The Determination of Heavy Metals in the Ligurian Sea. III. Distribution of Copper, Iron, and Nickel in the 0-200 Metre Layer in Open Sea

Dissolved Cu, Fe and Ni were determined in sea water samples from 9 stations in the Ligurian Sea located along the two traverses Imperia-Capo Corso and Nice-Calvi and at depths between 0 and 200 m. The samples were preconcentrated from small volumes of sea water by complexation with ammonium pyrrolidine-dithiocarbammate (APDC), extraction with CCl₄ and determination by AAS with electrothermal atomisation. The geographical distribution shows that in the central part of the inner traverse there is a maximum of Cu and Fe concentration; the vertical distribution shows no significant depletion of the dissolved elements in the epithalassa.

The results allow for a first approach to the more general problem of the distribution of the trace elements in the Ligurian Sea.     

Identification of Enterococcus faecalis bacteria resistant to heavy metals and antibiotics in surface waters of the Mololoa River in Tepic, Nayarit, Mexico

Heavy metal and antibiotic resistance have been shown to have a strong correlation in nature, and their inter-relation is an important subject of study. We report an analysis of surface waters of the Mololoa River in the municipality of Tepic, state of Nayarit, Mexico. This river has two distinctive sources of contamination: sewage waters and trash confinements. Our findings demonstrate a correlation between the river flow pattern and resistance to heavy metals or to heavy metals and antibiotics in isolated bacteria of the genus Enterococcus, specifically Enterococcus faecalis. The Mololoa River provides a model to study the relationship between water flow and generation of biodiversity, and more importantly, it constitutes a model for studying genetic diversity of bacteria affecting human health.     

Degradation of benzimidazoles by photoperoxidation: metabolites detection and ecotoxicity assessment using Raphidocelis subcapitata microalgae and Vibrio fischeri

Environmental Science and Pollution Research - Benzimidazoles (BZ) are among the most used drugs to treat parasitic diseases in both human and veterinary medicine. In this study, solutions...     

Degradation of antidepressant pharmaceuticals by photoperoxidation in diverse water matrices: a highlight in the evaluation of acute and chronic toxicity

Environmental Science and Pollution Research - Photoperoxidation (UV/H2O2) was used to degrade three of the worldwide most consumed antidepressant pharmaceuticals—bupropion, escitalopram, and...     

Cointegrated land use and CO2 emissions—the silent Columbian cattle revolution

The objective of this research is to discuss the relationship between the growth of livestock and the environmental impact it generates in Colombia. For this, data were extracted from the FAO STAT for the period of 1961 to 2017. The livestock inventory has had a significant growth during the last 50 years. This has generated environmental exposure and the release of carbon, sequestered by continuous deforestation performed in the practice of extensive livestock. Recurring to vector error correction models, we observed the existence of long-term relations between CO₂ emissions from dairy cattle and emissions from slaughtered cattle, deforestation, pastures, and forest development. Changes in CO₂ emissions from dairy cattle tend to be anticipated by changes in CO₂ emissions from the other analyzed sources, which prove how the current investment in dairy cattle results from the accumulated debates in Colombia regarding the different sources of livestock emissions.

     

Assessment of compost dosage in farmland through ecotoxicological tests

A research project was carried out to evaluate ecotoxicological effects of mature compost addition to agricultural soil, using a battery of ecotoxicological tests. The following species were selected: plant of Lepidium sativum, earthworm Eisenia foetida, aquatic crustacean Daphnia magna and bacteria Vibrio fischeri. The tests were classified as “direct tests” using solid compost samples and “indirect tests” using compost leaching test eluate. The direct bioassays were performed using compost added to artificial soil in concentrations ranging from 2.5 to 100 % (w/w); the indirect ones considered compost eluate, added to a standard solution in the same concentrations used in the direct tests. Both tests aimed at obtaining the ecotoxicological parameters (LC₅₀ and EC₅₀). These values were then utilized to implement the Species Sensitivity Distribution (SSD) analysis and extrapolate the Hazard Concentration (HC), a useful threshold to preserve the biodiversity of agricultural ecosystems. Results indicated an increase in compost toxicity with greater compost concentrations; in particular, for direct tests compost dosage below 10 % showed low toxicity, while for indirect ones the toxicity was higher. Furthermore, SSD analysis showed a Hazardous Concentration (HC₅) for direct bioassays of 3.5 % and for indirect of 14 %.     

Economy-wide impacts of climate change: a joint analysis for sea level rise and tourism

While climate change impacts on human life have well defined and different origins, the interactions among the diverse impacts are not yet fully understood. Their final effects, however, especially those involving social-economic responses, are likely to play an important role. This paper is one of the first attempts to disentangle and highlight the role of these interactions. It focuses on the economic assessment of two specific climate change impacts: sea-level rise and changes in tourism flows. By using a Computable General Equilibrium (CGE) model the two impacts categories are first analysed separately and then jointly. Considered separately, in 2050, the forecasted 25 cm. of sea level rise imply a GDP loss ranging from (−) 0.1% in South East Asia to almost no loss in Canada, while redistribution of tourism flows – which in terms of arrivals favours Western Europe, Japan, Korea and Canada and penalises all the other world regions – triggers GDP losses ranging from (−) 0.5% in Small Island States to (−) 0.0004% in Canada. GDP gainers are Australia, New Zealand, Western Europe, Middle East and South Asia. The impact of sea level rise and tourism were simulated jointly and the results compared with those of the two disjoint simulations. From a qualitative point of view, the joint effects are similar to the outcomes of the disjoint exercises; from a quantitative perspective, however, impact interaction does play a significant role. In six cases out of 16 there is a detectable (higher than 2% and peaking to 70%) difference between the sum of the outcomes in the disjoint simulation and the outcomes of the joint simulations. Moreover, the relative contribution of each single impact category has been disentangled from the final result. In the case under scrutiny, demand shocks induced by changes in tourism flows outweigh the supply-side shock induced by the loss of coastal land.

Levels of PCDD/Fs and trace elements in superficial soils of Pavia Province (Italy)

Trace elements and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in soils from rural and light-industrialized sites (n=168) of Province of Pavia (Northern Italy). Most of the trace element values fit in typical ranges of concentrations in soils and are similar to the ones reported for rural sites in Italy or sites with no direct anthropogenic impact. Total concentrations of 2,3,7,8 chlorine substituted PCDD/Fs in superficial soils ranged between 24.4 and 1287 pg g(-1) dw (0.5-28.9 pg WHO(98)-TEQ g(-1) dw). The North Eastern part of the Province presented significantly higher levels (p<0.001) than the rest of the Province for As, Cd, Hg, Pb, Zn and PCDD/Fs. While the existence of a defined heavy metal polluting source for this specific site has been suggested, in the case of PCDD/Fs, profiles were not linked to any specific emission source fingerprint. In the whole extension of Pavia Province, OCDD/F dominated the 2,3,7,8 chlorine substituted congener soil pattern, followed by the 1,2,3,4,6,7,8 hepta-CDD/F congener. Principal Component Analysis (PCA) showed that this profile could not be associated to any described PCDD/F emission source fingerprint and was relatively similar to the baseline deposition of sites with no direct impact of PCDD/F emission sources independently of land use.     

Changes in soil organic carbon contents and nitrous oxide emissions after introduction of no-till in Pampean agroecosystems

We reviewed published results to estimate no-till effects on SOC and denitrification in the Argentine Pampas and the potential of no-till to mitigate the global warming effect. On an equivalent mass basis, 42 paired data sets were used for SOC comparisons of no-till vs. plow till (moldboard plow or disk plow), 18 paired data for comparison of no-till vs. reduced till (chisel plow or harrow disk), and 20 paired data for comparison of plow till vs. reduced till. Twenty-six denitrification data sets were used for evaluation of tillage system and fertilization effects on N2O emission. Changes in SOC under no-till were not correlated to time since initiation of experiments. Averaged over years a 2.76 Mg ha(-1) SOC increase (P = 0.01) was observed in no-till systems compared with tilled systems, but no differences were detected between plow and reduced till. The SOC under tillage explained most of the SOC variation under no-till (R2= 0.94, P = 0.01). The model had a positive intercept and predicted a relatively higher increase of SOC in areas of low organic matter level. The conversion of the whole pampean cropping area to no-till would increase SOC by 74 Tg C, about twice the annual C emissions from fossil fuel consumption of Argentina. Emissions of N2O were greater under no-till with a mean increase of 1 kg N ha(-1) yr(-1) in denitrification rate for humid pampean scenarios. The increased emissions of N2O might overcome the mitigation potential of no-till due to C sequestration in about 35 yr, and therefore no-till might produce global warming.