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Mercury (Hg) exposure poses substantial risks to human health. Investigating a longer chain from economic activities to human health can reveal the sources and critical processes of Hg-related health risks. Thus, we develop a more comprehensive assessment method which is applied to mainland China—the largest global Hg emitter. We present a map of Hg-related health risks in China and estimate that 0.14 points of per-foetus intelligence quotient (IQ) decrements and 7,360 deaths from fatal heart attacks are related to the intake of methylmercury in 2010. This study, for the first time, reveals the significant impacts of interprovincial trade on Hg-related health risks across the whole country. For instance, interprovincial trade induced by final consumption prevents 0.39 × 10 −2 points for per-foetus IQ decrements and 194 deaths from fatal heart attacks. These findings highlight the importance of policy decisions in different stages of economic supply chains to reduce Hg-related health risks.

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During the 50 years since the concept of urban metabolism was proposed, this field of research has evolved slowly. On the basis of an analogy with an organism's metabolism, the concept of urban metabolism has become an effective method to evaluate the flows of energy and materials within an urban system, thereby providing insights into the system's sustainability and the severity of urban problems such as excessive social, community, and household metabolism at scales ranging from global to local. Researchers have improved this approach, evolving from models of linear to cyclic processes and then to network models. Researchers account for flows of energy and materials, ecological footprints, inputs and outputs, and the characteristics of the system's ecological network. However, the practical methods of analysis need to be improved. Future analysis should focus on establishing a multilevel, unified, and standardized system of categories to support the creation of consistent inventory databases; it should also seek to improve the methods used in the analysis to provide standards and guidance that will help governments to achieve sustainable development. Finally, researchers must improve the ability to provide spatially explicit analyses that facilitate the task of applying research results to guide practical decision-support.

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Recently, it has been reported that the combination of permanganate (Mn(VII)) and bisulfite can lead to a rapid degradation of organic contaminants, where soluble Mn(III) is proposed to be responsible. Interestingly, in this work, we demonstrated the involvement of high-valent Mn-oxo species (possibly Mn(V)) as well as sulfate radical in the Mn(VII)/bisulfite system, by using methyl phenyl sulfoxide (PMSO) as a chemical probe. It was found that the combination of Mn(VII) and bisulfite resulted in appreciable degradation of PMSO under various conditions, while negligible PMSO was degraded by manganese dioxide (MnO 2 ) in the presence of bisulfite under similar conditions. This result indicated that Mn(III) intermediate formed in situ in both Mn(VII)/bisulfite and MnO 2 /bisulfite systems as proposed in literature exhibited sluggish reactivity toward PMSO. In parallel, the formation of methyl phenyl sulfone (PMSO 2 ) product in the Mn(VII)/bisulfite system was observed, suggesting the role of high-valent Mn-oxo species as an oxygen-atom donor in conversion of PMSO to PMSO 2 . Moreover, the yield of PMSO 2 (i.e., mole of PMSO 2 produced per mole of PMSO degraded) was quantified to be 20−100%, strongly depending on the [Mn(VII)]/[bisulfite] ratio as well as solution pH. The competitive contribution of sulfate radical, which oxidized PMSO to hydroxylated and/or polymeric products but not to PMSO 2 , accounted for the yield of PMSO 2 less than 100%. This work advances the fundamental understanding of a novel class of oxidation technology based on the combination of Mn(VII) and bisulfite for environmental decontamination.