CHARACTERIZATION AND QUANTIFICATION OF
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OESTROGENIC ENDOCRINE DISRUPTORS IN
LAKE VICTORIA IN TANZANIA, UGANDA AND
KENYA
Venue: Entebbe, Kampala, Uganda
Date: 25th to 28th May 2014
VicRes Scientific Conference
Mdegela, R.H1., Mbuthia, P.G2., Byarugaba, D.K3., Mabiki, F1.,
Msigala, S1., Waweru, P. K2., Saphan, M3 and Mwesongo, J1
LAKE VICTORIA
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
Sub-optimal productivity
of fish in Lake Victoria
• Climate challenge –
global warming
• Overfishing
• Diseases – Infectious
and non-infectious
•
•
Pollution - Point and
non-point sources
THREATS FROM POLLUTION
3
Increased human
population
 Unplanned (informal)
settlements
 Poor management of
wastes
 Direct disposal of
wastes in water
bodies (Rivers &
Lake)

POLLUTANTS OF CONCERN
4

Conventional
group of pollutants
and challenges
Pesticides
Heavy metals

Emerging group of
pollutants and
challenges
Endocrine
disruptors
Pharmaceuticals
Justification
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






Exposure of fish to oestrogenic endocrine
disruptors:
Alter normal functions of natural hormones
responsible for critical physiological processes
A challenge of great concern worldwide
Many Developed countries, have determined:
Sources, concentrations, identities,
Health effects in aquatic & terrestrial animals
In developing countries, such studies are limited
Environmentally Important Oestrogens
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Oestrogenic hormones include:
17 β -estradiol – β E2 17α-estradiol – α E2
Estriol - E3
Estrone - E1
Mestranol - M
17α-ethynylestradiol – EE
 Important characteristics
Low water solubility
Associated with suspended solids

Aim of the study
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
To detect and quantify selected
oestrogenic endocrine disruptors in water
in Lake Victoria in view to assess their
contribution to health status of fish
STUDY AREA:
LAKE VICTORIA, MWANZA GULF
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Maganga beach, Nyashishi River, Butimba
River, Nyakurunduma River, Mirongo River, Old
Igombe Landing site, Butuja, Shede and
Kigongo Ferry (9 sites)
Lake Victoria, Napoleon Gulf, Jinja, Uganda
Rwebitookeisland, Bidico, Wairaka, wanyange,
Masese, kakira, wanyange drainage, kirinya-fish
industry, kirinya–leatherindustry,
NWSC, and area with no human activity (11 site)
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Figure 1: Lake Victoria, Winam Gulf, Kenya
Railway sewage, Tilapia beach, Dunga, Rivers: Kisat,
Luanda, Otiako, Nyamasaria, Tako, Wigwa, Auji & Kibos (11
sites)
•Homabay landing site, Rivers: Awach, Nyakwanya, Arujo (4
10 sites)
Collection of water samples
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
Three water samples were collected from
each of the sampling points that included
Inshore
Intermediate point 1(00 meters from
inshore)
Offshore (500 meters from the inshore)
Rivers (100M before entry into lake)
At entry point into the lake
At 500 meters from the river entry points
Collection of water samples
(cont……)
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
Water samples
were collected in
clean 2.5 liter
glass bottles

Extractions done
within 12-24
hours after
collection
Fish samples
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



Mwanza: Live Tilapia fish were fished where all the
water sampling points converged.
In Jinja (Live 44 Tilapia),
Kisumu and Homabay (71 Tilapia and 52 Nile
perch) live fish samples were caught from the
selected water sampling sites and others purchased
from fishermen at the landing sites.
Each fish sampled was examined for gross and
histopathological lesions externally and internally.
Extraction of pollutants in water
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
Extraction of water
samples carried out
according to Swart
and Pool (2007)
with minor
modifications
Detection and quantification
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The detection and quantification used
Estrogen (El/E2/EE) ELISA KIT
 Competitive ELISA technique as per
manufacturers recommendations
 Total oestrogens (E1, E2 and EE)
Estrone(E1),
17-β Estradiol (E2)
Ethynylestradiol (EE)

Results: Validation of the Assay
1.4
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
y = -0.3446x + 1.7173
R² = 0.9314
Absorbance (450 nm)
Absorbance (450 nm)
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1.2
y = -0.2825x + 1.4855
R² = 0.9856
1
0.8
0.6
0.4
0.2
0
0
0.016
0.16
1.6
(a) Concentration of total oestrogens in water
extract from a sewage pond effluent (pg/L)
0
0.05
0.15
0.5
3
(b) Concentration of total oestrogens in standards
(µg/L)
Degree of agreement of the two established
correlation coefficients was 94.5%
Results: Total estrogenic EDs (mean ± SD)
concentration (pg/L) in water at different sites
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Rivers at entry
a
Rivers before entry
b
Off shore
Intermediate
Inshore
a
a
a
50
100
150
200
Concentration of total oestrogens (pg/L)
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Results: Total estrogens concentration (ng/L)
in Homabay, Kenya
Results: Total oestrogens, Estrone and
Estradiol (ng/L) in water from different sites
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Beach offshore
Beach intermediate
Beach landing site
E2
E1
Total
Rivers offshore
Rivers entry point
Rivers before
0
500
1000
1500
Concentration (ng/L)
2000
3.5
Concentration of estrogens (μg/L)
3
2.5
2
Conc. Total Es
Conc. E1
1.5
Conc. E2
Conc. EE2
1
0.5
0
0m
20
100m
500m
C3/1
Site of sample collection
C3/2
C3/3
Results: Comparison of estrogens levels
(μg/L) in Napoleon Gulf and selected
waste water sites in Kampala Uganda
Summarized Eds Results
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Mwanza Gulf:
1. Total oestrogens - 0.39 – 38.9 ng/L
2. Estrone (E1) - 0.37 – 6.36 ng/L
3. 17-β Estradiol (E2) - 0.0021 – 0.12 ng/L
4. Ethynylestradiol (EE) - 0.0026 – 0.032 ng/L

Summarized Eds Results
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
1.
2.
3.
4.
Napoleon Gulf
Total oestrogen -200 800 ng/L
Estrone (E1) - 9.8 - 49
ng/L
17-β Estradiol (E2)- 145
- 305 ng/L
Ethynylestradiol (EE) 45
- 360 ng/L

Kisumu
Total Estrogen
- 0.57 – 64.21 ng/L
1.

Homabay –
Total Estrogen
- 0.35 – 3.63ng/L
1.
Gross Abnormalities in Fish
1. Missing tail/fins
- 18.3 %
2. Missing eye/opacity
- 17.3
3. Deformed body
- 11.5
4. Deformed head (jaw, face) heart - 8.7
5. Kinked back and tail
- 6.7
6. Abnormal body color
- 3.8
7. Growth on back
- 3.8
8. Operculum absent
- 2.9
9. Missing scales
- 1.9
10. Dropsy
- 1.0
11.Splenic granulomas/ increased MM
12.Cystic formation in gonads - 2.4
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13.Aspermia, cystic and atretic gonads
Dorsal fin starting from the middle of
the back
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25
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Prevalence of lesions in gonads
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Prevalence of lesions in gonads
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Cysts embedded in the testicular parenchyma: 2.4%
Loosely attached fluid filled cysts: 1.2%
Histopathological Lesions
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Discussion/Conclusions
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
All water samples analyzed were positive
for total, E1, E2 and EE oestrogenic
endocrine disruptors

Some areas had low concentrations,
similar finding to other studies (Campbell
et al., 2006)

Although low, their potential impact on fish
health must be considered
Discussion/conclusions
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


In all countries highest estrogens concentration were
detected in rivers 100 meters before and at entry
point into the lake, fish landing sites and water from
sewage treatment plants.
Significant difference (P<0.05) was observed for
estrogens levels in river water samples and different
lake sampling points.
This study shows existence of oestrogen EDs at
different concentrations, and rivers are the main
sources of pollutants into Lake Victoria.
Conclusions/recommendations
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
Findings from this study therefore calls for
intervention that would minimize the
discharge of domestic waste water into
the rivers and eventually into the lake

Measures for treatment of polluted water
before being discharged into the lake
should be among target strategic points
Conclusions/recommendations
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
Oestrogenic pollutants be considered
among emerging pollutants in developing
countries

Further studies
 Profiling of oestrogenic pollutants
 Effect studies of oestrogenic endocrine
disruptors in fish
ACKNOWLEDGEMENTs
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SIDA –
 VICRES PROJECT
 IUCEA
 UNIVERSITY OF NAIROBI
 SOKOINE UNIVERSITY AGRICULTURE
 MAKERERE UNIVERSITY
 ALL LAKE VICTORIA – FISHERIES
STAKEHOLDERS

THANK YOU FOR LISTENING & SUPPORT
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