PHD-Department of Environmental Health

Permanent URI for this community

https://repository.ku.ac.ke/handle/123456789/5942

Browse

Browsing PHD-Department of Environmental Health by Subject "Nairobi City County"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.