Research Journal of Environmental and Earth Sciences 2(1): 36-38, 2010
ISSN: 2041-0492
© M axwell Scientific Organization, 2009
Submitted Date: November 17, 2009
Accepted Date: November 26, 2009
Published Date: January 10, 2010
Preponderance of Bisphenol-A in Harvested Rain Water in Enugu Municipality,
South East, Nigeria
1
C. M aduka Ignatius, 2 C. Ezeonu F rancis, 3 E. Neboh Emeka and 4 N. Shu E lvis
Department of Chemical Pathology, University of Nigeria Teaching Hospital {UNTH},
PM B. 0112 9, Ituku-O zalla, Enug u State. Nig eria
2
Departm ent of Applied Biochemistry, Nnam di Azikiw e University (N AU ),
PM B 5025 Aw ka. A nam bra State. Nigeria
3
Department of Chemical Pathology, College of Medicine, Enugu State University of Science
and Techno logy (ESUT ), Park Lane, Enugu State. Nigeria
4
Department of Pharmaco logy and T herapeutics, College of M edicine, U niversity of
Nigeria Enugu Campu s (UNEC ). Enugu State Nigeria
1
Abstract: Bisphenol-A (BPA), a plasticizer, used in the manufacture of plastics and a well-known endocrine
disruptor has been known to lead to various health hazards. The present study is aimed at estimating the BPA
content of harvested rainwater in Enugu municipality, Nigeria, henc e its preponde rance. BP A levels w ere
estimated in harvested rainw ater samples stored in plastic storage drums (n= 24) and metal tanks (n=48). A ll
the 48 storage devices were in constant use for over 6 months and were used to continually harvest rainwater
for dom estic uses. 40 drinking tap water samples were also analyzed alongside the rainwater as control. BPA
was analyzed u sing E colog enia ® Supersensitive B PA ELIS A kit, from Japan Enviroche micals Ltd, Japan. The
results show a statistically significant increase (P=0.0227) in the BPA level of rainwater compared to the
drinking tap water. A comparison of the two storage containers shows a highly significant increase (P= 0.0003)
in the rainwater stored in the plastic containers co mpa red to that in me tal containers. B PA tends to be highly
increased in rainwater in the region, possibly due to increased industrialization, with greater amount in samples
stored in plastic containers than that stored in metal containers. This may be attributed to leaching from the
plastics. Both drinking of harv ested rainw ater from the region an d water stora ge in plastic containers should
be discouraged.
Key w ords: Preponderanc e, Bisp henol-A, harvested rain water, endocrine disruptor, Enugu and N igeria
INTRODUCTION
In recent years, a growing body of scientific research
indicates that substances in the environment may interfere
with the normal function of the endocrine system of
humans and wildlife. These compounds may be manmade (so called xenoestrogens), such as industrial
chemicals, crop protection chemicals, or they may be
natural like the phytoestrogens (Lintelmann et al., 2003).
Fish in Detroit River and Lake St. Clair have been
detected with sexual abnormalities and scientists say they
may be linked to estrogen, or chem icals that mimic
estrogen, showing up in waterways (Danzo, 1998). The
increasingly widespread use in recent years of exogenous
estrogenic and progestational hormones, coupled with the
normal excretion of natural hormones in urine has raised
concern about the concentration in wastewater (Taback
et al., 2003). BPA is a plasticizer used in the manu facture
of plastics and u pon discharge to the environmen t;
bisphenol-A (BPA ) is distributed betwee n air, water,
soils, sediments, and biota compartments (Cooper and
Kavlock, 1997). Based on moderately high water
solubility, the very low vapor pressure (5.32 x 10G 6 P a at
25ºC), and the low Henry’s Law constant (10G 5 – 10G 6 P a
m 3 /mol), it is concluded that bisphenol-A may have the
tendency to partition into water and that the rate of
evap oration from soil and water will be low .
Therefore, transportation of bisphenol-A in the
aquatic environment is considered to be the predominant
pathway for distributing the compound between
environmental compartments (Lintelmann et al., 2003).
In the receiving water, Bisp henol-A is expected to
partition into particulate matter, sedim ents and biota. The
half lives in sediments; surface water and ground water
indicate that bisphenol-A is persistent (Lintelmann et al.,
2003). The ab iotic degradation o f bisphenol-A in wa ter is
assumed to be negligible, because the molecule contains
no hydrolyzable functional groups. It has been reported
by Mihovec et al. (2002) that the concentration of
environmental hormones in surface and ground water are
less than 10 ppb and rarely exceeds 10 ppm.
Corresponding Author: C. Maduka Ign atius, D epartm ent of Chemical Pathology, University of Nigeria Te achin g
Hospital (U NT H), PMB. 01 129, Ituku-O zalla, Enugu State. Nige ria
36
Res. J. Environ. Earth Sci., 2(1): 36-38, 2010
Table 1: BPA level (mg/l) in the Tap and Rainwater Samples
Tap water (n=40)
Harvested Rain water
(n= 48)
25% perc entile
0.11
0.11
75% perc entile
0.29
0.60
Minimum
0.01
0.03
Maximum
0.52
0.92
mean
0.20
0.40
median
0.20
0.35
standard deviation
0.07
0.16
standard error
0.03
0.09
l ow e r 9 5 % C I
0.14
0.20
u p pe r 9 5 % C I
0.27
0.59
P-value
0.0227
There appears to be a worldwide concern over
decreasing huma n sperm concentration but this has been
highly controversial (Seshagiri, 2001). Decreasing sperm
counts are attributed to the deleterious effects of
environmental contamination by heavy metals and
estrogenic chem icals like BPA (Mehta and A nandk umar,
1997; Beno ff et al., 2000; Sh arpe, 2000 ). Apart from their
effect on ho rmones, these tox ic chemicals can m utate the
DNA of our bodies, disturbing the normal nucleotide
sequence (Danzo, 1997). The body has an emergency
response team of enzy mes to straighten out the mess made
by the environmen tal toxins (Latini et al., 2004). There
have been many reports on endocrine disruptors but none
had been done on its p reponderance in this region.
Due to paucity of information about this group of
compounds in Nigeria and the presence of plastic and
chemical industries in this region, also because most
people in the region make use of harvested rainwater as
their source of drinking water, the study is aimed at
estimating the BPA level in harvested rain w ater from this
region and also the effect of storage containers on the
level of BP A in harve sted rain water, hence the
predisposition of individuals residing in the locality to the
possible dangers of hormone disruption .
Tab le 2: T he effect of storage container on BPA level (mg/L ) in
Harvested Rainwater
Metal Container
Plas tic Container
(n=24)
(n=24)
Mean
0.14
0.65
Standard deviation
0.06
0.10
P-Value
P=0.003
Batch No. T2KSI of 2007. Samples and standards were
analyzed in duplicates and the average used for the
calculation. Internal quality control serum was used for
each batch of the assay.
An alysis of Results: Results were expressed as mean ±
standard deviation (± S D). Significant differences
between means were determined by students T-test
using graph pad p rism co mpu ter softw are pro gram me.
MATERIALS AND METHODS
Design and conduct of the water study: Potable water
samples (harvested rain w ater and tap w ater) were
harvested from different parts of Enugu and its environs,
South-East Nigera. W ater sam ples w ere random ly
collected from different parts of the town.
A total of forty (40) tap water and forty-eight (48)
rain water samples were randomly collected for BPA
study. Twenty-four (24) of the harvested rain water
samples have been stored in plastic containers whereas
the remaining twenty-four (24) were stored in metal
storage tanks for more than a period of six (6) months.
The study was conducted at Life Care research and
diagn ostic Laboratories in Enugu, southeast Nigeria
between the periods of September 2008 and June 2009.
RESULTS AND DISCUSSION
Table 1 show s the co lumn statistics of B PA (mg/l) in
the studied water sam ples. Mean ± SD , BPA level of
0.20±0.07 and 0.40 ± 0.16:g/l, respectively were obtained
in tap and rainwater sources with median values of 0.20
and 0.35 :g/L. There is a statistically significant increase
(P=0.0227) in the BPA levels in the rainwater compared
to the tap wa ter.
There is a highly significant increase (P= 0.003) in
BPA in the harvested rain water stored in plastic container
compared to that stored in metal water container
(Table 2).
The level of BPA in harvested rain and tap water
sources in Enugu, Nige ria we re evaluated. The results
indicate presence of significant amount of both chem icals
in the w ater sam ples studied in this env ironm ent.
There was a statistically significant increase
(P=0.0227) in the mean BPA level of rain water compared
to the drinking tap water. This indicates a preponderance
of BPA in the harvested rain water compared to the tap
water sources. This might be attributed to the increase in
chemical and p lastic-related industries in the region, all of
which release this endocrine disruptor into the
environm ent. The appa rently lower amount obtained in
tap water may be attributed to a reduction in the level
during its treatment. The level obtained in this study
exceeds that recorded by the US Environmental
Sam ple collection: All the water samples were collected
from the various sou rces directly into clean, sterile and
dry glass test tubes. The samples were taken to the
laboratory immediately after collection and analyzed
within 7 days of collection.
Analytical techniques:
Sam ple Pre-T reatm ent: The water samples were
centrifuge at 3000g for 10 minutes and the supernatant
fluid filtered off. Methanol was added to the remaining
fluid to form a final methanol concentration of 10% (v/v)
Sam ple Analysis: BPA w as analyzed by ELISA method
(Cheesbrough, 2002) using ecological ® supersensitive
BPA ELISA kit from Japan Envirochemicals Ltd, Japan,
37
Res. J. Environ. Earth Sci., 2(1): 36-38, 2010
Protection Agency (Luks-Betlej et al., 2001) in municipal
drinking water despite the water treatment process.
In municipal drinking water, concentrations range
from less than 1ppb to 3 ppb (Luks-Be tlej et al., 2001).
This calls for se rious concern co nsidering the recorded
deleterious effects of this endocrine disruptor (Gray et al.,
1999; Ohlson and Hardell, 2000). The result also showed
a highly significant increase (P=0.0003) in BP A in
harvested rain water stored in plastic containers compared
to those stored in metal containers for periods greater than
six (6) m onths.
Food and bodily contact with PVC is hazardous
because of the various plasticizers and additives utilized
in it (Ohlso n and Hardell, 2000). B isphenol-A (BPA) is
the most common plasticizer in PVC. B PA leaches into
liquid and fatty produ cts packaged in it (Ohlson and
Hardell, 2000). The high level obtained from the plastic
containers in the present study may be associated to this
leaching from the plastic containers.
Cooper, R.L. and R .J.
Karlock, 1997. Endocrine
disruptors and reproductive
development. J.
Endocrinol., 152: 159-66.
Danzo, B.J., 1997. Environmental xenobiotics may
disrupt normal endocrine function by interfering with
the binding of physiological ligands to steroid
receptors and b inding proteins. Env iron. H ealth
Perspect, 105: 294-301.
Danzo, B.J., 19 98. The effects of en vironmen tal
hormones on rep roduction. C ell. Mol. Life. Sci., 54:
1249-1264.
Gray, L.E., J. Ostby, E. Monosson and W. Kelce, 1999.
Environmental antiandrogens. T oxico l. Ind. Health,
15: 48-64.
Latini G, C. De F elice and A. Verrotti, 2004. Plasticizers,
infant nutrition and reproductive health. Reprod
Toxicol., 19: 27-33.
Lintelmann, J., A. Katayama, N. Kurihara, L. Shore
and A. Wenzel, 2003. Endocrine disruptors in the
environment (IUPAC Technical Report). Pure. Appl.
Chem., 75: 631-681.
Luks-Betlej, K., P. Pupp, B. Janoszka and H. Paschke,
2001. Solid phase micro extraction of phthalates from
water. J. Chromatogr., 938: 93-101.
Mehta, R.H. and T.C . Anandkumar, 1997. Declining
semen quality in Bangalorean s: A preliminary rep ort.
Curr. Sci., 72: 621-622.
Mihovec, G.M., Z. Smit, D. Puntaric and J. Bosnir, 2002.
Phthalates in underground w aters of the Zagreb area.
Croat. Med. J., 43: 493-497.
Ohlson, C. and L. Hardell, 2000. Testicular cancer and
Oc cup ational e xp o su re s w ith a focus on
xenoestrogens in polyvinyl chloride plastics.
Chemosphere., 40: 1277-1282.
Sesh agiri, P.B., 2001 . Molecu lar insigh t into the causes of
male infertility. J. Bio. Sci., 26: 429- 435.
Sharpe, R.M., 2000. Lifestyle and environmental
contribution to male infertility. Br. Med. Bull., 56:
630- 42.
Taback, H.H., R.N. Bloomhuff and R.L. Bunch, 2003.
Steroid hormones as water pollutants, II. Studies on
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CONCLUSION
The toxic effect of BPA o n health is not in doubt.
This study established a high level of this substance in
harvested rainw ater stud ied in this environment esp ecially
that stored in plastic containers for more than six months.
This calls for serious environmental concern.
Concerted effort should be made towards increased
inspection of the plastic and other industries by the
environmental protection agencies and discouraging the
use of PVC-laden materials as storage containers
especially for long- term storage. Also, the municipal
water treatment plants should be improved to minimize
the level of these co mpou nds in the drinking tap water.
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