No abstract

Effects of the polychaetes Nereis diversicolor and Arenicola marina on the distribution, metabolism and removal of [ 14 C-4, 5, 9,10]-pyrene in sediment microcosms were studied over 42 and 53 d, respectively. Unmetabolized pyrene, water-and organic-soluble pyrene metabolites were quantified in sediment, interstitial water and overlying water, and 14 CO 2 production was also assessed. Both N. diversicolor and A. marina enhanced fluxes of sediment-associated pyrene and metabolites into overlying water but to different extents. The major pathway of pyrene removal from sediments with N. diversicolor was release of water-soluble metabolites, probably formed by metabolism in N. diversicolor. In contrast, flushing of unmetabolized pyrene due to bioturbation was the major removal route from sediments with A. marina. Additionally, increased 14 CO 2 production and concentrations of water-soluble metabolites were also observed in overlying water indicating that A. marina also stimulated the metabolism of pyrene. The high production of water-soluble metabolites was probably due to endogenous metabolism in the lugworm itself, whereas the increased 14 CO 2 production indicated a stimulation of microbial metabolism. After 42 d, only 75% of the originally added amount of pyrene remained associated to sediment particles in microcosms inhabited by N. diversicolor, whereas no significant reduction was observed in microcosms with A. marina due to the necessity of using large amounts of sediment in the lugworm experiment. The actual flux of pyrene and metabolites to overlying water was higher in microcosms with A. marina than with N. diversicolor. Both A. marina and N. diversicolor significantly enhanced the removal pyrene from the sediment, but differences in feeding and life strategies resulted in different removal paths and extents.

The paper presents results of analyses of 4182 samples collected from January 1995 to December 1996 for the Danish National Pesticide Monitoring Program. The program basis is a random sample control supplemented with a target control. The objectives of the control are to monitor consumer exposure to health hazards and to enforce national and European Community regulations. The Danish Veterinary and Food Administration is responsible for establishing methods, data manipulation, and evaluation, but actual analyses are performed at 4 regional laboratories. In addition to a description of the Danish National Pesticide Monitoring Program on food, the effects of lowering the reporting limits are discussed. Pesticides included are those in current use as well as chlorinated pesticides like lindane, DDT, and HCB, occurring in food now primarily as a result of environmental contamination. Commodities analyzed are fruits, vegetables, cereals, bran, fish, and animal products such as meat, butter, cheese, fat, and eggs. In fruits and vegetables, residues were detected in 10% of 2515 samples, with higher incidences of detection for foreign commodities. Violation rate was 0.6%. In food of animal origin, low levels of organo- chlorine pesticides were detected in most fish samples and in more than half of the animal product samples. However, no results exceeding maximum residue limits were found. No residues of organo- phosphorus pesticides were detected in the 231 meat samples analyzed.