| dc.description.abstract | Western Province of Kenya has prevalence of grass-roofed traditional houses, where
cooking is done in open fire places using various biomass types, which leads to
accumulation of soot under the roofs. Polycyclic Aromatic Hydrocarbons (PAHs) result
from incomplete combustion of organic compounds and are emitted in gaseous phase,
which may adsorb on to soot particles, or particulate phase. Exposure to mixtures of . \ PAHs increases incidences of cancer in human populations. The high indoor temperatures
probably cause volatilisation of the adsorbed PAHs, leading to higher continuous human
exposure to PARs. Data indicate that cancer cases are rampant in the region, yet no
studies had been done to show potential causes of these cancers. The objective of this
study was to extract, characterize and quantify the levels of PAHs in accumulated soot in
grass-roofed houses in Western Kenya and to determine the variations in concentration of
PAHs in the accumulated soot with biomass type used and house age. The houses were
classified according to the predominant fuel source (perennial indigenous trees, exotic
trees, shrubs and crop residues, and dung), and house age (0-5, 5-10, >10 years). The
study design was factorial two, laid out in randomised complete block arrangements with
fuel source as the main factor and house age as the second factor. The soot samples,
collected from four houses in each sampling unit, were extracted by Soxhlet using
dichloromethane, cleaned on silica gel column and analyzed by gas chromatography
using open tubular capillary columns with flame ionization detector. Identification of
PAHs was based on retention times of authentic standards and verified by gas
chromatographic-mass spectral analysis. Quantification was based on peak area responses
using the internal standard method and concentrations corrected for recovery. Separation
of means and analysis of variance was done using a factorial two in randomized complete
block design model. The PAHs levels significantly (P~0.05) varied with biomass type in
the order: Dung ~ perennial indigenous trees ~ exotic trees ~ shrubs and crop residues.
Use of dung and wood from perennial indigenous trees as fuel should be discouraged
since they were higher emitters (P~0.05) of PAHs. The PAHs emitted during indoor
biomass burning significantly accumulated (P~0.05) in soot with time. The accumulation
patterns of some PAHs varied (P~0.05) with variation in biomass type used. These results
indicate that indoor burning of biomass fuel emits. PAHs which accumulate in the
accumulated soot; posing health risks to the inhabitants. | en_US |
