Assessment of three plant-based biodiesels using a Daphnia magna bioassay

Abstract

Biodiesel is an alternative fuel that is gradually replacing petroleum-based diesel use. Although biodiesel is considered friendlier to the environment, the potential toxic effects of biodiesel to aquatic organisms are still uncertain due to the wide range of feedstocks used to generate the fuel. The aquatic cladoceran Daphnia magna (D. magna) has been commonly used as a lethal and/or sub-lethal toxicological model organism in ecological risk assessments for contaminated water environments. In this work, we evaluated whether significant differences exist in the sensitivity of freshwater aquatic life to different biodiesels. The acute toxicity of three plant-based biodiesels was investigated using D. magna over a 96-h period. In addition, diesel fuel was tested as a reference. Increased immobility was observed as time progressed following exposure. Testing revealed of the four fuel products, diesel proved most toxic to D. magna, with half maximal effective concentration (EC₅₀) values of 4.7 μg/mL (24 h) and 3.4 μg/mL (72 h). Among the biodiesels, safflower methyl biodiesel was most toxic, with EC₅₀ values of 1026 μg/mL (24 h) and 71 μg/mL (48 h). Our data indicate that although not all biodiesels were toxic, the short-term exposure of D. magna to sub-lethal concentrations of biodiesels affects their mobility and thus decreases their reproductive potential. Overall, this research provides insights into the sub-lethal effects of biodiesels on an aquatic organism.

from Enviromental via alkiviadis.1961 on Inoreader http://ift.tt/2zMLZAl

Predicting spatio-temporal concentrations of PM 2.5 using land use and meteorological data in Yangtze River Delta, China

Abstract

The prediction of PM_2.5 concentrations with high spatiotemporal resolution has been suggested as a potential method for data collection to assess the health effects of exposure. This work predicted the weekly average PM_2.5 concentrations in the Yangtze River Delta, China, by using a spatio-temporal model. Integrating land use data, including the areas of cultivated land, construction land, and forest land, and meteorological data, including precipitation, air pressure, relative humidity, temperature, and wind speed, we used the model to estimate the weekly average PM_2.5 concentrations. We validated the estimated effects by using the cross-validated R² and Root mean square error (RMSE); the results showed that the model performed well in capturing the spatiotemporal variability of PM_2.5 concentration, with a reasonably large R² of 0.86 and a small RMSE of 8.15 (μg/m³). In addition, the predicted values covered 94% of the observed data at the 95% confidence interval. This work provided a dataset of PM_2.5 concentration predictions with a spatiotemporal resolution of 3 km × week, which would contribute to accurately assessing the potential health effects of air pollution.

from Enviromental via alkiviadis.1961 on Inoreader http://ift.tt/2Aejlaz

Imperative roles of halotolerant plant growth-promoting rhizobacteria and kinetin in improving salt tolerance and growth of black gram ( Phaseolus mungo )

Abstract

The salinity stress causes a major threat for plant growth, yield, and biomass production. The present study was designed to assess the effect of exogenously applied kinetin and halotolerant plant growth-promoting rhizobacteria (H-PGPR) on alleviation of salt stress in black gram (Phaseolus mungo). A total of 15 rhizobacterial isolates obtained from a salt-affected area were analyzed for their capability to improve growth of P. mungo plants growing in greenhouse conditions. Out of the tested rhizobacteria, the two bacterial isolates which exhibited maximum growth potential were screened and their growth-promoting attributes were evaluated. The role of screened H-PGPR and/or kinetin (8 and 10 μM) was evaluated in P. mungo plants irrigated with three levels of brackish water (S1 = 3, S2 = 5, and S3 = 7 dSm⁻¹) under field condition. Salt stress reduced transpiration rate, stomatal conductance, salt tolerance index, growth, leaf area, photosynthetic pigments, leaf relative water content (LRWC), biomass production, and seed yield in subjected plants. Conversely, the salinized plants treated with kinetin and/or H-PGPR exhibited improved levels of chlorophyll contents, LRWC, root growth, shoot growth, biomass production, and seed yield. The H-PGPR and/or kinetin supplementation also reduced electrolyte leakage in salt-stressed plants. Overall, the present findings will be of great value to recognize the mechanism of salt stress alleviation in P. mungo plants under the influence of H-PGPR and/or kinetin.

from Enviromental via alkiviadis.1961 on Inoreader http://ift.tt/2k7ZVhk

The impact of hydro-biofuel-wind energy consumption on environmental cost of doing business in a panel of BRICS countries: evidence from three-stage least squares estimator

Abstract

The renewable energy sources are considered the vital factor to promote global green business. The environmental cost of doing business is the pre-requisite to analyze sustainable policies that facilitate the eco-minded entrepreneurs to produce healthier goods. This study examines the impact of renewable energy sources (i.e., hydro energy, biofuel energy, and wind energy) on the environmental cost of doing business in a panel of BRICS (Brazil, Russian Federation, India, China, and South Africa) countries, for the period of 1995–2015. The study employed principal component analysis to construct an "integrated environmental index" by using three alternative and plausible factors including carbon dioxide emissions, fossil fuel energy consumption, and chemicals used in the manufacturing process. The environmental index is used as an interactive term with the three cost of doing business indicators including business disclosure index, the cost of business start-up procedures, and logistics performance index to form environmental cost of doing business (ECDB) indicators. The results of three-stage least squares (3SLS) estimator show that foreign direct investment (FDI) inflows supported the green business while trade openness deteriorates the environment, which partially validates the "pollution haven hypotheses (PHH)" in a panel of countries. There is no evidence for environmental Kuznets curve (EKC) hypothesis; however, there is a monotonic decreasing relationship between per capita income and ECDB indicators. The hydro energy supports the sustainable business environment, while biofuel consumption deteriorates the environmental impact on the cost of business start-up procedures. Finally, wind energy subsequently affected the ECDB indicators in a panel of BRICS countries. The overall results conclude that growth factors and energy sources both have a considerable impact on the cost of doing business; therefore, there is a momentous need to formulate sustainable policy vista to magnetize green business across countries.

from Enviromental via alkiviadis.1961 on Inoreader http://ift.tt/2juhNiP

Role of nature reserves in giant panda protection

Abstract

Giant panda (Ailuropoda melanoleuca) is a flagship species in nature conservation of the world; to protect this species, 67 nature reserves have been established in China. To evaluate the protection effect of giant panda nature reserves, we analyzed the variation of giant panda number and habitat area of 23 giant panda nature reserves of Sichuan province based on the national survey data released by State Forestry Administration and Sichuan Forestry Department. Results showed that from the third national survey to the fourth, giant panda number and habitat area of 23 giant panda nature reserves of Sichuan province failed to realize the significant increase. Furthermore, we found that the total population growth rate of 23 nature reserves in the last 12 years was lower than those of the province total of Sichuan and the national total of China, and the total habitat area of the 23 nature reserves was decreasing in the last 12 years, but the province total and national total were all increasing. We propose that giant panda protection should pay more attention to how to improve the protective effects of nature reserves.

from Enviromental via alkiviadis.1961 on Inoreader http://ift.tt/2BtYUVb

Health risk evaluation of heavy metals in green land soils from urban parks in Urumqi, northwest China

Abstract

Here, we sampled, tested, and analyzed heavy metals in soil obtained from green land in urban parks of Urumqi. Analysis included soil nutrient contents, particle size distribution, and health risks of heavy metal contaminants. Results showed that (1) organic matter and rapidly available phosphorus contents of all samples ranged from 6.07–58.34 and 6.52–116.15 mg/kg, with average values of 31.26 and 36.24 mg/kg, respectively; (2) silt (particle size 20–200 μm) comprised most of the particle distribution, accounting for 46.56–87.38% of the total, and the remaining particles were clay particles (0–20 μm) and sand (200–2000 μm); (3) calculations of HQ_ing, HQ_inh, and HQ_derm for eight heavy metals in three exposure patterns revealed values less than 1 for children and adults, indicating a level of carcinogenic risk for these heavy metals; and (4) calculating the carcinogenic risks of nickel, chromium, and cadmium through breathing pathway indicating no potential carcinogenic risk for any of the three. This research showed high soil nutrient content, providing fertile ground for plant growth in the green land of these urban parks. However, measures such as using sprinklers and increased green vegetation areas have been proposed to improve soil texture. This research can serve as a reference point for soil environmental protection efforts as well as future plant growth in urban Urumqi parks.

from Enviromental via alkiviadis.1961 on Inoreader http://ift.tt/2id5I4O

IJERPH, Vol. 14, Pages 1468: Oral Mucositis in Pediatric Patients in Treatment for Acute Lymphoblastic Leukemia

IJERPH, Vol. 14, Pages 1468: Oral Mucositis in Pediatric Patients in Treatment for Acute Lymphoblastic Leukemia

International Journal of Environmental Research and Public Health doi: 10.3390/ijerph14121468

Authors: Isabella Ribeiro Rebecca Limeira Ricardo Dias de Castro Paulo Ferreti Bonan Ana Valença

Oral mucositis in oncologic patients is the most undesirable event of the chemotherapeutic treatment. This study aimed to identify damage to the oral cavity resulting from chemotherapy in pediatric patients with acute lymphoblastic leukemia (ALL). This is a prospective study with a sample of 42 children and adolescents evaluated for 10 consecutive weeks after diagnosis. The modified Oral Assessment Guide (OAG) was used, and data were analyzed by Spearman's rank correlation coefficient (α = 5%). Changes to the normal lips and saliva were positively related to an increase in the OAG score during all 10 weeks of evaluation. Alterations to the labial mucosa were correlated with an increase in the OAG score from the 2nd to 10th week, which was also found for changes in the tongue and in the swallowing function in Weeks 1, 6, 8, 9, and 10 and for gum changes from the 5th to 7th week. No significant vocal changes were correlated with the total OAG score at any point during the monitoring period. Changes in lips, cheek and/or palatal mucosa, labial mucosa, and gum areas and in swallowing function were positively correlated with an increase in the severity of oral mucositis in patients with ALL after beginning chemotherapeutic treatment.

from Enviromental via alkiviadis.1961 on Inoreader http://ift.tt/2AcHZrZ