Review
Environmental Sciences
Kang Wang, Guangliang Liu, Yong Cai
Summary: This review synthesizes possible pathways for Hg methylation in marine waters, including abiotic and biotic pathways, aiming to improve the understanding of seawater Hg methylation. Future research needs to focus on new techniques development and application, as well as bridging the gaps between microbial gene screening, Hg methylation capability, and environmental relevance.
CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2022)
Article
Environmental Sciences
Feng Cao, Shouye Yang, Daqiang Yin, Rui Wang
Summary: A comprehensive investigation was conducted to explore the distributions of total mercury (THg) and methylmercury (MeHg) in sediments and porewater along a typical transect from the Yangtze River Estuary (YRE) to the East China Sea (ECS) open shelf. The study found that THg concentrations in surface sediments varied across sites, higher in the estuary mixing region, especially within the turbidity maximum zone (TMZ). MeHg concentrations in surface sediments were higher in the estuary mixing region and the ECS open shelf than in the river channel, with higher MeHg/THg ratios in sediments and porewater at the open shelf sites.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Jiang Xu, Garret D. Bland, Yuan Gu, Hasti Ziaei, Xiaoyue Xiao, Amrika Deonarine, Danny Reible, Paul Bireta, Thomas P. Hoelen, Gregory Lowry
Summary: The study found that marine sediments contained 20-50% of total Hg in the <0.5 µm size fraction, while terrestrial and river sediments only contained 0.5-3.0% in this fraction. X-ray absorption spectroscopy revealed that metacinnabar (beta-HgS) was the main mercury species in marine sediment, while organic Hg-thiol (Hg(SR)(2)) was predominant in terrestrial sediment. Single-particle inductively coupled plasma time-of-flight mass spectrometry analysis indicated that half of the Hg in the <0.5 µm size fraction of marine sediment existed as individual nanoparticles.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Geoffrey Millard, Chris S. Eckley, Todd P. Luxton, David Krabbenhoft, Jennifer Goetz, John McKernan, John DeWild
Summary: This study measured mercury methylation and demethylation rates using stable isotope tracers in sediments and water of a shallow branch of the Nacimiento Reservoir. The results showed high methylmercury concentrations in the hypolimnetic waters and higher methylation rates in littoral sediments during late summer. Modelled results indicated that the remaining hypolimnetic methylmercury could originate from profundal sediments, highlighting the importance of addressing methylation in both the water column and sediment for remediation strategies.
ENVIRONMENTAL POLLUTION
(2023)
Article
Environmental Sciences
Changle Zhu, Shaoyang Lv, Qing Zhao, Xia Liu, Zhigang Wang, Xiangmin Zheng, Limin Zhou, Yongjie Wang
Summary: The study focused on the seasonal cycling of mercury and methylmercury in vegetated sediments in the Dongtan wetlands of the Yangtze River Estuary, as well as the potential health risk of mercury in estuarine wetlands. The results revealed significant differences in the seasonal variations of total mercury and methylmercury, with the activity of methylating bacteria identified as a major contributor to elevated methylmercury levels. It was also found that the addition of mercury greatly increased the production of methylmercury, even under suboxic conditions, indicating a long-term health risk in the wetlands.
MARINE ENVIRONMENTAL RESEARCH
(2023)
Article
Environmental Sciences
Tao-Tao Yang, Yong Liu, Sha Tan, Wen-Xiong Wang, Xun Wang
Summary: The study found that both methylation and demethylation of mercury occurred in fish exposed to organic or inorganic mercury in the diet, with demethylation being faster. Intestinal microbiota play a predominant role in mercury biotransformation, significantly influencing mercury speciation and distribution. Modulating the gut microbiome could be a possible solution to minimize mercury contamination in fish.
ENVIRONMENTAL POLLUTION
(2021)
Review
Environmental Sciences
Maetha M. Al-Sulaiti, Lama Soubra, Mohammad A. Al-Ghouti
Summary: This study provides insights into the cycle of mercury and methylmercury in the marine environment and evaluates the global contamination problem using DPSIR analysis. Despite mitigation measures and guidelines, the current emissions and stability of mercury still pose a serious risk to human health.
CURRENT POLLUTION REPORTS
(2022)
Article
Environmental Sciences
Xiaodan Zhang, Lumin Sun, Xianxu Huang, Jingting Zhuang, Zhenbin Gong, Dongxing Yuan
Summary: The concentrations and isotopic compositions of mercury in the Jiulong River Estuary were investigated. The study found that there were no significant differences in mercury concentrations between dry and wet seasons in both surface water and sediment. However, large variations in Hg isotopic compositions were observed. Soil erosion was identified as the major source of mercury in surface sediment, while precipitation and natural soil were the main sources in surface water. Additionally, underground water and industrial and urban waste also contributed to mercury pollution in surface water, and atmospheric dry deposition was another source.
WATER AIR AND SOIL POLLUTION
(2022)
Article
Environmental Sciences
Jose Lourenco Friedmann Angeli, Julie Rosemberg Sartoretto, Bianca Sung Mi Kim, Paulo Alves de Lima Ferreira, Beatriz Benedetti, Michel Michaelovitch de Mahiques, Rubens Cesar Lopes Figueira
Summary: The present study found historical anthropogenic mercury accumulation in the Santos estuary, with large spatial and temporal variations in mercury distribution. The highest contamination was observed in the upper estuary, with industrial activities being the primary source of mercury pollution.
MARINE POLLUTION BULLETIN
(2022)
Article
Environmental Sciences
Mariana Vezzone, Ricardo Cesar, Aline Serrano, Rodrigo Lourenco, Ana Paula Rodrigues, Zuleica Castilhos, Roberto Meigikos dos Anjos, Helena Polivanov
Summary: This study investigated the mercury concentrations in Rodrigo de Freitas Lagoon in Rio de Janeiro, Brazil to assess the ecological and human health risks associated with consuming contaminated fish. Sediments and fish samples were collected for mercury determination, and a model for estimating mercury in fish was evaluated. For human health risk assessment, the hazard quotient was calculated for fishermen and market consumers. The results showed high mercury concentrations in the northern section of the lagoon, posing a potential health hazard for fishermen but no risk for market consumers.
WATER AIR AND SOIL POLLUTION
(2023)
Article
Environmental Sciences
D. V. Kim, V. V. Sattarova, K. I. Aksentov, E. A. Lopatnikov, M. V. Ivanov, A. V. Alatortsev, M. S. Melgunov
Summary: Twenty-seven sediment samples from the eastern Laptev Sea were analyzed for mercury and total organic carbon as well as grain-size distribution. The average total mercury (THg) concentrations in sediments are 29 +/- 14 mu g kg-1. A significant correlation of THg content with total organic carbon and clay and silt fractions was shown. The 210Pb-dated sediment core was used to evaluate the contamination degree and flux of THg in sediments from the eastern Laptev Sea. The average sedimentation rate for the all dated intervals was 0.17 cm/year. The THg flux increased from 20 to 28 mu g/m2/year in the period of 1892-1950 to 53-59 mu g/m2/year in the modern period of 2011-2015. According to various indices, the ecological risk from THg in studied sediment was low.
MARINE POLLUTION BULLETIN
(2023)
Article
Engineering, Environmental
Ying Li, Dan Li, Beibei Song, Yanbin Li
Summary: This study found that most marine microalgae cannot directly methylate inorganic mercury, but six species can significantly induce the demethylation of methylmercury. The rates of microalgae-mediated demethylation were similar to that of photodemethylation, indicating that microalgae may play an important role in the degradation of methylmercury in marine environments.
Article
Biodiversity Conservation
Meng Ge, Guijian Liu, Houqi Liu, Yuan Liu
Summary: The Hg concentration in the surface sediments of the Yellow River Estuary was significantly higher than the background, possibly due to atmospheric deposition, while the As concentration was comparable to the background, mainly originating from agricultural non-point sources and natural sources. The sequential extraction experiment showed low risk of mobility and bioavailability for both Hg and As in the sediments. Multiple indices and guidelines indicated a good state regarding Hg and As contamination in the surface sediments from the YRE.
HUMAN AND ECOLOGICAL RISK ASSESSMENT
(2021)
Article
Environmental Sciences
Robert L. Jenkins, Davina L. Passeri, Christopher G. Smith, David M. Thompson, Kathryn E. L. Smith
Summary: The effects of interior headland restoration on estuarine sediment transport processes were assessed using process-based numerical modeling in the Grand Bay estuary. The modeling results showed that the restored headland features acted as a sediment source and provided some sheltering effect on nearby shoals and marsh shorelines. Sediment fluxes were sensitive to wind directions and the presence of the restored headlands, but the greatest sediment fluxes were always export fluxes from the estuary. Mean sea level rise had a significant impact on suspended sediment concentrations, and SLR allowed for the suspension and deposition of sediments on the marsh platform. The influence of SLR was more impactful than the influence of the restoration features on changing sediment dynamics.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Quang Tri Ho, Michael S. Bank, Atabak M. Azad, Bente M. Nilsen, Sylvia Frantzen, Stepan Boitsov, Amund Maage, Tanja Kogel, Monica Sanden, Livar Froyland, Rita Hannisdal, Helge Hove, Anne-Katrine Lundebye, Ole Jakob N. ostbakken, Lise Madsen
Summary: Marine fish from the Northeast Atlantic Ocean are rich in nutrients but also contain contaminants such as mercury and POPs. Concentrations of these contaminants increase from North to South and are associated with sediment contamination and sea temperature. Consuming seafood from the NEAO poses potential risks to human consumers.
ENVIRONMENT INTERNATIONAL
(2021)