HEALTH RISK OF BREAST-FED CHILDREN EXPOSED TO SELECTED POLYHALOGENATED HYDROCARBONS IN THE CZECH...
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Transcript of HEALTH RISK OF BREAST-FED CHILDREN EXPOSED TO SELECTED POLYHALOGENATED HYDROCARBONS IN THE CZECH...
HEALTH RISK OF BREAST-FED CHILDREN
EXPOSED TO SELECTED POLYHALOGENATED HYDROCARBONS IN THE CZECH REPUBLIC
V.BENCKO1, M.ČERNÁ2, L.JECH3
1CHARLES UNIVERSITY OF PRAGUE, FIRST FACULTY OF MEDICINE,
INSTITUTE OF HYGIENE AND EPIDEMIOLOGY, CZECH REPUBLIC
2NATIONAL INSTITUTE OF PUBLIC HEALTH,
CENTER OF ENVIRONMENTAL HEALTH,
PRAGUE, CZECH REPUBLIC
3AXYS VARILAB LTD., CZECH REPUBLIC
HUMAN EXPOSURE
TO ENDOCRINE DISRUPTERS (EDs)
IS WIDESPREAD AND IS CONSIDERED
TO POSE A GROWING THREAT
TO HUMAN HEALTH.
GROWING INTEREST IN HEALTH IMPLICATIONS OF THIS DEVELOPMENT CAN BE DEMONSTRATED BY PRESENT
EC AND US EFFORTS TO CO-ORDINATE STRATEGIC RESEARCH IN THIS FIELD.
EXTRAPOLATION OF DOSE/RESPOSE DATA
FROM BOTH EXPERIMENTAL ANIMALS
AND EPIDEMIOLOGY STUDIES HAS BEEN
LARGELY BASED ON MODELS ASSUMING
LINEAR CORRELATION AT LOW DOSES.
PRESENT DISCUSSION: • EXPOSURE ASSESSMENT - POOR EXPOSURE
DATA IN ECOLOGICAL STUDIES. FREQUENTLY ROUGH ESTIMATES DERIVED FROM CONTAMINATED ITEMS OF LOCAL FOOD BASKET SURVEYS.
• EXTRAPOLATION TO LOW DOSE/EXPOSURE BASED ON MODELS ASSUMING LINEAR CORRELATION INCLUDING NON-GENOTOXIC CARCINOGENS.
POLYHALOGENATED HYDROCARBONS
CAN BE TREATED AS EXAMPLES.
POLYHALOGENATED HYDROCARBONS: PCDDs/DFs & PCBs
EXPOSURE ASSESSMENT • EDs ABILITY TO CROSS THE PLACENTAL
BARRIERIN UTERO EXPOSURE OF THE DEVELOPING ORGANISM
• EXPOSURE OF NEONATES DURING CRITICAL
DEVELOPMENTAL PERIODSBREAST-FED INFANTS EXPOSED TO EDs AT LEVELS 10-40 TIMES HIGHER THAN THOSE IN THE GENERAL POPULATION
OBJECTIVES:
THIS PRESENTATION SUMMARISES
AND REVIEWS THE DATA CONCERNING BIOMONITORING OF HUMAN EXPOSURE
TO PCDDs/Fs AND PCBs
IN THE CZECH REPUBLIC (CR)
BY PRESENTATION OF A DATA OF A PROJECT SUPPORTED BY THE MINISTRY OF
ENVIRONMENT OF THE CR.
METHODS:
TO PRODUCE COMPRABLE RESULTS WITH THOSE FROM THE PREVIOUS WHO/ECEH STUDIES (1996) WE USED
THE SAME PROTOCOL WITH AN EXCEPTION OF POOLING OF THE BREAST MILK SAMPLES. THE INDIVIDUAL
SAMPLES WERE USED FOR FURTHER IMPROVEMENT OF EXPOSURE ASSESSMENT OF INFANTS. CLEANED UP EXTRACTS OF BREAST MILK SAMPLES WERE ANALYSED
FOR PCDDs/Fs AND NON-ORTHO PCBs BY HR GC-MS CHROMATOGRAPHY (VG ULTIMA 2) AND PCB
CONGENERS BY GC-MS (VARIAN SATURN). DONORS WERE PRIMIPARE RESIDED IN 7 DIFFERENT AREAS OF THE CR. THEY WERE INCLUDED IN THE STUDY ONLY
AFTER HEAVING VERBAL AND WRITTEN INFORMATION AND GIVEN WRITTEN CONSENT.
Estimated exposure of breast-fed infants to total WHO-TEQ (median values)
0,0
50,0
100,0
150,0
200,0
250,0
300,0
UH1 UH2 UL KO Praha KL Telč LB
WH
O-T
EQ
pg
/kg
b.w
.
PCDDs PCDFs nonorto PCB monoortoPCB
0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 80,0 90,0 100,0
UH1
UH2
UL
KO
Praha
KL
Telč
LB
Ranges of exposure of breast-fed infants to WHO-TEQ from PCDDs (pg/kg b.w.)
0,0 50,0 100,0 150,0 200,0 250,0 300,0 350,0
UH1
UH2
UL
KO
Praha
KL
Telč
LB
Ranges of exposure of breast-fed infants to WHO-TEQ from PCDFs (pg/kg b.w.)
0,0 100,0 200,0 300,0 400,0 500,0 600,0
UH1
UH2
UL
KO
Praha
KL
Telč
LB
Ranges of exposure of breast-fed infants to WHO-TEQfrom non-orto PCBs (pg/kg b.w.)
0,0 100,0 200,0 300,0 400,0 500,0 600,0
UH1
UH2
UL
KO
Praha
KL
Telč
LB
Ranges of exposure of breast-fed infants to WHO-TEQ from mono-orto PCBs (pg/kg b.w.)
Estimated exposure of breast-fed infants to total PCB (median values)
14,3
4,5
6,7
4,43,9
2,82,0
2,6
0,0
2,0
4,0
6,0
8,0
10,0
12,0
14,0
16,0
UH1 UH2 UL KO Praha KL Telč LB
mg
/kg
b.w
.
0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0
UH1
UH2
UL
KO
Praha
KL
Telč
LB
Ranges of exposure of breast-fed infants to total PCBs (mg/kg b.w.)
0 200 400 600 800 1000 1200
UH1
UH2
UL
KO
Praha
KL
Telč
LB
Ranges of exposure of breast-fed infantsto total WHO-TEQ (pg/kg b.w.)
RESULT:
THE UNCERTAINTY IN CONTEMPORARY BACKGROUND LEVELS OF PCBs AND PCDDs/Fs AND
THE UNKNOWN EXTEND OF THE BODY BURDEN RESULTED IN INCLUDING THE SYSTEMATIC
MONITORING OF PCBs IN HUMAN FLUIDS AND TISSUES INTO THE SYSTEM OF MONITORING THE
ENVIRONMENTAL IMPACT ON POPULATION HEALTH OF CR SINCE 1994. THE RESULTS OF Σ 81 SAMPLES ANALYSIS OBTAINED WERE USED FOR EXPOSURE
ASSESSMENT OF THE BREAST-FED CHILDREN IN THE SELECTED LOCALITIES COMPARABLE WITH
RESULTS OF WHO/ECEH EUROPEAN MULTICENTRIC ROUND STUDIES.
DIFFICULTY IN USING
THE PRESENTED DATA AVAILABLE FOR HEALTH RISK ASSESSMENT:
REALISTIC EXPOSURE ASSESSMENT
IN ADULTS BASED CONSIDERED AS APPROPRIATE ON BLOOD LEVELS ONLY.
CONCLUSIONS:• DESPITE THE PRESENCE OF PCBs, PCDDs AND
PCDFs IN HUMAN MILK,
BREAST-FEEDING SHOULD BE ENCOURAGED.
• CONVINCING EVIDENCE OF THE BENEFITS
OF HUMAN MILK TO THE OVERALL HEALTH AND DEVELOPMENT OF THE INFANT.
CONCLUSIONS:
THE DATA PRESENTED TILL NOW DOES NOT CONFIRM IDEAS ABOUT WIDESPREAD EXCESSIVE
EXPOSURE OF CZECH POPULATION TO POLYCHLORINATED BIPHENYLS VIA
CONTAMINATION OF A FOOD BASKET EXCEPT OF THE LIMITED LOCALITIES. HOWEVER, THE QUESTION IF AND TO WHAT EXTENT THE
PRESENT HEALTH STATUS OF CZECH POPULATION MIGHT BE INFLUENCED BY THE
PAST EXPOSURE TO POLYHALOGENATED HYDROCARBONS REMAINS TO BE ASSESSED.
ACKNOWLEDGEMENT:
THE AUTHOR ACKNOWLEDGES DEVOTED
COLLABORATION OF COLLEAGUES ON THE RESEARCH
GRANTS SUPPORTED BY THE CZECH MINISTRY
OF ENVIRONMENT, SUPPORTING PROJECT VaV 520/1/99
& PARTIAL SUPPORT BY THE PROJECT LN00B107,
MINISTRY OF EDUCATION OF THE CZECH REPUBLIC.
ADDRESS FOR CORRESPONDENCE:
Prof. VLADIMÍR BENCKO, M.D., Ph.D.CHARLES UNIVERSITY OF PRAGUE
FIRST FACULTY OF MEDICINEINSTITUTE OF HYGIENE & EPIDEMIOLOGY
STUDNIČKOVA 7CZ 128 00 PRAGUE 2CZECH REPUBLIC
TEL/FAX +420224919967E-MAIL: [email protected]