Assessment of Heavy Metal Concentration in the Environment and Perceived Health Risks by the Community around Kadhodeki Dumpsite, Nairobi county
Loading...
Date
2014-02-22
Authors
Njagi, Joan Murugi
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Solid wastes constitute a disaster for human health and environmental
degradation. Dumpsites in Kenyan urban settlements are used as sources of
nutrient rich soils for cultivating crops without regard to the risks of perceived
toxic heavy metal pollution from the wastes. Water sources near the dumpsites
are used as domestic water source for the people living near such sites. This
water is often contaminated by toxic heavy metals leaching from the dumpsite.
Heavy metals are known to accumulate in the plants then passed to the humans
through the food chain. Prolonged consumption of unsafe concentrations of
heavy metals through foodstuffs may lead to the accumulation of heavy metals
in the humans causing disruption of numerous biochemical processes. The aim
of this study was to determine the level of heavy metals in the vegetables, soil
and water samples collected around Kadhodeki dumpsite. The study also sought
to assess the knowledge, attitude and perceptions of the health risks posed by the
site to the residents of the village. Heavy metal determination samples collected
was carried out using X- ray fluorescence (XRF) analytical method. A
descriptive cross sectional survey was carried out to assess the knowledge,
attitudes and perceptions of people living around the study area. The analytical
data was subjected to statistical tests of significance using ANOVA and post
hoc analysis by Tukeys test (P<0.05) to determine whether there was any
significant difference between the study sites. Chi square was used to
determine if there were associations between the study variables in the survey.
The research found that the vegetables under study had low levels of essential
metals Fe, Mn, Zn and Cu while they had higher levels of Ni, Co, V, and more
than maximum allowable levels (MAL) of Hg and Pb. V, Mn, Cu, Ni, Hg
concentrations in the soil were higher than MAL for agricultural soils while Fe,
Zn were within the limits. The water was contaminated by high than allowed
levels of Mn (366-856 μg/l) and Fe (5132-12402 μg/l) in drinking water while
Zn (40-336 μg/l) was below the WHO limits. The people living in Kadhodeki
village had inadequate knowledge about the health risks which was
significantly associated with the level of education (χ2 = 20.86 df=1 P<0.01). A
significant association between level of education and perception was also
revealed (χ2=13.57, df=1, p<0.01). Insignificant associations between age and
the number of years the participants had lived in the village were found for the
variables of knowledge, attitude and perception. Health education to the people
living in Kadhodeki village on the dangers posed by the vegetables grown
around the dumpsite should be done to prevent further consumption of
contaminated crops. Farmers growing edible crops around the site should be
advised to stop doing so and instead encouraged to grow other crops which can
provide some earning and at the same time reclaim the land.
Description
Department of Community Health