Updating risk remediation-endpoints for petroleum-contaminated soils? a case study in the Ecuadorian Amazon region

In Ecuador, the regulatory framework for the remediation of petroleum-contaminated soils is based on predefined concentration endpoints for a selected range of petroleum hydrocarbon compounds. However, such approach may lead to over or under-estimation of the environmental risk posed by contaminated soils. In this study, the end-point remediation criteria according to Ecuadorian Environmental legislation were evaluated using different approaches. The first one was based on Total Extractable Petroleum Hydrocarbons (TEPH) and the second one on Total Bioavailable Petroleum Hydrocarbons (TBPH). Both were compared with ecotoxicological determinations using EC50 -Microtox® bioassay at 5 and 15 min of exposure. The correlation (R2) between EC50 values vs TEPH was of 0.2 and 0.25 for 5 and 15 min, respectively. Meanwhile, R2 between EC50 and TBPH was of 0.9 and 0.65 for 5 and 15 min, respectively, demonstrating a stronger correlation. Our results suggest that a contaminated site where the concentration of the TEPH is higher than the relevant regulatory concentrations may be deemed to present an acceptable risk even though their concentrations exceed the target values in soils. The results also challenge the notion that hormesis is associated with TEPH, contrary to some literature. This study is the first in Ecuador to propose incorporating bioavailability into environmental regulations, highlighting the need for further research to establish realistic and achievable remediation goals based on toxicity studies involving various trophic levels

Environmental Impact Assessment of Remediation Strategy in an Oil Spill in the Ecuadorian Amazon Region

Past petroleum-extraction activities in Ecuador have contaminated its Amazon region. To assess the environmental impact attributed to remediation activities regarding the cleanup of these oil spills, two scenarios were studied according to Life Cycle Analysis methodology: (1) No-action, which means to leave the contamination in place without any further action and (2) Environmental remediation, where the environmental-load attributed to the remediation of the representative oil spill was studied. Results indicated that the no-action scenario presented a higher environmental impact for 12 out of the 16 environmental categories evaluated (climate change, ozone depletion, human toxicity non-cancer effects, particulate matter, ionizing radiation human health, ionizing radiation ecosystem, photochemical ozone formation, acidification, terrestrial eutrophication, marine eutrophication, freshwater ecotoxicity, mineral, fossil and renewable resource depletion). Moreover, the no-action scenario presented a global weighted score of contamination of 5.45 points, while the remediation scenario got a score of 3.3 points, which means that the remediation decreased by 39% of the global environmental impact due to the remediation activity applied, showing the positive influence of environmental remediation to mitigate the effects attributed to the presence of pollution sources associated to the petroleum industry in the Ecuadorian Amazon region

Environmental Impact Assessment of Remediation Strategy in an Oil Spill in the Ecuadorian Amazon Region

Past petroleum-extraction activities in Ecuador have contaminated its Amazon region. To assess the environmental impact attributed to remediation activities regarding the cleanup of these oil spills, two scenarios were studied according to Life Cycle Analysis methodology: (1) No-action, which means to leave the contamination in place without any further action and (2) Environmental remediation, where the environmental-load attributed to the remediation of the representative oil spill was studied. Results indicated that the no-action scenario presented a higher environmental impact for 12 out of the 16 environmental categories evaluated (climate change, ozone depletion, human toxicity non-cancer effects, particulate matter, ionizing radiation human health, ionizing radiation ecosystem, photochemical ozone formation, acidification, terrestrial eutrophication, marine eutrophication, freshwater ecotoxicity, mineral, fossil and renewable resource depletion). Moreover, the no-action scenario presented a global weighted score of contamination of 5.45 points, while the remediation scenario got a score of 3.3 points, which means that the remediation decreased by 39% of the global environmental impact due to the remediation activity applied, showing the positive influence of environmental remediation to mitigate the effects attributed to the presence of pollution sources associated to the petroleum industry in the Ecuadorian Amazon region

Evaluation of the Use of Lime and Nanosilica for the Improvement of Clay Soil Structure and Degradation of Hydrocarbons

Soil structure is an important key in the bioremediation process; for instance, clay soils tend to have high absorption of pollutants and low rates of bioremediation due to their high plasticity and oxygen restrictions. This work assesses seven different treatments for contaminated clay soil using lime, silica nanoparticles, and both components in combination. After a three-month treatment, the variation of the soil granulometry, pH, porosity, cation exchange capacity (CEC), humidity, organic matter, respirometry, and humic acids were measured in order to evaluate the improvements regarding soil structure. Furthermore, total petroleum hydrocarbon (TPH), polycyclic aromatic hydrocarbons (PAHs) and heavy metals were monitored before and after the treatments. The combined treatment using lime and nanosilica presented the best results, reducing the percentage of clays from 61% to 5% and showing a relationship between improved of soil structure and the reduction of pollutants, with a 35% removal for TPHs being the highest obtained with the seven treatments

Evaluation of the Use of Lime and Nanosilica for the Improvement of Clay Soil Structure and Degradation of Hydrocarbons

Soil structure is an important key in the bioremediation process; for instance, clay soils tend to have high absorption of pollutants and low rates of bioremediation due to their high plasticity and oxygen restrictions. This work assesses seven different treatments for contaminated clay soil using lime, silica nanoparticles, and both components in combination. After a three-month treatment, the variation of the soil granulometry, pH, porosity, cation exchange capacity (CEC), humidity, organic matter, respirometry, and humic acids were measured in order to evaluate the improvements regarding soil structure. Furthermore, total petroleum hydrocarbon (TPH), polycyclic aromatic hydrocarbons (PAHs) and heavy metals were monitored before and after the treatments. The combined treatment using lime and nanosilica presented the best results, reducing the percentage of clays from 61% to 5% and showing a relationship between improved of soil structure and the reduction of pollutants, with a 35% removal for TPHs being the highest obtained with the seven treatments

Evaluation of the Use of Lime and Nanosilica for the Improvement of Clay Soil Structure and Degradation of Hydrocarbons

Soil structure is an important key in the bioremediation process; for instance, clay soils tend to have high absorption of pollutants and low rates of bioremediation due to their high plasticity and oxygen restrictions. This work assesses seven different treatments for contaminated clay soil using lime, silica nanoparticles, and both components in combination. After a three-month treatment, the variation of the soil granulometry, pH, porosity, cation exchange capacity (CEC), humidity, organic matter, respirometry, and humic acids were measured in order to evaluate the improvements regarding soil structure. Furthermore, total petroleum hydrocarbon (TPH), polycyclic aromatic hydrocarbons (PAHs) and heavy metals were monitored before and after the treatments. The combined treatment using lime and nanosilica presented the best results, reducing the percentage of clays from 61% to 5% and showing a relationship between improved of soil structure and the reduction of pollutants, with a 35% removal for TPHs being the highest obtained with the seven treatments

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)