Effect of Petroleum Products on the Larvicidal Activity of Aedes Mosquitoes in Ika North-East LGA, Delta State, Nigeria

Aims: The recent yellow fever outbreak in Delta State, especially in Ika North East local government, triggered the need for this study. Background: Diseases caused by Aedes are by far raising serious concerns in the world. Objective: To evaluate the larvicidal activity on the use of petroleum products in the control of Aedes mosquitoes. Methods: Mosquito species were collected using 350ml deep ladle and identified in the field using their resting positions in their local habitats. Larvae and pupae were separately exposed to 0.005, 0.01, and 0.02%ml of kerosene and petrol in single and mixed forms. The experimental sets were triplicated. Data was analyzed using ANOVA and Turkey’s test to compare mortality, and time of mortality. LC50 and LC95 were computed using Probit analysis. Results: Results revealed that all concentrations of treatment caused complete mortality in larvae except in 0.005%ml and 0.01%ml of kerosene alone and kerosene and petrol mixture at 50 minutes of exposure. All concentrations of treatment equally caused complete mortality in pupae except in 0.005%ml of kerosene (Mean= 10.00) at 30 minutes. The differences between mortality and time mortality records were significant (p< 0.05). Kerosene and petrol mixture and kerosene alone had the lower LC50 and LC95 0.0021 and 0.0088ml respectively in the larvae group. Kerosene and petrol mixture had lower LC50 and LC95 0.0037 and 0.0050, respectively. Conclusion: Therefore, scaling up this intervention on a large scale in endemic areas would reduce larvae density and disease outbreaks.

Investigation of Thermal Comfort Changes Using Summer Simmer Index (SSI): A Case Study in Different Climates of Iran

Objective: This study aimed to assess the thermal comfort trend using a metrological parameter based on the Summer Simmer Index (SSI), for different climates of Iran between 1985 and 2014. Methods: This is a Time-series study. The new SSI was calculated using metrological data in a 30 year- period for illustrating the changes to the thermal comfort or discomfort level through summer months in different climates of Iran. Mann- Kendall test and Sen's Slope were used to compare the upward or downward trend of the index during this period. Results: The worst thermal condition was observed in the southern and central regions of the country. A few stations were put in comfort zone (77≤SSI<83°F). The fluctuations of SSI were not considerable during the study period (P<0.001). However, a commonly upward trend was observed, indicating rising temperature. This initial assessment, which can be reported daily along with other atmospheric parameters at meteorological stations, could play a significant role in reducing the heat-related complications among exposed individuals and a basis for taking appropriate protective measures. Conclusion: Based on the results obtained in this study, which has been investigated in Iran for a long period of time, considering intrinsic features of the SSI index, such as ease of calculation and interpretation and also the possibility of calculating the index using daily reported meteorological data, the use of SSI as a screening index of thermal stress in order to adopt preventive policies in outdoor settings in climates of Iran is recommended.

Diversity of Woody Species and Biomass Carbon Stock in Response to Exclosure Age in Central Dry Lowlands of Ethiopia

Objective: Empirical evidence on the potential of area exclosure in the restoration of severely degraded lands is crucially important. Thus, a study was conducted to examine the influence of exclosure age on vegetation structure, diversity, and biomass carbon stock in the central dry lowland of Ethiopia. Methods: Exclosures of 5, 15, >20 years old, and adjacent open grazing land were selected. Data on vegetation were collected using 20 × 20 m sampling quadrats which were laid along parallel transect lines. Results: The result showed that 17 woody species which represent 9 families were recorded at exclosures and open grazing lands. Shannon-Wiener (H') diversity index ranged from 0.74 (open grazing land) to 2.12 (middle age exclosure). Shannon evenness (E) index was higher in the middle age exclosure (0.80). Woody species basal area and tree density significantly (p < 0.05) increased with increasing exclosure age. The Aboveground woody biomass significantly (p < 0.05) varied from 12.60 (open grazing land) to 68.61 Mg ha-1 (middle age exclosure). Similarly, the aboveground biomass (AGB) carbon stocked was significantly (p < 0.05) higher in the middle (32 Mg ha-1) and old age exclosures (31 Mg ha-1). Conclusion: This study indicated that exclusion can restore the degraded vegetation and sequester and stock more atmospheric carbon dioxide in the aboveground biomass. Therefore, open degraded grazing land of the lowland areas can be restored into a promising stage through area exclosure land use management.

Sustainable Fishing? Ecological Footprint Analysis of an Artisanal Fishing Organization

Background: Small-scale fisheries are an important economic sector in terms of employment, national food security, enterprise development and foreign exchange earnings. Overfishing is one of the main impacts directly affecting fisheries. However, there are other kinds of global impacts not frequently considered. The ecological footprint indicator is not new but has been mostly overlooked by scholars in the artisanal fishing sector. The aim of this study was to evaluate the corporate ecological footprint of small-scale fisheries through a fishing cooperative at La Cruz de Loreto in Mexico, and determine its eco-efficiency as non-direct global impacts. Methods: The Compound Method Based on Financial Accounts (MC3.V.2 for its acronym in Spanish, version 2) was used. It includes the categories of emissions, materials, resources, services and contracts, land use and waste. Results: Eco-efficiency, determined by the organization´s ecological footprint, was 0.6 t/ha and its carbon footprint was 0.2 t/tCO2 per year, a low one when compared to others. The consumption category that contributed most to the footprint was indirect emissions and the ecosystem’s fossil energy, which could be explained by the characteristics of the fishing cooperative analyzed. Conclusion: The corporate ecological footprint for La Cruz de Loreto fishing cooperative is low when compared to others, but it indicates that they should improve in the category of indirect emission (reduce the consumption of electricity generated by fossil fuel and use of alternative energy) and should invest in the “forest” type of ecosystem to increase carbon sinks and mitigate the impacts.

CO2 Mitigation in the Power Sector of Thailand: Analyses of Cleaner Supply-side Options Beyond the Paris Agreement

Background: The drastically increasing share of fossil fuel supply to meet the rapidly growing electricity demand resulting in increasing Carbon dioxide (CO2) emissions, is the major concern in Thailand. In 2015, fossil fuels used in electricity generation in Thailand accounted for around 85.3% of the total electricity generation. Aim: The aim of the study is to analyze carbon dioxide mitigation options under the cleaner supply-side option beyond the Intended Nationally Determined Contribution (INDC) of Thailand. Methods: In this study, the Long-range Energy Planning (LEAP) model is used to analyze the share of electricity generation and CO2 mitigation from four main different scenarios, namely Business-as-Usual (BAU), Renewable Energy (RE), Carbon Capture Storage (CCS), and Carbon Tax (CT) scenarios during 2015 to 2050. The BAU scenario is constructed following the power development targets of the Power Development Plan in 2015. Results: The results illustrate that in the BAU scenario, electricity generation and carbon dioxide emissions from the power sector will increase by 57.7% and 37.3%, respectively in 2050 as compared to 2015. The imposition of carbon tax of $20/tCO2 from 2020 and an increase to $500/t CO2 by 2050 will have a high potential to reduce CO2 emissions from the power sector as compared with other scenarios. Conclusion: Results show that except for the RE scenarios considering the lower share of solar and biomass, all scenarios would help Thailand in achieving the target of INDC by 2030. Results provide that the share of imported electricity is higher with the imposition of carbon tax as compared to the scenarios with the promotion of renewable energy, CCS and EV technology.

Airborne Carcinogenic Trace Elements Distribution Associated with Long Term Exposure in Makkah Population

Background: More than 4 million international pilgrims visit Makkah each year during the Hajj and Umrah seasons. Since trace elements are natural ingredients that endure general biogeochemical cycling, conversion functions between environmental loadings, mass levels, and exposed receptors. Objective: This study aimed to evaluate the distribution of carcinogenic trace element levels related to long term exposure. Methods: Particulate Matter (PM10) sampling was conducted at six locations (Al-Haram, Arafat, Muzdalifah, Aziziyah, Al Nuzhah, and Al Awali). On-site measurement parameters included ambient temperature, wind speed, and direction over 37 weeks. Samples were investigated for Cd, Cr, As, Be, and Ni levels with inductive coupled plasma mass spectrometry. Quality assurance measures were achieved separately by analyzing a control sample to certify reliability, reproducibility, and linearity for each analysis. Results: Average particulate matter concentration for a one-year period presented significant variability, which exceeded the WHO guidelines for average exposure (25.0 µgm-3). PM10 average concentrations during round-1 (Spring), round-2 (Summer), round-3 (Autumn) and round-4 (Winter) were 120.1 ± 52.2 µgm-3, 223.4 ± 30.4 µgm-3, 77.6 ± 36.72, and 89 ± 62.7 µgm-3, respectively. The concentrations of Cd, Cr, As, Be, and Ni were found to be 0.098, 0.008, 0.26, 0.03, and 0.012 µgm-3, respectively. Conclusion: PM10 concentration was highly correlated (p-value <0.005) with Cd, Cr, As, Be, and Ni; thereby indicating the influence of manufacturing discharges and pollutants transported over long-distances. Higher ambient air temperatures may cause atmospheric instability in low air dispersion around Makkah. This highlights the importance of continuous air monitoring and calculation of dose exposure levels of both PM10 and trace elements.

Evaluation of Occupational Exposure to Silica Dust in Mining Workers in Eastern Iran

Background and Objective: Silica dust is present in almost all mining operations and can cause various health problems such as silicosis in workers. The present study aimed to determine the total and respirable dust levels and the crystalline silica content of the soil in the breathing zone of workers in Iranian mines. Methods: This cross-sectional study was carried out in 2016-2017 on six Iranian silica mines. Dust sampling was performed according to the National Institute of Occupational Safety and Health (NIOSH) method No. 0600. The samples were collected from the respiratory zone of workers at 114 stations in different units of the mines. The silica content was measured using the standard NIOSH method No. 7601. The crystalline silica content in bulk samples collected from the soil was determined by using the X-Ray Diffraction (XRD) spectroscopy method. Results: The highest concentration of crystalline silica dust was 2.81±0.49 mg/m3 and was observed in the air of crushing unit of mine no. 6, and the lowest was 0.08±0.208 mg/m3 and was measured in the management/administration unit of mine no.1. The mean silica content in the solid surface of the mines was 91%. The total and respirable dust levels in all units of the mines except management/administration were higher than the permissible limit. The free silica content of all collected samples was substantially higher than the permissible limits, and in some cases, it was as much as 100 times above the standard level, which reflects the extremely high risk of working in these mines. Conclusion: Exposure of workers with crystalline silica dust in all units was higher than the standard recommended limits. It is imperative to adopt immediate measures based on technical, managerial, and personal protection solutions to reduce the exposure of workers to silica.