HEALTH RISK OF BREAST-FED CHILDREN EXPOSED TO SELECTED POLYHALOGENATED HYDROCARBONS IN THE CZECH REPUBLIC V.BENCKO 1, M.ČERNÁ 2, L.JECH 3 1 CHARLES UNIVERSITY OF PRAGUE, FIRST FACULTY OF MEDICINE, INSTITUTE OF HYGIENE AND EPIDEMIOLOGY, CZECH REPUBLIC 2 NATIONAL INSTITUTE OF PUBLIC HEALTH, CENTER OF ENVIRONMENTAL HEALTH, PRAGUE, CZECH REPUBLIC 3 AXYS 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 BARRIER IN UTERO EXPOSURE OF THE DEVELOPING ORGANISM EXPOSURE OF NEONATES DURING CRITICAL DEVELOPMENTAL PERIODS BREAST-FED INFANTS EXPOSED TO EDs AT LEVELS 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.

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 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 MEDICINE INSTITUTE OF HYGIENE & EPIDEMIOLOGY STUDNIČKOVA 7 CZ PRAGUE 2 CZECH REPUBLIC TEL/FAX