PHD-Department of Environmental Health

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Browsing PHD-Department of Environmental Health by Subject "Kenya"

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    Acrylamide determination in selected plant-based foods and associated health risk among consumers in Kibera informal settlement in Nairobi City County, Kenya
    (Kenyatta University, 2023) Towett, Anne Chepngeno
    Acrylamide is a chemical substance classified as a genotoxin, neurotoxin and a Group 2A carcinogen. It can contribute largely to the disease burden in the world. Acrylamide has been used over time in various ways. It was demonstrated to be present in food as a food processing contaminant in the year 2002. It was found to be in significant amounts in commonly consumed foods. Dietary acrylamide is a key contributor to the exposure of acrylamide in human beings. The leading sources of dietary acrylamide include potato products, cereal products and roasted coffee. The study aimed at determining acrylamide in selected plant-based foods and associated health risk among consumers in Kibera informal settlement in Nairobi City County which was selected purposively. An analytical cross-sectional research design was used to carry out the study. The sample sizes for vendors and consumers were determined using Kothari’s and Fisher’s formulae, respectively. Study participants included 248 vendors and 384 consumers of selected foods who were recruited using convenience sampling technique. Research instruments included researcher- administered closed-ended questionnaire for food vendors and food frequency questionnaire for consumers. Step-on body weight scale was used to take consumers’ weights. A laboratory 4-digit weighing scale was used to weigh the food portion sizes. A total of 162 food samples were collected. A fine blade blender was used to grind and homogenize collected food samples while high performance liquid chromatographyultraviolet (HPLC-UV) machine was used to quantify acrylamide in food samples. Acrylamide was detected in all the samples analyzed. The highest acrylamide concentration was found in crisps (246.9µg/kg) and the least was found in mandazi (44.1µg/kg). All wheat-based samples exceeded the acrylamide Benchmark level (50µg/kg). The average acrylamide knowledge of vendors was 25.8% (poor) and that of consumers was 27.2% (poor). There was a statistically significant difference (p = 0.000) between acrylamide means of food groups analyzed. Acrylamide content was statistically significantly higher in coffee (p<0.05) than in all other food samples. Chapatti contributed most of dietary acrylamide intake at 38.19% with a mean exposure of 0.097 µg/kg bw/day. The average dietary acrylamide intake from the selected foods was 17.008µg/day. All the MOEs computed for consumption of all the selected foods were below 10,000 implying possibility of public health risk for neoplastic effects. All MOEs computed for peripheral neuropathy were of no public health concern. The research concluded that based on the BMDL10 for neoplastic effects, there is a possibility of public health risk for the MOEs below 10,000. The research recommends a diversification of diet by consumers so as to minimize consumption of acrylamide loaded foods. The results are beneficial to food safety teams in Kenya and beyond and also the community where the study was conducted since the results will be an eye opener on acrylamide health related issues surrounding the communities.
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    Influence of Land Use and Land Cover Changes on Groundwater Recharge and Pollution in Stony Athi Sub-Catchment, Kajiado County, Kenya
    (Kenyatta University, 2023) Mathenge, Morris Wahome; Gladys Gathuru; Esther Kitur
    The global economic growth and population increase has translated into increased anthropogenic land use and land cover changes. Changes in land use and land cover have the potential of altering the hydrological cycle. In the Stony Athi sub-catchment of Kajiado County, Kenya, demographic pressure and urbanization have transformed natural rangelands into agricultural, industrial and real estate developments. The objective of this study was to investigate the influence of land use and land cover changes on groundwater recharge and pollution vulnerability between 1984 and 2017. Specifically, the study was undertaken to; (a) quantify the spatial-temporal extent and magnitude of land use and land cover changes that have occurred in Stony Athi sub-catchment between 1984 and 2017; (b) to estimate the spatial-temporal variations of groundwater recharge due to land use and land cover changes; and (c) to evaluate the influence of land use and land cover changes on groundwater vulnerability to pollution. Quantification of spatial-temporal extent and magnitude of land use and land cover changes was achieved by classifying four satellite images through the supervised classification algorithm and finally applying post-classification change detection technique. Results showed significant (p < 0.05) land use and land cover changes between 1984 and 2017 with an increase in built-up areas (0.04% - 3.4%), agricultural land (0.06% - 0.7%) and grasslands (58.2% - 71.6%), but a decrease in shrub land (37.1% - 21.1%) and forested areas (2.5% - 1.4%). Estimation of the spatial-temporal variation of groundwater recharge due to land use and land cover changes was done using WetSpass-M, a Geographical Information System-based Hydrologic Model. Results indicated a decrease in groundwater recharge from 13.8% in 1984 to 13.2% in 2017. However, the observed temporal variations were not significant at p < 0.05. Spatial variations of groundwater recharge indicated that the highest recharge occur in forested areas at 251.1 mm per year while the lowest recharge occur in bare land at 0.4 mm per year. A modified DRASTIC model was used to evaluate the influence of land use and land cover changes on groundwater vulnerability to pollution. Potential of groundwater pollution vulnerability was categorized using a vulnerability index based on the United States Environment Protection Agency classification. Results indicated that 87% of the study area remained under low vulnerability between 1984 and 2017. Areas under moderate vulnerability decreased from 12% to 9% while areas under high vulnerability increased from 1% to 4% over the same period. The observed temporal variations in groundwater pollution vulnerability were not significant at p < 0.05. It was concluded that the land use and land cover changes in the study area have an influence on groundwater recharge and its vulnerability to pollution, though not statistically significant at p < 0.05. This study recommends continuous monitoring of groundwater quantity and quality, not only in the study area, but also in areas undergoing rapid changes in land use and land cover. Such monitoring will contribute to sustainable groundwater resource management. Future research could focus on other factors, which might affect groundwater dynamics in the study area such as climate change.
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    Quantification, characterization and carry over effect of aflatoxin in broiler chicken raised in Nairobi City County, Kenya
    (Kenyatta University, 2023) Kirinyet, Ruth C.
    Aflatoxin is a threat and a food safety concern particularly in developing countries due to the climatic conditions that favor the growth of the aflatoxin fungi. Consequently, this a major risk to feed ingredients used in the manufacture of animal feed and subsequently is a great risk to human consumers due to the detrimental effects of these toxins as they are regarded as Type 1 carcinogens. For that reason, a study to establish the carry over effect of aflatoxin in broiler chicken was carried out in Nairobi City County as there is limited data. The specific objectives of the study were to quantify and characterize aflatoxin levels in broiler feed and broiler meat, to determine carry over effect from broiler feed into broiler meat and to assess the knowledge of farmers on aflatoxin in Nairobi City County. The findings will provide a scientific basis for the endorsement of regulations that are key in the decision making process and policy formulation of food and feed with respect to Aflatoxins.The study utilized a cross sequential study design which included both cross sectional and longitudinal study. The longitudinal study was done for six weeks which corresponded to the period of raising broilers from day old chicks to slaughter. Detection and quantification of aflatoxin levels in broiler feed and meat was done using the (LC/MS-MS) technique. A structured questionnaire on knowledge of aflatoxin was administered and multistage randomn sampling was used. Two FGD comprising of twelve members each among farmers in two sub counties were conducted. A pretest of the questionnaire was carried out in Kiambu County. SPSS version 26 was used for quantitative analysis of questionairres and STATA version 12 was used to carry out one way and two-way ANOVA for laboratory analysis. NVIVO soft ware was used for analysis of data from FGDs. Tukey Kramer post hoc test was used for comparison of means and statistical significance was determined at 5%. Ethical approval was sought from relevant authorities before commencement of the study and consent was sought from the participants before taking part in the study. Results of the study show that majority of the farmers (58.2%) had knowledge on aflatoxin. There was a significant association (p<0.05) between socio demographic characteristics of farmers and knowledge on aflatoxin. Aflatoxin levels in broiler starter were; B1(17.26±3.07), B2 (2.44±0.84), G1 (8.87±2.41), G2 (0.9±0.44) and Total AF (29.47±6.13). Aflatoxin levels in broiler finisher were B1 (17.17±3.09), B2 (2.68±1.18), G1 (9.25±2.7), G2 (1±0.45) and Total AF (30.1±6.88). There was a significant association (p<0.05) in AFB1 and Total Aflatoxin levels in the gizzard, liver and muscle per week. AFB1 levels in the gizzard were below the WHO/FAO limit of 5 ppb however they were above the EU limit of 2ppb in week 5 and 6. In the liver AFB1 levels were above the EU limit in week 4, 5 and 6 and above the WHO/FAO limit in week 6. In the muscle AFB1 levels were all below the WHO/FAO and EU limit. Total Aflatoxin levels in the liver were above the EU limit in week 4, 5 and 6 and above the WHO/FAO limit in week 6. In the muscle Total Aflatoxin levels were all below the WHO/FAO and EU limit. There was a statistical significant difference (p<0.05) in the carry over ratio of aflatoxin per week. The highest carry over ratio of >10% was observed in the liver, followed by the gizzard and the least was in the muscle. The highest transfer ratio was observed in week 5 and 6 in the liver and in week 6 in the muscle. The carry over ratio in the muscle was below 1%. This study concluded that the farmers had adequate knowledge on aflatoxin occurrence in feeds and methods to reduce the occurrence, but had no knowledge on carry over effect. Although there were appreciable amounts of aflatoxin in the broiler feeds and broiler meat, the carry over effect was low in the muscle but higher in the liver and gizzard. The study recommends that there is need constant monitoring of Aflatoxin levels in poultry feed & products by KEBS & national & county government and application of stringent allowable limits in feed and feed ingredients.
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    Treatment of Moderate Acute Malnutrition Using Plumpy Sup among Children Aged 6 to 59 Months in Turkana County, Kenya
    (Kenyatta University, 2022) Majwa, Philimon Omondi; Margaret Keraka; Sophie Ochola
    In Kenya, 26% of children are moderately stunted, 11.4% severely stunted, 6.7% moderately underweight, 2.6% severely underweight, and 13.0% moderately wasted, with 2.5% severely. In Turkana County, 25.6% of children are moderately stunted, and 17.4% are moderately wasted. Plumpy Sup is used to treat moderate acute malnutrition through the supplementary feeding programme. With the increased reports of relapse and overstay of children aged 6 to 59 months in the supplementary feeding programme, there is limited documentation of the effectiveness of plumpy sup in a community-based programme in Turkana county. This prospective cohort study assessed the effectiveness of Plumpy sup in the management of moderate acute malnutrition among 300 children aged 6 to 59 months in Turkana central sub-county. The study employed stratified and multistage sampling, with data collected via desk review, key informant interviews, focused group discussions, and household interviews. Data on child morbidity status was collected using a two -week-day recall period, while a 24-hour dietary recall was used to collect data on the type and amount of food that the child consumed. Nutrient analysis was done using the Nutri-surv software in conjunction with the Kenya Food Consumption Table. Descriptive and inferential statistics were used to analyze the variables of interest. Survival analysis and log-rank test were used to establish the recovery rate of the children. At the 90th day, the mean energy intake, 556.1±56.9 kcal per day, of children aged six to 11months was below the recommended daily allowance of 675 to 806 kcal; Protein intake for children aged 6 to 11 months was 11.3±3.9 g per day; while Carbohydrate intake was 74.3±5.7 g per day, all below the recommended daily allowance. Morbidity prevalence was high (76.3% at baseline) at with 39.3% suffering from malaria, 21.7% from diarrhoea, and 7.7% from an eye infection.. Access to water and sanitation services from baseline to day 90 was statistically significant except for treatment with traditional herbs. The median day to recovery was 84 days for females and 70 days for males. The difference observed in recovery rate between males and females was not statistically significant. There was a significant relationship between caregivers’ socioeconomic status and the recovery rate of children on day one and day 42. There was no statistically significant difference in caregivers’ attitude on IYCF and recovery rate for all the days. There was no statistically significant association, all p>0.05, between the effectiveness of Plumpy sup and the morbidity status of the child. On factors affecting the effectiveness of Plumpy sup, a full model containing all predictors was statistically significant, χ2 (8, N=300) = 17.847, p=0.022; the model could distinguish between children who recovered and those who did not recover.