Abstract |
Bisphenol A (BPA), phthalates (PEs) and triclosan (TCS) are found in a wide range of
everyday consumer products. Many of these chemicals have been documented or suspected to
act as endocrine disruptors (EDCs) and several epidemiological studies indicate their association
with adverse human health effects. Children’s health is particularly at risk because, while their
vital systems are maturing, exposure to EDCs during the critical developmental phases of human
life can result in lasting adverse health effects that become apparent after birth or even later on
in life. So far, there are no literature reports regarding the estimation of the burden of possible
endocrine disruptive substances on Cretan children suffering from chronic diseases.
The aim of this thesis is to investigate the level of exposure of children suffering from
specific chronic health problems to BPA, six metabolites of phthalates [monomethyl phthalate
(MMP)], monoethyl phthalate (MEP), monobutyl phthalate (MBP), monoisobutyl phthalate
(MiBP), monobenzyl phthalate (MBzP) and mono(2-ethylhexyl) phthalate (MEHP)] and TCS
through the analysis of scalp hair samples. The study population consisted of 100 children aged
2-16 who were residents of the island of Crete, Greece. 75 of these children had previously been
diagnosed with chronic disease, namely obesity, diabetes, early puberty and thyroid disease, at
the pediatric obesity, pediatric diabetes and pediatric endocrinology clinics, respectively, of the
University General Hospital of Heraklion. Furthermore, the study population included 25 healthy
children of the general population in the same age range who constituted the control group.
For the isolation of the tested compounds, solid-liquid extraction was applied using
methanol as the extraction solvent. Detection and quantification of the analyzed compounds was
achieved using a liquid chromatography system coupled to a mass spectrometer (LC-MS). In
order to evaluate the efficiency of the applied method, the analytical parameters of linearity,
detection and quantification limits, recovery, accuracy and precision were checked and
determined for each tested substance. The validation of the analytical method demonstrated
that the experimental procedure followed is suitable for the simultaneous qualitative and
quantitative determination of BPA, six phthalate metabolites and TCS in hair samples.
According to the findings, diabetic children were more burdened with BPA (88.0%,
243.9 pg/mg) compared to the other studied groups of children and the control group. The mean
concentration values of BPA in the healthy children (116.8 pg/mg), children with endocrinological
problems (109.3 pg/mg) and obese children (95.0 pg/mg) showed considerable similarity
between them.
The results showed that the primary metabolite of DEHP, MEHP, recorded the highest
burden (based on mean concentrations) and detection frequency in the scalp hair samples, with
a percentage ranging from 92.0% in the control group to 100.0% in all tested groups of children.
The second phthalate metabolite with the highest recorded detection frequency in the samples
of children with endocrinological problems (92.0%) and obese children (96.0%) was MBP. For
diabetic children and children with endocrinological problems, the phthalate metabolite with the
next, in order, highest mean concentration was MMP, whose values showed an excellent
similarity between the above mentioned groups of children (108.7 pg/mg and 108.9 pg/mg,
respectively).
The detection frequencies of TCS were on similar levels in the samples of healthy
children (48.0%), children with endocrinological problems (52.0%) and obese children (56.0%).
The exposure of diabetic children to TCS (333.0 pg/mg) was higher than the exposure of the
other studied groups of children with a specific chronic health problem and the control group,
although a lower detection frequency of TCS was recorded in the samples of this group of
children (28.0%). The mean concentration values of TCS in children with endocrinological
problems (234.8 pg/mg) and obese children (181.4 pg/mg), although lower than the
corresponding value in diabetic children, were clearly higher than that in healthy children
(154.0 pg/mg mg).
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