DISSOLVED ORGANIC MATTER MODULATING THE UPTAKE, BIOTRANSFORMATION, AND ELIMINATION RATES OF PYRENE IN DAPHNIA MAGNA

作者：Ruotsalainen Anna Maija^*; Akkanen Jarkko; Kukkonen Jussi V K

来源：Environmental Toxicology and Chemistry, 2010, 29(12): 2783-2791.

DOI：10.1002/etc.335

• Dissolved organic matter
• Toxicokinetics
• Daphnia magna

In the current study the toxicokinetics of pyrene in Daphnia magna was determined in detail and the role of dissolved organic matter (DOM) in these processes was investigated Uptake biotransformation parent compound and metabolite elimination rates (k(u) k(m) k(ep), k(em)) depuration rates bloconcentration factors (BCFs) and biological half lives were studied in one natural humic water in two waters made from DOM isolates and in DOM free artificial fresh water The daphnids were exposed to pyrene for 24 h and depurated for another 24 h To analyze the data the two compartment model was used to obtain toxicokinetic parameters and the depuration data were analyzed by linear regression Extensive biotransformation of pyrene resulted in high metabolite concentration in the oil anisms (83% of total radioactivity) after 24 h exposure Depuration of the parent compound seemed to be biphasic at first depuration was rapid but after 4 to 10 h in uncontaminated water the disappearance rate came close to zero After a 24 h depuration time; 8% of the pyrene accumulated remained in the organism Overall the elimination of parent compound was faster than the elimination of metabolites which might imply inefficient excretion of water soluble biotransformation products from daphnids The effect of DOM on accumulation of pyrene was seen in a decreased uptake rate indicating lower bioavailability of the compound in waters that contain high-aromaticity DOM In the same waters DOM significantly accelerated pyrene biotransformation and overall elimination Altogether DOM appears to be able to affect toxicokinet

• 出版日期2010-12