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Item USE OF FISH BIOMARKERS TO ASSESS MICRO- POLLUTANT EXPOSURE AND EFFECTS IN LAKE KANYABOLI, KENYA(2016-11) CORNEL AKWIR OMONDIA lot of research in ecotoxicology is currently focused on identifying and developing suitable biomarkers for use in assessing environmental pollution. This study, set out to evaluate the use of a suite of biomarkers in Clarias gariepinus in assessing micropollutant exposure and effects in Lake Kanyaboli from November 2013 to April 2014. Fish were collected with the aid of a gill net of mesh size 4” and 5” whereas bottom sediment was collected by ErkMan crab sampler. The concentrations of Cadmium, Chromium, Zinc, Copper, and Lead in lake sediment and in the liver of Clarias gariepinus were determined using Flame Atomic Absorption Spectrophotometry (AAS). A necropsy-based health assessment index (HAI), the condition factor, hepatosomatic index (HSI), and splenosomatic index (SSI) were measured in fish from all the sampling stations. Fish were semi-quantitatively sampled from which an organ index was calculated to examine the micro- pollutant exposure and effects in fish from all the study stations. Metals concentrations were significantly (Fα, v1, v2 = 7.16; p < 0.05) higher in station 2 than at the other stations. The mean heavy metal concentration in Clarias gariepinus liver were Cd (nd-0.22±0.01), Cr (0.37 ± 0.01 - 1.67 ± 0.03), Zn (7.12 ± 0.03 - 13.40 ± 0.32), Cu (2.12 ± 0.12 - 4.16 ± 0.12) and Pb (1.63 ± 0.33 - 14.40 ± 0.58). Zn exhibited a significance difference between the stations (Fα, v1, v2 = 7.79; p < 0.05). Redundancy ordination analysis (RDA) revealed positive linear relation between heavy metals in sediments and fish liver except for Zinc concentration in sediments and fish liver which showed a negative relationship. The mean of the biomarkers were HAI (20.61 ± 1.01 - 47.43 ± 1.12), Condition factor (0.60 ± 0.03 - 0.91 ± 0.29), HSI (0.53 ± 0.03 - 0.67 ± 0.03), SSI (0.08 ± 0.00 - 0.12 ± 0.01) and Semi-quantitative histological assessment index (8.3 ± 0.41 - 17.63 ± 0.36). The multivariate analysis of the histology – based fish health assessment index (HBFHAI) showed that these biomarkers are being influenced by the concentration of heavy metals in sediments as well as fish liver and therefore qualified as biomarkers for assessing pollutant exposure and effects. It is concluded that histology-based fish health assessment index biomarkers can be used to assess the health of aquatic organisms and ecological health of Lake Kanyaboli and other aquatic habitats within the Lake Victoria Basin. However, a more comprehensive chemical analysis of water and sediments samples including the measurements of endocrine disrupting chemicals is recommended for future studies to further investigate possible causative agents regarding liver alterations identified.Item SCREENING, ISOLATION AND CHARACTERIZATION OF HYDROCARBONOCLASTIC BACTERIA FROM OIL CONTAMINATED SOILS(2017-05) Mwaura N. AgnesPetroleum and its products continue to serve as a principle source of energy for industries and daily life. However, their release into the environment is a worldwide concern since some products are acutely toxic or possess mutagenic, teratogenic and carcinogenic properties. Several oil disposal methods have been applied over time with bioremediation emerging as the most promising technology. It takes advantage of the versatility of soil microbes to degrade hydrocarbon contaminants. Unlike conventional disposal methods, bioremediation is an environmentally friendly and cost effective method that simulates natural processes for complete degradation of hydrocarbons into innocuous compounds. This study focused on isolation, morphological and biochemical characterization as well as molecular identification of bacteria possessing hydrocarbon-degrading properties. The study also aimed at optimizing appropriate culture conditions for the isolates as well as screening for alkane hydroxylase enzyme. Isolation of hydrocarbon degrading microbes from soils polluted with used motor oil around Ngara, Nairobi-Kenya was carried out using Bushnell Haas media supplemented with used engine oil. The isolates were screened for ability to utilize heating oil, hexane, octane, toluene and diesel oil hydrocarbons. Characterization of the isolates was carried out by performing Gram’s iodine and potassium hydroxide as well as starch, catalase and carbohydrate fermentation tests. The isolates were also identified through PCR amplification and sequencing of 16S rDNA gene and comparison of obtained sequences with those retrieved from Genbank database. Optimization of culture conditions of three efficient degraders was performed using diesel oil and cellular growth monitored through biomass determination. Hydrocarbon analysis was performed using GC-MS following culturing in diesel oil. Alkane hydroxylase (alkB) gene was amplified using alk-3F and alk-3R primer pair. Among 21 microbes isolated, nine were selected based on their ability to utilize the hydrocarbons and characterized. The isolates were observed to mineralize heating oil, hexane, octane and toluene as well as diesel oil. PCR amplification of 16S rDNA gene revealed that the nine isolates belong to six different genera; Pseudomonas, Acinetobacter, Klebsiella, Enterobacter, Salmonella and Ochrobactrum. Based on their ability to degrade the hydrocarbons, three isolates were selected and their growth conditions optimized. Optimum degradation of diesel oil was recorded at <1 % substrate concentration, pH 7, temperature of 37 0C and using yeast extract as a nitrogen source. GC-MS analysis of diesel oil degradation demonstrated that the isolates were capable of readily degrading linear, branched, cyclic and isoprenoid alkanes as well as aromatic hydrocarbons with fatty acids, aldehydes and alcohols produced as intermediate metabolites. Isolate 1C was identified as the most efficient hydrocarbon degrader based on utilization of the different hydrocarbons tested. Its alkane hydroxylase gene was successfully amplified indicating the isolate’s potential catabolic capability in degrading alkanes. Overall, the characterized bacterial isolates may constitute potential candidates for biotechnological application in environmental cleanup of petroleum contaminantsItem FACTORS INFLUENCING ADHERENCE TO ANTIRETROVIRAL THERAPY IN EMBU TEACHING AND REFERRAL HOSPITAL, EMBU COUNTY, KENYA(2017-03) EVANGELINE KANANU NJUE MUGOHAdherence to antiretroviral therapy is a major predictor of the survival of individuals living with HIV/AIDS. Appropriate use of antiretrovirals (ARV’s) has improved the health of many human immunodeficiency virus (HIV) positive individuals. The effectiveness of HIV treatment depends on sustenance of high levels of adherence to ARV; however, ARV regimens are often complicated and can be affected by varying dosing schedules, failing to have proper dietary requirements and patients developing adverse effects. The main objective of this study was to determine factors influencing adherence to Anti-retroviral drugs among HIV and AIDS patients 18 years and above in Embu Teaching and Referral Hospital comprehensive care clinic. A cross sectional study was carried out at EmbuTeaching and Referral Hospital in EmbuCounty, Kenya. Stratified random sampling was used to obtain relative proportion of male and female adult respondents in the sample population. Three hundred and thirty one HIV positive patients were chosen from a total of 1694 patients who were active in ART for more than one year. A semi-structured interview schedules was used to obtain demographic information and patients view on various dimension or ART services at the facility. The study revealed thatalmost half (48.2%) of the respondents had optimal adherence to ART treatment while 51.8% had sub-optimal adherence to ART treatment. Over a third (34.9%) of the patients indicated that travelling was the main cause of hindrance to optimal adherence to treatment. Other reasons included forgetfulness 23.5%, tiredness of taking drugs all the time 20.8% and side effects 20.8%. Patients aged below 25 years were more likely to have optimal ART adherence as compared to respondents aged 56 years and above (ᵡ 2 =10.745, df=4, pvalue = .030). Monogamously married and polygamous married patients more likely to have optimal adherence as compared to widowed or widower respondents (ᵡ 2 =17.944, df=4, p-value = .001). Majority (88.0%) of the respondents had disclosed their HIV status to other people of whom 46.9% had disclosed to their spouse/sexual partner and 49.7% of them had been accorded moral support. There was significant association between adherence to ART and the type of drug respondent was using with AZT, ddl, NFV having the highest proportion of sub-optimal adherence to treatment while respondents on D4T, 3TC, NVP had the lowest proportion of suboptimal adherence to treatment. Patients who had sub-optimal ART adherence significantly had longer waiting time and deemed costs of co-infection treatment to be higher as compared to respondents who had optimal ART adherence. Convenience of the facilities for people with chronic ailments and waiting time at the facilities were reported to be lower. The study concludes that majoritypatients had sub-optimal adherence to ART treatment. Adherence was significantly influenced by age; marital status; engagement in income generating activity;type of drug takenand costof coinfection treatment;health facility accessibility and perceived waiting time.The study recommends that HIV patients should be sensitized on importance of carrying ART drugs when travelling and the use of treatment assistants to ensure optimal adherence thus enabling them fully realize its life extending benefits as it has been shown that there is significant non-adherence among HIV positive patients on ART in the County.Item Extraction and Characterization of Gelatin from Lates niloticus Scales and Potential Industrial Applications(2016-07-31) CHEBON SAMMY KIPLAGATThis study sought to extract and characterize gelatin from Lates niloticus (Nile perch) scales, then blend it with polyvinyl alcohol (PVA). Hydrolysis of the scales was done using a crude alkaline protease harvested from a bacterium, Bacillus cereus strain wwcp 1, obtained from Lake Bogoria and the resulting solution lyophilized to obtain gelatin powder. The yield was calculated based on the dry weight of the scales and was shown to be 16.3%. The sample was characterized using infrared spectroscopy and showed peaks at 3442 cm-1, 1653 cm-1 and ~ 1590 cm-1 corresponding to Amide A, Amide I and Amide II bands respectively. Amino acid analysis of the sample was done using an Agilent 1260 HPLC. Glycine was the most abundant amino acid (21.7%), followed by proline (14.6%) and alanine (11.8%). Isoleucine, Histidine and Tyrosine were the least abundant (1.8, 1.4 and 0.9% respectively). Polyvinyl alcohol-gelatin blend films of various compositions ranging from 10% to 90% PVA were prepared by solution casting method, Differential Scanning Calorimetry (DSC) and Thermo-gravimetric Analysis (TGA) tests showed the films had glass transition, melting and thermal decomposition onset temperatures intermediate between those of the respective individual polymers ( PVA and gelatin). The thermal stability of the films reduced with the increase in the amount of the less thermally stable constituent. Lastly, potential applications of the prepared blend films were investigated. Batch experiments to assess the potential of the polymer blend films as adsorbent material were done using Methylene Blue dye. The films were found to adsorb up to 64% of the dye. The percent dye removal varied with initial concentration of the dye and contact timeItem SOIL MOISTURE CONSERVATION, CROPPING SYSTEMS AND SOIL FERTILITY EFFECTS ON SOIL AND MAIZE PERFORMANCE IN MACHAKOS COUNTY, KENYA(2019-05) NGIE MWENDE (B. Sc. [Hons], M. Sc.)The main causes of food insecurity in semi–arid parts of Kenya are low soil fertility, low and unreliable rainfall. These two causes are the main challenges facing small-scale farmers in food production especially in semi-arid areas of the country. To overcome these challenges, soil and water management technologies especially those in soil and water conservation need to be embraced. The aim of the study was to determine the effect of tied ridges, fertilizers and cropping systems on soil properties (moisture, pH and organic carbon), growth and yield parameters of maize; and to identify the most cost effective water and soil management technology. This study was carried out in four seasons at Katumani in Machakos County. The experiment was a 2 x 4 x 2 factorial, laid out in a randomized complete block design (RCBD). The treatments were: tied ridging, flat bed planting, farm yard manure 0 t/ha, farm yard manure 5 t/ha, nitrogen fertilizer 20 kg/ha, farm yard manure 5 t/ha + nitrogen fertilizer 20 kg/ha, maize mono crop and maize cowpea intercrop. Data collected included soil moisture content, soil pH, total organic carbon, growth parameters and maize yield. The results showed that, treatments with flat bed planting in maize mono crop significantly increased soil moisture content at 0–20cm depth as compared to tied ridging in maize cowpeas intercrop during short rains 2015. Application of farm yard manure at 5 t/ha increased soil moisture content at 2 and 4 weeks after planting. The soil moisture content ranged from 6.30% to 23.80%. During the short rains 2015, maize mono crop significantly increased vegetative growth in comparison to maize cowpeas intercrop. Treatment with flat bed and 20 kg N/ha in maize mono crop had the highest mean for vegetative growth. However, during the long rains 2016, treatment with tied ridging and 20 kg N/ha in maize mono crop registered the highest mean for vegetative growth. During the short rains 2015, treatments with maize mono crop significantly increased grain yield with a range of 1.35 t/ha 3.59 t/ha. Flat bed planting with farm yard manure 5 t/ha in maize cowpea intercrop significantly increased the grain yield by 165.93%. The harvest index during the short rains 2015 ranged between 0.35 and 0.48. Treatments with maize mono crop significantly increased gross benefit, net profit, gross margin and cost benefit ratio during short rains 2015 and long rains 2016. Application of farm yard manure 5 t/ha + 20 kg N/ha had the highest variable cost. The cost benefit ratio was positive during the short rains 2015 with a range of 1.47–2.98. The yield differences among the four seasons could have been as a result of variations/distribution in rainfall amount, soil moisture content and soil fertility as induced by the treatments. Flat bed planting increased the yields during the short rains 2015 when the amount of rainfall was high whereas tied ridging resulted in improved yields during short rains 2014, long rains 2015 and 2016 when rainfall amount was low. For the farmers to maximize yields and profits in the study area, adoption of flat bed planting with farm yard manure 5 t/ha and maize cowpeas intercrop during the seasons of high rainfall could be appropriate treatment combination according to the findings of this study. However, during seasons with low rainfall, tied ridging with 20 kg N/ha and maize mono crop could be recommended for adoption. Also, variations in seasonal rainfall should be considered when integrating different soil and water management practices because the effectiveness of different technologies vary with the seasons. Farmers in Machakos County may have to consider use of supplementary irrigation during the dry spells to increase soil moisture.Item FREQUENCY OF SULFADOXINE PYRIMETHAMINE RESISTANCE ASSOCIATED GENE MUTATIONS IN PLASMODIUM FALCIPARUM CLINICAL ISOLATES FROM KWALE COUNTY, KENYA(2020-01) WINFRED KENDI MUTWIRIMalaria persists to be one of the world’s complex and dynamic disease. The disease is more devastating in sub-Saharan Africa as it constitutes high cases of childhood mortality and morbidity. Management of the disease remains a problem as a result of the spread of parasites that are resistant to the available drugs. Due to the broadened spread of resistance to Sulfadoxine Pyrimethamine (SP), the artemether-lumefantrine which is a more effective and well-tolerated anti-malarial drug replaced the SP as the first-line regimen in treatment of uncomplicated malaria in Kenya. However, SP remains the suggested drug to treat and prevent malaria in expectant women and children under the age of five. This study sought to assess the presence of mutation in dihydrofolate reductase and dihydropteroate synthase genes associated with SP resistance a decade after Sulfadoxine-Pyrimethamine was withdrawn as the first-line anti-malarial drug of choice in Kenya. Smear-positive samples (N = 134) collected from a 2013 cross-sectional study in infants managed at Msambweni District Hospital were evaluated for mutations in dhfr and dhps (SP).The findings obtained were matched up with molecular data from infants in Western Kenya in a study carried out in 2003/05. In all the 134 samples, mutations at codons N51I, C59R, S108N had a high predominance at 80.6%, 72.4% and 93.3% respectively. The double mutant of Pfdhps A437G/ K540E had an occurrence rate of 82.1% and 78.4% respectively. Compared to the molecular data of 2003/05 study, the Pfdhfr triple mutant (S108N/N51I/C59R) genotype decreased to 63.4% in 2013 up from 68%. However, this reduction was not significant (p=0.387). There was no significant change in the prevalence of Pfdhps double mutant (A437G/K540E) genotype (p=0.485). The percentage of isolates which had the Pfdhps A437G/K540E/ Pfdhfr N51I/C59R/S108N quintuple mutant linked with SP-resistance did not change significantly over the two study periods under consideration (53.5% in 2003/05 versus 53.7% in 2013, p = 0.967).The high prevalence of SP resistance marker in the coastal Kenya could be attributed to circulation and SP drugs being sold over the counter which has maintained a selection pressure for the mutations and fixation in the key mutations in the inhabitants. Also the mutation could have a little effect on the fitness of fit of the parasite such that withdrawal of drug pressure did not offer any survival disadvantage hence the continued spread of resistant parasites. Further investigations should be done to determine the linkage between SP drug resistance associated mutations and efficacy of IPTi-SP since the mutation levels are still high. It is also recommended that doctors using SP for IPTi and IPTp should be more cautious and their use monitored to ensure cases of poor response are managed with a different drug.Item SEROPROFILE, GENETIC DIVERSITY AND DRUG RESISTANCE OF HEPATITIS B VIRUS AMONG INFECTED INDIVIDUAL ATTAENDING MAMA LUCY KIBAKI(2016) SEPHA NYATICHI MABEYAHuman immune deficiency virus (HIV) and Hepatitis B virus(HBV) coinfection is highly prevalent among high risk populations including pregnant women and infants. This poses a global public health challenge in laboratory diagnosis and is a major consideration for anti-HIV treatment. These viruses share common modes of transmission that is; through blood and body fluids. Further, there is little information on sero-profiles and circulating HBV genotypes in Kenya. This study aimed at determining seroprofiles, genetic diversity and drug resistance of HBV among HIV infected individuals attending comprehensive care clinic of Mama Lucy Kibaki Hospital Nairobi, Kenya. Ethical approval was sought from Kenyatta university ethics review committee and a cross-sectional study was conducted whereby the participants/guardians who gave consent/assent were included into the study. Their demographic data was collected using a questionnaire and 5ml of blood was collected from each participant using systematic sampling technique. The HBV seroprofiles were determined using the HBV-5 panel rapid diagnostic cassette according to the manufacturer’s instructions (Healthaw Medical limited, Hangzhou, China) . Viral DNA was extracted using Qiagen® Miniviral DNA isolation kit and the HBV-pol gene amplified by nested PCR. The amplified products were sequenced using the Big Dye® sequence terminator kit (Applied Biosystem®) on an automated ABI 310 sequencer (Applied Biosystem, Foster City CA). The generated sequences of HBV were analysed for drug resistance and genetic diversity determined using Molecular Evolutionary Genetics Analysis (MEGA5). Four hundred participants were recruited and 293 were females, 107 were males with their age ranging between 4 months and 73 years. Of the 400 sera; (111) 27.8% were HBV immunized, 19 (4.8%) were recovery cases, 12 (3%) had acute disease, 10 (2.5%) were chronic, 9 (2.3%) had occult HBV and 7 (1.8%) asymptomatic. The prevalence of HBV/HIV was found to be 7.25% based on the presence of surface antigen. After the confirmation of HBV DNA by gel electrophoresis, 13 samples were successfully amplified, purified and sequenced. All the 13 sequences were confirmed as HBV genotype A. Nucleotide drug resistance mutations were found in six (6) participants’ samples. These were rtV173L, rtL180M, rtM204V which are major mutations associated with lamivudine, telbivudine and emtricitabine resistance. This study indicates that the utility of HBV seromarkers and infection staging are important in disease diagnosis. The findings confirm that, HBV genotype A remains the most predominant genotype circulating in Nairobi.This study proposes a need for a continuous surveillance of HBV genotype trends and evolution of drug resistance because the current findings have major implications on treatment of HBV in KenyaItem SYNTHESIS AND SPECTROPHOTOMETRIC ACTIVITY OF PHTHALOCYANINE CONJUGATED TO METAL NANOPARTICLES AND EVALUATION OF THEIR ANTIBACTERIAL PROPERTIES(2021-11) NYAMU N, SAMUEL (MSc. Chemistry)ABSTRACT {In recent times, microbial pathogens have increasingly shown multi-drug resistance leading to a growing concern. Analysis of 624 isolates from Kenya revealed 88% of isolates tested Were multi-drug resistant. It is estimated that about 4,150,000 deaths will be attributed to antimicrobial resistance (AMR) in Africa by 2050. Therefore, current research is increasingly focusing on antimicrobial photodynamic therapy that utilizes non-toxic photo. sensitizer exhibiting visible light activity towards the generation of free radicals and singlet oxygen which kill pathogens. The photo-sensitizer may be conjugated to visible-light responsive nanoparticles to further increase their photochemical activities, Phthalocyanine (Pc) is one of the promising dyes that have shown notable photochemical stability, a high degree of aromaticity and ease of structural modification resulting in increased activities. Despite these attractive properties, its antibacterial properties remain under researched, therefore, this study aimed to tuning the photodynamic antibacterial activity of Pc by using electron withdrawing and electron donating group, conjugating the obtained compounds to silver nanoparticles (AgNps) and 2ine oxide nanoparticles (Zn0-Nps) and evaluating the activity of the resulting composites against drug resistant strains Escherichia coli, Staphylococeus aureus, Bacillus subtilis and Salmonella typhi. 2,9,1623-tetraciodo. 3.10,17,24-tetra-(3 methoxyprop-I-nyl) Pc (6) and. 2,9,16,23-tetra-iodo-3,10,17.24-tetra cthylsulfonyl Pc (10) were synthesized respectively. The Pc derivatives were synthesized upon exposure to microwave radiation under solvent-free conditions. Both Pc 6 and 10 Were B-form in nature with monoclinic structure confirmed by powder XRD. Pc (6) had two absorption bands between 345-364 nm for B-band and 660-680 nm for Q-band while Pc (10) indicated two major absorption bands between 354-360 nm for B-band and 685,689 nm bands for Q-band of UV-Vis absorption in different solvents, FTIR confirmed the Presence of attached substituent groups to the Pes. Pc 6 and 10 showed singlet oxygen quantum yield (A) values of 0.53 and 0.63 and fluorescence quantum yield (DE) value of 0.14 and 0.13 respectively. The Pc 10 exhibited zone of inhibition >230.12 ug/ml for all the strains, making it more effective as compared to Pc 6. In addition, all strains of tested bacteria were susceptible to Pc 10 at a concentration > 31.25 jig/ml. ‘This implies that Substituting Pc with electron withdrawing allows it to release more singlet oxygen in Presence of light and which results to oxidation of the bacterial wall. AgNp and Zn0-Np were synthesized by microwave assisted extraction, The UV-Vis was used to confirm the formation of nanoparticles and also characterization done using FTIR, TEM and SEM, AgNps were of diameters < 58.5 nm that easily conjugated to Pc while Zn0-Nps were of large grain size > 95, the particles aggregated making it difficult to conjugate with Pes, Conjugation of Pc 10 with AgNp < 10 nm resulted to a more superior antibacterial as compared to unconjugated Pe 10. There was no significant different for zone' of inhibition for Pc 10 conjugated to AgNp when compared to positive control ciprofloxacin at $00 ua/ml for all the strains except for B. subtilis. It had minimum inhibitory concentration (MIC) values of 3.91, 1.96, 1.96 and 15.63 ug/ml, for E. coli, S aureus, B. subtilis and S phi respectively. Both Pc showed no toxicity on Vero cells at concentration of 600 jig/ml In overall, this work reports the successful tuning of the photo-chemical and antibacterial Photodynamic properties of Pc using electron withdrawing and donating substituent, The Pc 10 with electron withdrawing group exhibit superior antibacterial activity which is further enhanced by conjugation with AgNp of < 10 nm.Item MODELING THE EFFECTS OF INTERFERENCE IN FERTILITY RATE: A CASE STUDY OF RWANDA, INDONESIA AND KENYA(2016) ODERO EVERLYNE AKOTHMany studies have been done on fertility for many years. However, very little has been documented in the existing literature concerning modeling of fertility in the presence of interference, yet interference to fertility is a common phenomenon. In this study fertility data sets for Rwanda, Indonesia and Kenya were modeled before and after interference. The parameters of the model were estimated ted by the maximum likelihood estimation method. The model life table approach was used to determine the Net Fertility Value, Fo. A relationship between fertility rate in the presence of interference and population growth was also determined Using Akaiko's Information Criteria (AIC) population growth was also determined. Using Akaike's Information Criteria, (AIC), it was established that amongst the distributions fitted; Gamma, Weibull and Lognormal, was established that amongst the distributions fitted: Gamma. Weibull and Lognormal Gamma gave the best fit for the fertility rate data, for all the countries studied, and interference simply shifts the Gamma distribution parameters. The result of this study would help the Governments to understand fully the effect of interference on fertility rate and plan for it. Demographers would also benefit from this study since it can be used to project population growth after an interference.Item CHILD EXPOSURE TO LEAD IN THE VICINITIES OF INFORMAL USED LEAD-ACID BATTERY RECYCLING OPERATIONS IN SLUMS, KENYA(2016-11) MAUREEN AUMA ONDAYOLeadexposure frominformal used lead-acidbattery (ULAB) recyclingoperations is a seriousenvironmental healthconcern. Researchshows that youngchildrenliving inthe vicinitiesoftheseoperationshaveelevatedbloodleadlevelsandfatalitieshavealsobeen reported. FromJanuary2015 toAugust 2015, thestudy investigatedchildexposure to lead inthevicinitiesof informalULABrecyclingoperations inNairobi slums,Kenya. This was in consideration of activity patterns of children under seven years that influencedexposurelevelsthroughhousedustandsoil.Topsoil (N=232)andfloordust (N=322)sampleswerecollectedfromdwellingunits(N=120)andpreparatoryschools (N:44)andanalyzedusing inductivelycoupledplasma-optical emissionspectrometer (ICP-OES) at theMines aridGeological Department Laboratory in theMinistryof Mining,Nairobi.Fromthe lead levels insoil andhousedustobtained,childblood lead levelswere subsequently predictedusing the IntegratedExposureUptakeBiokinetic Model forLead inChildren(IEUBK),Windowsversion.Results indicatedhigh indoor andoutdoor lead contamination instudied areas. Lead loadings inall the floor dust samples (100%) fromDandota, Kariobangi andMukuruslums exceeded theUSEPA guidancevaluefor leadonfloorswitharangeof65.2-58,l94ug/ft2.Control floordust samples recorded lower lead loadingsas compared to thevalues recorded inDandora, Kariobangi andMukuruslums. 70.7%ofthesoil samplescollectedfromwastedumps, industrial sites, residential areas, playgrounds and preparatory schools in Dandora, Kariobangi andMukururecorded leadconcentrations that exceeded the respectiveUS EPAguidancevalues for lead insoils. Leadconcentration inall (100%of) thecontrol soil sampleswerebelowtherespectiveUSEPAguidancevalues. Fromthe IEUBKwin predictions,nearly99.9%ofchildren<7yearsoldlivingnear informalULABrecycling operations inDandora, Kariobangi andMukuru slums, were at riskof being lead poisonedwithpredictedbloodleadlevelsabovetheCDCreferencevalueforbloodlead. 99.9%ofexposedchildrenlivinginDandora,KariobangiandMukumslumsarelikelyto havebloodlead levelsabove20kg/dL, 19kg/dLand34kg/dLrespectively.Thestudy establishedthatDandora,Kariobangi andMukuruslums facevastenvironmentalhealth challenges,withmanychildrenat riskofleadpoisoningduetotherapidunprecedented growthof informalULABrecycling. Thesoil andhousedust results demonstrate the need for coordinatedefforts towards decreasing leademissions frominformal battery recycling inNairobi slumsand to remediateexisting soilsparticularlyaroundbattery workplaces and dumpsites. Childblood lead levels should be clinically tested and appropriateinterventionmeasurestaken.Item PREVALENCE OF ECHINOCOCCOSIS IN DOGS, CATTLE, SHEEP AND GOATS, LEVEL OF KNOWLEDGE AND ASSOCIATED ECONOMIC LOSSES(2018) MABEL INYANGALA GACHENGOCystic Echinococcosis (CE) is an emerging and re-emerging zoonotic infection caused by the larval stage of the dog tapeworm of the genus Echinococcus. It causes great public health and economic problems and remains neglected in Sub-Saharan Africa. The level of knowledge is poor in most developing countries. This study was carried out to determine the prevalence of echinococcosis and its trend, level of knowledge and associated economic losses in Laikipia West Sub-County. A total of 4969 animals (522 cattle, 3428 sheep and 1019 goats) slaughtered in abattoirs were inspected for hydatid cysts; a questionnaire was administered to one adult member from each of the 300 household using mobile data collection Kit. Faecal samples from 401dogs were used to determine prevalence of echinococcosis in dogs. Data from Veterinary office meat inspection reports 2010-2014 were used to determine trends and associated economic losses due to CE. The prevalence of CE in slaughtered animals was 8.8% in cattle, 1.7% in sheep and 1.7% in goats. Prevalence of echinococcosis in dogs was 0.5% (2/401). The level of knowledge of echinococcosis was 25% (n=300). A total of 98,495 animals were inspected during the period 2010-2014 and results showed an increasing trend with time for both prevalence and economic loss. There was evidence of CE transmission and the level of knowledge of Echinococcosis was low. The public health implications and economic losses call for concerted control efforts. More elaborate studies on echinococcosis are recommended in dogs and man.Item PRODUCT DESIGN STRATEGY UTILISATION IN DETERMINING THE PERFORMANCE OF MICRO AND SMALL TEXTILE ENTERPRISES IN NAIROBI CITY COUNTY, KENYA(2023-09) ADONIJAH OMBURAKenyan textile micro and small enterprises (MSEs) face a myriad of performance challenges, key being low product differentiation. This is when enterprises imitate each other's products. Scholars have recommended research into the most effective business strategies textile micro-enterprises can utilize in order to address low product differentiation. The purpose of this study was therefore to determine the utilization of product design strategies on the performance of textile MSEs in Nairobi and thereafter develop a textile MSE product design guide that will be used in improving product innovations. Focussing on Nairobi City County's CBD, the first objective set to explain the product design strategies used by MSEs in the textile sub-sector. The second objective intended to determine the number of product innovations generated by textile MSEs in the combined year’s 2016 and 2017. The third objective of the study determined how product design strategies affect textile performance. The fourth and last objective focussed on the creation of a textile MSE product design guide. This study took up a deductive, epistemological investigation that followed a pragmatic philosophy with the following theories underpinning it: the Componential Theory of Creativity (CToC); the Concept Knowledge Theory (C-K); the Resource Based View theory (RBV) and the Dynamic Capabilities Theory (DCT). Purposive and snowball sampling were used to identify the textile MSEs before surveys with descriptive and explanatory designs and quantitative data analysis were done. A chi-square goodness of fit test revealed significant variation in textile MSEs' product innovations. The test was statistically significant for the variation in the amount of product innovations by textile MSEs. A second multiple logistic regression test indicated that both benchmarking strategies and research strategies had a significant influence on innovation. Thereafter, a Pearson chi-square independence test revealed a statistically significant association between the two strategies under study and their product innovation, however, the association strength was found to be weak as indicated by a Lambda test and confirmed by Phi coefficient as well as a contingency coefficient test. The ANOVA effect size analysis test was then used to reveal that the combined strategies had medium to small effects on the dependent variable. In conclusion, the test results showed that there was a significant influence of product design strategies on the performance of textile MSEs in Nairobi City County, Kenya. In light of this, a comprehensive product design guide, specifically tailored for textile micro and small enterprises (MSEs), and to be used in improving product innovations was developed. Other recommendations from the study include: improving the work environment and intrapreneurship orientation; using combination strategies for increased performance (innovation) and using design guides like the one proposed by the study. Recognition of design management as a critical intervening variable that affects the performance of textile MSEs was also made. Due to their limitation in size of the MSEs, the study also found the need to use association and collaboration to improve performance, while diversification strategy can be effectively employed to mitigate competition and imitations. Additionally, association and collaboration with design consultative units in Research institutions, Universities, government departments, or NGOs for robust R&D and NPD was encouraged.Item FACTORS INFLUENCING ENROLMENT AND RETENTION OF STUDENTS IN PHYSICS IN SECONDARY SCHOOLS IN IMENTI SOUTH SUB-COUNTY KENYA(2016) KAIRO NKIROTE CATHERINEDespite the place of physics in science, technology and national development, the number of students taking physics as their choice in secondary schools is declining. The purpose of this study was to investigate factors influencing enrolment and retention of students in physics classes in secondary schools in Imenti South Sub-County of Meru County. The study was based on achievement motivation theory. The study adopted descriptive survey research design. The target population was 14,097 subjects comprising of 13,943 students and 154 physics teachers in secondary schools in Imenti South Sub-County. Simple random sampling technique was adopted to select students and physics teachers from the population in Imenti south Sub-county. The sample size was 364 respondents comprising of 356 students and 8 physics teachers. Data was collected by use of three questionnaires, for the form two students, form three students and the other for the physics teachers. Piloting was carried out in two secondary schools in the neighbouring Imenti North Sub-county where 42 students and 4 physics teachers participated. Spearman Brown formulae was used to estimate the reliability co-efficient of the instruments. The reliability coefficient of 0.851 and 0.957 for students and teachers questionnaire respectively was obtained. The research instruments were validated with the help of supervisors. The data collected was cleaned, coded and entered into the computer for analysis. Statistical Package for Social Science version18 was used for data analysis. The data was analyzed using descriptive statistics and the findings presented using tables, graphs and charts. The study established factors influencing enrolment and retention in physics include; lack of adequate teaching and learning apparatus, poor performance in physics, teaching methods used in practical lessons, playing with electrical gadget and making models during early childhood, naming constants and principles after male scientists. The research findings will provide important information to policy makers and other stake holders in the Ministry of Education on the influence of available teaching and learning physics resources in schools in regard to enrolment and choice of physics. The study will provide information to physics teachers on the influence of the methodologies used in teaching physics on selection of physics by the students. This may help physics teachers to know which intervention measures to take while teaching in order to improve student’s enrolment in physics. The study is of significance to the students because it enlightens them on the importance and the benefits of studying physics. The study also will sensitize the parents on the importance of physics and their role in exposing children to experiences that demonstrate physics knowledge during childhood. This will help in improving enrolment and retention of students in physics in secondary schools.Item ACOUSTIC ANALYSIS OF EKEGUSII VOWELS AND STOPS(2020-10) OTIENO NYANSERA PETERPreceding a theoretical exploration of issues in a language is a basic research. Through such basic descriptive study, the vitality of the language is aided and documented. This is vital especially for the less studied languages such as EkeGusii that has not been phonetically studied and documented especially using scientific methods. Following Peterson and Barney (1952), this work is an acoustic study of the vowels and voiceless stops of Ekegusii. Its goal is to transcend the impressionistic descriptions previously in the 1960s by Whiteley (1965) and Guthrie (1967). Specifically, the work explores the seven vowels of Ekegusii /i e ɛ a ɔ o u/ along with the intervening voiceless stops /p t k/ within the Source-Filter Theory of sound production. The purpose of this study is to give a complete description of the vowels and stops and document them for reference by various fields from linguistics to machine translation. The scope of impressionistic phonetics is limited by capabilities of human senses and is not verifiable while experimental phonetics like this present study extends and backs-up impressionistic description. The main objective of this study is to give a complete description of the acoustic qualities of the vowels and stop consonants from the oral data got from a purposively selected sample of twelve (four males, four females and four children), bearing in mind their speech mannerisms, geographical and dialectal considerations. Audio data was recorded as the informants read out word lists and carrier phrases bearing target sounds into a microphone connected to a computer running on Praat sampled at 44100 Hz. Analysis of audio data is primarily done using Praat software. Further, quantitative data analyses were done using MS-Excel spread sheets and SPSS with the results presented in tables, charts and written descriptions for each sound, each subject and group. The study mainly found out that EkeGusii adopts a seven vowel system with length contrast making the vowels to be phonologically fourteen. The vowels also display age, sex and dialectal variations. Results for stop consonants show that stops can be discriminated by features such as voice-onset-time, burst intensity and stop duration. Significantly, the research findings provide useful basis for codification and documentation of EkeGusii phonetics for the two dialects.Item AN ASSESSMENT OF THE RELATIONSHIP BETWEEN HEAD TEACHERS’ LEADERSHIP STYLES AND PUPILS’ ACADEMIC PERFORMANCE IN PUBLIC PRIMARY SCHOOLS IN MALINDI SUB-COUNTY, KENYA(2016-11) FREDER MWALUNGO KATUNDAThis study aimed at investigating the relationship between head teachers’ leadership styles on pupils’ academic performance in public primary schools in Malindi Sub County, Kenya. More often than not, head teachers find themselves on the receiving end of poor performance in public primary schools. Most parents tend to attribute poor performance of their children to head teacher’s leadership styles. The objectives of the study were to: find out the relationship between democratic leadership style and pupils’ academic performance; determine relationship between the autocratic leadership style and pupils’ academic performance; find out the relationship between the transformative leadership styles and pupils’ academic performance; and determine the leadership the relationship between the transactional leadership styles and pupils’ academic performance. This study was based on Fiedler’s contingency theory and rationale theory of performance. quantitative methods were used in this study. The study adopted the correlational research design that sought to measure the relationship between the variables. The study targeted a population of 750 teachers and head teachers from 30 public primary schools in Malindi Sub County. The sample was 200 participants consisting of 192 teachers and 8 head teachers. The sample was obtained through stratified sampling to establish the number of head teachers and teachers to include in the study sample. Simple random sampling was used to select 8 head teachers from 30 schools and 192 teachers from 720 teachers. Questionnaires were used; one for teachers and another for head teachers to collect data. Pilot study was carried out in two neighbouring schools which were not included in the study. The validity of the instruments was ascertained by the supervisor and two other lecturers who gave verdict on their appropriateness. The reliability was verified by using the test retest method whereby Pearson Product Moment correlation was 0.75. To cover ethical issues, clearance was done with Mount Kenya University and a permit was obtained from NACOSTI and official letters from the County Director of Education and the District Education Officer. The participants signed informed consent forms and were assured of their privacy and confidentiality. The data was analyzed quantitatively using both descriptive and inferential statistics. The findings established that independent variables had positive and significant relationship with pupils’ academic performance since the estimated Pearson Linear correlation coefficient statistic was significant at the 99% level for all the variables (Sig.<.01, r>.9). All the null hypotheses filed to be accepted. The study concludes that from the three tests on a hypothesis that is correlation, regression and coefficient, all indicates rejection of the null hypothesis paving a way for alternative hypothesis. The study recommends that head teachers ought to be given refresher courses on appropriate leadership styles to be applied in their institutions. The ministry of education should allow teachers to teach in one school for at most 10 years so as to gain experience before transferring to another school. Quality assurance officers needed to be visiting schools regularly to establish level of performance and offer necessary intervention where things are not in order. The study findings are expected to provide useful information to head teachers in helping them to re-examine and appraise their own leadership styles and hence make adjustment where necessary.Item EVALUATION OF PERFORMANCE APPRAISAL TOOL ON EMPLOYEE PERFORMANCE IN KENYA COMMERCIAL BANK, NAIROBI COUNTY(2017-06) LEAH NJERI NYAMUPerformance appraisals improve the work performance of employees by helping them realize their full potentials in carrying out their firm's mission and also, to provide information to employees and managers for use in making work-related decisions. They provide feedback to employees; determine training and development needs, numbers to be promoted as well as the levels of motivation. Performance appraisals, however, are beset with difficulties as a result of their complex nature. The general objective of the study therefore, was to evaluate the performance appraisal tool on employees‟ performance in Kenya Commercial Bank. The research design used in the study was descriptive research design because it was appropriate for the achievement of the research objectives. The population for the study was 355 and a sample size of 107 was selected using cluster sampling method to group the target population according job titles. The study applied purposive sampling to select Nairobi County because of easy of accessibility. Questionnaires were used as instruments for the study and 107 questionnaires were distributed to the members of staff and subordinate as the respondents. The data was analyzed using descriptive analysis. Organized data was interpreted on account of concurrence and standard deviation to objectives using a computer package SPSS version 21. The researcher in addition used correlation analysis and a multiple regression analysis to determine the relationship between dependent and independent variables and their level of significance. The research was based on Attribution Theory, Implicit Theory, Equity Theory and Expectancy Theory. The information obtained from this study provided commercial bank Human Resource Managers and decision makers with better insights into employee performance appraisal programs that could be used to improve employee performance.Item ASSESSMENT OF THE PHARMACEUTICAL MANUFACTURING INDUSTRY IN KENYA TO FORECAST LOCAL PRODUCTION SUFFICIENCY(2017-10) SARAH KADESA VUGIGIThe World Health Organization’s global strategy on public health aims to support Member States to improve access to essential medicines. The desire of Kenya Government to implement this is expressed by formulation of Kenya National Pharmaceutical Policy (2010) which encourages local production of essential medicines for self-sufficiency. The pharmaceutical manufacturing industry in Kenya is engaged in production of various types of dosage forms but its capacity and capability to produce essential medicines for Kenyans have not been determined. The aim of this study was to assess the pharmaceutical manufacturing industry in Kenya to forecast local production sufficiency. This was attained by evaluating the manufacturing capability, production capacities and compliance with international marketing authorization standard of the Kenyan pharmaceutical industry. The 24 licensed manufacturers of medicines for human use were assessed. Data was collected on the current drug situation in Kenya by scanning Pharmacy and Poisons Board database to determine range of products that are registered in Kenya. Local pharmaceutical manufacturer’s product lists, Kenya Essential Medicines list and pharmaceutical tender lists of three major procurers in Kenya (Kenya Medical Supplies Authority, Kenyatta National Hospital and Mission for Essential Drugs and Supplies) were examined to establish the proportion of products which was manufactured locally. Prices competitiveness and market share of local products were evaluated and subsequently, pharmaceutical equivalents of 150 locally manufactured essential medicines were determined. Data on production capacity for 5 years (2010-2014) and compliance of facilities with good manufacturing practices standard and other prerequisites of marketing authorization was obtained using a structured questionnaire. Results showed that solid dosage forms were majority (54.9 %) of local products and sterile preparations were minority (2.7 %). Locally manufactured products accounted for 14.5 % of registered and 21.5 % of retained products. Local firms manufactured 38.4 % of products listed as essential medicines and 55.6 %, 24.5 % and 21.8 %, respectively, of pharmaceutical products procured by Kenya Medical Supplies Authority, Kenyatta National Hospital and Mission for Essential Drugs and Supplies. The overall percentage of local pharmaceutical equivalents was 32.5 % for registered products. There was no variation between mean prices of local and imported pharmaceutical equivalents. Scatter diagrams demonstrated that imported pharmaceutical products comprised both low and highly priced brands. The overall utilized production capacity (two shifts) was 21.5 %; tablets (24.1 %), capsules (12.8 %), liquids (25.3 %), dry syrups (21.8 %), external preparations (21.3 %) and oral rehydration salts (23.6 %). This study projected the year for self-sufficiency in non-sterile medicines produced in the local industry as 2043. Good manufacturing practices standard was satisfactory at 11 facilities while the rest were striving to achieve compliance. Research and development of new products was limited in most facilities with 1 % of the workforce deployed in this department. It is concluded from this study that Kenya depends heavily on imported drugs for her essential medicines needs. Majority of local products were less competitive than imported products and production capacity was underutilized. Majority of manufacturers adhered to current good manufacturing practice standards but were inadequate in research. This study recommends augmentation of research and development by the local pharmaceutical industry to generate new products. In addition, substantial government support is required to propel the industry to improve product range, product competitiveness and production capacity utilization.Item EFFECTIVENESS OF DIFFERENTIATED INSTRUCTION IN ENHANCING STUDENTS’ ACADEMIC ACHIEVEMENTS, SELF-CONCEPT OF ABILITY AND MOTIVATION TOWARDS LEARNING OF CHEMISTRY IN SECONDARY SCHOOLS IN MAARA SUB-COUNTY, KENYA(2016-11) ROSE GATUNE MUGWIRIAStudents perform poorly in Kenya Certificates of Secondary Education Chemistry examinations in Kenya. Chemistry is important for understanding composition, properties and behavior changes of matter that form the environment. The teaching of Chemistry aims at developing scientific attitudes, concept, principles and skills in learners. Differentiating instruction means tailoring instruction to meet individual needs of learners. Differentiating instruction consists of efforts of teachers to respond to the variance among learners in the classroom. This study investigated the effectiveness of differentiated instruction in enhancing students‟ academic achievements, self-concept of ability and motivation towards learning of chemistry. The study was guided by Howard Gadner Theory of multiple Intelligence. Quasi experimental research design was employed and in particular Solomon‟s four group design was used. The research was carried out in Four Day co-educational secondary schools in Maara sub-county, Kenya. The target population was 12,187 chemistry students. The accessible population was 1,242 form two chemistry students in Day co educational secondary schools. A purposive sampling technique was used to draw the participating schools. Simple random sampling was used to select and to assign participating schools in Experimental and Control groups. The sample size was 165 form two chemistry students. The research instruments used were Chemistry Achievement Test, Students‟ Self Concept of Ability Questionnaire and Students‟ Motivation Questionnaire. The instruments were piloted to determine their reliability, while validity of the instrument was ascertained by experts‟ opinions from Department of Education and Resource Development of Chuka University. Reliability coefficient for CAT, SSCAQ and SMQ was 0.74, 0.80 and 0.77 respectively. The experimental groups (E1 and E2) were taught using differentiated instruction teaching approach while the control groups (C1 and C2) were taught through conventional teaching approach. Statistical Package for Social Sciences (SPSS) version 21 was used for data analysis. The raw data obtained was analyzed using descriptive statistics (Mean, Standard deviation, percentages) and inferential statistics (One-way ANOVA, ANCOVA and t-test). The level of significance for acceptance or rejection of null hypotheses was at α = 0.05. The findings of the study indicated that differentiated instruction significantly improved the students‟ achievement, self concept of ability and motivation towards learning chemistry. It was also found out that when students were taught using differentiated instruction, gender did not affect their achievement in chemistry. The findings are expected to form a frame of reference for further research on innovative teaching strategies in chemistry education as well as in science education in general.Item FUNCTIONALIZED GEOPOLYMERS DERIVED FROM CLAY AND RICE HUSK FOR REMOVAL OF SELECTED HEAVY METALS AND METHYLENE BLUE FROM AQUEOUS SOLUTION(2018-10) MAINGI MUKORA FRANCISWith the onset of industrialization, humanity has witnessed various ecological issues in the society and disturbance of ecosystem. Heavy metals and methylene blue are very toxic substances known to cause detrimental effects to human health when ingested even at low concentrations. Several techniques are available for removal of heavy metals, and dyes from the wastewater such as chemical precipitation, ion exchange, adsorption, membrane among others. Among these technologies adsorption is preferable for wastewater treatment due to its simplicity in design, high efficiency and availability of materials involved. Geopolymers are inorganic polymers and have been in use in construction industries as alternatives to ordinary portland cement but very little information is available on their use in environmental pollution management. This study aimed at synthesizing and functionalizing amorphous geopolymers from common clay and rice husk ash for use as adsorbents in removal of heavy metal ions and methylene blue from contaminated water. There is adequate literature indicating that clay minerals contain both silicates and alumina while rice husk ash contains substantial amounts of silica. This work therefore reports synthesis of geopolymers GP 1, GP-2 and GP-3 using clays and rice husk ash that were functionalized using citric acid and EDTA for use in adsorption of heavy metals and colour. Characterization of the geopolymers was done using FT-IR, EDS, XRD and SEM. Batch experiments using Pb (II), Cd (II), Zn (II) ions and methylene blue (MB) were done. FT-IR indicated presence of Al-O and Si-O bonds which are the finger prints of geopolymers. XRD analysis showed presence of amorphous phase between 18-36° (2θ) an indication that geopolymerization occurred. SEM analysis revealed the formation of a heterogeneous matrix which consists of a dense continuous gel with microcracks and voids on geopolymer adsorbents. The mean percentage uptakes of 99.32 ± 0.04, 99.74 ± 0.01, 91.33 ± 0.06 and 91.99 ± 0.57 of Pb (II), Cd (II), Zn (II) and MB were achieved respectively. Various equilibrium models were employed and from the correlation coefficients (R2 > 0.94), the data was found to fit best in Langmuir Freundlich model (Sips). The highest adsorption capacities of Pb (II), Cd (II), Zn (II) and MB were 326.5, 175.5, 169.9 and 20.74 mg/g respectively, attained using GP-3E. Increased adsorption of Pb (II), Cd (II), Zn (II) ions and MB was observed upon functionalization as well as when Si/Al ratio increased. Kinetic studies showed that a pseudo- second order model was more suitable than the first order in explaining the adsorption mechanism. This indicated that the adsorption transient behaviour used valence forces or exchangeable electrons and that chemisorption was more pronounced in the rate determining step. Thermodynamic studies revealed that the adsorption process was endothermic and physisorption since values of ∆H° obtained were < 40 kJ/mol. From the adsorption data, it‟s evident that synthesized geopolymers are potential adsorbents for removal of heavy metals and MB and may be employed in wastewater management.Item RISK ASSESSMENT DUE TO NATURALLY OCCURRING RADIOACTIVE MATERIALS IN KILIMAMBOGO, KENYA(2023-12) NYAMBURA CATHERINEMan is continually exposed to ionizing radiation whose main origin is either natural or artificial. The primordial radionuclides found in building materials are important sources of radon and thoron in the indoor air. The main objective of this research was to assess exposure due to radioactive elements in indoor air, crops and building materials (soil and rocks), and determine the level of the risks. The concentration levels of radon, thoron, and thoron progeny were measured in mud-walled, iron sheet walled, and stone walled modern houses in Kilimambogo region, Kenya. Radon and thoron concentration levels were determined using passive radon–thoron discriminative monitors (RADUET), while thoron progeny levels were measured using thoron progeny monitors. The activity concentration of 226Ra, 232Th and 40K present in the different environmental samples like rocks, soil, and cassava crop were determined using a Thallium- activated sodium-iodide scintillation (NaI (TI)) detector Model TS-2L. Elemental concentration in water samples was determined using an atomic absorption spectrophotometer (AAS). The mean external dose received indoors by the residents due to radionuclides present in rock and soil samples was measured to be 0.91 ± 0.26 mSv y-1 and 0.86 ± 0.19 mSv y-1 respectively. This is comparable to the total exposure dose limit of 1 mSv y-1 recommended by ICRP for members of the general public. This means that, soil and rocks in the region does not pose any radiological risk to the residents of Kilimambogo region. Consequently, they can be used for agriculture and construction of dwellings. The doses received due to intake of cassava tubers and leaves was 1.82 ± 0.60 mSv y-1 and 0.81± 0.30 mSv y-1 respectively, totaling to 2.63 ± 0.70 mSv y-1. The ingestion dose contributes to 42.1% of the total dose received by the resident from measured sources. Residents should therefore reduce the intake of cassava. The annual effective dose received by the residents of Kilimambogo and Gatuanyaga regions due to inhalation of radon and thoron was determined for the three types of dwellings, from their respective progenies and found to be 1.3 ± 0.2 mSv y-1, 1.1 ± 0.1 mSv y-1 and 1.4 ± 0.2 mSv y-1 for radon progeny and 2.4 ± 0.4 mSv y-1, 0.5 ± 0.1 mSv y-1 and 1.5 ± 0.2 mSv y-1 for thoron progeny in mud-walled, iron sheet-walled and stone-walled houses respectively. It was observed that, residents living in iron sheet - walled houses with cemented floors received the lowest doses from inhalation of the radon isotopes hence such houses are safer than other types of dwellings. Residents living in mud houses and uncemented houses should consider improving the ventilation of their houses to reduce radiation exposure. The lifetime cancer risks for the residents due to intake of metal carcinogens, Cd, Ni and Pb in borehole and surface water was also estimated. The cumulative cancer risk in the borehole samples was 0.12 ± 0.06 and 0.19 ± 0.09 in the dry and wet seasons respectively. Those from surface water sources were 0.10 ± 0.07 and 0.21 ± 0.06 in the dry and wet seasons respectively. In both seasons, the cancer risks were much greater than the acceptable risks of 10-6 to 10-4 by a factor of 1000 and above. This indicates that about 10% of the residents are likely to die of cancer related ailments. RESRAD computer simulation code was used to estimate the doses received by the resident farmer and the quarry worker scenarios at time, t = 0 years. The doses received by the resident farmer and quarry worker scenarios were 0.22 mSv y-1 and 0.16 mSv y-1 respectively only for the external radiation pathway. This risk is low and does not pose any significant health risk to the residents. The data measured in this research will be used by future researchers as baseline study.