Work

Quantification of anthropogenic and marine sources to atmospheric mercury over the marginal seas of China and impact on the sea–air exchange of mercury

Year: 2025

Type: article

Abstract: . Mercury in the atmosphere is a crucial environmental concern due to its toxicity and ability to travel long distances. In the marginal seas, the contributions of terrestrial anthropogenic vs. natural sources on atmospheric mercury have been rarely quantified and their roles in mercury sea-air exchange are not well understood. To address this issue, this study integrated observations from island, cruise, and inland campaigns. Positive correlations were observed between total gaseous mercury (TGM) concentrations and environmental parameters such as temperature, relative humidity, and wind speed, indicating the significant influence of natural sources on atmospheric mercury in the marine environment. The application of the TGM/BC (black carbon) ratio underscored the effects of continental outflows. By utilizing a receptor model and linear regression analysis, a robust method was developed to quantitatively estimate the contribution of anthropogenic and natural sources to TGM. Anthropogenic sources accounted for an average of 59 %, 38 %, and 26 % of TGM over the Bohai Sea, Yellow Sea, and East China Sea, respectively. The sea-air exchange fluxes of mercury were estimated as 0.17±0.38, 1.10±1.34, and 3.44±3.24 ng m-2 h-1 over the three seas above, respectively. Upon omitting the contributions of anthropogenic sources, the sea-air exchange fluxes of mercury could be enhanced by 207.1 %, 32.4 %, and 5.8 %, respectively. This study elucidated the role of anthropogenic emissions in shaping the marine atmospheric mercury and the modulation of sea-air exchange fluxes, thereby informing valuable assessments regarding the influence of future reduced anthropogenic mercury emissions on the marine mercury cycle and ecosystems.

Source: Atmospheric chemistry and physics

DOI: 10.5194/acp-25-13815-2025