Spatial and Temporal Trends of Persistent Organic Pollutants across Europe after 15 Years of MONET Passive Air Sampling

Atmospheric aggravation potential of a wastewater treatment plant concerning organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ether emissions

The pollution potential of a municipal wastewater treatment plant (WWTP) in Bursa, Türkiye, in terms of organochlorine pesticides (Σ22OCPs), polychlorinated biphenyls (Σ46PCBs), and polybrominated diphenyl ethers (Σ14PBDEs), was investigated in air samples. Concentrations were determined using polyurethane foam disk samplers at key processes, such as the aeration tank (AT) and settling chamber (SC) of the WWTP and the background area (BA) at an urban site. Atmospheric concentration levels of PBDEs at the SC are 1.3 times higher than at the AT site. PCBs concentration levels are listed as SC > BA > AT from high to low. The highest OCPs concentration levels were detected at the BA site while the lowest concentration levels were obtained for the SC site. Compared to organochlorine pollutants (PCBs and OCPs), PBDEs levels were higher by two orders of magnitude ranging from 0.2 to 54.3 ng/g. While the presence of OCPs was not significant, an unusual abundance of mirex was observed. HCB, HCHs (excluding β-HCH), and p,p'-DDE resulting mainly from the settling tank indicate enhanced mass transfer from wastewater to air. Regarding PCBs, the level and detection frequency of dioxin-like PCBs (118, 123) in the aeration tank and the settling chamber were remarkable. The upper levels of PBDEs congeners 17, 85, 138, 153, and 154 resulting from the settling tank suggest an enhanced mass transfer from water to air as the source medium. Although the primary fate of trace organics in WWTPs is expected to be sorption to sludge, the present study has shown that WWTPs can be a non-negligible source of local atmospheric PCB and PBDE pollution. However, this study provides a snapshot of the levels of persistent organic pollutants and emissions, and there is no doubt that more detailed and long-term studies are needed.

A Decade of Global Atmospheric Monitoring Delivers Mixed Report Card on the Stockholm Convention

Time trends in atmospheric concentrations serve to evaluate how effective the Stockholm Convention is in reducing or eliminating environmental releases of persistent organic pollutants (POPs). Twelve years (2005-2016) of continuous monitoring with a global network of 20 sampling sites reveals that concentrations of the pesticide endosulfan began to drop coincident with its listing as POP in 2011. Concentrations of other POPs started to decrease prior to listing and during the sampling period declined very slowly or not at all. Concentrations of some unintentionally produced POPs (hexachlorobenzene, hexachlorobutadiene) increased to become the most abundant and most widely dispersed POPs in the global atmosphere. Their formation processes and release locations need to be identified to facilitate the Convention's goal of curbing releases from unintentional production.

Characteristics of typical intermediate and semi volatile organic compounds in Shanghai during China International Import Expo event

To ensure good air quality during the China International Import Expo (CIIE) event, stringent emission-reduction measures were implemented in Shanghai. To assess the efficacy of these measures, this study measured typical categories of intermediate/semi volatile organic compounds (I/SVOCs), including alkanes (C10-C26 n-alkanes and pristane), EPA-priority polycyclic aromatic hydrocarbons (PAHs), alkylnaphthalenes, benzothiazole (BTH) and chlorobenzenes (CBs), at an urban site of Shanghai before and during two CIIE events (2019 and 2020; non-CIIE versus CIIE). The average concentrations of alkanes and PAHs during both 2019 and 2020 CIIE events decreased by approximately 41% and 17%, respectively, compared to non-CIIE periods. However, the decline in BTH and CBs was only observed during CIIE-2019. Secondary organic aerosol (SOA) formation from alkanes, PAHs and BTH was evaluated under atmospheric conditions, revealing considerable SOA contributions from dimethylnaphthalenes and BTH. Positive matrix factorization (PMF) analysis further revealed that life-related sources, such as cooking and residential emissions, make a noticeable contribution (21.6%) in addition to the commonly concerned gasoline-vehicle sources (31.5%), diesel-related emissions (20.8%), industrial emissions (18.6%) and ship emissions (7.5%). These findings provide valuable insights into the efficacy of the implemented measures in reducing atmospheric I/SVOCs levels. Moreover, our results highlight the significance of exploring additional individual species of I/SVOCs and life-related sources for further research and policy development.