Corrugated Iron Sheet Research Articles

Effect of Different Storage Vessels on the Microbiological and Physicochemical Properties of Rainwater Harvested from Different Rooftops in Owerri, Nigeria

This study evaluated the effect of different storage vessels on the microbiological and physicochemical properties of rainwater harvested from different rooftops in Owerri. Different storage vessels were assembled and used to stored rainwater delivered by using different catchments. The catchments used were corrugated iron sheet roof, asbestos roof, stone coated roof, aluminum roof, and thatched roof. Rainwater was also collected directly from rainfall, in the open environment and stored in the vessels. The storage vessels were plastic contain, metal tank, earthen ware pot, and block/cemented tank. The study was designed in such a way that each of the storage vessels received water from each of the catchments for storage. In all, a total of 24 storage vessels were used. Each of the catchment delivered rainwater to a peculiar plastic container, metal samples were allowed to stay in the vessels for some days before they were taken to the laboratory for analysis using standard methods. From the results observed, the storage vessels made more microbial impact on the stored rainwater samples that physicochemical impact. Six bacterial and mould organisms were isolated from the stored rainwater samples. However, the molecular identification study for the bacterial organisms revealed plasmid possessed E. coli, P. aeruginosa, and Enterobacter sp., which made them resistant to the antibacterial drugs. From the observation of the present study, storage vessels may impact more on bacterial contamination than physicochemical or metal contamination. This study has shown the effect of different storage vessels on the microbiological and physicochemical properties of rainwater harvested from different rooftops in Owerri, Nigeria.

Kitchen fine particulate matter (PM2.5) concentrations from biomass fuel use in rural households of Northwest Ethiopia.

Combustion of solid biomass fuels using traditional stoves which is the daily routine for 3 billion people emits various air pollutants including fine particulate matter which is one of the widely recognized risk factors for various cardiorespiratory and other health problems. But, there is only limited evidences of kitchen PM2.5 concentrations in rural Ethiopia. This study is aimed to estimate the 24-h average kitchen area concentrations of PM2.5 and to identify associated factors in rural households of northwest Ethiopia. The average kitchen area PM2.5 concentrations were measured using a low-cost light-scattering Particle and Temperature Sensor Plus (PATS+) for a 24-h sampling period. Data from the PATS+ was downloaded in electronic form for further analysis. Other characteristics were collected using face-to-face interviews. Independent sample t-test and one-way analysis of variance were used to test differences in PM2.5 concentrations between and among various characteristics, respectively. Mixed fuels were the most common cooking biomass fuel. The 24-h average kitchen PM2.5 concentrations was estimated to be 405 μg/m3, ranging from 52 to 965 μg/m3. The average concentrations were 639 vs. 336 μg/m3 (p < 0.001) in the thatched and corrugated iron sheet roof kitchens, respectively. The average concentration was also higher among mixed fuel users at 493 vs. 347 μg/m3 (p = 0.042) compared with firewood users and 493 vs. 233 μg/m3 (p = 0.007) as compared with crop residue fuel users. Statistically significant differences were also observed across starter fuel types 613 vs. 343 μg/m3 (p = 0.016) for kerosene vs. dried leaves and Injera baking events 523 vs. 343 μg/m3 (p < 0.001) for baked vs. not baked events. The average kitchen PM2.5 concentrations in the study area exceeded the world health organization indoor air quality guideline value of 15 μg/m3 which can put pregnant women at greater risk and contribute to poor pregnancy outcomes. Thatched roof kitchen, mixed cooking fuel, kerosene fire starter, and Injera baking events were positively associated with high-level average kitchen PM2.5. concentration. Simple cost-effective interventions like the use of chimney-fitted improved stoves and sensitizing women about factors that aggravate kitchen PM2.5 concentrations could reduce kitchen PM 2.5 levels in the future.

Surface runoff and soil erosion from Nitisols and Ferralsols as influenced by different soil organic carbon levels under simulated rainfall conditions

Soil erosion poses a challenge to the environment and the sustainable use of natural resources, particularly in relation to agricultural production. The study aimed to assess the influence of different soil organic carbon (SOC) levels on runoff and soil erosion under varying levels of rainfall intensity. The study was conducted in pre-selected farmers' fields representing low, moderate and adequate SOC levels in Nitisols and Ferralsols. Two parallel experiments were set up in each type of soil using a split-plot layout arranged in Randomized Complete Block Design. The main plots were the different soil organic carbon levels while the sub-plots were the different simulated rainfall intensities. Rainfall simulation was then conducted to determine runoff and sediment losses on each soil type. The simulation was done using a land type sprinkler nozzle rainfall simulator (460 788 type) in an experimental plot of 1 m2, fenced with corrugated iron sheets with a small opening left for runoff collection. Runoff and sediment losses were determined from the volume collected in the jar. The data was subjected to analysis of variance and significant mean differences were determined using Tukey’s Honest Test at a 95% confidence level. Pearson correlation was applied to assess the relationship between runoff volume and sediment loss. The results showed that Ferralsols recorded significantly higher runoff and sediment losses compared to Nitisols, by 60.27% and 53.14% respectively. However, adequate SOC level portrayed a significant effect in reducing erosion in both soil types, where it reduced runoff and sediment loss by 45.30% and 48.38% in Ferralsols and by 65.31% and 48.22% in Nitisols, respectively. In both soil types, runoff yield was positively correlated to rainfall intensity while sediment yield was inversely correlated with SOC levels. Therefore, the study recommends incorporation of organic matter to adequate levels in both soils, for reduced soil erosion.

The Risk of Flooding to Architecture and Infrastructure amidst a Changing Climate in Lake Baringo, Kenya

Climate change has grown more apparent in recent years with people becoming more aware of its potentially disastrous consequences. Flooding is one of the many consequences of a changing climate in Kenya known to cause immense devastation resulting in the loss of lives and property. This paper discusses the risk of flooding in Kenya as one of the many outcomes of climate change in the face of urgency to adapt Kenya’s built environment to flooding which is likely to continue to prevail in the decades as a result of the looming climate change. It also sought to evaluate the physical, traumatic, and psychological effects on communities affected by flood events. This cross-sectional survey, both qualitative and quantitative in nature, executed between 13th January 2021 and 14th July 2021 with 132 respondents along the western shoreline of Lake Baringo, near Marigat Town focused on the flood levels, structures, their materials, and quantities. Results show that the area covered by Lake Baringo increased by 18% from 236 km2 to 278 km2. The depth of floods ranged from 0.3 m to 1.2 m and exceeded 1.6 m during heavy rainfall up to 3.2 m with homes completely submerged by the lake. Flooding was experienced more by residents living in low areas nearer to the shoreline of the lake as compared to those living on higher grounds. 100% of the structures didn’t have the architectural technology to withstand the impacts of flooding with 59% of housing made of corrugated iron sheets both on wall and roofing, 22% of mud houses roofed with either corrugated iron sheets, 10% being timber with thatch and only 8% stoned walled houses. This predisposed all the residents to the harmful impacts of flooding. Piled sandbags by locals as a mitigating measure proved inadequate to withstand the forces of the rising waters. Flood walls were built around local lodges near the lake but the rising water level quickly breached these defences. The study recommends that county and national governing authorities develop flood adaptation strategies for resilience. These include long-term land-use planning, the establishment of early warning systems, evacuation plans, identification of vulnerable or high-risk populations, measures to ensure water quality, sanitation, and hygiene. Flood-resilient architecture including stilt and floating houses that mechanically rise and fall with respect to the highest water mark are recommended during flood events. Bridges on swollen rivers and resilient construction materials like reinforced concrete are to be used for sustainable development for flood risk adaptation.

Comparative Analysis on Roof Covering Materials Sustainability as Constructed by Bamboo and Corrugated Galvanized Iron Sheet in Rural Areas Around Wolkite, Ethiopia

One of the most important components of any building is the roof, which protects the interior of the building from environmental influences. It is sustainable to switch roofing materials from expensive roofing materials to inexpensive and environmentally friendly materials. Today's roofing materials have negative effects on the environment due to the manufacturing process. Therefore, this research has mainly focused on the development of sustainable roofing materials through life cycle cost analysis. Approximately ten bamboo samples from homeowners in the Wolkite area and one Adama corrugated galvanized sheet were taken to analyze the life cycle costs. Data on the ecological and socio-economic aspects of the selected roofing materials were collected with the help of interviews and questionnaires. The cost of galvanized corrugated iron sheet of 1.8m2 was $38.19 while the cost of bamboo was $3.91; the researchers concluded that treated bamboo roofs have lower life cycle costs per 1.8 square meters (approximately 89.76% less than corrugated galvanized iron), more environmentally friendly. And also using bamboo as roofing material, create a good job opportunity for the society by cultivating and preparing bamboo to the construction input.

Sulphate Removal in Industrial Effluents Using Electrocoagulation Sludge as an Adsorbent

The high concentration of sulphates is detrimental to the infrastructure of wastewater treatment plants. Hence in this study, we present the application of electrocoagulation sludge as an adsorbent to remove sulphates from industrial effluents before they are released back to the environment. The sludge contains iron and aluminium cations and cationic complexes that precipitate sulphates in water. Corrugated iron sheet was used as a sacrificial electrode during electrocoagulation (EC) to generate sludge. FTIR, XRD, SEM, TEM, and Zeta Potential were used to characterize the sludge. The following parameters: contact time, pH, initial concentration, and adsorbent dosage were optimized to 120 min, 2, 100 mg/L and 150 mg, respectively. For the synthetic water, the sulphate removal was 99.1%, whereas for the real water it was found to be 98.7%. The adsorption capacity of the EC sludge was 66.76% for 2 h under acidic conditions. The Langmuir isotherm fitted better than the Freundlich isotherm. This confirmed the homogenous distribution of the active sites on the EC sludge. At different EC’s sludge, the pseudo-second order kinetic model produced the best fitting experimental results which confirmed the removal of sulphate ions by chemisorption. This approach (method) is useful for purifying industrial effluents before they are discharged into the environment.

Assessment of Excess Gamma Dose Exposure Level in Typical Nigeria Commercial Building Materials Distribution Outlets

The gamma dose rate exposure levels from different brands of building materials at commercial distribution stores/shops in two major cities in Ondo State, Nigeria, were measured using a well calibrated Inspector 1000 scintillator detector. The results showed that the different brands of building materials which are Corrugated iron sheet, Aluminum roofing sheets, Conduit pipes, Paints, Cement, PVC pipes, Wash hand basin, Bath tub, Water closet, Kitchen zinc, Asbestos, Floor tiles, Wall tiles, Bullet proof door, Binding wire, rings and rods, Red bricks, Galvanized pipes, Copper pipes, Water tanks contributed excess annual effective doses of 0.332 mSv/y and 0.311mSv/y to store keepers in Ikare Akoko and Akure cities respectively. The indoor and outdoor annual effective dose of each of the investigated two cities are correlated using simple linear regression equations. The results of the modeling and experiment show that annual effective dose received by the occupants of these shops/stores was about 12 % higher than what could be received in a typical natural radiation environment in the two cities because the building materials acts as a source of radiation indoor. The research indicated that the typical habit of using poorly ventilated and confined space as stores/shops by the sales men might subject them to internal exposure through inhalation of radon gas and its short-lived decay products. Implementation of the developed equations would definitely promote rapid determination of outdoor annual effective dose through indoor annual effective dose and ultimately save time and other valuable resources.

Urban Spatial Risk Assessment of Fire from Fueling Stations on Buildings Case Study: Lubaga Division, Kampala City, Uganda

The discovery of oil and gas in Uganda has attracted many investors, leading to increase in fuel/gas distributing companies and fueling stations creating rapid demand for land to locate the stations compared to available open urban land. Because of the explosive and combustion characteristics of fuel stored and dispensed at stations, several studies have been conducted on different fires at fueling stations such as static fire, jet fire, vapor cloud explosions, open fires, etc. but there was need to assess spatially the risk of fire from stations, its consequences and sovereignty on buildings surrounding them. This was done basing on seven parameters—proximity of buildings to stations, building materials, distance between buildings, wind speed, temperature, slope and vegetation. Analytical hierarchy process and pairwise comparison were used to weight the parameters based on their relative importance. Weighted sum tool was applied to generate the fire risk maps for the quarters—December to February, March to May, June to August, and September to November from 2008 to 2013. The parameters were overlaid with the buildings in each risk zone for all the four quarters and their influences determined. The highest contributors were proximity of the buildings to stations, building materials and separation between buildings. Most of the affected buildings were made of rusted corrugated iron sheets and wood; the separation distance from one building to another ranged from 0 - 4 m. Most of buildings located within 100 m from stations were at moderate risk level and within 50 m were at highest risk level. The period of December to February and June to August had the highest risk. The findings can be used to guide planners and policy makers on building location vs. material vs. separation. It can also guide developers on where, when and how to carry out their developments.

Relationship between Rainfall, Surface Runoff and Soil Loss on an Experimental Farm in the Middle Belt of Nigeria

Rainfall induced depletion of soil nutrients resulting from runoff and soil erosion are a main threat for agricultural lands, tending to reducing soil fertility, soil productivity and eventually leading to the un-sustainability of agricultural production systems. It is based on the problems associated with soil loss that the required mulch type, mulch cover and slope of the farming field need to be properly investigated and determined. This research therefore analyzed surface runoff and soil loss under different mulch treatment at a farm site in Benue State, in the middle-belt region of Nigeria. The main aim is to analyze the effect of varied mulching will have on runoff and soil loss volumes resulting from rainfall and examine the implication of the results on soil management practice in the region. Experimental plots of 20m long by 3m wide were carved out with an outlet down slope of 1.5m2 (20m×3m+1.5m2 = 61.5m2 ) were bordered with corrugated iron sheets and inserted with runoff and soil loss receptors. The experimental plots were treated with weighted organic materials (mulching, in tons) and planted with maize with plots of zero (0) tons as control (T1). The maize planted was spaced 25cm on row and 75cm on columns. The experimental plots were replicated and symbolized as (T1) = bare surface (0 tons A, B and C), (T2) = surface mulch +maize (4 tons A, B and C) and (T3)= surface mulch + maize (8 tons A, B and C). Rainfall data was collected over ten (10) rain events and runoff and soil loss measurements was analyzed with using correlation statistics, variability and regression. The results show that 96.14% runoff occurs on T1, 3.22% and 0.63% runs off on the T2 and T3 respectively with corresponding 193.7kg, 3.1kg and 0.5kg soil loss. The study finds out that mulching reduces simultaneously both runoff and soil loss in the region. The amount rainfall only has no significant effect on amount of runoff and volume of soil loss. The study revealed that, surface cover combined with simple cropping controls runoff and soil loss by 67% and 61% respectively. This will be useful to farmers in addition to the fact that mulching also has a collateral benefit of stimulating microbial activities and regulating soil moisture and temperature.

Carbon Storage of Wooden Houses, Trees, and Grazing Land in Rural Areas of Enemorina Ener District, Southern Ethiopia

In Ethiopia, wood was the main construction material for rural houses. In 2013, about 79% of the rural houses of Ethiopia were fully made of wood. Although carbon storage of wood is well known for climate change mitigation, there is lack of information on carbon stock of wooden houses in Ethiopia. Thus, a study was conducted to analyze the carbon stock of dominant land uses that surround rural wooden houses in three agro-ecologies and representative three peasant associations (PA) or Kebeles in Southern Ethiopia. Field measurement and household survey were made by selecting sixty-four houses made of wood, grass or corrugated iron sheet. Transects were laid starting from the wooden houses to lay out plots to collect samples of wood, grass, soot inside houses, soil and trees for carbon determination. The service age of wooden houses was estimated in triangulated interview as 5-150 years. The total carbon stock of newly constructed rural grass covered wooden house was 28.35- 49.26 kg C m-2, which was greater than the other surrounding land uses. The grazing land total carbon stock was 50.5-86.8% and the scattered trees carbon was 9.5-59.7% of the total carbon stock of the respective PA grass covered wooden house. Since soil is the common below ground carbon stock, the total carbon of a land use is mostly affected by the above ground carbon stock. Grass covered houses contained greater above ground carbon stock but grazinglands contained greater below ground carbon stock. Soot accumulation of 0.4-1.3 g m-2 inside the houses’ roof indicated the presence of indoor pollution. The total carbon stock increased with increasing altitude and geoclimatic variables were significantly correlated with carbon stock of the land uses (p&lt;0.05; r = ±0.999). Therefore, wooden houses need to be considered in climate change mitigations. The shift of carbon stock from natural environment to wooden houses in human dominated landscapes was indicator of a lack of forests, and then efforts should be strengthened to increase forest cover.

The Impact of Social Disparities on Microbiological Quality of Drinking Water Supply in Ugu District Municipality of Kwazulu-Natal Province, South Africa.

This study was undertaken to highlight the social disparity between rural and urban areas in terms of housing patterns, provision of safe drinking water, access to sanitation facilities, education, employment rate and health-related to diarrhoeal episodes in Ugu District Municipality of KwaZulu-Natal Province of South Africa. To achieve this aim, a survey was conducted using a structured questionnaire. Drinking water samples were collected from the point of supply and the storage containers to assess the microbiological quality of drinking water in both rural and urban areas. Results of this study revealed prominent residential segregation between rural and urban communities, whereby the houses in the rural areas were generally constructed with corrugated iron sheets, or mud brick and mortar whereas conventional brick-and-mortar construction was used to build those in the urban areas. All of the urban households had flush toilets in their houses (100%), while 98.2% of the rural households were relying on pit latrines and 1.8% were reported to defecate in an open field. The District unemployment rate was at 58.1% in rural areas and none among the urban community. Results also showed that only 13.6% of the rural dwellers completed their secondary education compared to 70.4% of the urban areas. The diarrhoeal episodes were high in rural areas (34.1%) while none of these episodes was reported in urban areas. Great disparity in the water supply persists between rural and urban communities. For the former, the standpipes located outside their homes (90.9%) remain the sole mode of access to drinking water, while in the urban area, all households had pipes/taps inside their houses. Assessment of the drinking water quality revealed only the stored drinking water used by the rural community of Ugu District was contaminated. High prevalence of E. coli ranging from 63.3 % to 66.7% was recorded only in stored water after the sequencing of 16S rRNA genes. Species-specific PCR primers exposed the presence of enteropathogenic Escherichia coli at a rate ranging between 1.4% and 3.7% in this water Overall, this study has been able to highlight the disparity left by the legacy of racial segregation in the Ugu Municipality District. Therefore, the local government must intervene in educating homeowners on safe water storage practices.

Effect of Different Tillage Practices on Production of Soya Bean - Maize (Zea mays l. - Glycine max l.) in Clay Loam of Assosa, Ethiopia

Conservation agriculture is a newly emerging technology having significant impact on soil characteristics and crop production. Conservation tillage like no tillage had been reported to improve the properties of the soil and in turn crop production. Thus, the study had been carried out at Assosa Agricultural research center with the aim of determining the effect of different tillage methods on crop yield of both sole maize and soya bean including their intercropping. Eighteen experimental runoff plots of 8m long and 3m wide each were framed with corrugated iron sheets. The experimental design used was randomized complete block design (RCBD) with six treatment in factorial combinations vis-A -vis three cropping systems (sole maize, sole soya bean and intercropping of maize with soya bean), with tillage system (no tillage and convectional tillage), that were replicated three times.

Path Loss Prediction Model for GSM Fixed Wireless Access

This research investigated the effect of building materials on GSM signals quality. Measurements were conducted on MTN, Glo, Airtel and Etisalat networks using Radio Frequency Signal Tracker on six different building patterns. The results showed that building with alucoboard wall cladding had the highest signal loss while the sandcrete building/unrusted corrugated iron sheet roof had the least signal loss. Also, a model to predict signal penetration through building walls was developed. It was developed using the principles of Fresnel Refraction Coefficient and the knife-edge diffraction. The total losses from the transmitter to the receiver was modelled as a combination of three different effects; losses due to free-space propagation from transmitter to building; the penetration loss was modelled as a combination of the wall penetration loss and the diffraction loss. The results show that despite the condition of the building walls, movement of people in the environment/room also affected the wireless signal quality as well as the chairs and gadgets in the room. The indoor signal path loss in the rooms increased from when the walls were plastered and continued until when the walls were covered with curtains, both rooms reduced by 4dBm. The mean squared error ranged between 1.6dBm and 2.1dBm with a standard deviation between 11.1 and 11.5.

Malaria vector abundance is associated with house structures in Baringo County, Kenya.

Malaria, a major cause of morbidity and mortality, is the most prevalent vector borne disease in Baringo County; a region which has varied house designs in arid and semi-arid areas. This study investigated the association between house structures and indoor-malaria vector abundance in Baringo County. The density of malaria vectors in houses with open eaves was higher than that for houses with closed eaves. Grass thatched roof houses had higher density of malaria vectors than corrugated iron sheet roofs. Similarly, mud walled houses had higher vector density than other wall types. Houses in the riverine zone were significantly associated with malaria vector abundance (p<0.000) possibly due to more varied house structures. In Kamnarok village within riverine zone, a house made of grass thatched roof and mud wall but raised on stilts with domestic animals (sheep/goats) kept at the lower level had lower mosquito density (5.8 per collection) than ordinary houses made of same materials but at ground level (30.5 mosquitoes per collection), suggestive of a change in behavior of mosquito feeding and resting. House modifications such as screening of eaves, improvement of construction material and building stilted houses can be incorporated in the integrated vector management (IVM) strategy to complement insecticide treated bed nets and indoor residual spray to reduce indoor malaria vector density.

Corossitivity of Pollutants from Gas Flares on Galvanised Roofing Sheets in Idu, Rivers State, Niger Delta of Nigeria

The rate of corrosion of roofing sheets especially those made of galvanized sheets is very high in the Niger Delta of region Nigeria. This could be due to the high level of atmospheric pollutants emitted mainly from gas and other industrial activities. To determine the impact of atmospheric pollutants, two shades were constructed at Idu, an oil bearing community with three gas flares. The shades were installed windward to provide maximum exposure to atmospheric pollutants and the rate of corrosion monitored nine-month period. The first shade was inclined at 30o while the second was inclined at 70°. A sheet was removed from each of the shades monthly and comparison made with its original characteristics and corrosion rate noted. The rate of corrosion is the speed at which any metal in a specific environment deteriorates. The corrosion of galvanized corrugated iron sheet is the deterioration of galvanized corrugated iron sheet as a result of air pollutant reactions. Pollutants act faster in dry season than rainy season when acid rain is diluted beyond pH of 5.3 which is more than its corrosion strength. Besides at the inclination of 70° does not allow pollutants to settle on the roof and therefore corrosion is minimal.

Quality assessment and public health status of harvested rainwater in a peri-urban community in Edo State of Nigeria.

The harvested rainwater is an alternative water source in communities where there is limited or scarcity of water distribution system. However, contamination of roof-harvested rainwater is of immense concern to the general public health. Therefore, this study was initiated to assess the levels of physicochemical quality and heavy metal concentrations in the harvested rainwater from Oluku communities in Benin City, Edo State, Nigeria. The roof-harvested rainwater samples were collected from 20 independent different residential households in Oluku communities, between April 2015 and September 2015. Physicochemical analyses were carried out using standard analytical methods, and heavy metal concentrations were determined using atomic absorption spectrophotometry. The evaluation of the rainwater harvesting shows that 60% (12/20) of the roofs were made of corrugated iron sheets; aluminum sheets, 20% (4/20); asbestos, 10% (2/20); and open space was 10% (2/20). Also, the storage systems used for the storage of harvested rainwater were as follows: PVC tanks, 20% (4/20); drums, 30% (6/20); buckets, 25% (5/20); and wells, 25% (5/20). The physicochemical indicators investigated (temperature, nitrate, chlorine content, electrical conductivity, phosphate, total dissolved solids, and sulfate) were within World Health Organization (WHO) guidelines. However, some pH levels of the roof-harvested rainwater were acidic and below the WHO standard. Furthermore, a high value of turbidity was observed in some locations and exceeded the WHO guidelines. Though some heavy metal indicators (Zn, Na, K, and Ca) in this study were within the WHO guidelines, some locations revealed heavy metal (Cu, Fe, and Cd) concentrations slightly above the WHO guidelines. There is need for proper rainwater harvesting system and continuous monitoring of harvested rainwater for potable uses.

Eave tubes for malaria control in Africa: prototyping and evaluation against Anopheles gambiae s.s. and Anopheles arabiensis under semi-field conditions in western Kenya

BackgroundWhilst significant progress has been made in the fight against malaria, vector control continues to rely on just two insecticidal methods, i.e., indoor residual spraying and insecticidal bed nets. House improvement shows great potential to complement these methods and may further reduce indoor mosquito biting and disease transmission. Open eaves serve as important mosquito house entry points and provide a suitable location for intercepting host-seeking anophelines. This study describes semi-field experiments in western Kenya with eave tubes, a household protection product that leverages the natural behaviour of host-seeking malaria mosquitoes.MethodsSemi-field experiments were conducted in two screen-houses. In both of these a typical western Kenyan house, with mud walls and corrugated iron sheet roofing, was built. Eave tubes with bendiocarb- or deltamethrin-treated eave tube inserts were installed in the houses, and the impact on house entry of local strains of Anopheles gambiae and Anopheles arabiensis was determined. Experiments with open eave tubes (no netting) were conducted as a control and to determine house entry through eave tubes. Insecticidal activity of the inserts treated with insecticide was examined using standard 3-min exposure bioassays.ResultsExperiments with open eave tubes showed that a high percentage of released mosquitoes entered the house through tubes during experimental nights. When tubes were fitted with bendiocarb- or deltamethrin-treated inserts, on average 21% [95% CI 18–25%] and 39% [CI 26–51%] of An. gambiae s.s. were recaptured the following morning, respectively. This contrasts with 71% [CI 60–81%] in the treatment with open eaves and 54% [CI 47–61%] in the treatment where inserts were treated with fluorescent dye powder. For An. arabiensis recapture was 21% [CI 14–27%] and 22% [CI 18–25%], respectively, compared to 46% [CI 40–52%] and 25% [CI 15–35%] in the treatments with open tubes and fluorescent dye.ConclusionsInsecticide-treated eave tubes resulted in significant reductions in recapture rates for both malaria vector species, representing the first and promising results with this novel control tool against Kenyan malaria vectors. Further field evaluation of eave tubes under more realistic field conditions, as well as their comparison with existing approaches in terms of cost-effectiveness and community acceptance, is called for.

Livelihood diversification amongst pastoralists and conflict with arable crop farmers: Empirical evidence from Kwara state, Nigeria

The study identified causes of conflicts, settlement pattern of pastoral farmers and analyzed the influence of livelihood diversification on conflicts between pastoralists and indigenous crop farmers. Using multistage sampling procedure to select 280 respondents, data were collected by means of structured interview schedule and analyzed by frequency distribution, Pearson Correlation and one-way ANOVA. Results show that high pressure on land (WMS = 4.87) and unfavourable land tenure system (4.56) mainly caused the conflicts. Crop and pastoral farmers had an average farm size of 2.9ha and 1.7ha, respectively. Majority (75.5%) of pastoralists were engaged in crop production, while only 12.1% of crop farmers were involved in livestock rearing. Also, 57.9% and 32.9% amongst crop farmers and 14.2% and 15.0% amongst pastoral farmers were involved in trading and commercial (vehicular) transport business, respectively. Furthermore, 16.4% and 7.9% of the pastoralists lived in mud and block- walled houses with corrugated iron sheets, respectively. Transformational approach was identified as most acceptable solution of conflict resolution by both crop and pastoral farmers. There was a significant difference between farm size (F=9.33) and educational level (F=8.93) of crop and pastoral farmers. There was also a significant relationship between cause of conflicts and pastoralists’ livelihood diversification (r=0.74) and number of years’ of pastoralists in settlement (r=0.29). The study concluded that increasing involvement of the pastoralists in crop production, involvement in other employment opportunities and erection of permanent building structure ignited unhealthy rivalry between the two groups.

Effect of Different Sun Drying Surfaces on the Functional Properties and Microbial Loads of Unripe Plantain Flours

In order to test the effect of commonly used traditional sun-drying surfaces on some qualities of the product, four traditional sun drying surfaces; wooden, corrugated iron sheet, rock and cement surfaces were used to sundry unripe plantain. The sundried samples were milled to flours. Functional, pasting properties and microbial loads of the resulting flours were determined using standard methods. Values of the functional properties determined except bulk density (packed) and solubility were higher in the rock followed by samples dried on cement surface compare to others. Functional properties except oil absorption and solubility generally improved with storage. Pasting property shows that, samples dried on the rock followed by samples dried on cement surface had the highest values in terms of peak viscosity, trough and final viscosity. There was no significant difference (P≥0.05) in breakdown and pasting temperature. Results of the microbial loads monitored for a period of two months show that at the initial stage, flours of samples sundried on rock had the highest microbial growth while samples dried on corrugated iron had the lowest. There was no significant difference (P≥0.05) in others. There was increase in microbial loads of samples dried on rock and corrugated iron but decreased in others after one month of storage. After storing for a period of two months, microbial loads of samples dried on the rock and cemented surfaces increased while no growth was recorded for samples from wooden and corrugated iron. The report from this research work revealed that rock and cemented surfaces are recommended for sun drying unripe plantain for better functionality of the flour while wood and corrugated iron surfaces are recommended based on microbial load for better storability.

From Mud and Stick-walled Houses to Corrugated Iron sheet Houses: A New Strategy for Preventing Human-Vector Contact in Marigat Sub-county a Leishmaniasis-endemic Area in Kenya

Department of Technical and Applied Biology, Technical University of Kenya, Kenya 2 Department of Science and Health, Daystar University, Kenya 3 Centre for Biotechnology, Research and Development, Leishmaniasis Laboratory, Kenya Medical Research Institute, Kenya