Prof. Shem Wandiga CV- 2019

Dr. Shem O. Wandiga is Professor of Chemistry at the department of Chemistry, University of Nairobi and Acting Director, Institute for Climate Change and Adaptation. Professor Wandiga’s research interests lie in studying sources and sinks of biogenic gases; persistent organochlorine pesticides in the tropics; trace metals concentration in various environmental media; complexes of Group VB metals with sulfur and oxygen binding ligands; and climate change and health.

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OYOO, PROFWANDIGASHEM.  Submitted.  Effects of Chemical Events on Environment in Africa. Pontifical Academy of Science's Study Week on "Chemical Events in the Atmosphere and Their Impact", November 1983, P.649-673.. : Academic Press Elsevier. Int. Abstract
OYOO, PROFWANDIGASHEM.  Submitted.  DDT Persistence in a Tropical Climate. Kenya Journal of Science and Technology. Series (A), (1984) 5, 31-44.. : Academic Press Elsevier. Int. Abstract
OYOO, PROFWANDIGASHEM.  Submitted.  National Standards and Environmental Pollution. paper presented at a Seminar organized by Kenya Bureau of Standards on National Standards and Technology for Development. Hotel Oceanic, Mombasa , 1982.. : Academic Press Elsevier. Int. Abstract
OYOO, PROFWANDIGASHEM.  Submitted.  Induced Optical Rotation in Zinc(II) and Cobalt(II) Complexes Derived from 1,1,1-Tris- (aminomethyl) ethane and cis, cis-1,3,5-Triaminocyclohexane,. Science and Technology Journal, 1980 Series A: 1 (1), 23-26.. : Academic Press Elsevier. Int. Abstract
OYOO, PROFWANDIGASHEM, OYOO PROFWANDIGASHEM.  Submitted.  "Dipole Moments of Halogenogermanes from Non-Resonant Absorption of Vapours. Chem. Soc. Faraday Trans. 11, 70 719 (1974. : Academic Press Elsevier. Int. Abstract
OYOO, PROFWANDIGASHEM, OYOO PROFWANDIGASHEM.  Submitted.  The Electric Dipole Moments of Monohalogen Derivatives of German. Letters. 7, 71 (1971).. : Academic Press Elsevier. Int. Abstract


Mbugua, SN, Sibuyi NRS, Njenga LW, Odhiambo RA, Wandiga SO, Meyer M, Lalancette RA, Onani MO.  2020.  New Palladium(II) and Platinum(II) Complexes Based on Pyrrole Schiff Bases: Synthesis, Characterization, X‑ray Structure, and Anticancer Activity. ACS Omega.

New palladium (Pd)II and platinum (Pt)II complexes (C1–C5) from the Schiff base ligands, R-(phenyl)methanamine (L1), R-(pyridin-2-yl)methanamine (L2), and R-(furan-2-yl)methanamine (L3) (R-(E)-N-((1H-pyrrol-2-yl) methylene)) are herein reported. The complexes (C1–C5) were characterized by FTIR, 1H and 13C NMR, UV–vis, and microanalyses. Single-crystal X-ray crystallographic analysis was performed for the two ligands (L1–L2) and a Pt complex. Both L1 and L2 belong to P21/n monoclinic and P-1 triclinic space systems, respectively. The complex C5 belongs to the P21/c monoclinic space group. The investigated molar conductivity of the complexes in DMSO gave the range 4.0–8.8 μS/cm, suggesting neutrality, with log P values ≥ 1.2692 ± 0.004, suggesting lipophilicity. The anticancer activity and mechanism of the complexes were investigated against various human cancerous (Caco-2, HeLa, HepG2 …

Maina, J, Wandiga S, Gyampoh B, Gachene C.  2020.  Effects of Supplemental Irrigation on Crop Yields: Case Study Kales (Brassica Oleracea) Crop. Journal of Ecological Engineering. (21):209-213. AbstractEcological Engineering

The aim of this study was to investigate the effects that supplemental irrigation (SI) has on Kale (Brassica Oleracea) crop yields as compared to wholly rain-fed crop. The experiments were conducted in Kieni, Central Kenya where the rainfall pattern was bimodal. The planting for rain-fed crops was done in three blocks each measuring 10m x1m with a spacing of 30cm between plants and 45cm between rows of plants and the procedure repeated for the crops receiving SI. The average weekly yields were computed for both crops for each season comprised of 14 weeks. The average weekly yields were subjected to Analysis of Variance (ANOVA) to determine whether the average yields from rain-fed and supplemental irrigated crops were statistically different. This was done by MS Excel 2016 spread sheets by setting a statistical level of significance of 5%. F value was 17.94 higher than the critical value of 4.01 while the P-value of 9x10-5 was lower than the 5% level of confidence meaning that there was a significant difference in the yield means of rain-fed and SI crops. The total rain-fed crop yields for the period was 147.0 Kgs and that of the one under SI was 238Kgs, an increase of about 62%. Therefore, supplemental irrigation can be adopted in areas where rainfall trends are declining to increase crop yields when all other factors remain constant for farmers to increase resilience.


Muraga, JM, Wandiga SO, Abong'o DA.  2019.  Assessment Of Dissolved Ions And Microbial Coliforms In Water From Selected Sites Of The Upper Athi River Subcatchment Area, Kenya..

The Upper Athi River sub-catchment area has experienced exponential growth of human population since the turn of the century. This has led to establishment of satellite towns such as Ngong, Kiserian, Ongata Rongai, Mlolongo, Kitengela and Ruai. These towns have either no or inadequate supply of water from the local governments, that is, Kajiado, Machakos and Nairobi. Communities in this area of study have therefore resorted to obtaining ground water through drilling boreholes and digging shallow wells for their domestic needs. This is done without proper information on whether the water meets quality standards set out by Kenya Bureau of Standards (KEBS). This study therefore sought to assess the water quality in this area to determine whether ground water meets these standards. It also compared these levels of dissolved ions and coliforms to those of river water in the recharge area of the Upper Athi sub-catchment area. Twenty one water samples comprising of eleven boreholes, five shallow wells and five river water samples were collected from the Upper Athi sub-catchment area in the months of December 2011 which was a dry month and in May 2012 which was a wet month. The samples were analysed for dissolved ions and microbial coliforms. The metal ions analysed included Ca, Cd, Cr, Cu, Fe, Mg, Mn, Na, Pb and Zn while anions included Cl-, CO32-/HCO3-, F-, NO2-/NO3- and SO42- as well as faecal coliforms. Physical parameters analysed included pH, electrical conductivity (EC) turbidity, total dissolved solids and colour. The analysis of cations was carried out using atomic absorption spectrophotometry while chlorides and total alkalinity were analysed using titrimetric method. Levels of fluoride and nitrate were analysed using ion selective electrodes, sulphate using gravimetric method and microbial coliforms using lactose broth methods. The results showed that levels of dissolved ions in ground water were higher than in surface water while surface water had higher number of faecal coliforms. The high levels of dissolved ions in ground water was attributed to the geology of area while high levels of iron and faecal coliforms in river water samples was attributed to anthropogenic activities The results from the samples analyzed show that pH of boreholes and shallow wells (ground water) water was higher than that of river water (surface water). pH levels ranged from 7.16±0.003 - 9.34±0.004 for ground water and 7.24±0.002-8.00±0.003 for surface water. Electrical conductivity was also higher in ground water ranging from 669±0.002μS/cm-1568±0.004μS/cm while that of surface water ranged from 382±0.003μS/cm-1202±0.002μS/cm at Magadi road. Turbidity was vi higher for surface water than that of ground water ranging from 74.3±0.004 NTU- 95.4±0.003 NTU and below detection limits (BDL) levels for ground water with the exception being borehole at Athi Primary school which had turbidity of 18.6±0.03 NTU. Colour was high for surface water ranging from 159±0.002 c.u to 343±.004 c.u while that of ground water ranged from 1.5±0.003 51.2±0.004 c.u in borehole 5 located at Athi Primary School. Total Dissolved Solids were higher in ground water ranging from 231.68.00±0.003mg/l - 1003.52±0.004mg/l in shallow well located at near Brookshine School, Kangundo road while that of surface water ranged from 244.48±0.002mg/l-769.28±0.003mg/l. From the chemical parameters analysis, fluorides were significantly higher in ground water ranging from 0.37±0.003 to 9.36±0.002 ppm at Mlolongo which exceeded the KEBS limits for drinking water of 1.5ppm. Iron levels were higher in river water samples ranging from 2.11±0.002 to 18.401±0.003 ppm at Kangundo Road Bridge. Even though ground water had lower levels of iron that river water, it ranged from <0.001ppm to 1.93ppm against the 0.3ppm recommended by KEBS. Lead levels in ground water ranged from <0.001ppm to 2.64ppm at borehole BH4 located at Brookshine School. This was way above the recommended levels of 0.03ppm by KEBS. The levels of microbial coliforms were higher in river water ranging from 140-294 c.f.u/100ml during the dry month of December 2011 and 156-309 c.f.u/100ml during the wet month of May 2012. Ground water recorded coliforms ranging from zero to 40 c.f.u/100ml. Within the ground water system shallow wells had a higher count of coliforms than in boreholes. The high levels of fluorides have led to increased cases of dental fluorosis especially among young children in the area of study. Adults are at risk on increased bone fractures in their lifetime. High levels of lead in some ground water could lead to mental retardation since lead is a very toxic metal even at very low levels. There is therefore need to develop a long-term plan of providing safe drinking water by the county governments. There is also the need to establish regulations that require private water vendors and water companies to invest in water treatment plants that reduce levels of dissolved ions in ground water before distributing the water to local communities

Maina, J, Wandiga S, Gyampoh B, KK GC.  2019.  Analysis of Average Annual Rainfall and Average Maximum Annual Temperature for a Period of 30 years to Establish Trends in Kieni, Central. Journal of Climatol Weather Forecasting. 7:249.

The aim of the study was to analyze average annual rainfall and average maximum annual temperature records for
30 years in the study area to establish trends hence confirm the presence or absence of climate change. The analysis
was accomplished with the use of MS Excel spreadsheets. The meteorological datasets were 1984-2013 records for
rainfall and 1981-2012 for temperature. The rainfall climatological standard normal was computed for a 25-year
period between 1989 and 2012 which was used to compute the average annual rainfall anomaly. The temperature
provisional normal was computed for a period of 10 years due to lack of adequate data. The average annual rainfall
anomaly for 1984-2013 periods was -8.8 mm an indication of a declining rainfall trend while the annual maximum
temperature for 1981-2012 period was 0.5°C a positive trend showing that the annual maximum temperatures
are rising in the study area. Therefore, the declining average annual rainfall accompanied with rising maximum
temperatures were indicators of the presence of climate change.

Keywords: Average annual rainfall; Average maximum temperature; Trends; Climatological standard normal;
Datasets; Climate change

Wandiga, SO, Bola OT.  2019.  Impact of Renewable Technology on Lignocellulosic Material of Palm Fruit Fibre: Strategy for Climate Change and Adaptation. :175-201. AbstractWebsite

This study aims to explore low temperature and pressure to extract the lignocellulosic content of palm fruit fibre and pyrolyse it for energy (bio-oil) and chemical feedstock productions as alternative technology to improper disposal causing environmental pollution as strategies for climate change and adaptation. Design/Methodology/Approach: Burning of refuse and agricultural residue releases harmful gases or carbon emission to the climate which causes global warming. Renewable technology can therefore be introduced to utilize agricultural residues to produce energy and chemical feedstock. Vacuum pyrolysis of the lignocellulosic material prepared from palm fruit fibre was performed by considering pyrolysis temperature of 200, 250, 300, 350 and 400 °C and biomass particle size of 0.25, 0.30, 0.42 and 0.55 mm. The bio-oil produced at different process parameters was then characterized by gas chromatography–mass spectrometry (GC-MS) and ultimate analysis. The response was efficiently used for modelling and optimization of the process parameters. The results showed that experimented and predicted data are in reasonable agreement with the values of coefficient of determination, R2 (0.8098) and Adj. R2 (0.700). Findings: It was found that the optimal conditions for pyrolytic product were temperature 300 °C, biomass particle size 0.55 mm and retention time between 14 and 18 min. Temperature and particle size had effect on the yielded gaseous products, liquid and char materials. And various chemical compounds were produced at different process parameters. Research Limitation/Implications: The contribution of renewable technology framework is a process of educating for climate stewardship, at this stage of practical and theoretical. It is good approach of converting residues to useful products as one of the ways of solving climate change problem with the relevant stakeholders that its true potential can be assessed. Social Implications: Educating the public for climate stewardship will be more effective if it adopts an approach which seeks a co-production of knowledge. Clean environment with less global warming will be attained. Originality/Value: This agricultural residue can be recommended for biofuel, biogas and used as chemical feedstock for industrial purpose. The char can also be used to increase soil organic components. These benefits can therefore be used for policy making on residue disposal and as strategy for climate change and adaptation or mitigation in Nigeria and other African countries.

Addisu, A, Olago D, Wandiga S, Oriaso S, Amwata DA.  2019.  Smallholder Farmers Vulnerability Level to Climate Change Impacts and Implications to Agricultural Production in Tigray Regional State, Northern Ethiopia. Journal of Agriculture and Crops, Academic Research Publishing Group . 5(12):237-250.

Vulnerability to climate change impact is the most pressing issues for less developed countries whose economy mainly depends on the agricultural sector. The demand for food is growing swiftly whereas impacts of climate change on the global food production are increasing. More area specific research outputs and evidences-based policy directions are needed to tackle the ever changing climate and to reduce its impacts on the agricultural production. The aim of this study was to investigate subsistence farmer household’s vulnerability level to climate change impacts and its associations with household’s agricultural production. Then primary data was collected from 400 households from Kolla Temben District, Tigray Regional State, North Ethiopia. Multistage sampling techniques were applied to select households for interview from the district. In the first stage, 4 Kebelles (Kebelle - administration unit) were selected randomly out of 27 Kebelles and then400 households were selected for interview through systematic random sampling techniques (Figure 1). Multiple regressions were used to examine the associations between household’s vulnerability to climate change impacts and agricultural production. Grounded theory and content analysis techniques were use to analyze data from key informant interviews and focus group discussions. For every single unit increase in household vulnerability to climate change impacts, there was an average agricultural production decrease between 16.99 and 25.83 (Table 4). For single unit increase in household’s vulnerability to climate change impact, there was a decrease of total crop production, Total income, total livestock, total food consumption and food consumption per adult equivalent. Rainfall decrease, small farmland ownership, steep topography, frequent flood occurrences and large family size are among the major factors that negatively affect household’s agricultural production and total income. The more the vulnerable the households, the less in total annual crop production, total livestock size, total income from agricultural production and the more dependent on food aid). There is a negative association between household’s vulnerability level to climate change impacts and agricultural production (crop production, total livestock ownerships and total income from crop production). More access to irrigation and agricultural fertilizers, improved varieties of crops, small family size, improve farmland ownership size, more access to education and Agricultural Extension services are an effective areas of intervention to improve household’s resilient, reduce households vulnerability level to climate change impacts and increase household’s total agricultural production.

Githanga, D.  2019.  The effects of aflatoxin exposure on Hepatitis B-induced immunity in Kenyan children. Curr Probl Pediatr Adolesc Health Care 2019. :1-14. Abstractresearchgate

Background: Globally, approximately three million children die each year from vaccine preventable infectious diseases mainly in developing countries. Despite the success of the expanded immunization program, not all infants and children around the world develop the same protective immune response to the same vaccine. A vaccine must induce a response over the basal immune response that may be driven by population-specific, environmental or socio-economic factors. Mycotoxins like aflatoxins are immune suppressants that are confirmed to interfere with both cell-mediated and acquired immunity. The mechanism of aflatoxin toxicity is through the binding of the bio-activated AFB1-8, 9-epoxide to cellular macromolecules. Methods: We studied Hepatitis B surface antibodies [anti-HBs] levels to explore the immune modulation effects of dietary exposure to aflatoxins in children aged between one and fourteen years in Kenya. Hepatitis B vaccine was introduced for routine administration for Kenyan infants in November 2001. To assess the effects of aflatoxin on immunogenicity of childhood vaccines Aflatoxin B1-lysine in blood serum samples were determined using High Performance Liquid Chromatography with Fluorescence detection while anti-HBs were measured using Bio-ELISA anti-HBs kit. Results: The mean § SD of AFB1-lysine adducts in our study population was 45.38 § 87.03 pg/mg of albumin while the geometric mean was 20.40 pg/mg. The distribution of AFB1-lysine adducts was skewed to the right. Only 98/205 (47.8%) of the study population tested positive for Hepatitis B surface antibodies. From regression analysis, we noted that for every unit rise in serum aflatoxin level, anti-HBs dropped by 0.91 mIU/ml (¡0.9110038; 95% C.I ¡1.604948,¡0.21706). Conclusion: Despite high coverage of routine immunization, less than half of the study population had developed immunity to HepB. Exposure to aflatoxin was high and weakly associated with low anti-HBs antibodies. These findings highlight a potentially significant role for environmental factors that may contribute to vaccine effectiveness warranting further research.


Masenge, EM, Wandiga SO, Shiundu PM, Madadi VO.  2018.  Analysis of Total Petroleum Hydrocarbons in Water from Ngong and Mathare Rivers, Nairobi County, Kenya. International Journal of Scientific Research in Science, Engineering and Technology . 4(8):252-256. Abstract

Unsustainable industrial development has created negative impacts to global ecosystem quality and biodiversity due to increased load of chemical and biological contaminants released into environment. Ecological sustainability of Nairobi River Basin in Kenya, hangs in the balance between socioeconomic exploitation and environmental management. Nairobi, Ngong and Mathare rivers constitute the three main tributaries of Nairobi River Basin. The basin has witnesssed increased pollution load, destruction of the wetlands and encroachment of the buffer zones due to rapid urbanisation. The objective of this study was to investigate the extent of total petroleum hydrocarbons (TPH) contamination in Mathare and Ngong rivers. We collected water from eight sampling sites constituting the upstream, midstream and downstream of the two rivers. The samples were extracted using HPLC grade dichloromathane and analysed for Total Petroleum Hydrocarbons (TPH) using a Gas Chromatography equipped with Flame Ionisation Detector. TPH in Mathare River ranged from 59.66±8.64 to 463.92±2.63 µg/L, whereas levels in Ngong’River ranged from 11.85±0.10 to 1,219.95 µg/L. The concentration increased downstream indicating the influence of industrial and urbanistion on the pollution load. The results suggest that industries and municipal activities in the City are contributing to TPH contamination in the Nairobi River Basin tributaries and therefore they are likely to jeopardize ecological quality of the rivers ecosystems if protective measures are not taken.

Gioto, V, Wandiga S, Oludhe C.  2018.  Determinants of Household Food Security Status and Challenges of Building Resilience to Climate Variability and Change Posed by Drought in Tharaka …. Handbook of Climate Change Resilience. 2(1):1-29.

Climate change and variability pose momentous severe threats to agricultural development and consequently to economic growth and increased poverty levels. In reference, this paper examines the determinants of household food security status and assesses the challenges of building resilience to climate variability and change posed by drought in Tharaka Nithi, Kenya. The study coverage is Tharaka North and Tharaka South sub-counties which are semiarid and cover an area of 1,569 square kilometers (km2) with a total population of 158,023 people; this is about 65% of Tharaka Nithi County (Kenya). The sub-counties have three main livelihood zones (LZs). These are marginal mixed farming at 52%, mixed farming at 38%, and rain-fed cropping at 10%.

The area is exposed to climate change, aggravated by minimal adaptive capacity. Climate variability and climate change threaten food production leading to about 20–30% of the population being in poor and borderline food consumption score. The year 2017 describes one of the cyclical drought situations with low productivity and depleted range land conditions exposing approximately 30,000 persons in need of humanitarian assistance. This study reflects on challenges of building resilience to climate variability and change posed by drought using a transdisciplinary approach. The problems of the household food security status were poor rainfall performance, high temperatures, low livestock prices, high food prices, poor crop production, poor pasture and browse quality, and inadequate water for both domestic and livestock use. The solutions to the above-listed issues lie in the increased advocacy, rainwater harvesting structures, marketing linkages, timely early warning knowledge management, and eco-based farming practices. The study also found that there was a significant relationship between the household level of education, family size, household income, and household head age with food security. Findings of this study will form a platform for policy makers.

Climate variability Climate change Tharaka Nithi Drought and resilience

M’mboroki, KG, Wandiga S, Oriaso SO.  2018.  Climate change impacts detection in dry forested ecosystem as indicated by vegetation cover change in —Laikipia, of Kenya. Environmental monitoring and assessment. 190(4):255.

The objective of the study was to detect and identify land cover changes in Laikipia County of Kenya that have occurred during the last three decades. The land use types of study area are six, of which three are the main and the other three are the minor. The main three, forest, shrub or bush land and grassland, changed during the period, of which grasslands reduced by 5864 ha (40%), forest by 3071 ha (24%) and shrub and bush land increased by 8912 ha (43%). The other three minor land use types were bare land which had reduced by 238 ha (45%), river bed vegetation increased by 209 ha (72%) and agriculture increased by 52 ha (600%) over the period decades. Differences in spatiotemporal variations of vegetation could be largely attributed to the effects of climate factors, anthropogenic activities and their interactions. Precipitation and temperature have been demonstrated to be the key climate factors for plant growth and vegetation development where rainfall decreased by 200 mm and temperatures increased by 1.5 °C over the period. Also, the opinion of the community on the change of land use and management was attributed to climate change and also adaptation strategies applied by the community over time. For example unlike the common understanding that forest resources utilisation increases with increasing human population, Mukogodo dry forested ecosystem case is different in that the majority of the respondents (78.9%) reported that the forest resource use was more in that period than now and also a similar majority (74.2%) had the same opinion that forest resource utilisation was low compared to last 30 years. In Yaaku community, change impacts were evidenced and thus mitigation measures suggested to address the impacts which included the following: controlled bush management and indigenous grass reseeding programme were advocated to restore original grasslands, and agricultural (crop farming) activities are carried out in designated areas outside the forest conservation areas (ecosystem zoning) all in consultation with government (political class), community and other stakeholders. Groups are organised (environmental management committee) to address conservation, political and vulnerability issues in the pastoral dry forested ecosystem which will sustain pastoralism in the ecosystem.

Yanda, PZ, Wandiga SO, Kangalawe RYM, Opondo M, Olago D.  2018.  Adaptation to Climate Change - Induced Malaria and Cholera in the Lake Victoria Region.

AIACC Working Papers, published on-line by Assessments of Impacts and Adaptations to Climate Change (AIACC), is a series of papers and paper abstracts written by researchers participating in the AIACC project. Papers published in AIACC Working Papers have been peer reviewed and accepted for publication in the on-line series as being (i) fundamentally sound in their methods and implementation, (ii) informative about the methods and/or findings of new research, and (iii) clearly written for a broad, multi-disciplinary audience. The purpose of the series is to circulate results and descriptions of methodologies from the AIACC project and elicit feedback to the authors. The AIACC project is funded by the Global Environment Facility, the Canadian International Development Agency, the U.S. Agency for International Development, and the U.S. Environmental Protection Agency. The project is co-executed on behalf of the United Nations Environment Programme by the global change SysTem for Analysis Research and Training (START) and The Academy of Sciences for the Developing World (TWAS).

Odhiambo, RA, Aluoch AO, Njenga LW, Kagwanjac SM, Wandiga SO, Wendt OF.  2018.  Synthesis, characterisation and ion-binding properties of oxathiacrown ethers appended to [Ru(bpy)2]2+. Selectivity towards Hg2+, Cd2+ and Pb2+†. Journal of Royal Society of Chemistry. (8):3663-3672.

A series of complexes with oxathiacrown ethers appended to a [Ru(bpy)2]2+ moiety have been synthesized and characterised using 1H NMR, 13C NMR, IR, electronic absorption and emission spectroscopies, mass spectrometry and elemental analyses. The complexes exhibit strong MLCT luminescence bands in the range 608–611 nm and one reversible metal centred oxidation potential in the range 1.00–1.02 V. Their selectivity and sensitivity towards Hg2+, Cd2+ and Pb2+ metal ions have been investigated using electronic absorption, luminescence, cyclic and differential pulse voltammetry titrations. Their responses towards selected cations and anions have also been investigated using electronic absorption and luminescence. While the complexes are selective towards Hg2+ and Cd2+ ions, none of them is selective towards Pb2+ ions. In particular, complex 2 gives a selective change in the UV/Vis absorbance with Hg2+ making it possible to detect mercury down to a detection limit of 68 ppm. The binding constants and limits of detection of the complexes have been calculated, with values ranging from 4.37 to 5.38 and 1.4 × 10−3 to 6.8 × 10−5 for log[thin space (1/6-em)]Ks and LOD respectively.

Abong'o, DA, Wandiga SO, Jumba IO.  2018.  Occurrence and distribution of organochlorine pesticide residue levels in water, sediment and aquatic weeds in the Nyando River catchment, Lake Victoria, Kenya. African Journal of Aquatic Science . 48(3):255-270. Abstractdoi. org

Samples of water, sediments and aquatic weeds were collected from 26 sites in the Nyando River catchment of the Lake Victoria basin in 2005–2006. The objective was to investigate levels of organochlorine pesticides that have either been banned or are restricted for use in Kenya. The pesticides investigated were lindane, aldrin, endosulfan, endrin, dieldrin, DDT, heptachlor and methoxychlor. These pesticides had previously found wide applications in public health and agriculture in Kenya for control of disease vectors and crop pests respectively. Results showed that mean concentrations were highest for methoxychlor (8.817 ± 0.020 µg l−1) in water, sediments (92.893 ± 3.039 µg kg−1), and weeds (39.641 ± 3.045 µg kg−1), the weeds also tended to accumulate aldrin (15.519 ± 3.756 µg kg−1). The results show that the pesticides are still in use and are detected in the catchment. Stringent management and public awareness measures are required to enforce the ban on the organochlorine pesticides in order to safeguard the environment and ecosystems of Lake Victoria.

Taiwo, BH, Wandiga SO, Mulugetta Y, undefined.  2018.  Improving knowledge and practices of mitigating green house gas emission through waste recycling in a community, Ibadan, Nigeria . Journal Article of Waste Management. v: 81:22-32. Abstractscience direct

Throughout the world, waste sector has been implicated in significant contribution to anthropogenic greenhouse gas (GHG) emissions. Involving communities in recycling their solid waste would ensure climate change effect mitigation and resilience. This study was carried out to improve waste management practices through a community-led intervention at Kube-Atenda community in Ibadan, Nigeria. The study adopted a quasi-experimental design, comprising mixed method of data collection such as semi- structured questionnaire and a life-cycle-based model for calculating greenhouse gas generation potentials of various waste management practices in the area. A systematic random sampling was used to select sixty (60) households for a survey on knowledge, attitude and practices of waste management through Recovery, Reduction, Reuse and Recycling (4Rs) before and after the training intervention. Data collected were summarized using descriptive statistics, chi-square test, t-test and ANOVA at p = 0.05. The mean age of the respondent was 49.7 ± 16.7 and 68.3% were females. Respondents’ knowledge scores before and after the intervention were significantly different: 7.07 ± 1.48 and 11.6 ± 1.6 while attitude scores were: 8.2 ± 2.3 and 13.5 ± 0.8. There were significant differences in the major waste disposal practices in the community before and after the intervention. All (100%) the participants were willing to participate in waste recycling business and the model predicted that adoption of 4Rs strategy had a great potential in saving greenhouse gas emissions in the community. The behavior of the community people has changed towards waste management that promote climate change mitigation and adaptation through waste reduction, reuse, and resource recovery.

Wandiga, SO, Ndunda EN, Madadi VO.  2018.  Organochlorine pesticide residues in sediment and water from Nairobi River, Kenya: levels, distribution, and ecological risk assessmenta. Environmental Science and Pollution Research. (25):34510–34518(2018). AbstractSpringer link

Production and use of most organochlorine pesticides (OCPs) was banned through the Stockholm Convention on persistent organic pollutants. However, appreciable amounts are still detected in the environment due to their persistence, illegal use, and releases from contaminated soils and obsolete stocks. The present study investigated the levels of OCP residues in Nairobi River. Sediment and water samples were collected from three sites along the river and screened for 17 OCPs using gas chromatography electron capture detector (GC-ECD). Mean pesticide residues ranged from 0.01 to 41.9 μg kg−1 in sediment and below detection limit to 39.7 ng L−1 in water. In sediment α-HCH, β-HCH, γ-HCH, heptachlor epoxide, and p,p′-DDD were detected in all samples, while α-HCH, γ-HCH, δ-HCH, heptachlor epoxide, endosulfan I, and endrin were detected in all water samples. Levels of OCPs in water were below the WHO maximum allowable limits for surface water. However, values higher than the sediment quality guidelines for sediment samples in Racecourse Road Bridge and Outering Road Bridge were reported, thus confirming the toxicity to aquatic organisms. Consequently, as these compounds are known to bio-accumulate in fatty tissues, continued use of the river water poses a health risk to animals and humans.


Masese, FA, Wandiga SO, Mbui D.  2017.  Water Quality Status of Selected Sources of Domestic Water in Kenya.

In Kenya, water scarcity is a major issue due to destruction of water catchment, poor management of water supply and contamination of national water resources. The government’s long-term objective is to ensure that all citizens have access to safe drinking water. Although the government has increased the budget for improving access to water, many citizens still do not have access to potable water. The study analysed contaminants from selected sources of domestic water in the counties of Machakos, Nakuru, Kiambu and Nairobi. The following physico-chemical parameters were investigated–pH, conductivity, total suspended solids (TSS) and total dissolved solids (TDS), dissolved oxygen (DO), chemical oxygen demand (COD), anions (Cl-and PO43-), E. Coli and total coliforms. Water samples were collected from eight sampling sites in dry and wet seasons and analysed following standard methods. pH values varied from 6.3–9.1 in the dry season, and 6.9–9.5 in the wet season, conductivity from 244.0–5758.0 µS/cm in the dry season and 141.0–2004.0 µS/cm in the wet season, TDS from 113.0–5,824.0 mg/L in the dry season and 82.0–183.0 in the wet season, temperature from 24.1–25.2 C in the dry season and 25.3–25.8 C in the wet season, TSS from 0.00–0.01 mg/L in the dry season and 0.01–0.02 mg/L in the wet season, COD from 112.0–255.0 mg/L in the dry season and 90.6–154.0 mg/L in the wet season, DO varied from 2.8–4.2 mg/L in the dry season and 3.1–4.2 mg/L in the wet season, nitrates from 2.5–19.6 ppm, phosphates from 0.03–2.24 mg/L, while E. Coli varied from 13–4,300 CFU/ml. The values obtained for most parameters …

JK, A, O WANDIGAS, A A’oD, O MV, EM O.  2017.  OrganochlorinePesticides Residue Levels in Airand Soilfrom Nairobiand Mount Kenyaregions, Kenya. Journal of Applied Chemistry. 10(7):PP05-11.

Thestudy investigates the organochlorine pesticides residue level in air and soilat sites in Nairobi and Mount Kenya regions, Kenya. Air and soil samples from four sites were collected and analysed for selected organochlorine pesticides (OCP) using gas chromatography equipped with electron capture detector and confirmed using GC/MS. The targeted pesticides were α-HCH, β-HCH, γ-HCH (lindane), α- endosulfan, β-endosulfan and Endosulfansulfate. The samples were collected seasonally between the monthsof July 2012 and April 2013. The residue levels of organochlorine pesticides in air samples during month of October ranged between0.027±0.004 to5.735±0.575 ng/M3, while during the Month of February the concentration ranged between 0.013±0.00 to 9.375±1.65 ng/M3 and the levels during the month of April ranged between 0.013±0.00 to 11.508±0.26ng/M3. Organochlorine pesticide detected in soil during month of October ranged between BDL to 131.206 ± 14.41ng/Kg, while during the Month of February the concentration ranged between 0.418± 0.01to 38.361 ±5.39 ng/Kg and the levels during the month of April ranged between 0.406± 0.00to 26.877± 8.89 ng/Kg. The residue levels of the analysedPOPs in air and soil were generally high at the Dandora and Industrial area sites. This indicates that industrial activities such as Tetra-Pac, general plastics, Phillips industries waste and stock piles are the main sources of the new POPs in Nairobi. The high concentration level poses a health risk to residents of Dandora and Industrial area workers.

Keywords: Dandora, Kabete, Industrial area, Mount Kenya, organochlorine pesticide residues, air, soil

Peter, O, Daniel O, William O, Shem W.  2017.  Households’ climate change adaptive capacity in the Lake Victoria Basin, Kenya. Journal Of Humanities And Social Science. 22(3):26-32.

A households’ climate change adaptive (CCA) capacity simply refers to the household head’s potential to effectively respond to climate change induced forcings. The households’ adaptive capacity hinges on several factors. This paper reports the evaluation results of the households’ CCA capacity in the Lake Victoria Basin (LVB), Kenya. The knowledge, attitude and practices (KAP) of households are said to be predictors of households’ CCA capacity. There is evidence that over the past 30 years, a number of permanent streams in the LVB, Kenya, have dried up. Across sectional survey was conducted in Gwasi and Nyando areas within the LVB, Kenya. The level of education of respondents was 44.2% (n=523) primary, 35% high school and 20.8% diploma training and above. The level of awareness of CC was 62% and 94.6% among the male respondents in Gwasi and Nyando respectively. About 57.9% (n=523) stated that both human activities and natural changes are responsible for the CC. Approximately 27.2% (n=261) and 33.5 % (n=262) in Gwasi and Nyando respectively store roof catchment water. Approximately 35.3 % (n=261) and 22.2% (n=262) in Gwasi and Nyando respectively keep donkeys for water transport. These results reveals that the CCA was positively influenced by household heads’ KAP
Keywords: Households, adaptive capacity, climate change and variability.

O., OD, O. WS,.A. A’oD.  2017.  SYNERGYSTIC EFFECTS OF TITANIUM (IV) OXIDE MODIFIED CLAY FOR DISINFECTION AND PURIFICATION OF WATER. European International Journal of Science and Technology. 6(5):26.

Access to potable water is a problem facing developing countries worldwide. The spread of water related diseases is expected to grow worse in the coming decades with water scarcity occurring globally even in regions currently considered water rich. A study was carried out to assess the effectiveness of titanium oxide (TiO2) modified clay filters in water purification. Clay soils used for the filter making and samples filtration were collected from Kenyatta University, Department of Ceramics and Got Ramogi in Thika and Bondo Sub-counties respectively. The chemical compositions of the clay samples were determined using X-ray fluorescence. Clay filters were molded and coated with TiO2 (DEGUSSA P25, calcination at 600oC) and degradation of methyl orange was used to test its photo catalytic activity. The water parameters analyzed were turbidity, pH, total suspended solids, total dissolved solids, Escherichia Coliform (E.coli), pesticides and heavy metals. Results showed that modified clay filters reduced turbidity from 24.667 NTU to 0.0212 ± 0.0016 NTU, TSS from 276 ± 14.730 mg/L to 1.00 ± 0.328 mg/L. The E. coli colonies were reduced from 4310.83 ± 15.718 c.f.u/100 to 0.00 c.f.u/100ml and the spiked 1000ppm of lead, copper and organochlorine pesticides to below detection limits. Improved efficiency of the TiO2 modified clay filters had the enhanced ability to reduce the contaminant levels in water. Key words: Modified clay filters, DEGUSSA P25, photo catalyst activity, physico-chemical and biological parameters, water filtration

M., KG, O. WS, O. OS.  2017.  Assessment and Mapping of Vulnerability Due to Climate Change for Dry Forested Pastoral Ecosystem. Elixir International Journal. (110):48286-48289.

The objective of the study was assessment and mapping of the community villages in order to rank degree of vulnerabilities to climate change. On sensitivity to vulnerability, the majority of the respondents indicated that it was high (59.6%), medium (16.3%) and low (20.8%).of which on response to exposure to vulnerability, the respondents who indicated high (61.7%), medium (24.2% and low (11.3%).On vulnerabilities in response to adaptive capacity to vulnerability, was high (3.3%), medium (12.5%) and low (81.3%). This study demonstrated that participatory approach of addressing vulnerability to climate change which involved all stakeholders is effective in this dry forested pastoral ecosystem.

Onifade, TB, Wandiga SO, Bello IA, Jekanyinfa SO, Harvey PJ.  2017.   Conversion of lignocellulose from palm (Elaeis guineensis) fruit fibre and physic (Jatropha curcas) nut shell into bio-oil Conversion of lignocellulose from palm (Elaeis guineensis) fruit fibre and physic (Jatropha curcas) nut shell into bio-oil. African Journal of Biotechnology,. 16(46):2167-2180. Abstractdoi. org

Harmful gases are released into the atmosphere through burning of residues which is commonly practiced in Nigeria and can be attributed to climate change issues. Agricultural residues have the potentials to be used as energy and chemical source and meet its deficit in the country. This paper focuses on utilization of lignocellulosic materials obtained from two agricultural residues through renewable technology to produce bio-energy and chemical feedstock. The lignocellulosic materials were extracted from palm fruit (Elaeis guineensis) fibre and physic nut (Jatropha curcas) shell, and pyrolyzed under low temperature and pressure at various particle sizes. The main properties of solid (lignocellulosic) materials were tested and the bio-oil produced was analyzed using GC-MS. Results show proximate analyses (volatile, ash and fixed carbon contents) and ultimate analysis (carbon, oxygen, nitrogen, magnesium, phosphorus and zinc). The pH value of the bio-oil from both residues increased with increase in temperatures. The density, viscosity and calorific value of the palm and physic residue oil are 831.99 and 947.5 kg/m3, 0.695 and 1.58 cPa at room temperature, 22.33 and 14.169 kJ/g, respectively. Aromatics and other compounds are major dominant compounds in the palm fruit fibre oil which is characterized for bio-fuel production. Physic nut shell oil contains aromatic ethers, cyclic ethers, secondary amides and organic halogen compound which are important chemical feedstock. Conversion of these residues to useful products will alleviate the energy supply deficit, improve social and economic development, promote clean and healthy atmosphere of the nation and significantly contribute to global climate change mitigation.

Addisu, A, Daniel O, Shem W, Philip O, Silas O.  2017.  Household’s adaptive capacity level to climate change impacts and food security in Northern Ethiopia, Kolla Temben District. International Journal of Interdisciplinary Research and Innovations . 5(3):9-13. Abstractresearch publish

This study was conducted in Kolla Temben district of the Tigray regional state, north Ethiopia. The main
aim of this study was to investigate the relationship between households’ adaptive capacity to climate change and
food security status. Data on generic and area specific indicators of food security status, adaptive capacity and
other factors were collected from 400 households and were statistically analysed. The study revealed that there was
a statistically significant positive relationship between adaptive capacity to climate change and food security status.
Rainfall fluctuation, small land holding, pest and insect infestation were found to be among the area specific
determinants of household’s food security status in the arid and semi-arid areas of northern Ethiopia. The
recommended solutions to improve household’s food security in the ever-changing climate were: institutionalize
measures to improve household’s adaptive capacity to climate change; reverse household’s vulnerability level to
climate change impacts through evidence based policy initiatives, and; revise existing system to deal with new
infestations of pests. Policy decision makers should also give attention to climate change impact research to
moderate damages related to climate change as the climate will continue to change for many decades regardless of
the extent of global efforts on mitigation.


Gioto, V, Wandiga S, Oludhe C.  2016.  Climate Change Detection across All Livelihood Zones in Tharaka Nithi County. Journal of Meteorology and Related Sciences. 9(2):14-24.

Kenyan agriculture is largely rain-fed and principally dependent on rainfall. According to FEWS NET report for Kenya in August 2010 based on historical data from 70 rainfall stations and 17 air temperature stations to interpolate the long-rains precipitation and temperature trends for all of Kenya from 1960 to 2009 (Funk et al, 2010). The FEWS NET report indicate that in Kenya long-rains traditionally occur between March and June and short rains in October to December. The authors report that Kenya has experienced trend of decreasing rainfall and rising temperatures as Sudan. In Central Kenya, one of the country’s key agricultural regions, the area receiving adequate rainfall to support reliable rain-fed agriculture has declined by roughly 45 per cent since the mid 1970s (Funk et al, 2010). This study investigates change in temperature and rainfall pattern across all livelihood zones in Tharaka Nithi County. Data was collected for 39 years (1976 - 2015) period for the area of Study and in addition divisions were made to three non overlapping climate period of 30 years (1982 - 1991, 1992 – 200 and 2002 - 2012). The data were subjected to Gaussian kernel analysis, moments, regression, and non-parametric approaches based on Mann-Kendal statistics to justify any change in the average monthly and annually rain fall and temperature trend. The results indicate common change points and transitions from wet to dry (upward shift). The test indicates rainfall variation over the study area is significant (p= 0.05).The study recommended on the use of the information for Agricultural development and general socio-economic improvement.

E, O, O. WS, DA A, O MV, W MJ.  2016.  Organochlorine Pesticides Residues in Water and Sediment from Rusinga Island, Lake Victoria, Kenya. IOSR Journal of Applied Chemistry. 9(9):56-63.

This study was carried out to investigate the organochlorine pesticide residue level in representative sites in Rusinga Island of Lake Victoria, Kenya. Sediment and water samples from five sites along the shores of Rusinga Island in Lake Victoria were collected and analysed for selected organochlorine pesticides (OCP) using gas chromatography equipped with electron capture detector and confirmed using GC/MS. The pesticides targeted were p,p’-DDT, γ- HCH, α- HCH, β-HCH, δ-HCH, aldrin, dieldrin, heptachlor, heptachlor epoxide, p,p’-DDE, p,p’-DDD, endrin, endrin, aldehyde, endosulfan sulfate, methoxychlor and endosulfan. The samples were collected seasonally between the months of September 2012 to May 2013. The residue levels of organochlorine pesticides in water samples during dry season ranged between BDL to 9.84±1.20μg/L. The levels in wet season ranged between below detection limit (BDL) to 15.53±0.20 μg/L. Organochlorine pesticide detected in sediment during dry season ranged between BDL to 32.91 ± 3.84. Wet season the levels ranged between below detection limit (BDL) to 24.84±2.65 μg/Kg. The present result shows that organochlorines pesticides are still detected in our environment which can negatively affect our environment. This study provides baseline data on the levels of OCP residues in sediment and water from Lake Victoria. This will inform policy makers on the quality of water of Lake Victoria Basin as well as supplement the country’s studies as an obligation for all parties to the Stockholm Convention on POPs. Keywords: Lake Victoria,Organochlorine pesticide residues, Rusinga Island, , sediment and water pollution.
I. Introducti


Rodrigues, AJ, Oyoo WS, Odundo FO, Wambu EW.  2015.  Socio-economic factors influencing the spread of drinking water diseases in rural Africa: case study of Bondo sub-county, Kenya. Journal of Water and Health. 13(2):500-509. Abstract

Socio-economic and medical information on Bondo sub-county community was studied to help establish the relationship between the water quality challenges, community health and water rights conditions. Health challenges have been linked to water quality and household income. A total of 1,510 households/respondents were studied by means of a questionnaire. About 69% of the households have no access to treated water. Although 92% of the respondents appear to be aware that treatment of water prevents waterborne diseases, the lowest income group and children share a high burden of waterborne diseases requiring hospitalization and causing mortality. Open defecation (12.3%) in these study areas contributes to a high incidence of waterborne diseases. The community’s constitutional rights to quality water in adequate quantities are greatly infringed. The source of low-quality water is not a significant determinant of waterborne disease. The differences in poverty level in the sub-county are statistically insignificant and contribute less than other factors. Increased investment in water provision across regions, improved sanitation and availability of affordable point-of-use water purification systems will have major positive impacts on the health and economic well-being of the community.

Wandiga, SO.  2015.  Critical Water Issues in Africa. In Water Challenges and Solutions on a Global Scale. :Chapter6,95-113., Washington, DC: American Chemical Society Abstract

Water scarcity, purity and delivery have become major challenges of humanity especially in Africa. Globally 748 million and in Africa 325 million people lack access to safe water. Water diseases kill 842,000 people annually. The majority of those who lack water live in rural areas. Africa is second to Australia in dryness but is home to 15% of global human population and has only nine percent of global renewable water resources. Most of Africa’s surface water has become polluted by human activities and its wells are becoming dry. Impacts of climate change and climate variability are making water scarcity more stressful.

Technologies used for water harnessing are outmoded and inefficient. Africa needs to modernize its water purification technology; it requires adopting new methods like roof, pavement and urban water catchment to recharge its declining ground water level. Provision of safe drinking water policy need to change from piped water to every home to supply of point of use technologies at every home. There exist some potential new technologies that still require further research. The chapter highlights some recent development of nanoscience materials in water treatment that give promise to future trends. Similarly, small scale water harnessing technologies are outlined for ground water recharge and drinking water

S.N., M, W.S O, K.G N.  2015.  Photo Catalytic Inactivation of Escherichia coli Using Titanium (IV) Oxide- Tungsten (VI) Oxide Nanoparticles Composite. International Journal of Photocatalysis. 19:204-211. Abstractphoto_catalytic_inactivation_of_escherichia_coli_using_titanium__iv__oxide-tungsten__vi__oxide_nanoparticles_composite.pdf

This work focused on synthesis of Titanium (IV) Oxide and Tungsten (VI) Oxide composite and testing the composite as a photocatalyst in deactivation of Escherichi coli in water. Modified wet chemistry method was used and the synthesized nanoparticles calcined at 575° C, taken through XRay Fluorescence and X-Ray Diffraction. The result showed a particle size diameter of 18.99nm. The nanoparticles photocatalytic inactivation efficacy of Escherichia coli in water was tested. 3M Petrifilms from 3M Microbiology Products, U.S.A., was used for Escherichia coli colony forming units’ counts. ATUV 8W G8 T5 lamp from PHILIPS emitting between 350-600nm was used as energy source. The catalyst reduced Escherichia coli count by log 3.415 at an optimum catalyst amount of 0.75 g/L at pH 7.3 using the Chick-Watson model for disinfection kinetics. This work proved that photocatalysis is a promising technology in water purification with possible and practical opportunities existing especially for small-scale point-of-use water purification units where potable water could be treated for disinfection of pathogens or trace priority pollutants remaining in water distribution network after conventional treatment methods. This work proved that nano particles can provide solutions in treatment of drinking water especially for poor communities living in the tropics.


Ongeri, DM, LALAH JO, Wandiga SO, Wandiga SO, Michalke B.  2012.  Seasonal variability in cadmium, lead, copper, zinc and iron concentrations in the three major fish species, Oreochromis niloticus, Lates niloticus and Rastrineobola argentea in Winam Gulf, Lake Victoria: impact of wash-off into the lake. AbstractWebsite

Trace metals Cadmium (Cd), Lead (Pb), Copper (Cu), Zinc (Zn) and Iron (Fe) were analyzed in edible portions of three main finfish species namely Lates niloticus, Oreochromis niloticus and Rastrineobola argentea sampled from various beaches of Winam Gulf, Lake Victoria, Kenya, in order to determine any seasonal and site variations and the results showed significantly (p < 0.05) higher mean concentrations of Cd, Cu, Zn and Fe during the wet season compared to the dry season for all the three species indicating the impact of wash-off into the lake during the rainy periods. The overall mean concentrations of the heavy metals (in μg/g dry weight) in all combined samples ranged from 0.17-0.40 (Cd), 0.47-2.53 (Pb), 2.13-8.74 (Cu), 28.9-409.3 (Zn) and 31.4-208.1 (Fe), respectively. It was found that consumption of Rastrineobola argentea can be a significant source of heavy metals especially Zn, to humans, compared with Lates niloticus and Oreochromis niloticus, if only the muscle parts of the latter two are consumed.




Ssebugere, P, Kiremire BT, Kishimba M, Wandiga SO, Nyanzi SA, Wasswa J.  2009.  DDT and metabolites in fish from Lake Edward, Uganda. Website

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