Transcript Analysis of Ground Water quality Around Open Dumpsites in Lagos

Baseline Analysis of Ground Water Quality Around Open Dumpsites in
Baseline
Analysis
of Ground
Quality
Around
Open Dumpsites
Lagos,
Nigeria:
Focus on Water
Polynucelar
Aromatic
Hydrocarbons
( PAHs) in
Lagos, Nigeria: Focus on Polynucelar Aromatic Hydrocarbons
By Mayowa Dayo
.
Introduction to Study Area
Lagos State (aka. Las Gidi, Eko) ~ 60% of
Nigeria’s industrial and commercial
centers (1). Situated on the Southwestern
coast of Nigeria
It has the largest population of people
(15-17million) and the smallest
geographic area (1)
In 1996 Lagos State Environmental
Protection Agency (LASEPA) was
established.
Major dumpsites are located in
neighborhoods of people with lower
income.
Background
Dumpsites
Open dumps are the simplest and
cheapest method of disposing of
waste
Primary means of waste
management especially in
developing countries (3).
Water infiltrates and permeates
through dumpsites producing
leachate, which may contain
undesirable and toxic chemicals.
Motivation: The need to categorize
the long-term effects of
environmental pollution on the
health outcome of exposed people
in nearby communities.
Polynucelar Aromatic Hydrocarbons
PAHs
PAHs are a type of organic compounds that
are produced when complex organic
substances are exposed to incomplete
combustion or high-pressure processes.
PAHs occur naturally but mostly produced
through anthropogenic sources such as
burning of refuse, tires, petroleum, coal,
motor exhaust and smoking.
Modes of exposure include ingestion,
dermal contact & inhalation.
The main pathway of carcinogenesis is
through PAH metabolite interaction with
DNA.
Why PAHs: known carcinogens & chronic
PAH toxicity may lead to increased risk for
cancer such as skin, lung, bladder, liver &
stomach cancer
Aims and Hypothesis
Aims:
To determine spatial distances between major dumpsites and
usable water catchments and to graphically depict populations at
risk to PAH exposure due to geographic proximity to dumpsites
in Lagos
To determine the baseline level of PAHs in groundwater aquifers
around 2 dumpsites in Lagos, Nigeria
To determine the increased risk of cancer in people that
consume polluted water.
To create a policy brief aimed at LASEPA and other responsible
bodies in Lagos, Nigeria.
Hypothesis:
Ground water around open dumpsites in Lagos is contaminated
with PAHs
Methods
Sampled wells & boreholes in
houses around Olushosun and
Solous dumpsites
6 samples from Olushosun & 8
from Solous collected over two day
period (July 9th and July 10th). And 2
control samples
GPS used to collect coordinates of
each dumpsite and sampling site.
Data on temperature, pH, distance
of well/borehole to dumpsite, water
depth and well depth were collected
on site.
Chemical analysis performed at
LASEPA using GC/FID method
for PAHs.
Samples were analyzed for the
presence of 18 PAHs commonly
found in drinking water.
Research in Progress
Continued statistical analysis
T-test to compare means of PAHs found in each site
1-sample t-test with maximum contamination level of PAHs in drinking
water (as proposed by EPA , 0.2 ppb) as predefined value.
Risk assessment modeling
Hazard - Can the Identified agents present a carcinogenic hazard to
humans and under what circumstances?
Dose - At what level of exposure might effects occur?
Exposure – what are the conditions of human exposure
Risk – character of the risk? How well do data support conclusions?
Uncertainties
Questions?