dc.contributor.author | Mwaura, S | |
dc.date.accessioned | 2013-05-08T15:01:01Z | |
dc.date.available | 2013-05-08T15:01:01Z | |
dc.date.issued | 2003 | |
dc.identifier.citation | Mwaura, S(2003). An Assessment of potential Health hazards in sweetpotatoes (ipomoea batatas) / grown and consumed in urban areas" around Nairobi | en |
dc.identifier.uri | http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/20419 | |
dc.description | Msc-Thesis | en |
dc.description.abstract | This study was carried out to investigate the safety of urban grown food crops
with respect to contamination by heavy metals. Sweetpotatoes, grown and
consumed around Nairobi, were used as the reference food crop.
This study involved laboratory analysis and a dietary survey. In the laboratory
analysis, levels of cadmium and lead in sweetpotatoes, soils and water were
determined. The survey was conducted at Kangemi location in Westlands
division for the purpose of determining the amounts of sweetpotatoes eaten in a
typical peri-urban low-income population, and hence postulate approximate
amounts of cadmium and lead ingested by the consumers of sweetpotatoes in
the population.
The sweetpotato samples were collected along the banks of Nairobi River and
along the roadsides of Thika-Nairobi freeway. Soil and water samples were also
collected to determine whether there existed a correlation between the levels of
cadmium and lead in the sweetpotato samples, soil and water. Effects of
cooking, variety (White and orange fleshed) and distance from the kerb sides (5
and 10 metres) on the levels of cadmium and lead in sweetpotatoes were also
investigated. In the survey, 24-hour recall was used to determine consumption
levels in different age-categories. Subjects in the survey were selected
purposively.
The results of the study showed that; Distance from the freeway had no
Significant difference (p> 0.05) in the levels of cadmium and lead. However,
higher concentrations were found nearest the kerbsides. There was significant
difference (p< 0.05) in the levels of lead and cadmium across the up-stream and
down-stream sections of Nairobi River. There was no significant difference (p>
0.05) in the levels of lead and cadmium across the orange and white-fleshed
varieties. There was no significant difference (p>0.05) in the levels of lead and
cadmium in cooked and raw sweetpotato samples. Levels of both lead and
cadmium in sweetpotato samples showed a positive relationship with those found
in the soil and water with correlations of 0.73 and 0.74 for soil and water
respectively.
Generally, consumers of sweetpotatoes grown within the city consume both lead
and cadmium in excess of FAO I WHO provisional tolerable intakes. The highest
amounts of lead and cadmium that were ingested by the study subjects were 0.1
mg Pb I Kg b.w I week and 0.01 mg Cd I Kg b.w I week against provisional
tolerable weekly intakes of 0.05 mg I Kg b.w I week and 0.007-0.008 mg I Kg b.w
I week for lead and cadmium respectively. | en |
dc.description.sponsorship | University of Nairobi | en |
dc.language.iso | en | en |
dc.subject | Potential Health hazards | en |
dc.subject | Sweet potato (Ipomea batatas) | en |
dc.subject | Urban areas | en |
dc.subject | Nairobi | en |
dc.title | An Assessment of potential Health hazards in sweetpotatoes (ipomoea batatas) / grown and consumed in urban areas" around Nairobi | en |
dc.type | Thesis | en |
local.publisher | Department of Food Science, Nutrition and Technology, University of Nairobi | en |