MATERIALS AND METHODS 519 adolescents aged 14-17 years were
examined, of which 349 were included in the
main group (186 boys and 163 girls) and 170 in
the control (89 boys and 81 girls) groups.
The children of the main group lived in
the village of Kenkiyak, Temir district of the Ak-
tobe region of Kazakhstan, where an oil field has
been developed since 1959. As a control group,
children living in the village of Kobda, an environ-
mentally friendly area, where there are no oil and
gas enterprises, were examined.
Inclusion criteria:
adolescent children
living in the survey area for at least 10 years or
more; with informed consent to conduct research
and process personal data, in accordance with
the requirements of the Ethical committee of
West Kazakhstan Medical University named after
Marat Ospanov.
The exclusion criteria:
the presence of
acute and chronic inflammatory diseases from the
examination program; autoimmune, hereditary
and mental diseases.
To determine physical development, body
length was measured in centimeters using a
stadiometer, weight –
in kilograms using a floor
scale.
The indicators of the harmony of physical
development in terms of body length and weight
were determined using centile scales of
nomograms proposed and tested by N.A.
Matveeva and Yu. G. Kuzmichev. This method
was developed on the basis of the centile method
recommended by the WHO in the form of an
international standard as a screening test to
identify
children
5-17
years
old
with
developmental disabilities.
The indiactors of physical development
according to centile scales are presented in a
system of two coordinates, where the vertical
indicates the body length (cm), and the
horizontal indicates the body weight (kg).
One-dimensional age centile scales are
plotted in parallel to each coordinate axis,: on the
right scales for body length, above - for body
weight. In the center there is a nomogram for
assessing the correspondence of body weight to
its length. Numbers 1-8 on scales and nomo-
grams indicate centile intervals. The average val-
ues of length and body weight, limited at the 4th
and 5th centile intervals, are shaded; the medi-
ans (50
th
centiles) are marked with a dotted line.
Body length was assessed using one-
dimensional centile scales. For this, the value of
the child's body length was found on the ordinate
axis. From this point, the perpendicular was re-
stored to its intersection with the age scale of
body length located in the right margin of the
figures.
The indicators that fell into the 4-5
th
in-
tervals were characterized as average, in the 3
rd
–
low, in the 2
nd
–
low, in the 1
st
–
very low, 6
th
–
increased, in the 7
th
–
high, in 8
th
–
very high.
Body weight was assessed using age cen-
tile scales located in the upper field of the figures
and nomograms in which centile body weight
intervals are presented per unit of body length
(weight index/body length).
The assessment of body weight by age
centile scales was carried out similarly to the as-
sessment of body length.
According to the nomograms proposed
for use, the physical development of children was
regarded as harmonious if the body weight corre-
sponded to the 4-5 interval; disharmonious –
when assessed by the 2-3
rd
or 6-7
th
intervals;
sharply disharmonious –
when assessed by the 1
st
or 8
th
centile interval of the nomogram.
In this regard, 3 groups of physical devel-
opment were distinguished: normal physical de-
velopment, risk, with deviations in physical devel-
opment.
The concept of «normal physical develop-
ment» corresponds to an average, decreased or