Microplastic pollution has become an increasingly important environmental issue worldwide in recent years because of its ubiquitous presence in different environmental media and its potential to affect the health of organisms and ecosystems. Aquaculture contributes significantly to the world's food production and nutritional supply, especially in developing countries. Widespread occurrence of microplastics in aquaculture systems has raised great concern regarding aquaculture production and food safety issues of aquaculture products. China is a world leader in aquaculture production, with freshwater aquaculture accounting for 59.1% of total aquaculture production of the world in 2020. Therefore, this review mainly focuses on recent research progress related to microplastic pollution in freshwater aquaculture systems in China. Results from the literature show that microplastics are present in freshwater aquaculture systems at abundances comparable to natural waterbodies in China. Microplastics can be ingested and remain in the body of aquaculture products. Exposure to microplastics can adversely affect the health of aquatic organisms and aquatic ecosystem functions. However, risks of microplastics in real world environment remain uncertain. Consumption of freshwater aquaculture products is not a major pathway for human exposure to microplastics. To provide scientific guidance for governmental decision-making and pollution control, future work should focus on progress in toxicological methodology and understanding the impacts of microplastics at community and ecosystem levels.

The timing and extent of the last glaciation in the Altai Mountains are key to understanding climate change in this critical region. However, robust glacial chronologies are sparse across the Altai Mountains, especially in the Chinese Altai, impeding the correlation of glacial events and examination of the possible climate forcing mechanisms. Here, we report twenty new Be-10 exposure-ages obtained from two moraines in the headwater area of the Xiaokelanhe River, Chinese Altai. The inner latero-frontal moraine yields exposure-ages ranging from 16.60 +/- 1.00 to 20.41 +/- 1.15 ka (n = 5), reflecting a limited advance during the global Last Glacial Maximum (LGM). The morpho-stratigraphically older moraine remnants have exposure-ages of 14.36 +/- 0.94-38.98 +/- 2.23 ka (n = 15). The tentatively determined moraine age of 34.10 +/- 4.99 ka suggests that the local LGM in the Xiaokelanhe River likely occurred during Marine Isotope Stage (MIS) 3 or earlier. From a compilation of the 20 new, and 79 previously published exposure-ages, we observe at least three distinct glacial events during the last glacial, with the local LGM occurring prior to MIS 2. A comparison between the timing of glacial activities and climate proxies suggests a potential combination of summer solar insolation, North Atlantic climate oscillations, and atmospheric CO2 levels, as triggers for glacial movements during the last glacial cycle. Precipitation delivered by the mid-latitude westerlies may have also contributed to glacial advances during MIS 3. These correlations remain tentative however, due to limited chronological control.

The timing of neoglacial advances in the Antarctic Peninsula (AP) is not yet well constrained. Accurate temporal reconstruction of Neoglaciation in the AP is needed to better understand past glacial responses and regional and global teleconnections during the Holocene. Here, we examine all available information about neoglacial advances in the South Shetland Islands (SSI) as well as in the broader geographical context of the AP region and Antarctic continent. In order to shed light on the contrasting chronologies existing for neoglacial advances in these regions, we focused on a case study where a detailed picture of the Holocene deglaciation was already available. Lake sediments revealed that Byers Peninsula, west of Livingston Island (SSI), was fully deglaciated during the Holocene Thermal Maximum. To complement this approach, we identified glacially polished bedrock surfaces, erratic boulders and a moraine ridge near the present front of the glacier in the SE corner. We applied cosmogenic ray exposure (CRE) dating using in situ Cl-36 for basalt rocks and Be-10 for granitic rocks in: (i) 8 samples from glacial erratic and ice-rafted boulders, (ii) 2 samples from moraine boulders, (iii) 2 samples from polished bedrock surfaces, and (iv) 1 sample from an erratic boulder deposited on one of these surfaces. The CRE dates indicate that the onset of deglaciation started around 9.9 +/- 1.2 ka, with two phases of glacier expansion during the Mid-Late Holocene forming moraines at similar to 4.1 +/- 0.5 and similar to 1.0 +/- 0.2 ka, respectively. The main neoglacial advances in the AP and the SSI were mostly synchronous and coincided with cold periods, as shown by other records (e.g. glacio-isostatic marine terraces, marine and lake sediments). In addition, these periods of glacial expansion show a similar timing to those recorded in the Arctic. These results suggest that Neoglaciation was driven by global climate forcing in both polar areas despite temporal variations at regional and local scale. (C) 2020 Elsevier Ltd. All rights reserved.

Background: Black carbon (BC) caused by incomplete combustion of fossil and bio-fuel has a dual effect on health and climate. There is a need for systematic approaches to evaluation of health outcomes and climate impacts relevant to BC exposure. Objectives: We propose and illustrate for the first time, to our knowledge, an integrated analysis of a region-specific health model with climate change valuation module to quantify the health and climate consequences of BC exposure. Methods: Based on the data from regional air pollution monitoring stations from 2013 to 2014 in the Pearl River Delta region (PRD), China, we analyzed the carcinogenic and non-carcinogenic effects and the relative risk of cause-specific mortality due to BC exposure in three typical cities of the PRD (i.e. Guangzhou, Jiangmen and Huizhou). The radiative forcing (RF) and heating rate (HR) were calculated by the Fu-Liou-Gu (FLG) plane-parallel radiation model and the conversion of empirical formula. We further connected the health and climate impacts by calculating the excess mortalities attributed to climate warming due to BC. Results: Between 2013 and 2014, carcinogenic risks of adults and children due to BC exposure in the PRD were higher than the recommended limits (1 x 10(-6) to 1 x 10(-4)), resulting in an excess of 4.82 cancer cases per 10,000 adults (4.82 x 10(-4)) and an excess of 1.97 cancer cases per 10,000 children (1.97 x 10(-4)). Non-carcinogenic risk caused by BC was not found. The relative risks of BC exposure on mortality were higher in winter and dry season. The atmospheric RFs of BC were 26.31 W m(-2), 26.41 W m(-2), and 22.45 W m(-2) for Guangzhou, Jiangmen and Huizhou, leading to a warming of the atmosphere in the PRD. The estimated annual excess mortalities of climate warming due to BC were 5052 (95% CI: 1983, 8139), 5121 (95% CI: 2010, 8249) and 4363 (95% CI: 1712, 7032) for Guangzhou, Jiangmen and Huizhou, respectively. Conclusion: Our estimates suggest that current levels of BC exposure in the PRD region posed a considerable risk to human health and the climate. Reduction of BC emission could lead to substantial health and climate co-benefits.