaceuticals. In this study, passive sampling devices of diffusive gradients in thin films (DGTs) were developed for sampling 35 pharmaceuticals in surface waters. The results demonstrated that hydrophilic-lipophilic balance (HLB) was more suitable for DGT-based devices compared with XAD18 and XDA1 resins. For most pharmaceuticals, the performance of the HLB-DGT devices were independent of pH (5.0-9.0), ionic strength (0.001-0.5 M), and flow velocity (0-400 rpm). The HLB-DGT devices exhibited linear pharmaceutical accumulation for 7 days, and time-weighted average concentrations provided by the HLB-DGT were comparable to those measured by conventional grab sampling. Compared to previous studies, we extended DGT monitoring to include three antiviral drugs used for COVID-19 treatment, which may inspire further exploration on identifying the effects of COVID-19 on ecological and human health.

Face mask-A potential source of phthalate exposure for human.

Face masks are necessary for fighting against the coronavirus disease 2019 around the world. As the face mask is usually made from polymers and phthalates are widely-used additives into the polymers, the face mask could be a potential source of phthalate exposure to humans. However, limited knowledge is available on the occurrence and risks of the phthalates from the face mask. In this study, twelve phthalates were determined in 56 mask samples collected from different countries. The phthalates were detected in all the samples with total levels ranging from 115 ng/g to 37,700 ng/g. Estimated daily intakes (EDIs) of the phthalates from the masks ranged from 3.71 to 639 ng/kg-bw/day, and the EDIs of the phthalates from masks for toddlers were approximately 4-5 times higher than those for adults. Non-carcinogenic risks in relation to the phthalates in masks were found to be within safe levels, yet 89.3% of the mask samples exhibited potential carcinogenic effects to humans. The extent of the risks for wearing masks located at a moderate level comparing with other skin-contacted products. This study unveiled a potential source of phthalate exposure to human, and indicated necessity of managing types and levels of additives in the face masks.