Spatiotemporal variations and the ecological risks of organophosphate esters in Laizhou Bay waters between 2019 and 2021: Implying the impacts of the COVID-19 pandemic.

Organophosphate esters (OPEs) are a group of synthetic chemicals used in numerous consumer products such as plastics and furniture. The Coronavirus Disease 2019 (COVID-19) pandemic significantly slowed anthropogenic activities and reduced the emissions of pollutants. Meanwhile, the mismanagement of large quantities of disposable plastic facemasks intensified the problems of plastic pollution and leachable pollutants in coastal waters. In this study, the joint effects of the COVID-19 outbreak on the occurrence of 12 targeted OPEs in the waters of Laizhou Bay (LZB) were investigated. The results showed that the median total OPE concentrations were 725, 363, and 109 ng L-1 in the sewage treatment plant effluent, river water, and bay water in 2021, decreased significantly (p < 0.05) by 67%, 68%, and 70%, respectively, compared with those before the COVID-19 outbreak. The release potential of targeted OPEs from disposable surgical masks in the LZB area was ∼0.24 kg yr-1, which was insufficient to increase the OPE concentration in the LZB waters. The concentrations of most individual OPEs significantly decreased in LZB waters from 2019 to 2021, except for TBOEP and TNBP. Spatially, a lower concentration of OPEs was found in the Yellow River estuary area in 2021 compared with that before the COVID-19 pandemic due to the high content of suspended particulate matter in the YR. A higher total OPE concentration was observed along the northeastern coast of LZB, mainly owing to the construction of an artificial island since 2020. The ecological risks of the OPE mixture in LZB waters were lower than those before the COVID-19 outbreak. However, TCEP, TNBP, and BDP should receive continuous attention because of their potential ecological risks to aquatic organisms.

Dynamic variation and inhalation exposure of organophosphates esters and phthalic acid esters in face masks.

The coronavirus pandemic (COVID-19) has posed a huge global health threat since December 2019. Wearing face masks is known as an effective measure for controlling the wide spread of COVID-19 and its variants. But on the other hand, face masks could be a potential source of organophosphate esters (OPEs) and phthalic acid esters (PAEs) as they are extensively added in masks. However, knowledge associated with the occurrence as well as inhalation risks of OPEs and PAEs in masks is limited. In this study, OPEs and PAEs were determined in different types of mask samples collected from the local market. OPEs and PAEs were detected in mask samples ranging from 36.7 to 855 ng/g, and from 251 to 3830 ng/g, respectively. Relatively lower OPEs and PAEs concentrations were observed in disposable mask for toddlers. Simulated inhalation experiment indicated that the mass loss of OPEs and PAEs was 136 and 3910 ng/mask in disposable masks, 71.9 and 763 ng/mask in disposable mask for toddlers, 924 and 1020 ng/mask in N95 mask after 12 h, respectively. Significantly negative correlations were exhibited between the decrement of OPEs in masks and the increment of OPEs in corresponding polyurethane foams (PUFs) during the course, elucidating OPEs released from masks could be well captured by PUFs. With regard to the variation over time, predominant OPE and PAE analogues showed semblable release and absorption tendency in mask and corresponding PUF. Inhalation exposure risk of OPEs and PAEs was estimated based on the increment of pollutants in PUF. The estimated daily intakes (EDIs), hazard index (HI) and carcinogenic risk (CR) were also calculated and they were within the threshold levels. This study provides the evidence of OPEs and PAEs releasing from the face masks during wearing and unveiled a potential source of OPEs and PAEs exposure to humans.

COVID-19 face masks: A new source of human and environmental exposure to organophosphate esters.

For the first time, organophosphate ester (OPE) content was studied in different types of surgical, self-filtering (KN95, FFP2, and FFP3) and reusable face masks used for COVID-19 prevention. OPEs were detected in all mask samples, although in highly variable amounts which ranged from 0.02 to a maximum of 27.7 µg/mask, with the highest mean concentrations obtained for KN95 masks (11.6 µg/mask) and the lowest for surgical masks (0.24 µg/mask). Twelve out of 16 tested analytes were detected, with TEP, TPHP, TNBP, TEHP and TClPP being the most common OPEs as well as present at the highest concentrations. The non-carcinogenic and carcinogenic risks of OPE inhalation were calculated as being always several orders of magnitude lower than threshold levels, indicating that the use of face masks is safe with regard to OPE contamination. However, given the wide range of OPEs observed in different masks, it can be concluded that some masks (e.g. reusable) are less OPE-contaminated than others (e.g. KN95). With regard to environmental pollution, the disposal of billions of face masks is adding to the already substantial levels of microplastics and associated toxic additives worldwide, an impact that is lessened by use of reusable masks, which also have the lowest economic cost per user. However, in situations of relatively high risk of viral inhalation, such as poorly ventilated indoor public spaces, we recommend the use of FFP2 masks.