ENVIRONMENTAL LONG-TERM PCB EXPOSURE OF CHILDREN IN SLOVAKIA

ENVIRONMENTAL LONG-TERM PCB EXPOSURE OF CHILDREN IN SLOVAKIA

Eva Sovcikova, T.Trnovec, A.Kocan, J.Petrik, B.Drobna, L.Wsolova

of the 5th FP ProjectEvaluating Human Health Risk from Low-dose and Long-term PCB

Exposure (PCBRISK)

THE FUTURE FOR OUR CHILDREN Central and Eastern European Chapter Meeting of the International Society of Environmental Epidemiology

4-6 September, Balatonföldvár 2003

Children from exposed area (Michalovce district) and background area (Svidnik & Stropkov district) were examined

Inclusion criteria were

1. Children born and living in the same area, till now. Children were recruited

through their schools.

Their parents (especially mothers) permanently live in the respective

area for at least 5 years before the child’s birth.

2. Examiner (IPCM) and pediatrician (from local IPH) informed teachers and parents

about the schedule of investigation on common meetings.

Participated parents confirmed their agreement in the application form for including

of their child in the study.

- Blood sampling Venous blood (17.2ml) was withdrawn from each fasting subject (determination of PCBs, by Gas-chromatographia, thyroid hormones and heavy metals).

- The thyroid status: The subjects' thyroid status was examined by portable ultrasonography. - The anthropometric measure of children (weight, height of body, and measure of thickness of the skin layer on the arms and under the shoulder) was realized by basic equipments. - The hearing status was examined by the acoustic reflex decay test, tympanometric examination, audiometric screening, brainstem evoked potentials and oto-acoustic emissions. - Dental examination included oral hygiene, gingival health, developmental defects of enamel and caries, using the appropriate indices: Plaque Index, Loe-Silness Gingival Index, FDI Index, clinical DMFS index. Dental Questionnaire completed parents of all children.

Steps of investigation

Michalovce

KošiceBratislava

Svidnik&Stropkov

HungaryAustria

Czech Republic Poland

The

Ukr

aine

MAP OF SLOVAK REPUBLIC

Legend:

MICHALOVCE district - polluted area

SVIDNIK&STROPKOV district - non-polluted area

The neurobehavioral examination

Computer version of tests

* Simple Reaction Time: self-colored 77 stimuli were applied on display, (cca 5 min training, evaluation: measure of reactions (ms). * Viena Color Determination test: 2 minutes were applied rectangles (1x2 cm) in 6 colors (red, green, blue, yellow, black, white), training, evaluation of correct responses.

* Tapping (1 min knocking by preferred hand finger on the computer mouse and 1 min by non preferred hand finger), training, evaluation of taps number by each hand.

* Benton Recognition test (10 geometrical pictures were applied on display individually and after 10 sec, similar 4 pictures were applied), without training. Evaluation of correct pictures, number recognition.

Non-computer version of tests

* Digit Span (WISC - short hearing memory): repeating of randomly read numbers (from 2- 9, forward and backward). Evaluation: the last correct repeated number.

* Symbols (WISC – attention, motor and memory processes): completing of correct symbols of randomly ordered numbers after instruction. Evaluation: the number of correct completed symbols, time 90 sec.

* Cubes (WISC – hand coordination, attention, memory and solution proccess). Evaluation: speed of correct performance after instruction, each of 10 pictures is evaluated from 45-150 sec.

* Raven Color Nonverbal Intelligence test (solution of mental tasks): The solution of 36 pictures in sequence (max time 45 min). Evaluation: number of correct performances. Questionnaire for the filling by parents at home and Scale of child behavior at home. Raven Intelligence test (adult form) for mothers. The solution of 60 pictures (max time 45 min). Evaluation: number of correct performances. Teachers filled the Scale of Behavior at school for each child.

Total Boys Girls

MichalovceDistrict

Stropkov&SvidnikDistricts

MichalovceDistrict

Stropkov& Svidnik Districts

MichalovceDistrict

Stropkov& SvidnikDistricts

Number ofvolunteers

325 244 119 125 116 119

PCBs 218 242 108 123 110 119Lipid contentdetermination

218 242 108 123 110 119

T4, T3, anti-TPO,anti-TSH

218 242 108 123 110 119

Heavy metals inblood

218 242 108 123 110 119

Heavy metals inSerum

218 242 108 123 110 119

USG ThyroidGland examination

218 242 108 123 110 119

Samples in Total(blood, serum)

220 242 109 124 111 119

Psychologicalexamination

235 242 119 124 116 118

Dentalexamination

210 224 103 107 116 108

Table 1 Collected samples and other examinations from exposed area (Michalovce district) and from non-exposed area (Svidnik & Stropkov district).

RESULTS OF NEUROBEHAVIORAL EXAMINATION

- Levels of PCBs (with, with ½, and without LOD [ng/g lipi]) were not normal distributed (Fig 1). In continuation of analysis we used only levels of PCBs without LOD [ng/g lipi]. Collected samples and other examinations are in Tab 1.

- Descriptive analysis of PCBs in blood of children from both exposed and non- exposed area, distribution by genders are in Tab 2. Minimum of PCBs: 17.6 [ng/g lipi], Maximum of PCBs: 6476.4 [ng/g lipi].

- Children were distributed by Median of sum PCBs: Significantly higher number of children was with sum of PCBs < Me of all children in non-exposed area. Higher number of children with sum of PCBs > Me of all children was in exposed area (Fig 2). Significant difference was in sum between genders. Significantly higher levels of PCBs were in boys.

- Significant relations of PCBs levels in children and time of breast feeding (in weeks) were found (Fig 3).

- Significant relations between time of mothers´ living in the same area before child was born (in years) (Fig 4A) and significant relations between years when mother worked in chemical production and PCBs level in children were found (Fig 4B).

- - Evaluation of PCB congeners (153, 138+163, 180) between genders are in Tab 3.- Spearman Rank Correlation coefficients of measured PCB congeners, performance in behavioral tests and anthropometric parameters showed: Significantly lower performance in sensomotor (SRT, VDT) and in memory tests (DS, BNT) in children with higher level of measured PCB congeners were found. Levels of PCB congeners distributed by quartiles showed significant tendency of higher levels of congeners and lower performance in tests. The equivalent relations of PCB congeners and performance were in boys and girls, in boys these differences were stronger. Anthropometric parameters and PCB congeners showed negative significant relations too (Tab 4, Fig 5, 6, 7, 8).

Sum of PCBs without LODs [ng/g l

6500,0

6000,0

5500,0

5000,0

4500,0

4000,0

3500,0

3000,0

2500,0

2000,0

1500,0

1000,0

500,00,0

Sum of PCBs without LODs [ng/g l

Fre

qu

en

cy

200

100

0

Std. Dev = 654,78

Mean = 528,2

N = 433,00

Fig 1 Frequencies of sum PCBs in all children.

0

20

40

60

80

100

120

140

160

180

non-exposed group exposed group

num

ber o

f chi

ldre

n

Children with sum of PCB< Me (320.9))

Children with sum of PCB> Me (320.9)

Fig 2 Distribution of children by Median of sum PCBs.

Sum of PCBs withot LOD [ng/glipi] Exposed area

Sum of PCBs withot LOD [ng/glipi], non Exposed area

BOYS Sum of PCBs withot LOD [ng/glipi] Exposed area

GIRLS Sum of PCBs withot LOD [ng/glipi] Non exposed area

Mean 742.163 315.283 587.236 470.128

Median 487.284 268.212 344.303 280.824

Std. Deviation 814.100 326.295 684.666 620.351

Minimum 40.6 17.6 17.9 17.6

Maximum 6476.4 1826.4 4677.1 6476.4

Table 2 Descriptive analysis of PCBs in blood in all children and distributed by gender.

0

100

200

300

400

500

600

700

800

I. II. III. IV.

38.16 =2א p <0.001

24.63 = 2א p <0.001 Expon.grup

Control grup

Sum

of P

CB

s w

ithou

t LO

Ds

[ng/

g l]

Time of breast feeding (weeks)

Fig 3 Relation of PCBs levels in children and time of breast feeding (weeks).

0

2

4

6

8

10

12

14

16

18

I. II. III. IV.

0

100

200

300

400

500

600

700

800

900

1 2

Sum of PCBs without LODs [ng/g l]

Kruskal-Wallis test

7.70= 2 א

p= 0.0525

Sum

PC

B w

itho

ut L

OD

s [n

g/g]

(m

edia

n)

Wilcoxonov test

W = 3849

p= 0.0476

1 non-work in chemical production (years)

2 work in chemical production (years)

Mot

hers

l ive

in t h

e sa

me

area

(ye

ars)

Fig 4 Relations of mothers living in the same area (years) with PCBs levels (A). Work time of mothers in chemical production with PCBs (B).

A

B

Tab 3 The PCBs congeners without LOD [ng/g lipi] in children distributed by gender.

Boys 220 PCB153 PCB 138 PCB 180Mean 191.130 120.011 168.895

Median 117.393 73.108 96.855

Std. Deviation 210.105 136.850 205.804

Minimum 17.866 13.265 13.453

Maximum 1414.730 1011.225 1427.265

Girls 211Mean 154.348 96.740 135.075

Median 97.397 59.457 80.729

Std. Deviation 179.786 111.591 203.297

Minimum 13.670 8.931 10.804

Maximum 1757.080 1000.254 2285.59

n=428 153 138 180

Simple Reaction Time r 0.2176 sig 0.000

0.2255 0.000

0.2075 0.000

Me SRT 0.2895 0.000

0.2968 0.000

0.2748 0.000

BENTON Memory Test

- 0.1734 0.000

- 0.1678 0.001

-0.1533 0.001

Digit Span (backward) -0.2208 0.000

-0.2332 0.000

-0.2269 0.000

Viena Discrimination Test (sum)

-0.1550 0.001

-0.1630 0.001

-0.1419 0.003

Thickness of fat under Shoulder - blade

-0.2830 0.000

-0.2664 0.000

-0.2979 0.000

Thickness of fat under Arm

-0.3128 0.000

-0.2908 0.000

-0.3225 0.000

Weight of body -0.2980 0.000

-0.2806 0.000

-0.2953 0.000

Height of body -0.1870 0.000

-0.1907 0.000

-0.1883 0.000

EVALUATION OF PSYCHOLOGICAL EXAMINATION AND ANTROPOMETRIC PARAMETERS IN RELATION WITH PCBs CONGENERS

Table 4 Spearman Correlation coefficients of congeners 153,138,180 and performance in neurobehavioral tests and antrophometric parameters in all children.

Fig 5 Performance in Simple Reaction Time test and PCB congeners in blood distributed by quartiles in all children.

300

350

400

450

500

550

I II III IV

Quartile of sum of PCBs

Sim

ple

Re

ac

tio

n T

ime

(m

s)

mean

median

300

350

400

450

500

550

I II III IV

Quartile of PCB153Sim

ple

Rea

ctio

n Ti

me

(ms)

mean

median

300

350

400

450

500

550

I II III IV

Quartile of PCB138+PCB163

Sim

ple

Re

act

ion

Tim

e

(ms)

mean

median

300

350

400450

500

550

600

I II III IV

Quartile of PCB 180

Sim

ple

Re

actio

n T

ime

(ms) mean

median

Fig 6 Performance in Viena Discrimination sensomotor test and PCB congeners in blood distributed by quartiles in all children.

140

145

150

155

160

165

I II III IV

Quartile of PCB153

Vie

na

Dis

crim

inat

ion

Te

st

(su

m o

f co

rre

ct)

mean

median

140

145

150

155

160

I II III IV

Quartile of sum of PCBs

Vie

na

Dis

crim

inat

ion

Te

st

(su

m o

f co

rre

ct)

mean

median

140

145

150

155

160

165

I II III IV

Quartile of PCB138+PCB163

Vie

na

Dis

crim

inat

ion

Te

st

(su

m o

f co

rre

ct)

mean

median

140

145

150

155

160

165

I II III IV

Quartile of PCB 180

Vie

na

Dis

crim

inat

ion

Te

st

(su

m o

f co

rre

ct)

mean

median

Fig 7 Performance in Digit Span memory test (backward) and PCB congeners in blood distributed by quartiles in all children.

2,5

3

3,5

4

4,5

I II III IV

Quartile of sum of PCBs

Dig

it S

pan

(W

ISC

) b

ack

war

d

(su

m) mean

median

2,5

3

3,5

4

4,5

I II III IV

Quartile of PCB153

Dig

it S

pan

(W

ISC

) b

ack

war

d

(su

m) mean

median

2,5

3

3,5

4

4,5

I II III IV

Quartile of PCB138+PCB163

Dig

it S

pan

(W

ISC

) b

ack

war

d

(su

m) mean

median

2,5

3

3,5

4

4,5

I II III IV

Quartile of PCB 180

Dig

it S

pan

(W

ISC

) b

ack

war

d

(su

m)

mean

median

Fig 8 Performance in Benton memory test and PCB congeners in blood distributed by quartiles in all children.

7

7,58

8,5

99,5

10

I II III IV

Quartile of PCB153

Be

nto

n M

em

ory

Te

st

(su

m o

f co

rre

ct)

mean

median

77,5

88,5

99,5

10

I II III IV

Quartile of sum of PCBs

Ben

ton

Mem

ory

Tes

t

(s

um

of

corr

ect)

mean

median

7

7,5

88,5

9

9,5

10

I II III IV

Quartile of PCB138+PCB163

Be

nto

n M

em

ory

Te

st

(su

m o

f co

rre

ct)

mean

median

7

7,5

8

8,5

9

9,5

10

I II III IV

Quartile of PCB 180

Ben

ton

Mem

ory

Tes

t

(s

um

of

corr

ect)

mean

median

CONCLUSIONStatistical evaluation of PCBs level showed significant differences between children from area environmentally polluted by PCBs and children from non-exposed area.Important factors influenced level of PCBs in children were:time of breast feeding, living of mothers in the same area when child was born, and time of mothers ´work in chemical production. Neurobehavioral parameters and levels of PCBs sum and congeners showed significantly longer reaction times, lower short memory performance and lower eye-hand coordination.In the exposed area the anthropometric parameters of children were lower. Quality of neurobehavioral performances and anthropometric parameters in relation with level of PCBs and other measuredparameters between children will show the new relations in multifactor analysis.

TASKS PERFORMED BY COMPUTER

SAMPLING, THYROID GLAND AND DENTAL EXAMINATION AND ANTHROPOMETRIC MEASURE

HEARING: AUDIOMERTRY, BERA test, OTOLARYNGOLOGY examination