Pollution
Volume:1 Issue: 4, Autumn 2015

A comprehensive evaluation of the residual levels of Organochlorine insecticides (OCIs) in the sediment cores of Cochin Estuarine System (CES) is highlighted in this research article. It assessed the distribution pattern and impact of these xenobiotics in this environmental niche. Fifteen persistent organochlorine compounds (OCs) were quantitatively analysed in the six sediment core samples collected from specific sites of CES, during November 2009. Among these contaminants, residual levels of HCH, Cyclodienes and DDT were the dominant entities. According to the sediment quality guidelines (SQGs), the higher concentration of these persistent toxicants found in the CES was enough to pose ecological risk to the bottom dwelling consumers. This study provides a better understanding of these trace organics in the environment and could develop more effective strategies for protecting this vulnerable ecosystem from further pollution. Further, sediment screening bioassays can also be conducted for both sediment quality evaluation and identification of existing potent toxicants.

In this research, gasoline vapours including Benzene, Toluene, Xylene (BTX) and Total Volatile Organic Compounds (TVOCs) emitted from vent pipes of underground storage tanks (USTs) were measured at six gas stations in Tehran. Thereafter, gas station No. 29 was selected as a pilot station and equipped with a vapour control system. The vapours were measured during the summer of 2013 and winter of 2014 in two states, before and at the time of gasoline discharge from a petrol tanker to the UST. The results reveal that the average of BTX and TVOCs are 161.22, 200.81, 229 and 647.01 ppm, respectively, higher than the World Health Organisation (WHO) guidelines. The average of TVOCs and BTX in the situation in which the control system is inactive at the pilot station, are 259.13, 55.9, 73.03 and 96.88 ppm, respectively. After activating the control system at the pilot station, the VOCs were reduced by 0.01 ppm. Almost 99.99% control was obtained for this system and 87% of the people living around the pilot station were satisfied and no longer had any complaints about the bad odour of VOCs. It can be concluded that gasoline discharge from the petrol tanker to UST, is the main reason behind the overproduction of VOCs in Tehran''s gas stations (P<0.001). So, the most important element is to reduce VOCs at Tehran''s gas stations by installing a vapour control systems in all the stations and activating the systems at the time of gasoline discharge.

Duckweeds are of special interest, as they are naturally growing weeds that have the capacity to tolerate and remove toxic pollutants, including heavy metals from the environment. Studies have revealed that duckweed (Lemna minor) can tolerate and remove heavy metals from aqueous solutions. In the present study, the efficiency of L. minor in the removal of Ni and Cr individually from aqueous solutions was investigated at concentrations of 3.05, 3.98 and 4.9 mg/L for Ni and 1.91, 2.98, and 4.2 mg/L for Cr. Experiments were run for 22 days, after which the metal content in the plant was estimated by atomic absorption spectrophotometer (AAS). The duckweed showed higher percentage of Ni removal than Cr. Specific Growth Rate (SGR) was found to be reduced at high concentrations of both Ni and Cr. Statistical analysis suggested that the growth of the plant was affected by the toxic effect of both Ni and Cr. Bioaccumulation of Ni was higher than Cr in L. minor. The mechanism of removal of both Ni and Cr followed second order kinetics. It is suggested that these duckweeds can remove Ni and Cr from aqueous solution and can also accumulate the same in considerable concentrations, at low initial metal concentrations.

Haraz-Ghareh Su is one of the seven sub-basins of the Caspian basin, located on the southern shores of the Caspian Sea, and as such, is in danger of water crisis due to absence of proper systematic policy and strategy. In this study, the pressure factors on the Haraz-Ghareh Su water resources were identified using DPSIR model. Then, the pressure parameters on the freshwater resources in the Caspian Basin were scored and prioritized into two categories: human and non-human criteria and eight sub-criteria with the help of questionnaires (the opinion of 36 specialists in environmental planning and management, as well as the use of FANP). Thereafter, the data layers were processed with the help of IDRISI software, and eventually, the data were overlaid in the ArcGIS and the final plan was made. The findings of the study shows that, among 8 effective sub-criteria on the environmental planning and management of the freshwater resources in the Haraz-Ghareh Su Basin, agricultural water consumption with 0.243 score points and dam-making with 0.039 score points are considered most and least important sub-criteria, respectively. Consequently, after the compilation and scoring of sub-basins of the Caspian basin, it appears that the sub-basin of Haraz-ghare Su with 0.158627 points had the worst situation in terms of the planning and management of freshwater resources in the Caspian basin. In order to decrease the pressure on the freshwater resources in the Haraz-Ghareh Su Basin, the formulation of long-term policy and strategy in this basin seems to be essential.

An adsorbent was developed from matured leaves of the Aloe barbadensis miller plant for removing Pb(II) from aqueous solutions. Adsorption was carried out in a batch process with several different concentrations of Pb(II) by varying amount of adsorbent, pH, agitation time and temperature. The uptake of the metal was initially very fast, but gradually slowed down indicating penetration into the interior of the adsorbent particles. The experimental data closely followed both Langmuir and Freundlich isotherms. A small amount of the adsorbent (1 g/50ml) could remove as much as 86% of Pb(II) in 35 min from a solution of concentration 0.3 mg/50ml at 25°C. The adsorption continuously increased in the pH range of 2.0–5.0, beyond which the adsorption could decrease up to pH 7.0 when the adsorption could not be carried out due to precipitation of the metal. The adsorption was exothermic at ambient temperature and computation of the parameters, ΔH, ΔS and ΔG, which indicated the interactions to be thermodynamically favorable.

Today, the cement industry is one of the major air polluting industries in the world. Hence, in this study, owing to the importance and role of contaminants from the plant, an appraisal of the emission contributions in addition to other factors have been discussed. There are several reasons behind the importance of modeling air pollutants. First, the assessment of standards for air pollution, and the fact that the measurement points are limited. Furthermore, in all industrial areas, measurement and installation of assessment and monitoring stations are not feasible. The AERMOD model is a dispersion steady state model which is utilized to determine the concentration of various pollutants in different areas from urban and rural, flat and rough, shallow diffusion in height, from standpoint and different shallow sources. In this model, it is assumed that the dispersion of concentration in Stable Boundary Layer (SBL) in two horizontal and vertical directions are similar to that of horizontal within Gaussian convectional boundary layer (CBL). With regard to assessment of the parameters and pollutants of stack outlet, the amount of particulate matter was measured as the most important pollutant in the region. Then, via dispersion and diffusion modeling of pollution (AERMOD) along with environmental measurements, the nature of dispersion of this pollutant in the analysis of the surrounding areas was verified. According to the presented results, the highest level of concentration for particulate matters in all areas affected by cement factory amounts to 43.68 (μg/m3) which occurred at a distance of 1500 m in the east direction and 2100 m in the north direction.

Collection of Municipal Solid Waste (MSW) accounts for a significant proportion of most municipal budgets, and has drawn some degree of researchers‟ interest. This study was conducted in Ota, Southwest Nigeria, to explore the use of Visual basic program as an innovative tool to select the most economic haulage system among three systems found in literature (conventional-, modified- and Stationary- hauled system) for collection and transfer of MSW to disposal sites. Factors that affect the costs of collection and transportation of waste such as: vehicle cost, total time spent on waste collection, and gross travel cost, were considered in the analysis. The result of the study shows that the stationary hauled method of waste collection is the optimal and economical method of collection. This method recorded a 56% and 43% reduction in total cost of daily travel per waste collection, as compared to the conventional and the modified systems, respectively. The application of visual basic program proffers implementable solutions to reduce the cost of MSW transportation to disposal sites. This would reduce travel time and costs of vehicle fueling, and increase the prompt collection of waste which would in turn facilitate the development of an aesthetically balanced and environmentally friendly municipality that would perhaps boost economic development.

Exhaust emissions contribute greatly to air pollution, the social cost of which may occur as danger to human health, attracting huge medical expenses, causing absenteeism and hence loss of productivity. These are incentives to reduce exhaust emissions to the barest minimum. Two major cities in Ghana, Accra and Kumasi, are struck by vehicular traffic jams especially during rush-hours and are grappling with the situation perceived to be worsened by driving pattern, a travel-related characteristic with a tendency to increase vehicular emission and hence, atmospheric pollution. Driving patterns were studied in the Kumasi Metropolis using questionnaires purposively administered to drivers who visited the Driver and Vehicles Licensing Authority. Parameters were analyzed with SPSS. Results indicate that drivers plied highway (90.0%), feeder (6.7%) and urban (3.3%) roads. Drivers (90%) had no knowledge of how driving patterns contribute to emissions, effect of idle and hot emissions and hot-and-cold starts dynamics. This could explain the failure of drivers to allow vehicle engines to stabilize for over 5 min and also to put off engines when stuck in traffic. Drivers changed speed as often as 4 times/km due to vehicle congestion and intermittent traffic lights, intersections and roundabouts. This may explain the difficulty in maintaining constant speed; thereby compelling drivers to exhibit frequent gear-changing behaviours as well as unstable and inconsistent speed profiles, as the commonest driving patterns. Such characteristics potentially increase energy consumption, emission level and abatement cost significantly and therefore, call for intensified educational programmes aimed at curbing this environmental peril.

The aim of the present study was to evaluate Vitamin C (VC) as a potent natural antioxidant to mitigate the genotoxic effects of Arsenic trioxide and sodium fluoride in Swiss albino mice in vivo. The study was divided into eight groups consisting of control treated with normal saline (Group I), Group II, III, IV, V, VI, VII and the VC group with only Vitamin C (500 mg/kgbw). Arsenic trioxide (4 mg/kgbw) and Sodium fluoride (8 mg/kgbw) were administered singly, as well as in combination to swiss albino mice, with and without VC. In this study, the genotoxic effect of arsenic (As) and fluoride (F) in mice using comet, chromosomal aberration and lipid peroxidation assay was investigated. The results revealed that VC efficiently ameliorates the genotoxic effect of As and F by increasing the frequency of chromosomal aberrations and primary DNA damage along with increased malondialdehyde (MDA) level. In conclusion, VC mitigates the genotoxic effects of the two well-known water contaminants (As and F) effectively and efficiently at the given concentration in vivo.

Municipalities in developing countries spend the highest proportion of their annual budget on unsatisfactory solid waste management service. Until recently, solid waste management services in Ethiopia were mainly the responsibilities of municipalities, which culminated in inadequate service provision. Thus, the integration of Micro and Small Enterprises (MSEs) by the government has recently being considered as an option. Participation of MSEs in SWM started in 2003/04 in Addis Ababa, the capital city of Ethiopia and expanded to other cities following the proclamation of a National Solid Waste program in 2007. This review is aimed at identifying the role of MSEs in solid waste management in selected cities, including the opportunities and challenges for future directions. Limited resources and lack of support, perception and awareness of the community, inadequate training, unorganized fee collection strategy and limited revenue were among the challenges identified. The benefits and potential opportunities include organized and quality service delivery, environmental protection and safety, job opportunity, willingness to pay and social equity. In conclusion, the findings in this review show the importance of MSEs in solving solid waste management problems. However, the challenges need due considerations and appropriate interventions such as legalization of the informal sector, clear working guidelines and regulations, close support and monitoring, and transparent system in general.