Auto-mechanic Workshops Research Articles

Microbiological and physiochemical analyses of oil contaminated soil from major auto mechanic workshops in ado Ekiti metropolis

The ability of microorganisms to utilize used oil in contaminated soil from some selected major mechanic workshops in Ado Ekiti metropolis as a sole source of carbon and energy was studied. Soil samples collected from the two major mechanic workshops at Adebayo, and Irona Quarters in Ado-Ekiti were analyzed for the microbiological and physicochemical qualities using the basic microbiological methods. The physicochemical properties of the soil samples shows that the value of pH range from 5.45 to pH 5.58, percentage of carbon range from 3.98 % to 4.20%, nitrogen content varies from 2.20 to 2.40. The total heterotrophic bacterial counts from the mechanic workshops ranges from 7.52 x 106 to 8.25 x 106cfu/g while the total heterotrophic fungal counts ranges from 5.54 x 106 to 6.25 x 106 cfu/g. The bacterial recovered from the oil contaminated soils include Staphylococcus spp., Pseudomonas aeruginosa, Bacillus spp., E. coli and Acinobacter spp. The frequency of occurrence of the microbial isolates revealed that Bacillus cereus 5 (31.25%) occurred most, followed by Pseudomonas aeruginosa (18.75%), Acinetobacter spp. (18.75%) and E. coli (18.75%) while Citrobacter freundii (12.50%) had the lowest frequency of occurrence. The results of this study have showed that some of the isolated organism can be used for bioremediation of the contaminated soil.

Great Abilities of Shinella zoogloeoides Strain from a Landfarming Soil for Crude Oil Degradation and a Synergy Model for Alginate-Bead-Entrapped Consortium Efficiency.

Oil contamination is of great concern worldwide and needs to be properly addressed. The present work aimed to contribute to the development of bacterial consortia for oil recovery. We investigated the community structure of a landfarming-treated soil (LF2) by metagenomics to unravel the presence of hydrocarbon degraders. Moreover, we isolated Shinella zoogloeoides LFG9 and Bacillus swezeyi LFS15 from LF2 and combined them with Pseudomonas guguanensis SGPP2 isolated from an auto mechanic workshop soil to form the mixed consortium COG1. Bacterial isolates were tested for biosurfactant production. Additionally, the bioremediation potential of COG1 was studied as free and entrapped consortia by gas chromatography-mass spectrometry, in comparison to the single strains. Results revealed the presence of Actinobacteria (66.11%), Proteobacteria (32.21%), Gammaproteobacteria (5.39%), Actinomycetales (65.15%), Burkholderiales (13.92%), and Mycobacterium (32.22%) taxa, indicating the presence of hydrocarbon degraders in soil LF2. All three isolated strains were biosurfactant producers capable of degrading crude oil components within 14 days. However, Shinella zoogloeoides LFG9 performed best and was retained as candidate for further bioremediation investigation. In addition, COG1 performed better when immobilized, with entrapment effectiveness manifested by increased fatty acids and aromatic compound degradation. Attempt to improve crude oil biodegradation by adding surfactants failed as sodium dodecyl sulfate restrained the immobilized consortium performance.

Occupational exposure in automobile repair workshops: toxicological effects of contaminated soil in Wistar rats.

Automobile repair workshops contribute immensely to the generation of soil and water contamination. This study was conducted to compare the soil microbial load, heavy metals, and consequent toxicological effects, in three (3) automobile mechanic sites. Soil samples were randomly collected from 3 different auto mechanic workshop in Abeokuta town of Ogun-State, Nigeria. Bacterial and fungal counts were done via standard procedures. High-performance liquid chromatography was employed for the aflatoxin quantification. Also, 24 Wistar rats were divided into 4 groups (n=6), group 1-Control animals: orally administered distilled water, Group 2-administered soil sample solution from Ita Oshin mechanic site (I M), Group 3-administered soil sample solution from Ajebo mechanic site (A M), while Group 4-administered soil sample solution from Laderin mechanic site (LM), for two (2) weeks. Conventional methods were used to determine some physical and biochemical parameters in the rat's serum and tissues. Eight bacterial and fungal genera were identified from the soil samples with Bacillus subtilis and Aspergillus niger occurring most frequently. The levels of heavy metals (lead, zinc, chromium, and cadmium) analyzed were higher than the WHO permissible heavy metal limits in all samples. The activity of liver function enzymes ALP, AST, and ALT was significantly increased in the serum of animals exposed to the 3 soil solution samples when compared with the control group, with the highest recorded at Site II. High level of heavy metals and aflatoxins could predispose to several health-related hazards when humans are exposed to contaminated soil solutions around and within automobile mechanic areas.

Assessment of Trace Metal Content in Soils of Automobile Workshops around Bori Urban Area, Rivers State, Nigeria

This study was designed to assess the concentration of trace metals (Cr, Cd, Mn, Ni, Pb, Zn) in soils of automobile workshops around Bori Urban, Rivers State, Nigeria. Samples were collected from three auto mechanic workshops within the Bori urban area, Rivers State, Nigeria. The soil samples were prepared by standard procedures, and analyzed using the Atomic Absorption Spectrophotometer, AAS (Solaar Thermo Elemental Atomic Absorption Spectrometer-Model SE 71906). Detectable concentrations (mg/kg) of the metals, Zn, Mn, Pb, Cd, Ni and Cr were 4.05 ± 1.02, 9.64 ± 0.71, 13.39 ± 2.28, 2.46 ± 0.42, 2.86 ± 0.79 and 2.76 ± 0.99 respectively. The concentrations and contamination factors (CFs) across the three auto mechanic garages were of the order, Pb > Mn > Zn > Cd > Ni > Cr and Cd > Cr > Ni > Mn > Pb > Zn respectively while the pollution load index (PLI) values for the three auto mechanic garages were all greater than 1, indicating a decline in the soil quality for the three studied sites following the order station 3 > station 1 > station 2. The Geo accumulation index (Igeo) revealed that the soils were extremely contaminated by Cd and were all contaminated with trace metals when compared with regulatory standards such as WHO and world average values in shale. Therefore, regular monitoring of the soil in the studied sites be carried out to mitigate dangers implicit in the continued presence of the metals determined.  

Pollution and Health Risk Implications of Heavy Metals in the Surface Soil of Asafo Auto-Mechanic Workshop in Kumasi, Ghana

Pollution and Health Risk Implications of Heavy Metals in the Surface Soil of Asafo Auto-Mechanic Workshop in Kumasi, Ghana

Application of Steam Enhanced Extraction Method on BTEX Contaminated Soil in A Nigerian Petroleum Depot and Automobile Workshop Sites in Ilorin Metropolis, Nigeria

The contamination of soil in the environment is a natural consequence of industrialization and urbanization. Organic chemical pollutants dissolve into groundwater, absorb and adsorb into soil grains. Benzene, toluene, ethylbenzene and xylene (BTEX) are major causes of contaminated soil. This is due to fuel leakages or spillages, various forms of hydrocarbon burning/combustion and land disposal petroleum base oil. Contaminated soil samples were excavated from two different locations within the Ilorin metropolis; pipelines and products marketing company, a Nigerian petroleum depot, Ilorin depot and auto mechanic workshop of over ten years. Steam enhanced extraction method was employed through injection of steam to contaminated soil from steam generator into soil pot where contaminated soil was placed. The condensation of steam on soil particles provides energy to release desorbed contaminants molecules from the soil and the mobilized contaminants vapor was transferred into the recovery pot via the pipe that was connected to the soil pot. After the remediation process, the steamed soil samples were taken to the laboratory where the sonication extraction technique was used to extract the contaminants (BTEX) from the steamed soil samples of 30, 60 and 90 minutes respectively. The extract from the steamed soil samples of 30, 60 and 90 minutes was subjected to Gas Chromatography fitted with flame ionization detector analysis to determine the exact amount of BTEX removed after the remediation process. Pre-treated soil sample of auto mechanics workshop was found to be 4.5004 x 10-1 mg/kg and post-treated soil samples were found to be 1.8164 x10-1 mg/kg, 8.7519 x10-1 mg/kg and 5.7006 x10-2 mg/kg for 30, 60 and 90 minutes respectively after remediation process while Pre-treated soil sample of a Nigerian petroleum depot was found to be 6.6049 x 10-1 mg/kg and post-treated soil samples were found to be 2.9320 x10-1 mg/kg, 1.9855 x10-1 mg/kg and 1.0237 x10-1 mg/kg for 30, 60 and 90 minutes respectively after the remediation process. This study established the effectiveness of the remediation process of hydrocarbon contaminated soil using steam enhanced extraction method an In situ remediation technique.

Isolation and Identification of Phenol-Degrading Bacteria from Oil-Contaminated Sites

This work is aimed at isolating and identifying phenol-degrading bacteria from oil-contaminated sites. Five soil samples from three auto-mechanic workshops within Katsina metropolis were collected. The samples were analyzed by selective enrichment technique, which resulted in the isolation of four bacterial species. The species were further subjected to the Vitek 2 compact microbiological system analysis. Cupriavidus pauculus, Pontoea spp, Proteus mirabilis 1 and Proteus mirabilis 2 were identified. Result from the present study showed that the bacteria could utilize phenol as their carbon source. Proteus mirabilis 1 and Proteus mirabilis 2 showed lower phenol degradation potential, under similar conditions. Cupriavidus pauculus and Pontoea sp. showed significant increases (p<0.05) in their optical densities. The optical density increment is strongly correlated with increase in colony forming units of the bacteria. This study further showed that the isolates could tolerate high phenol concentrations and may serve as strong putative isolates in bioremediation of phenol-contaminated sites.

Heavy metal levels in spent engine oils and fingernails of auto-mechanics

Abstract The levels of some heavy metals in spent engine oils and in the fingernails of auto-mechanics were studied. Engine oils and fingernails were collected from auto-mechanics who had practiced between ≤ 5 years, ≤ 10 years and ≤ 15 years in 3 auto-mechanic workshop clusters. Pb, Ni, V, Cd, and As levels were determined using Atomic Absorption Spectrophotometer. The mean levels of Pb, Ni, V and Cd in spent engine oils were 14.31, 2.25, 0.38 and 2.07 ppm respectively, and these far exceeded their permissible exposure limits. The mean levels of heavy metals in the fingernails of auto-mechanics who had practiced for ≤ 5 years, ≤ 10 years and ≤ 15 years were all considerably below their pathological thresholds. Thus, auto-mechanics in the study area are exposed to unsafe levels of Pb, Ni, V, and Cd, but no immediate threat of their toxicities in the study population exist. However, a progressive bioaccumulation of the heavy metals was observed with increase in years of practice.

Assessment of heavy metal pollution in soils: a case study of Nsukka metropolis

Owing to population growth and urbanization, there has been an increase in the number of auto mechanic workshops, vulcanizer’s shops and engine oil retail shops along the roads within Nsukka with a direct increase in heavy metal concentration in dust. Emissions from these activities pose serious environmental concern along the major roads. This study is centered on the assessment of heavy metal pollution in dust and top soil along major roads within Nsukka metropolis. Soil and dust samples were collected along major roads at maximum distance of five meters from the roads edge, with control samples collected 400 m away from the nearest road. Heavy metals (Cadmium, Zinc, Iron, Lead, Chromium, Arsenic, Copper, Nickel, and Manganese) concentrations in the dust and soil were analyzed using Atomic Absorption Spectrophotometry method. The result of the analyzed heavy metal concentration showed no significant variation from the background concentration. The concentrations of Pb and Cr showed little variation, whereas As showed the greatest variation from the background value. The results of heavy metals contamination factor in soil and dust ranged from low contamination to very high contamination (CF < 1; to CF ≥ 6). High and very high contamination values were obtained for As, Cr, and Mn in both dust and soil samples. The enrichment factor of heavy metals ranged from EF ≤ 1 (background rank) to EF> 40 (extremely high enrichment). Among the analyzed heavy metals, Zn, Pb, As, and Cr showed the highest enrichments in both soil and dust samples respectively. The result of Igeo ranged from Igeo ≤ 0 (uncontaminated) to 2 < Igeo < 3 (moderately to heavily contaminated). In the dust and soil samples, Igeo for Zn, Pb, Cd, Ni, and Cu show no contamination; Igeo for As and Cr showed moderate contaminations in some locations whereas that of Mn showed moderate to heavy contamination. Results of PLI ranged from PLI < 1 (no pollution) to 3 <PLI (extremely heavy pollution).

Technical Properties and Potential Application of Waste Engine Oil as Bitumen Modifier in Pavement Construction

The gradually exhausting crude oil reserves worldwide have made experts in the building industry to explore alternative resources for road construction materials. This study was designed to evaluate the potential applications of engine oil wastes as a bitumen modifier. The Waste Engine Oil (WEO) was obtained from an auto mechanic workshop. The base bitumen was replaced with WEO at 2, 4, 6, 8 and 10% respectively. The WEO modified bitumen properties which included penetration, softening point, flash point, solubility, specific gravity and viscosity were measured in accordance to ASTM standard procedures for a period of 5 days. From the results obtained it was observed that as the replacement level of the WEO increased, there was decrease in the viscosity, specific gravity, flash point and the softening point properties. Incorporating WEO into the base bitumen can at best be acceptable at 2% - 4%.

Distribution of Physicochemical Parameters through Soil Profiles around Auto-Mechanic Workshop Clusters in Yenagoa Metropolis, Nigeria

In this study, results of analyses were carried out on the physicochemical parameters of soils around auto-mechanic workshop clusters and a control site following standard procedures and methodologies within Yenagoa Metropolis for parameters like pH, conductivity, NO3, PO4, SOM, Ca, Mg, Na, K, CEC and THC. Values for the parameters were observed, in most instances to have followed the Distance-Decay Model. In such cases, the parameters showed higher levels at the top soils (0 – 15cm) than in lower soil profiles (15 – 30cm and 30 – 45cm) and generally decreased with increasing distances (50m and 100m) from the reference points (0m) at the auto-mechanic workshop clusters, depending on influencing factors. At the auto-mechanic workshop clusters, pH varied from 6.0 to 6.8 indicating acidification of soils, conductivity varied from 594 to 10,258.20úS/cm, nitrates from 3.3 to 4.6mg/kg, phosphates from 0.4 to 0.6mg/kg, SOM from 4.4 to 6.0% and calcium from 11.4 to 26.7meq/100g. Others were magnesium from 4.8 to 9.2meq/100g, sodium from 6.7 to 17.5meq/100g, potassium from 3.5 to 5.1meq/100g, CEC from 26.5 to 44.9meq/100g and THC from 4.5 to 5.4mg/kg respectively. Thus, it could be safely stated that operational presence of auto-mechanic workshop clusters did impact the physicochemical parameters of soils within closer vicinities as topsoils (0 – 15cm) and reference points (0m) more significantly than soils farther away from their vicinities. This raises health, environmental and food productivity concerns in soils of the study area.

Hazard quotient, microbial diversity, and plant composition of spent crude oil-polluted soil

BackgroundThe present work assesses the concentration of some heavy metal, plant species composition, and microbial diversity of spent crude oil-polluted soil from electric generator plant house, auto mechanic workshop, bakery, and auto spare part shops in four local governments areas (Egor, Ikpoba-Okha, Oredo, and Ovia North) in Edo State, Southern Nigeria.ResultsHazard quotient (HQ) of heavy metals varied in all the spent crude oil-polluted soil evaluated in the study. The HQ of heavy metals from auto mechanic workshop had the highest values for Cr (2.19), Mn (0.0965), Zn (4.1108), Fe (9.32015), and Cd (0.0155). The most frequent bacterial and fungal species found in all 16 sites were Bacillus subtilis (93.75%) and Aspergillus niger (100.0%) respectively. Auto spare part shops in Oredo had a bacterial count of 1.0 × 105 CFU/g while the bacteria count around power generator plants in Egor had a bacteria count of 1.71 × 105 CFU/g. Some of the plant species identified around all the sites include Acanthospermum hispidum, Alternanthera repens, Axonopus compressus, Cyperus esculentus, Eleusine indica, Paspalum scrobiculatum, and Tridax procumbens.ConclusionSpent crude oil pollution of the soil led to high amounts of heavy metal in the soil. However, the presence of higher plants and variable diversity and richness of microorganisms found in the soil are likely contributing to the remediation of the polluted soil.

Biodegradation Potentials of Waste Engine Oil by Three Bacterial Isolates

Environmental contamination by waste engine oil in cities all over the world constitute serious public health concern because its effects are unwholesome and unquantifiable. This study was carried out to biodegrade waste engine oil using bacterial isolates. Three bacteria were isolated from soil samples that have been contaminated with waste engine oil for over seven years in automechanic workshops at Ebelle. They were analysed using standard methods. The bacterial count was 89.4 ± 0.02cfu/g while the control was 3.6 ± 0.14cfu/g. The bacterial diversity identified in descending order were Bacillus sp. (25.41%), Pseudomonas sp. (22.13%), Corynebacterium sp. (18.44%), Acetobacter sp. (18.03%) and Aeromonas sp. (15.98%). The biodegradation efficiencies of three bacterial isolates; Bacillus, Pseudomonas and Corynebacterium species were observed taking records of change in physicochemical parameters (pH, electrical conductivity and total hydrocarbon content) for 40 days at 10 days interval with waste engine oil sample at concentrations of 10%, 20%, 30% and 40%. Corynebacterium sp. gave the highest percentage reduction in pH values of 52.92% at 10% contamination level while Pseudomonas sp. gave the highest percentage reduction of 53.04%, 52.99% and 53.01% at 20%, 30% and 40% crude oil contamination levels respectively. The pH values of the control was almost the same all through the period of incubation. Bacillus sp. gave the highest percentage increase in electrical conductivity value of 74.17%, 69.93% and 69.91% at 10%, 20% and 40% contamination level respectively while Pseudomonas sp. gave the highest increase of 70.45% at 30% contamination level. Also, the values at day 0 and the control were not so different from each other. Corynebacterium sp. gave the highest percentage reduction in total hydrocarbon content of 95.49%, 95.48%, 96.50% and 96.50% at 10%, 20%, 30% and 40% contamination level respectively. The result revealed a reduction in pH and total hydrocarbon content while there was an increase in electrical conductivity values. This indicated that biodegradation occurred. This study revealed that the bacterial isolates particularly Corynebacterium sp. possess the ability to biodegrade waste engine oil thereby guaranteeing environmental quality and sustained public health for all and sundry. &#x0D; Keywords: biodegradation, Corynebacterium sp., environmental sustainability, total hydrocarbon content

Microbiological and Physicochemical Evaluation of Oil-polluted Soil from Major Auto Mechanic Shops in Port Harcourt Metropolis, Rivers State, Nigeria

The capability of microorganisms to utilize spent oil in polluted soil from some major auto mechanic workshops in Port Harcourt metropolis as the sole source of carbon and energy was studied. Soil samples were collected from three (3) Auto mechanic workshops (Mile 3 Mechanic Village (N 4º48' 34.07'', E 6º59' 10.17''), Ikoku Mechanic Workshop (N 4º47' 54.28'', E 6º59' 36.42'') and Elekahia Zone H Mechanic Workshop (N4º49' 11.62'', E 7º1' 16.58'') in Port Harcourt, Rivers State, Nigeria from depths of 0–30 cm, 30–60 cm and 60–90 cm at the same spot from each station. Soil samples were analysed microbiologically and physicochemically using standard methods. The control sample was obtained behind the Biology Building of Rivers State University, Port Harcourt. The results of the total heterotrophic bacterial and fungal counts showed that the microbial load was high at a depth of 0 to 30 cm for all the samples analysed including the control. With 60-90 cm depth, low microbial counts were obtained. The total heterotrophic bacterial counts from the three mechanic workshops ranged from 6.8 X 108 to 2.3 X 109cfu/g while the total heterotrophic fungal counts ranged from 1.3 X 106 to 8.0X 106 cfu/g. The spent oil-utilizing microbial populations ranged from1.0 X 105 to 3.0 X 106cfu/g and1.0 X 105 to 8.0 X 105 cfu/g for the bacterial and fungal counts respectively. Five spent oil utilizing bacterial isolates of the genera, Pseudomonas, Klebsiella, Bacillus, Micrococcus and Proteus and five fungal isolates of the genera, Penicillium, Candida, Rhizopus, Fusarium and Aspergillus were obtained from spent oil-polluted soil in this study. The pollution index of the different physicochemical parameters obtained from the different sample stations was as follows: Electrical Conductivity (EC): Mile 3 had the highest with the mean of 12.50 ±0.0-13.20±0.0µs/cm, while Ikoku had the lowest with mean of 10.99 ± 0.0-11.50 ± 0.0 µs/cm. Ikoku had the highest pH level with mean of 7.0 ± 0.0- 8.5 ± 0.0 while Mile 3 had the lowest pH level with mean of 6.5 ± 0.0-7.59 ± 0.0. Ikoku had the highest Total Organic Carbon (TOC) with mean of 17.55 ± 0.0-20.60 ± 0.0 mg/kg while Elekahia had the lowest with the mean of 16.99 ± 0.0-18.0 ± 0.0 mg/kg. Ikoku had the highest Total Hydrocarbon Content (THC) with mean of 38,862 ± 0.0-40,500 ± 0.0 mg/kg while Mile 3 had the lowest with the mean of 20,550 ± 0.0-30,000 ± 0.0 mg/kg. From the Pollution Index Analysis, Ikoku Auto Mechanic Workshop is more contaminated with Spent oil than Mile 3 and Elekahia.

Heavy Metals Contamination in Soils in and Around Some Selected Auto Mechanic Workshops in Ga East Municipal Assembly of Greater Accra Region, Ghana

Welder and auto mechanics face a number of occupational health hazards. In this study, distribution of nine heavy metals from soil samples collected from twelve auto mechanics and welders' workshops in Ga East Municipal Assembly of Greater Accra Region, Ghana at the depth of 0”30 cm for laboratory analysis. The samples were analysed for Fe, Mn, Cu, Zn, Cr, Ni, Pb, Co, and Cd using Atomic Absorption Spectrophotometric (AAS). The results of the analysis indicate that majority of metal concentrations (mg/kg) in the samples were above control (background) levels and threshold limits recommended in soil samples by some countries. The level of investigated metals in the soil samples generally decreased in this order; Fe &gt; Mn &gt; Cu &gt; Zn &gt; Pb &gt; Ni &gt; Cr &gt; Cd &gt; Co. The results of the analysis ranged from as high as 313 mg/kg for Fe to as low as 0.30 mg/kg for Co in the soil samples. Quantification of contamination was high for Cu, Fe, Cr, Zn, Co, Cd and Pb, moderate for Mn and low for Ni. The geo-accumulation index values for metals in auto-mechanic workshops showed that the environment is highly polluted with Cu, Fe and Cr, and to a lesser degree with Pb, Mn. and Ni. Zinc (Zn), Co and Cd showed moderate pollution status.

Isolation and Characterization of Carbonoclastic Bacteria Diversity in Oil-contaminated Soil in Cape Coast Metropolis, Ghana

Aims: The study aimed at the quantification, isolation and characterization of hydrocarbon degrading bacteria in oil-contaminated and pristine soils.&#x0D; Methodology: Soil samples from petroleum hydrocarbon polluted sites at auto-mechanic workshops, a mechanic village, as well as pristine (control) soils, comprising of 14 sampling locations within Cape Coast Metropolis in the Central Region of Ghana were collected using standard sampling techniques. Collected soil samples were treated and cultured while enumerations, isolations and characterization of carbonoclastic bacteria associated were evaluated.&#x0D; Results: Bacterial populations isolated from hydrocarbon-polluted sites had higher aerobic counts ranging from 7.24-8.02 log10 cfu/g of soil when compared with the pristine sites (from 6.79-7.61 log10 cfu/g of soil). Also, soil samples from the mechanic village (8.76 to 7.48 log10 cfu/g of soil) recorded more bacterial counts than those from the mechanic garages (8.02 to 7.24 log10 cfu/g of soil). The calculated percentage profiles of all the hydrocarbon utilizing bacteria in the total culturable heterotrophic bacteria were low throughout the study, even though the percentage scores were all above 50%. A total of 19 hydrocarbon degraders were isolated. The isolates identified belong to the genera Pseudomonas, Proteus, Bacillus and Enterobacter.&#x0D; Conclusion: The outcome of the study based on the bacteria populations, identification profiles, coupled with their survival and multiplications in designated medium amended with crude oil as the carbon and energy sources, suggest their petroleum hydrocarbon degrading capabilities, hence may be used in bioremediation applications.

Comparison of Soil Samples from Selected Anthropogenic Sites within Enugu Metropolis for Physicochemical Parameters and Heavy Metal Levels Determination

This study compared the physicochemical parameters and heavy metal levels in soil samples from selected anthropogenic sites within Enugu metropolis, Enugu State, Nigeria using standard analytical methods. Soil samples at depths (0 - 20 cm) and (20 - 40 cm) were collected from waste dump sites, metal scrap dumps, fuel filling stations and auto-mechanic workshops and analyzed for physicochemical characteristics and heavy metal levels. Atomic absorption spectrophotometer was used for heavy metal determination while conventional analytical methods were employed for physicochemical parameters evaluation of the soil samples. At soil depths 0 - 20 cm and 20 - 40 cm the respective mean range of pH, electrical conductivity, organic matter and organic carbon contents in the soil samples were, 6.33 - 6.74, 101.46 - 123.21 μS/cm, 6.41% - 8.35% and 13.73% - 16.14% for auto-mechanic workshops; 6.92 - 7.43, 56.46 - 60.02 μS/cm, 1.53% - 2.20% and 11.93% - 12.60% for fuel filling stations; 7.14 - 7.84, 70.81 - 77.71 μS/cm, 3.81% - 4.12% and 8.57% - 9.24% for metal scrap dumps; 6.54 - 6.81, 94.40 - 100.71 μS/cm, 8.83% - 10.75% and 18.26% - 20.81% for waste dump sites. The pH of the top soil samples from auto-mechanical workshop was below the WHO recommended limits for agricultural purposes. The physic-chemical characteristics of the soil samples decreased with soil depths indicating therefore that anthropogenic activities greatly influence the soil characteristics at the top soils than the sub-soils. The electrical conductivity values of top and sub-soil samples from the studied auto-mechanical workshops were above the recommended limits. At soil depths 0 - 20 cm and 20 - 40 cm, the respective mean range of Zn, Pb and Cd in the soil samples were 17.29 - 19.16 μg/g, 0.704 - 0.96 μg/g and 0.26 - 0.33 μg/g for auto-mechanic workshops; 4.13 - 4.88 μg/g, 0.21 - 0.32 μg/g and 0.03 - 0.11 μg/g for fuel filling stations; 30.02 - 36.11 μg/g, 0.43 - 0.48 μg/g and 0.15 - 0.19 μg/g for metal scrap dumps; 9.30 - 10.84 μg/g, 0.53 - 0.60 μg/g and 0.38 - 0.45 μg/g for waste dump sites. The mean levels of Pb in soil samples from mechanic workshops and waste dump sites were above the recommended permissible limits for agricultural purposes. The study therefore indicated that these sites (auto-mechanic workshops and waste dump sites) could be major sources of Pb pollution to nearby farmlands, streams and the general environment. Plants grown on or around these sites may not produce high yields and could be severely contaminated with heavy metals which portend health danger to food consumers within the environment.

Floristic Distribution and Heavy Metal Levels Around Auto-Mechanic Workshop Clusters in the Yenagoa Metropolis, Bayelsa State, Nigeria

A floristic survey of plant species encountered around auto-mechanic workshop clusters in the Yenagoa Metropolis was conducted using stratified sampling technique and following standard methods in this study. Sampling was done at three intervals; reference point (0m), 50m and 100ms from 5 auto-mechanic workshop clusters and a control site. Results were expressed in simple percentages X±STD. The distributional patterns, frequency of occurrence and Sorensen’s Similarity Index of plant species around auto-mechanic workshop clusters were used to determine prevalence levels and variations from one sample site to another. It was observed that distance decay concept manifested conspicuously as plant species’ diversity increased with increasing distances from the reference points (0m) of the auto-mechanic workshop clusters. Overall plant species diversity at the reference point (0m) was 5±1, 25±23 at 50m and 36±12 at 100m around the auto-mechanic workshop clusters while 37±32 was observed at the control site, respectively. However, the control site showed highest species’ frequency distribution and diversity as compared to the auto-mechanic workshop clusters in this study. Heavy metal levels were generally observed to be higher in soils around auto-mechanic workshop clusters than at the control site showing evidence of anthropogenic effects in samples encountered at the auto-mechanic workshop clusters. Zn, Cu, Cd, Cr, Hg and Mn were noticed to have decreased with increasing distances suggesting distance decay while Ni and Fe increased with increasing distances in soils of the auto-mechanic workshop clusters. These had tremendous effects on the distributional patterns of most plant species in this study. This study has shown that plant species like Sc. dulcis (Scrophuriaceae), C. digitalis (Cyperaceae), Py. Polystachyos (Cyperaceae), A. tectorum (Poaceae), P. foetida (Passifloraceae), S. paramidalis (Rubiaceae), as well as C. mucunoides (Febaceae) remain better choices for use as bio-indicators for heavy metal studies around auto-mechanic workshop cluster in the Yenagoa Metropolis since despite exposure to prevailing natural and anthropogenic conditions, they still showed heavy metal tolerance and remediation potentials.

Human Risk on Heavy Metal Pollution and Bioaccumulation Factor in Soil and Some Edible Vegetables around Active Auto-Mechanic Workshop in Chanchaga Minna Niger State, Nigeria

Human Risk on Heavy Metal Pollution and Bioaccumulation Factor in Soil and Some Edible Vegetables around Active Auto-Mechanic Workshop in Chanchaga Minna Niger State, Nigeria

Safety Analysis of an Automobile Workshop Using Qualitative Risk Assessment Method and Risk Analysis Through the Structural Equation Modelling

Abstract Automobile repair service hazards are risk factors for multiple severe accidents, and scientific proof reveals a relationship between repair activity hazards and accidents in the auto-mechanic workshop. In this research, the investigators approximated the impact of risk factors for automobile repair activities, using novel parameters, for severity of hazards and influences on subjects, and based on literature. Next, insights into the relationship between latent variables which are appraised by manifest variables using the structural equation modelling were pursued. The respondents answered questionnaires on probability of hazard occurrence, severity and some identified measured variables. The authors appraised 44 out of the 80 and 98 out of 99 distributed questionnaires for the first and second modules, respectively. The risk levels ranged between low and medium for the medium scale establishment due to the nature of work done in the automobile repair centre which exposes the workers to the level of risk. For the second module involving the use of structural equation modelling, the factor loading was the least for safety behaviours (0.06) and highest for machine efficiency (0.90). Of the fifteen hypotheses formulated six were accepted. It is concluded that the safety behaviour of workers depends safety on the workers in the firm irrespective of other factors such as management commitment to safety, environmental contributions and safety, communications. Understanding the impact of risk factors for automobile repair activities in workers is necessary in elevating awareness absent these parameters and to eliminate accidents.