Within and between breeding-season changes in contaminant occurrence and body condition in the Antarctic breeding south polar skua

Blood Kinetics of Lipophilic and Proteinophilic Pollutants during Two Types of Long-Term Fast in King Penguins

In vertebrates, fasting is an intricate physiological process associated with strong metabolic changes, yet its effect on pollutant residue variation is poorly understood. Here, we quantified long-term changes in plasma concentrations of 20 organochlorine and 16 perfluoroalkyl pollutants in king penguins Aptenodytes patagonicus during the breeding and molting fasts, which are marked by low and high levels of protein catabolism, respectively, and by strong lipid use. The profile of measured pollutants in plasma was dominated by perfluorooctanesulfonic acid (PFOS, initial relative contribution of 60%). Initial total pollutant concentrations were similar in molting (3.3-5.7 ng g-1 ww) and breeding penguins (range of 4.2-7.3 ng g-1 wet weight, ww). Long-term fasting (25 days) for molting and breeding led, respectively, to a 1.8- and 2.2-fold increase in total plasma pollutant concentrations, although the rate and direction of change were compound-specific. Hexachlorbenzene (HCB) and PFOS concentrations increased in plasma (net mobilization) during both types of fasting, likely due to lipid use. Plasma perfluoroundecanoate (PFUnDA) and perfluorotridecanoate (PFTrDA) concentrations increased in breeders (net mobilization) but decreased in molting individuals (net excretion), suggesting a significant incorporation of these pollutants into feathers. This study is a key contribution to our understanding of pollutant variation in blood during long-term fasting in wildlife.

Short-term mass loads of per- and polyfluoroalkyl substances in a wastewater treatment plant from South China

Wastewater treatment plants (WWTPs) are one of the most important sources and sinks for per- and polyfluoroalkyl substances (PFAS). However, limited studies have evaluated short-term temporal variability of PFAS in WWTPs, particularly for their intra-day variations. For this purpose, a time-composite sampling campaign was carried out at a WWTP influent from South China for 1 week. Five out of ten PFAS were found in the influent, i.e., perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorobutane sulfonic acid (PFBS), and perfluorooctanesulfonic acid (PFOS). PFOA was the most domain PFAS whereas PFOS was detected occasionally, which might be associated with the prohibition of PFOS use in China. For the first time, we observed significant intra-day fluctuations in mass fluxes for PFOS. Different from a morning peak of pharmaceuticals reported previously, PFOS mass loads fluctuated sharply at noon and night on the weekdays. Furthermore, the mass fluxes of PFOA on the weekend were significantly elevated. For the other PFAS detected, no significant diurnal variations in mass loads were identified. Correlation analysis indicated that domestic activities (e.g., home cleaning) are likely to be the major source of these perfluorocarboxylic acids especially PFOA. In addition, flow fluxes had little effects on these PFAS mass load. These results can aid in future sampling campaigns and optimizing removal strategies for PFAS in wastewater.

Occurrence, spatial distribution, and sources of PFASs in the water and sediment from lakes in the Tibetan Plateau

Per-and polyfluoroalkyl substances (PFASs) are omnipresent globally and received increasing attention recently. However, there are limited data on PFASs in the Tibetan Plateau (TP), a remote high-altitude mountain region, which is regard as an important indicator region to study long-range transport behaviors of contaminants. This study investigates the occurrence, distribution, partitioning behavior, and sources of 26 PFASs in water and sediments from the four lakes of TP. The ΣPFAS concentrations ranged from 338 to 9766 pg L^-1 in water, and 12.2-414 pg g^-1 dry weight in sediments. Perfluorobutanonic acid (PFBA) and perfluorooctane sulfonate (PFOS) were detected in all samples. Qinghai Lake had the highest ΣPFAS concentrations in both water and sediments, while the Ranwu Lake had the lowest. The functional groups and CF₂ moiety units were investigated as essential factors influencing the partition behavior. Principal component analysis (PCA) combined back-trajectory was used to infer possible sources of PFASs. The results suggested that the main source of PFASs in Yamdrok Lake, Namco Lake, and Ranwu Lake on southern TP were mainly originated from South Asia via long-range atmospheric transport (LRAT); while for the Qinghai Lake of northern TP, LRAT, local emissions, and tourism activities were the primary sources of PFASs.

Spatiotemporal and life history related trends of per- and polyfluoroalkyl substances in Indo-Pacific finless porpoises from south China sea (2007-2020)

Per- and polyfluoroalkyl substances (PFASs) levels in Indo-Pacific finless porpoises (Neophocaena phocaenoides) in the Pearl River Estuary (PRE), near the most economically developed region in China, have not been characterized. We measured the hepatic concentrations of twelve PFASs, including nine perfluoroalkyl carboxylic acids (PFCAs) and three perfluoroalkane sulfonic acids (PFSAs) in the finless porpoises (n = 21) collected from the PRE between 2007 and 2020. The average level of PFSAs was more than 2-times higher than that of PFCAs. The order of six dominant PFASs was perfluorooctane sulfonate (PFOS) > perfluoroundecanoic acid (PFUdA) > perfluorodecanoic acid (PFDA) > perfluorotridecanoic acid (PFTrDA) > perfluorononanoic acid (PFNA) > perfluorododecanoic acid (PFDoDA). The levels of Hepatic PFOS of 29% samples exceeded the no observable adverse effect level (NOAEL) values. The concentration of PFASs in males was significant higher than in females. PFASs levels were significantly negatively correlated with body length in males and positively correlated in females. PFASs levels in the PRE finless porpoises were lower than in humpback dolphins possibly due to different foraging habitat toward the coast and the consumption of less fish. PFCAs levels in finless porpoises from the western PRE were higher compared to Hong Kong, possibly due to the high-intensity sources of terrestrial anthropogenic pollutants. Significant increasing spatiotemporal trends of PFSAs, PFCAs and PFASs were found in finless porpoises from 2007 to 2020, suggesting a continuously increased risk of PFASs exposure for PRE cetaceans in the last decade.

Microplastic Interactions and Possible Combined Biological Effects in Antarctic Marine Ecosystems

Antarctica and the Southern Ocean are the most remote regions on Earth, and their quite pristine environmental conditions are increasingly threatened by local scientific, tourism and fishing activities and long-range transport of persistent anthropogenic contaminants from lower latitudes. Plastic debris has become one of the most pervasive and ubiquitous synthetic wastes in the global environment, and even at some coastal Antarctic sites it is the most common and enduring evidence of past and recent human activities. Despite the growing scientific interest in the occurrence of microplastics (MPs) in the Antarctic environment, the lack of standardized methodologies for the collection, analysis and assessment of sample contamination in the field and in the lab does not allow us to establish their bioavailability and potential impact. Overall, most of the Southern Ocean appears to be little-affected by plastic contamination, with the exception of some coastal marine ecosystems impacted by wastewater from scientific stations and tourist vessels or by local fishing activities. Microplastics have been detected in sediments, benthic organisms, Antarctic krill and fish, but there is no clear evidence of their transfer to seabirds and marine mammals. Therefore, we suggest directing future research towards standardization of methodologies, focusing attention on nanoplastics (which probably represent the greatest biological risks) and considering the interactions of MPs with macro- and microalgae (especially sea-ice algae) and the formation of epiplastic communities. In coastal ecosystems directly impacted by human activities, the combined exposure to paint chips, metals, persistent organic pollutants (POPs), contaminants of emerging interest (CEI) and pathogenic microorganisms represents a potential danger for marine organisms. Moreover, the Southern Ocean is very sensitive to water acidification and has shown a remarkable decrease in sea-ice formation in recent years. These climate-related stresses could reduce the resilience of Antarctic marine organisms, increasing the impact of anthropogenic contaminants and pathogenic microorganisms.

New and legacy persistent organic pollutants (POPs) in breeding seabirds from the East Antarctic

Persistent organic pollutants (POPs) are pervasive and a significant threat to the environment worldwide. Yet, reports of POP levels in Antarctic seabirds based on blood are scarce, resulting in significant geographical gaps. Blood concentrations offer a snapshot of contamination within live populations, and have been used widely for Arctic and Northern Hemisphere seabird species but less so in Antarctica. This paper presents levels of legacy POPs (polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs)) and novel brominated flame retardants (NBFRs) in the blood of five Antarctic seabird species breeding within Prydz Bay, East Antarctica. Legacy PCBs and OCPs were detected in all species sampled, with Adélie penguins showing comparatively high ∑PCB levels (61.1 ± 87.6 ng/g wet weight (ww)) compared to the four species of flying seabirds except the snow petrel (22.5 ± 15.5 ng/g ww), highlighting that legacy POPs are still present within Antarctic wildlife despite decades-long bans. Both PBDEs and NBFRs were detected in trace levels for all species and hexabromobenzene (HBB) was quantified in cape petrels (0.3 ± 0.2 ng/g ww) and snow petrels (0.2 ± 0.1 ng/g ww), comparable to concentrations found in Arctic seabirds. These results fill a significant data gap within the Antarctic region for POPs studies, representing a crucial step forward assessing the fate and impact of legacy POPs contamination in the Antarctic environment.

Legacy and emerging organic contaminants in the polar regions

The presence of numerous emerging organic contaminants (EOCs) and remobilization of legacy persistent organic pollutants (POPs) in polar regions have become significant concerns of the scientific communities, public groups and stakeholders. This work reviews the occurrences of EOCs and POPs and their long-range environmental transport (LRET) processes via atmosphere and ocean currents from continental sources to polar regions. Concentrations of classic POPs have been systematically monitored in air at several Arctic stations and showed seasonal variations and declining trends. These chemicals were also the major POPs reported in the Antarctica, while their concentrations were lower than those in the Arctic, illustrating the combination of remoteness and lack of potential local sources for the Antarctica. EOCs were investigated in air, water, snow, ice and organisms in the Arctic. Data in the Antarctica are rare. Reemission of legacy POPs and EOCs accumulated in glaciers, sea ice and snow may alter the concentrations and amplify their effects in polar regions. Thus, future research will need to understand the various biogeochemical and geophysical processes under climate change and anthropogenic pressures.

South polar skua (Catharacta maccormicki) as biovectors for long-range transport of persistent organic pollutants to Antarctica

Migratory bird species may serve as vectors of contaminants to Antarctica through the local deposition of guano, egg abandonment, or mortality. To further investigate this chemical input pathway, we examined the contaminant burdens and profiles of the migratory South polar skua (Catharacta maccormicki) and compared them to the endemic Adélie penguin (Pygoscelis adeliae). A range of persistent organic pollutants were targeted in muscle and guano to facilitate differentiation of likely exposure pathways. A total of 56 of 65 targeted analytes were detected in both species, but there were clear profile and magnitude differences between the species. The South polar skua and Adélie penguin muscle tissue burdens were dominated by p,p'-dichlorodiphenyldichloroethylene (mean 5600 ng g^-1 lw and 330 ng g^-1 lw respectively) and hexachlorobenzene (mean 2500 ng g^-1 lw and 570 ng g^-1 lw respectively), a chemical profile characteristic of the Antarctic and Southern Ocean region. Species profile differences, indicative of exposure at different latitudes, were observed for polychlorinated biphenyls (PCBs), with lower chlorinated congeners and deca-chlorinated PCB-209 detected in South polar Skua, but not in Adélie penguins. Notably, the more recently used perfluoroalkyl substances and the brominated flame retardants, hexabromocyclododecane and tetrabromobisphenol A, were detected in both species. This finding suggests local exposure, given the predicted slow and limited long-range environmental transport capacity of these compounds to the eastern Antarctic sector.