MEASUREMENT OF ORGANOCHLORINE LEVELS IN POSTPRANDIAL SERUM OR IN BLOOD COLLECTED IN SERUM SEPARATOR TUBES

Whether organochlorine blood levels in fasting and postprandial specim ens provide equivalent measures of exposure and the extent to which co llecting blood in tubes containing material to separate serum and bloo d cells corrupts the specimen are unclear, In this paper, we present d ata from two studies that address both of these issues, In the first s tudy, 27 women provided fasting blood in plain, silicone-coated Vacuta iner tubes (red-topped) and in similar tubes containing serum separato r gel (SSTs), as well as a postprandial specimen in a red-topped tube, The specimens collected in SSTs were left to stand overnight, with th e gel in contact with the sample, In the second study, the blood of 12 industrial incinerator workers was collected in red-topped tubes and in SSTs, Blood in SSTs was left in contact with the gel for 5 days, Se rum organochlorine residue levels ([1,1-dichloro-2,2-bis(p-chloropheny l)ethylene] (DDE)) and polychlorinated biphenyls) in samples collected in red-topped tubes were highly correlated with levels measured in sa mples collected in SSTs (all Pearson r values were greater than or equ al to 0.79). Postprandial and fasting organochlorine levels were also highly correlated (Pearson r values greater than or equal to 0.89). Ou r results indicate that timing of the collection of blood in relation to meals and use of SSTs to collect blood specimens did not greatly af fect the relative classification of subjects with respect to serum lev el of DDE or polychlorinated biphenyls, The longer the specimen was in contact with the SST gel, however, the lower the level of organochlor ine that was detected and, at least for DDE, the greater the misclassi fication caused.