Antimony is considered a critical and strategically important metal and is used in a wide range of products. This study examines major antimony supply chain disruptions from 1913 to 2018 and... Show moreAntimony is considered a critical and strategically important metal and is used in a wide range of products. This study examines major antimony supply chain disruptions from 1913 to 2018 and analyses how resilience mechanisms and price feedback loops contributed to supply chain resilience. We found that the antimony di-versity of supply of both mining and refining is low, but is enhanced by recycling, around 25% of global anti-mony supply is produced via recycling of antimony bearing metal alloys. Based on production volume, almost 70% of antimony was mined as by-or co-product in 2018, indicating a high supply risk. However, the presence of unrecovered by-products can also make the supply more elastic. Substitution is possible for some antimony applications, but for one of the main applications, flame retardants, performance of substitutes is still considered inadequate. Overall, stockpiling played a significant role in both dampening and exacerbating supply disrup-tions. It is recommended that the mined production and processing capabilities are diversified, stockpiles are explored as a mechanism to absorb sudden shortages, and, most importantly, recycling of antimony (trioxide) should be further improved. Show less
Brink, S. van den; Kleijn, E.G.M.; Sprecher, B.; Tukker, A. 2020
Cobalt is considered a critical raw material. Global cobalt demand is expected to quadruple in the next four decades, due primarily to lithium-ion battery demand. Uniquely, this study provides... Show moreCobalt is considered a critical raw material. Global cobalt demand is expected to quadruple in the next four decades, due primarily to lithium-ion battery demand. Uniquely, this study provides detailed geographically explicit data on the cobalt supply chain, with the aim of both determining how susceptible primary cobalt production is to supply chain disruptions, and to evaluate possible supply risks. We conclude that the risks for supply chain disruptions are high. Firstly, the cobalt market is highly concentrated, with more than half of the cobalt mined in the Democratic Republic of the Congo, and almost half of the cobalt refined in China. Secondly, almost all cobalt is mined as a by-product of copper and nickel. Finally, political stability in production countries is considered to be medium to very weak. There are also several factors in play that reduce supply risks. The concentration of the individual mines, refineries and companies remains under the threshold of a concentrated market, and the estimated 80 artisanal cobalt mines further diversify the mined supply. A network analysis shows the important position of companies with high betweenness and degree centrality. A disruption at these companies can affect the functioning of the overall supply chain. The geographic and a network visualization provide useful insights in the supply risks. Based on the analysis, we recommend to diversify cobalt production, through the development of mines, refineries, and efforts to ensure socially and environmentally sustainable artisanal mining. Show less
Brink, S. van den; Kleijn, R.; Tukker, A.; Huisman, J. 2019
Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder characterized by vascular malformations. Many affected individuals develop recurrent nosebleeds, which can severely affect their... Show moreHereditary hemorrhagic telangiectasia (HHT) is an inherited disorder characterized by vascular malformations. Many affected individuals develop recurrent nosebleeds, which can severely affect their quality of life and are clinically difficult to treat. We report here that treatment with thalidomide reduced the severity and frequency of nosebleeds (epistaxis) in the majority of a small group of subjects with HHT tested. The blood hemoglobin levels of the treated individuals rose as a result of reduced hemorrhage and enhanced blood vessel stabilization. In mice heterozygous for a null mutation in the Eng gene (encoding endoglin), an experimental model of HHT, thalidomide treatment stimulated mural cell coverage and thus rescued vessel wall defects. Thalidomide treatment increased platelet-derived growth factor-B (PDGF-B) expression in endothelial cells and stimulated mural cell activation. The effects of thalidomide treatment were partially reversed by pharmacological or genetic interference with PDGF signaling from endothelial cells to pericytes. Biopsies of nasal epithelium from individuals with HHT treated or not with thalidomide showed that similar mechanisms may explain the effects of thalidomide treatment in humans. Our findings demonstrate the ability of thalidomide to induce vessel maturation, which may be useful as a therapeutic strategy for the treatment of vascular malformations. Show less
