Gasoline prices and economic policy uncertainty: what causes what,and why does it matter? Evidence from 18 selected countries

In this paper, we examine asymmetric causal relationships between gasoline prices and economic policy uncertainty in a panel of 18 countries over the period 1998–2017, using the recently introduced panel causality approach of Hatemi et al (Appl Econ, 48:2301–2308, 2016) that accounts for asymmetric dynamics and is robust to both cross-sectional dependence and slope heterogeneity. Empirical findings reveal asymmetric causal relationships between gasoline prices and economic policy uncertainty in the sampled countries. Specifically, results show that economic policy uncertainty and gasoline prices have positive and negative asymmetric bidirectional causal relations in 13 countries. No feedback causality was detected between gasoline prices and economic policy uncertainty in 5 countries. Based on the results, we infer that positive and negative asymmetric causal relations exist between economic policy uncertainty and gasoline price, with attendant policy implications in sampled regions.

     

Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediment Cores of Selected Creeks in Delta State,Nigeria

The spatial and seasonal distribution and concentrations of polycyclic aromatic hydrocarbons (PAHs) were investigated in core sediments of Ubeji, Ifie, and Egbokodo creeks in the Niger Delta, Nigeria. A total of 222 core sediment samples were collected during the wet season (August 2010) and the dry season (January 2011). The samples were dried, Soxhlet extracted, fractionated, and injected into a gas chromatograph with flame ionization detector (GC-FID). The concentrations of PAHs ranged from not detected to 2,654 μg/kg (wet season) and not detected to 3,513 μg/kg (dry season). In general, the concentrations of PAHs for a number of stations in this study are comparable to sites with high anthropogenic activities in the Niger Delta. The toxicity risk assessment based on the total BaP equivalent quotient of the seven carcinogenic PAHs (BaA, Chry, BbF, BkF, BaP, DBA, and Iper) was 97.416 μg/kg and did not exceed the method B cleanup level for benzo(a)pyrene (137 μg/kg), according to toxic equivalency factors, which implied that PAHs in sediments of the present study currently have minimal adverse effects. This study provided information on the concentrations and profiles of PAHs sediment cores, which is useful for source diagnosis, environmental quality management, contamination history, and environmental forensic studies.     

Biomonitoring ²¹°Po and ²¹°Pb in marine brachyuran crabs collected along the coast of Kudankulam, Gulf of Mannar (GOM), India

Activities of 21?Po and 21?Pb in whole-body and in various tissues of brachyuran crabs collected along the Kudankulam coast were studied. A non-uniform distribution of these radionuclides was observed between the various tissues. Of all the tissues, 21?Po and 21?Pb were found to accumulate more in the hepatopancreas and intestine. Among the crabs studied, Charybdis lucifera registered higher 21?Po and 21?Pb activity. Muscle tissue in all the species registered lower activity. The 21?Po/21?Pb activity ratio was found to be greater than unity. The biological concentration factor for organs varied between ~ 10? and 10? for 21?Po and ~102 and 10? for 21?Pb. A significant variation in the accumulation of 21?Po and 21?Pb was noted between species and between seasons (p < 0.05). The mean whole-body internal dose ranged from 1.42 to 6.86 μGy h?1 for 21?Po and from 3.0 × 10?3 to 8.0 × 10?3 μGy h?1 for 21?Pb. The external dose for 21?Po and 21?Pb was 2.41 × 10?? to 5.76 × 10?? μGy h?1 and 4.14 × 10?? to 8.26 × 10?? μGy h?1, respectively. The activity levels recorded are in agreement with values recorded in related organisms in other parts of the world. The total committed effective dose due to the intake of both radionuclides ranged from 80.3 to 871.7 μSv y?1. The median dose calculated due to 21?Po and 21?Pb in certain crabs in Kudankulam is less and would not pose any significant radiological impact on health or a cancer risk to the public, and the seafood is considered safe for human consumption.     

A mobile monitoring system to understand the processes controlling episodic events in Corpus Christi Bay

Corpus Christi Bay (TX, USA) is a shallow wind-driven bay and thereby, can be characterized as a highly pulsed system. It cycles through various episodic events such as hypoxia, water column stratification, sediment resuspension, flooding, etc. Understanding of the processes that control these events requires an efficient observation system that can measure various hydrodynamic and water quality parameters at the multitude of spatial and temporal scales of interest. As part of our effort to implement an efficient observation system for Corpus Christi Bay, a mobile monitoring system was developed that can acquire and visualize data measured by various submersible sensors on an undulating tow-body deployed behind a research vessel. Along with this system, we have installed a downward-looking Acoustic Doppler Current Profiler to measure the vertical profile of water currents. Real-time display of each measured parameter intensity (measured value relative to a pre-set peak value) guides in selecting the transect route to capture the event of interest. In addition, large synchronized datasets measured by this system provide an opportunity to understand the processes that control various episodic events in the bay. To illustrate the capability of this system, datasets from two research cruises are presented in this paper that help to clarify processes inducing an inverse estuary condition at the mouth of the ship channel and hypoxia at the bottom of the bay. These measured datasets can also be used to drive numerical models to understand various environmental phenomena that control the water quality of the bay.     

Prospects of localism in community energy projects in Nigeria

A notable feature of development aid since the 1960s has been a paradigm shift from centralised project planning and management to decentralised approaches. The transition from top-down to bottom-up elevates the concept of localism in project management for vulnerable groups. This change resonates well in community-based resource management schemes in privileging the locale in terms of generation of knowledge and how problems and remedies are enunciated. Localism conceptualised as devolving central-level government functions to non-state actors in social service delivery is contradictory and seems to negate state powers. This paper explores this trajectory to explicate the forms of localism and the contradictions from its multiple conceptualisations that influence energy access. Using qualitative methodology and interviews, it analyses renewable energy projects directed at poverty alleviation in rural communities in Nigeria while deploying a political ecology framework of power relations to highlight the dynamics of localism. While localism is touted as a constraint in the development process due to localism of action, the paper demonstrates its prospects and how scaling-up of operations may augur well for altering its conceptualisation and with far-reaching consequences for community sustainable energy projects.     

Role of adsorption behavior on metal build-up in urban road dust

Metal pollution of stormwater runoff can cause potential toxic impacts on the receiving water environment and human health. Effective pollution mitigation requires accurate stormwater quality modeling. Even though a significant knowledge base exists on the factors influencing metal build-up on urban roads, very limited studies have investigated how metal–particulate interaction influences metal build-up. This study quantitatively assessed the influence of particulate characteristics, together with vehicular traffic and land use, on the build-up of Zn, Cu, Pb, Cr, Ni and Cd on urban roads. The study outcomes revealed that the variability in metal build-up is highly influenced by the variability associated with metal adsorption to particulates. The percentage contribution from particulate properties influencing metal adsorption in the case of 150 μm size road dust particles was found to be higher(Zn 44%, Cu 52%, Cr 16%, Ni 27% and Cd 45%) when compared to traffic and land use characteristics(Zn 21%, Cu 13%, Cr and Ni 10% and Cd 34%). Similar adsorption behavior was noted for metals associated with 150 μm size road dust particles. Among different particulate properties influencing metal adsorption, effective cation exchange capacity showed a strong positive relationship with the build-up of Cd compared to other metals,highlighting the potential role of Cd in stormwater quality as a readily available metal. The build-up of metals such as Cr and Ni are highly influenced by metal oxides of Al, Fe and Mn and clay forming minerals, indicating that Cr and Ni are relatively stable in nature.     

Organochlorine pesticide in water and bottom sediment from Aiba Reservoir (Southwestern Nigeria)

Levels of organochlorine pesticides (OCPs) in water and sediment from Aiba reservoir (Southwestern Nigeria) have been assessed. The aim of the study was to investigate the pollution status of the reservoir water and the bottom sediment. Analytical measurements were carried out for 20 OCPs using standard literature methods. The results showed higher levels of OCPs in the bottom sediment than the water. Significant positive correlations at p<0.05 level were observed for OCPs compounds in water except γ-BHC and endosulfan III, whereas in sediments α-chlordane, dieldrin, endosulfan II, pp-DDT, endrin ketone and methoxychlor did not show any correlation, and aldrin was negatively correlated with pp-DDD. The mean levels of OCPs in both water and sediments were higher, in most cases, than recommended levels for drinking water. Owing to possible toxicity and bioaccumulation tendency of OCPs by the aquatic habitats, the levels of OCPs detected in water and sediment samples could be a source of future health problems. Environmental monitoring of the reservoir is highly recommended.     

Insecticide residues in the blood serum and domestic water source of cacao farmers in Southwestern Nigeria

The blood serum of cacao farmers and their domestic water sources were analyzed for insecticide residues in selected cacao growing communities of Southwestern Nigeria. The farmers were grouped into five exposure periods based on their years of involvement in insecticide application, viz, <5 years, 5-9 years, 10-14 years, 15-19 years and >20 years. The residue analyses revealed that 42 out of the 76 farmers had residues of diazinon, endosulfan, propoxur and lindane in their blood; and 47.6% out of these farmers belonged in the >20 years exposure duration period. About 34% of the farmers had diazinon with a mean concentration of 0.067 mg kg(-1), 29% endosulfan (mean=0.033 mg kg(-1)), 23% propoxur (mean=0.095 mg kg(-1)), and 17% lindane (mean=0.080 mg kg(-1)) in their blood. The residues of lindane, endosulfan and propoxur in all the exposure duration categories were found to be far below the no observable adverse effect level (NOAEL) while diazinon residues detected in the blood serum of the farmers in all the exposure duration categories exceeded the NOAEL of 0.02 mg kg(-1) for the insecticide. The study also revealed that the sources of drinking water had been contaminated with dazinon and propoxur in some of the farmers' localities; and the concentrations of the insecticides exceeded the acceptable daily intake (ADI). It is concluded that cacao farmers in Southwestern Nigeria may have been occupationally exposed due to insecticide application for mirid control in their cacao plantations; and the exposure at times is of such magnitude as to be hazardous to the farmers and their respective communities.     

Atmospheric particulate matter in Nigerian megacities

The paucity of data on air pollution indices in Nigeria prompted us to commence a national screening exercise regarding particulate matter loads. Six potential megacities (Aba, Abuja, Lagos, Kano, Maiduguri, and Port-Harcourt) representing the six geographical zones in Nigeria were chosen for the study. Sampling was achieved using a ‘Gent’ stacked filter unit sampler capable of collecting fractions of particulate matter with sizes of <10-μm and <2.5-μm simultaneously. The mean values for PM₁₀ are 550, 35, 87, 340, 246 and 130 μg m^?3 while for PM_2.5 the mean values are 100, 14, 25, 67, 20 and 30 μg m^?3 respectively for Aba, Abuja, Lagos, Kano, Maiduguri, and Port-Harcourt. Except for Abuja, the daily PM₁₀ mass loads exceeded the World Health Organization (WHO) guidelines daily limit where as the PM_2.5 values were within the WHO guideline limit. Their correlation matrix result indicates that some PM_2.5 fractions mass fractions were strongly correlated than the PM₁₀ fractions probably due to their long range transport potentials. Further work is in progress to determine the elemental profiles of both particulate fractions collected.     

Airborne fine particulate matter (PM2.5) at industrial,high- and low-density residential sites in a Nigerian megacity

Abstract

Airborne particulate matter PM_2.5 was collected in an industrial, a low-density, and a high-density residential area of Lagos from December 2010 to November 2011, and elemental composition was determined by proton-induced X-ray emission. Across the months, mass concentrations ranged from 13 to 237?µg?m^?3, exceeding the World Health Organization guideline value of 10?µg?m^?3. Data on 24 elements were obtained, with maximum values during Harmattan season months; source identification and apportionment studies by positive matrix factorization suggested that petroleum oil combustion (70%) was the major source of PM_2.5 and could pose a great hazard to Lagos receptors.