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A one-year greenhouse experiment was conducted to study the transfer of copper from contaminated agricultural soils to edible and nonedible structures of lettuce, tomato, and onion plants. Study soils were selected from two basins of central Chile (Santiago and Cachapoal) to represent two similar total soil copper gradients with different pH values. Results showed that free ionic Cu and Cu in saturation extracts were very low in comparison to total Cu contents of study soils (<0.002% and <0.04%, respectively). The concentrations of free ionic copper and of copper in saturation extracts were correlated to total Cu levels and to soil pH. Mean copper concentrations were higher in lettuce than in tomato and onion plants and in vegetables grown on acidic soils of the Cachapoal basin. However, copper levels in edible tissues of tomato and lettuce plants were similar to copper levels described for plants grown on unpolluted soils except for onion bulbs, which had higher values. This indicates that copper translocation to edible, above-ground structures seemed to be well regulated, as their concentrations were fairly constant. The study shows that Cu concentration in study vegetables depends on various factors, including plant species and tissue; site-specific soil factors, such as pH, organic matter, dissolved organic carbon, and conductivity; and several Cu pools, such as total, extractable, and free ionic Cu. Thus, our results support the intensity/capacity concept in that Cu concentration in plants or plant tissues depends not only on the availability of free copper ions in soil solution but also on other soil copper pools that supply the element to the soil solution.

Thermodynamic models were used to correlate experimental and field data for the concentrations of copper (Cu), anions, and cations in drinking water with Cu‐containing scales on the inner walls of pipes. This study focused special attention on the aging processes of these scales. Precipitation and dissolution were predicted to be the main aging causes for Cu scales present on the inner walls of pipes. When data were grouped by the solid that controls solubility, the average 8‐h stagnant Cu concentration in drinking water was found to decrease linearly with average pipe age. For these average values, langite was the most soluble and youngest film, followed in both solubility and age by cupric hydroxide, azurite, brochantite, malachite, and tenorite. The more stable solids—malachite and tenorite—were 8 and 16 times less soluble, respectively, than the most soluble solid, langite. Scales usually contained more than one compound, a finding that was attributed to temperature changes, variability of water composition, long stagnation periods, and aging. During the aging process, parts of a young scale surface area may be covered and blocked for further reaction by a precipitate. During long stagnation periods, such factors as changes in pH, oxygen, and carbon dioxide concentrations and precipitation of calcium solids may induce a different Cu compound precipitate.

Research Question/Issue We assess how ownership concentration influences the sensitivities of expansion investments and maintenance investments to changes in a firm's cash flow. We find the causal effect by exploiting the exogenous variation in the price of a firm's product. We also evaluate whether state versus private ownership affects the impact of ownership concentration on investment–cash flow sensitivities. Research Findings/Insights Using detailed data from 134 major copper mines operating in 29 countries over a 17‐year period, we show that a more concentrated ownership increases the sensitivity of expansion investments to changes in a firm's cash flow, while we do not detect a significant effect for maintenance investments. We also find that state ownership negatively moderates the effects of ownership concentration on the expansion investment–cash flow sensitivity. Theoretical/Academic Implications The findings improve our understanding of ownership structures and show the nuances of these structures when different ownership features are combined in the assessment of investment sensitivities. Practitioner/Policy Implications The asymmetric effects of ownership structures on different investment sensitivities call for a more fine‐grained analysis of incentives, benchmarking, and information disclosure policies. This issue is especially relevant in state‐owned enterprises (SOEs) and in firms with a low ownership concentration.