REGRESSING LEVELS OF PCDD PCDF IN HUMAN BLOOD-SAMPLES ON AGE - A NEW LOOK ON REFERENCE VALUES

Combining PCDD/PCDF levels in 69 blood samples from various studies in northern Germany, it can be shown that PCDD/PCDF accumulate with age, and that the relation between body load and age follows a straight line with an increment of about 0.6 ppt ITE per year. To distinguish between normal body burdens and high body burdens requiring further investigation, it therefore seemes inadequate to use one single value as a criterion. Instead, the use of a function is proposed which is derived from the 95 % upper limit of the prediction interval. Within the range of 5 up to 85 years of age, elevated PCDD/PCDF levels in blood (in ppt ITE) would be defined as being in excess of 0.6 times age (in years) plus 28.