| dc.description.abstract | The issue of pesticide residues arising from
pesticide use in controlling pests of agricultural,
veterinary and domestic importance may be considered
a recent world wide concern. Especially notorious
are the organochlorine insecticides which are persistent
and highly lipid soluble leaving residues in various
forms of life as well as the atmosphere, soil and
water. Presence of residues in food intended for
human consumption is undesirable as these chemicals
are poisonous and long-term exposure co"uld pose a
health hazard to man.
Realising the potential dangers of pesticide
residues and with the intention of protecting
consumers, most developed countries have set up
national food monitoring laboratories which carry out
frequent checks on the residue levels in both agricultural
and animal products. They have also set national
tolerances for pesticides in different commodities.
Despite the fact that organochlorine insecticides
have been used over the years for various purposes
in Kenya, there is little published information
regarding the pesticide residue situation in the country,
and also a general lack of co-ordinated research aimed
at realising this vital goal. National tolerances
for organochlorines in milk have been set by the
Kenya Bureau of Standards but for most other commodities,
the·Bureau has to rely on the FAO/WHO Codex Alimentarius
Commission's guidelines.
The aim of this study was to establish if organochlorine
pesticide residues occur in poultry products,
in Kenya and if they do, what their nature and levels
are. As part of the study, the risk to consumers of
such products was to be assessed by comparing detected
levels to Practical Residue Limit (PRL) levels set by
the Codex Alimentarius Commission.
One hundred and five chicken fat samples and aft
equal number of egg samples were collected from seven
different areas around Central Kenya and formed the
main part of the study. A subsidiary lot of forty
egg samp Le s were taken from the Coast Province.
Samples were taken from farmers on commercial as well
as small scale poultry establishments in the selected
areas.
The samples were processed using multiresidue
analytical methods which included both liquid-liquid
partitioning and column chromatographic clean up
procedures. Pesticides were then determined by a
Packard Model 128 Gas Chromatograph with an Electron
Capture detector employing a 63 Ni radioactive source
and Nitrogen as the carrier gas. Confirmation of
suspected residues was done by gas liquid chromatography
on the same instrument but employing a different
column.
A total of twelve organochlorine compounds were
detected from the two types of samples, the number of
compounds detected varying from one sample to the
other. Ten of the twelve compounds were allocated
to four groups, the~e being Lindane, Dieldrin
(comprises aldrin and dieldrin), Heptachlor (comprises
heptachlor and heptachlor epoxide), and the DDT
group (pp-DDT, pp-DDE, pp-DDD, op-DDT and op-DDD) .
rr_ and S-BHC were the other two compounds detected.
Of the one hundred and five chicken fat samples
examined, 99 samples (94%) were positive for lindane,
1 among these having a-level above the Codex Alimentarius
Commission's practical residue limit for lindane in
chicken fat; 16 samples (15%) were positive for heptachlor;
65 (62%) were positive for dieldrin; while
101 (96%) were positive for DDT, 2 (2%) among which
had levels above the PRL for DDT. Of the one hundred
and five egg samples in the main part of the study,
15 samples (14%) were positive for lindane with none
in which residue levels exceeded the practical residue
limit for lindane in eggs, none of the 105 samples
were positive for heptachlor; 40 samples (38%) were
positive for dieldrin; and 90 (86%) were positive
for DDT with 18 (17%) among these having levels above
the PRL for DDT in eggs. Of the fourty egg samples
from the Coast Province, seven (17.5%) were positive
for lindane; none were positive for either heptachlor
or dieldrin; while 33 samples (82.5%) were positive
for DDT, 6 (15%) among which had DDT residue levels
exceeding the PRL .• The highest incidence among the
two types of samples was for the DDT group followed
by lindane, dieldrin and lastly heptachlor.
The results of the study show that only in the
case of DDT (total) in eggs did the mean residue
concentration exceed the practical residue limit.
Notwithstanding the few individual values of other
compounds which exceeded the PRL values, the general
indication is that except for DDT in eggs, a serious
pesticide residue problem does not exist in the two
poultry products examined. | en |
