Advances in Bioscience and Biotechnology, 2013, 4, 993-998 ABB
http://dx.doi.org/10.4236/abb.2013.411132 Published Online November 2013 (http://www.scirp.org/journal/abb/)
Polychlorinated biphenyl congeners (PCBs) in nursing
primiparous and multiparous women
Sobia Khwaja1*, Rubina Mushtaq1, Rehana Mushtaq1, Masarrat J. Yousuf2, Fozia Tabbassum2
1Department of Zoology, Federal Urdu University of Arts, Science and Technology, Karachi, Pakistan
2Department of Zoology, University of Karachi, Karachi, Pakistan
Email: *gr8_dezirez@hotmail.com, *sobia_1988@hotmail.com
Received 17 June 2013; revised 30 July 2013; accepted 15 August 2013
Copyright © 2013 Sobia Khwaja et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Impact of PCBs was studied as a major source of
physiological effects even very low concentration of
PCBs transferred to the infants by mother’s milk.
Milk samples were collected from primipara and
multipara women. A significant variation pattern was
observed in the level of PCB congeners, as PCBs are
lipophilic in nature, another possibility arises that
great deals of residues are passed on to infants
through mother’s milk. A technique was developed to
find out polychlorinated biphenyls (PCB) in breast
milk. PCBs were extracted by Matrix Solid-Phase
Dispersion (MSPD) and analyzed by Gas Chroma-
tography with Electron Capture Detector. The preci-
sion (RSD < 10%, n = 125), recovery (85% to 110%)
and limit of quantification (between 0.50 and 3.00
µg·L1), the chi square analysis at p 0.05 has shown
that the PCB level was higher in multipara as com-
pared to primipara. The analysis of the thirty samples
revealed PCB levels above 6.85 µg·L1 in breast milk
samples by analyses of a mixture of PCB congeners.
All PCB congeners (28, 52, 101, 123 (+149), 118, 114,
153, 105, 138 (+163), 167, 156 (+171), 157, 180, 170,
189) were found at high level in primiparous and
multiparous. Thus, a high correlation between the
contamination of breast milk and environmental pol-
lution of PCBs was observed.
Keywords: Poly Chlorinated Biphenyls; Primipara;
Multipara; Breast Milk; Contamination; MSPD and ECD;
Pakistan
1. INTRODUCTION
The physiological impact of polychlorinated biphenyls
(PCBs) has been studied in humans and in animals. The
prime focus in human studies has been on the effects in
neonates, women and infants whereas research has also
done on adults. According to the National Health and
Nutrition Examination Survey (NHANES) concentration
of PCBs was examined in serum and lipid content of
people who were above twelve years of age.
Polychlorinated biphenyls (PCBs) are lipophilic sub-
stance. Humans are exposed to these persistent com-
pounds from different sources. PCBs have been banned
for 30 years, but are still found in telephone as dielectrics
and pole mounted transformers. Exposure pathways for
PCBs, as with most persistent organic pollutants, begin
in the outdoor environment [1]. PCBs are characterized
by its capacity for bio-accumulation, toxic effects and
long distance atmospheric transport. Therefore, they
were also present in those places where they have not
been used [2], and a number of PCBs congeners have
been determined in milk samples [3]. Acute prenatal ex-
posure of PCBs resulted in intrauterine growth retarda-
tion, reduced birth weight, delayed developmental mile-
stones, and other abnormalities in infants and children
[4,5]. A serious impact of PCBs exposure on human
neurodevelopment has been observed [6].
In humans, serum levels of PCBs caused increase in
several inflammatory diseases such as infection, sepsis,
septic shock and many others [7]. In the similar manner
the PCBs are deposited in mother’s milk and transferred
to their young children. It indicates that the new born
may receive the PCB concentration ratio at a greater
level as compared to fish and other food items [8].
The current state of knowledge suggests that low-level
exposures to PCBs are unlikely to cause any adverse
health effects. People at greater risk include Aboriginal
peoples, as well as anglers and hunters and their families
with the fact that not all of the 209 kinds of PCB have
the same effects [9].
Although their use has been restricted in Pakistan
decades ago, but PCBs lipophilic nature, these toxic and
*Corresponding author.
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S. Khwaja et al. / Advances in Bioscience and Biotechnology 4 (2013) 993-998
994
hazards chemicals easily entered into the food chain. As
a result mean concentration has been reported in food,
blood human tissues and breast milk [10-12]. Recent
research in Pakistan has given due importance on the
examination and quantity of climatic conditions in major
cities populations for determination of impact of indus-
trial pollution.
In Pakistan such studies are scanty and no comprehen-
sive study was conducted therefore the reliable data is
not normally available to carry out environmental health
and risk assessment. In this study, the residues of PCB
were analyzed in women milk samples which were col-
lected through women populace of Karachi. Our object
was to measure the concentration level of PCB residues
in lactating women those who are indirectly exposed
from these organic compounds. Present investigation will
provide useful data for upcoming researchers. Wide re-
search has been done globally but in Pakistan no studies
have been carried out to create awareness in the society.
The usages of PCBs are banned but present findings sig-
nificantly show that these toxic compounds are still in
practice illegally.
Objective
To assess level of Polychlorinatedbiphenyl (PCBs) and
their effects transferred to infants through mother milk
were studied associations with their health hazards. This
type of study has never done in Pakistan previously. This
integration of data from different sources with a mathe-
matical model allows us to assess infant’s disease levels,
immunological effects and overall uncertainty in pre-
dicted risks. The uncertainties resulting from the assess-
ments of exposure and pollution status of PCBs are
propagated through the risk characterization process.
2. MATERIALS AND METHODS
2.1. Study Population and Sampling
2.1.1. Milk Donors
The pregnant women who came to register their names
for delivery in Karachi Gynae hospitals were divided
into two groups multiparous and primiparous. They had
been asked about their consent for the milk sample col-
lection. They had been provided a questionnaire for this
purpose. After a brief history taken from these women
they were followed for their expected days of delivery.
They usually showed hesitation in providing the milk
sample but the staff nurse helped in this purpose. The
breast pump had been provided to the women and lady
nurse collected their samples in sterilized vials of 10 ml.
2.1.2. Analytical Method
Breast milk samples were brought to lab and stored at
30˚C till further analysis.
1) Extraction
Milk sample was extracted through matrix solid-phase
dispersion (MSPD) in manifold assembly. The 1-mL
breast milk sample was pipette into atared 10-mL conical
centrifuge tube and the weight was recorded. The sample
was spiked with labeled internal standard to give a con-
centration of 200 pg/g in the milk and mixed allowing
enough time for the internal standards to reach equilib-
rium with the milk components [13].
2) Instrumentation
Analyses were performed by gas chromatography us-
ing Perkin Elmer GC-Calrus 500. The standard PCB
congeners were purchased from Supelco Company. This
standard mixture of PCB was injected into GC (ECD) to
get the standard mixture peaks for comparison. Concen-
tration level of PCBs were determined analyzed using
Perkin Elmner Gas chromatograph Clarus 500 equipped
with electron capture detector (ECD), 300˚C, mode: con-
stant column + makeup flow, combined flow: 60 ml/min,
make up gas type: nitrogen; inlet: operated in split less
mode, initial temp: 200˚C, pressure: 17.38 psi, purge
flow: 15 ml/min, total flow: 19.2 ml/min; Oven: initial
temp: 100˚C, hold time: 5 min, ramp at 4.0˚C/min to
220˚C, two capillary columns were used for initial injec-
tions (calculations) and for confirmation injections (vali-
date initial injection of pesticides).
a) Initial injections: RTX5 w/Integra Guard, 30 m ×
0.25 mm × 250 µm ID × 0.25 µm film thickness, con-
stant pressure @ 17.38 psi, nominal initial flow: 33
cm/sec.
b) Confirmation injection: RTX35 w/Integra Guard,
30 m × 0.25 mm × 250 µm ID × 0.25 µm film thickness
constant pressure @ 17.38 psi, nominal initial flow: 33
cm/sec.
It is general practice in pesticide Labs. of CES to use
different chromatographic columns for quality assurance.
As far as the procedure was carried out for each batch of
6 samples calibration and its authenticity were regularly
observed during the start and end. To check the quality
control methods the use of reagent blanks surrogate and
matrix spike recovery was taken into consideration. For
each sample batch there was one procedural blank, one
laboratory control sample and a duplicate of sample.The
procedural blank was spiked with the solvent and a sur-
rogate internal standard PCBs congeners 198 and 194.
All samples were spiked with the surrogate compound to
determine efficiency. Results are calculated on the basis
of the mean value of samples. Internal spiking and re-
agent blank determined the recovery values. The recov-
ery values were in the range 92% - 157% for PCBs. The
limit of quantification was calculated on the basis of %
RSD and it was 0.001 - 0.01 µg/µl and limit of reportable
amount was obtained by multiplying with 3 and it was
0.003 µg/µl or 0.3 ng/µl PCB congeners.
Copyright © 2013 SciRes. OPEN ACCESS
S. Khwaja et al. / Advances in Bioscience and Biotechnology 4 (2013) 993-998 995
3) Statistical Analyses
A descriptive analysis was conducted for all PCBs.
Arithmetic means and standard deviation (SD) were cal-
culated for normally distributed variables while geomet-
ric means and 95% confidence interval are presented for
log transformed variables. The chi square test was ap-
plied for comparison between primipara and multipara
women. A p < 0.5 was taken statistically significant. The
simple relationship between PCBs load and milk was
studied using analysis of variance while the analysis of
covariance (ANOVA) was applied in order to adjust for
confounders. The analyses were carried out using the
SAS software (version 9.1; SAS Institute Inc., Cary, NC,
USA).
3. RESULTS
The detection of PCB congeners in all the samples ana-
lyzed indicates the spatial distribution in Karachi women.
Multiparous women were found to have more PCB con-
centration than primiparaous women. The results indi-
cated the remarkable difference between the two groups
of women. PCB 28 was entirely absent in primiparous
women on the other hand PCB 138 was not detected in
any of the milk samples from multiparaous women. By
looking into the individual concentration of each PCB
the primiparous milk samples were found to have the
concentration of PCB congeners as N.A, 0.058 ng/ml,
0.017 ng/ml, 0.006, 0.008 ng/ml, 0.083 ng/ml and N.A
for PCB 28, 52, 101, 138, 153, 180 and 209 respectively
(Table 1). On the other hand mean values for the same
PCB congeners in multiparous milk samples were de-
tected as 0.006 ng/ml, 0.025 ng/ml, 0.001 ng/ml, N.A,
0.003 ng/ml, 0.244 ng/ml and 0.166 ng/ml (Table 2).
The sum of mean values i.e., Σ PCB in multiparous
women was found to be 0.445 ng/ml where as the Σ PCB
in primiparous women samples was 0.172 ng/ml. The
one PCB congener i.e. PCB 209 make the difference as
this PCB concentration was entirely absent in primipara
samples whereas it was detected in the highest concen-
tration in multiparaous women milk samples as 0.166
ng/ml.
4. DISCUSSION
To best of our knowledge this study was the first to elu-
cidate the concentration status of PCB congeners in
women subject of Karachi. From the standpoint of Asian
countries the reports are available from Philippines [14]
and Japan [15].
According to [14] polychlorinated diphenyl ethers and
hexabromocyclododecanes had no significant relation-
ship between primiparous and multiparous women with
reference to its status of concentration. They have cov-
ered a range of POPs accumulation in breast milk of
women in addition to PCB congeners. The primiparous
mothers had significantly higher organochlorinated in-
secticides such as DDTs, CHLs and HCHs than multipa-
rous women and no such trend was reported with refer-
ence to PCB congeners determined a range of PCBs in
blood and milk samples of mothers [16]. They reported
the mean levels of many PCB congeners as 7.1, 2.7, 5.3
and 0.4 pg in primiparous mothers. The present investi-
gation concerning with the milk samples only as the mul-
tiparous women samples were found to have mean val-
ues as 0.445 ng/ml (Σ PCB) and primiparous women
milk samples indicated Σ PCB value as 0.172 ng/ml. Our
investigation indicate that multiparous women remain at
high risk of PCB transfer from their breast milk to the
infants than primiparous women was based on findings
from 30 mothers which includes 15 primiparous and 15
multiparous mothers (Figure 1).
It is known that the level of PCB congeners reflects
the mother’s exposure to these chemicals during their life
time. Mean concentrations of the sum of PCBs in the
analyzed milk samples seems to be relatively low as
114.8 ng/g in primipara and 101.8 ng/g in secundipara
[17]. Mean concentration of these chemicals shows an
incline trend of the persistent organic pollutants in mul-
tiparaous women residing in Karachi since the time when
chemicals like PCB were ban and restricted.
The concentrations of the PCBs [138, 153 and 180] in
first-time pregnant female and multiparous women re-
ported to be higher than those for pregnant serum fe-
males. A research report conducted by showed the PCB
congeners in women in the following order as PCB 138
(11.2 ng/g), PCB 153 (14.7 ng/g) and PCB 180 (8.3 ng/g)
for primiparous women and PCB 138 (6.1 ng/g), PCB
153 (5.3 ng/g) and PCB 180 (4.5 ng/g) for multiparaous
women [18].
The previous results clearly indicate that PCB-153 was
higher than PCB-28 in primiparous [19] same as present
investigation.
Present results indicate that residues of PCBs in breast
milk of women do not reliably decrease over the number
of child or course of lactation. This is contrast with a
more recent study on depuration of PCBs in milk [20].
It could be assumed from the above results that in the
developed countries rate of persistency of POP’s are
relatively reduced in human biological materials which
may be due to the awareness of hazardous effects of
PCBs or strict implementation of law in terms of use of
such banned chemicals.
Present investigation shows that human milk samples
were highly contaminated with PCBs. Their concentra-
tion was found to be comparatively higher than previous
finding. The use of such industrial chemicals should be
strictly monitored, as their deposition may increase the
environmental contamination.he disposal of PCB con- T
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S. Khwaja et al. / Advances in Bioscience and Biotechnology 4 (2013) 993-998
Copyright © 2013 SciRes.
996
Table 1. Statistical analysis of PCB residues (ng/ml) in milk samples of primipara women.
OPEN ACCESS
SD Name of PCBs Positive samples Positive test (%) Mean SE Range min - mix
PCB 28 00 00 00 00 00 00
PCB 52 5 33 0.058 0.236 0.063 0.484 - 11.507
PCB 101 5 33 0.017 0.128 0.034 1.599 - 4.943
PCB 138 2 13 0.006 0.077 0.020 1.387 - 2.530
PCB 153 5 33 0.008 0.089 0.023 1.516 - 3.036
PCB 180 6 40 0.083 0.0213 0.057 2.464 - 3.306
PCB 209 00 00 00 00 00 00
Σ PCB
0.172
Table 2. Statistical analysis of PCB residues (ng/ml) in milk samples of multipara women.
Name of PCBs Positive samples Positive test (%) Mean SD SE Range min - mix
PCB 28 4 27 0.006 0.081 0.021 1.425 - 2.565
PCB 52 7 46 0.025 0.157 0.040 1.425 - 6.175
PCB 101 4 27 0.001 0.041 0.010 0.855 - 1.045
PCB 138 00 00 00 00 00 00
PCB 153 4 27 0.003 0.059 0.015 1.140 - 1.710
PCB 180 9 60 0.244 0.219 0.056 17.86 - 28.50
PCB 209 4 27 0.166 0.328 0.084 7.790 - 23.75
Σ PCB
0.445
0
0. 5
1
1. 5
2
2. 5
3
M-1 M-2 M-3 M-4 M-5 M-6 M-7 M-8M-9M-
10 M-
11 M-
12 M-
13 M-
14 M-
15
Primipara Multipara
concentratio n of PCBs
Figure 1. Bar graph showing total PCB concentration in 15 primipara and 15
multipara.
centration as a waste product from some industries may
increase the risk of its entry in human body.
In the city of Karachi there are large area used as a
waste source. Municipal wastes are burned under low
temperature. It leads to the formation of PCBs under low
temperature. The pollution near the wastage sites are
likely to be more infected with the PCB concentrations
as compared to those living away from such sites. Fur-
ther, the PCBs come from electric appliances like tube
lights and also in materials like carbon paper and plastic
products which were dumped in considerable quantities
daily.
S. Khwaja et al. / Advances in Bioscience and Biotechnology 4 (2013) 993-998 997
It can be anticipated that if the same situation/condi-
tion continues in future then the pollution may rise more
and hence the concentration levels in human biological
materials may also high because the release of these con-
taminants are not at all controlled even now.
5. CONCLUSION
Our PCB contamination is a public health crisis which
has been ignored far too long. All samples were found to
be contaminated with PCB residues which are no longer
used in Pakistan.
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LIST OF ABBREVIATIONS
PCB: polychlorinated biphenyls
SD: standard deviation deviation
GC: gas chromatograph
pg: picogram
ml: milliliter
ng: nonogram
LOQ: limit of quantitation
ECD: electron capture detector