Retention of PCDDS and PCDFS in the liver of the rat and hamster after oral administration of a municipal incinerator fly ash extract

A single dose of an extract from 16 and 5 grams fly ash was administered orally to male rats and hamsters. In the rat 1,2,3,7,8‐PnCDD had the highest retention (41%) in the liver. The congener with the highest retention in the liver of the hamster was 2,3,4,7,8‐PnCDF (70.9%). In two oral multiple dose experiments with rats, highest liver retentions were found for 1,2,3,7,8‐PnCDD (51.7%) and 1,2,3,6,7,8‐HxCDD (59.8%). With the exception of 2,3,4,6,7‐PnCDF, all PCDDs and PCDFs retained in the liver of rat and hamster had a 2,3,7,8 chlorine substitution pattern. In both types of experiments with rats the retention of 2,3,7,8‐TCDF in the liver was very low, 1.1–2.8% of the total dose. In the liver of the hamster retention of 2,3,7,8‐TCDF was almost equal to that of 2,3,7,8‐TCDD, indicating that the hamster is probably metabolizing 2,3,7,8‐TCDF Jess efficiently than the rat. In all experiments 1,2,3,7,8‐PnCDD and 2,3,4,7,8‐PnCDF were retained in the liver more efficiently than 2,3,7,8‐TCDD. Based on first order pharmacokinetic calculations, it was found that the earlier published k_e value of 0.55 for 2,3,7,8‐TCDF in the liver of the rat was also applicable. Using the same calculations for 2,3,7,8‐TCDD (k_e = 0.029) a 30% difference was found between calculated and actual measurements, but calculated results were still within the 95% confidence limits of the actual measurements.     

Anthropogenic and naturally-produced organobrominated compounds in bluefin tuna from the Mediterranean Sea

In the present study, bioaccumulation potential of two pyrethroid insecticides, bifenthrin and permethrin, was measured using a Lumbriculus variegatus sediment bioaccumulation test. Two sediments differing in their physical characteristics and two different aging periods were tested. Desorption rates measured by Tenax extraction suggested that pyrethroids were bioavailable to L. variegatus, however bioavailability varied among chemicals, sediments and aging time, and was greater for permethrin than bifenthrin. The relatively low biota-sediment accumulation factor (BSAF) values resulted from the extensive biotransformation of pyrethroids by L. variegatus. Biotransformation capacity of L. variegatus to permethrin was further studied with a water-only exposure, and the percentage parent compound dropped to 36.0% after 14 d. These results indicated sediment-associated pyrethroids were bioavailable to L. variegatus, however bioaccumulation was limited because L. variegatus was capable of biotransforming the pyrethroids.     

Dietary exposure to dioxin-like compounds in three age groups: results from the Flemish environment and health study

Lipophilic contaminants are present in the environment and bioaccumulate in the food chain. Therefore, their intake via animal fat of various sources was assessed for three age groups of the Flemish population, participating in a large biomonitoring program of the Flemish government. In total, 1636 adolescents (14-15 years), 1186 mothers (18-44 years), and 1586 adults (50-65 years) participated in the study and completed a semi quantitative food frequency questionnaire. Individual consumption data were combined, via a so-called simple distribution approach, with recent data on polychlorinated dibenzo-p-dioxins/furans and dioxin-like polychlorinated biphenyls, measured via the chemical-activated luciferase gene expression (CALUX) bio-assay in food items available on the Flemish market. The median (95th percentile) estimated intakes of dioxin-like contaminants were 2.24 (4.61), 2.09 (4.26), and 1.74 (3.53) pg CALUX-TEQ kg(-1) bw d(-1) for, respectively adolescents, mothers and adults. These data are in the same range as those found in other European studies. The CALUX-TEQ results of respectively 59.8%, 53.7% and 36.2% of the adolescent, mother and adult population exceed the tolerable weekly intake (TWI) of 14 pg WHO-TEQ kg(-1) bw w(-1), as derived by the Scientific Committee on Food [Scientific Committee on Food, 2001. Opinion of the Scientific Committee on Food on the Risk Assessment of Dioxins and Dioxin-like PCBs in Food, CS/CNTM/DIOXIN/20 final Brussels, Belgium]. The main contributors of dioxin-like substances are fish and seafood (25-43% of the total intake), added fats (22-25% of the total intake) and dairy products (17-20% of the total intake).     

“They give you lots of information,but ignore what it's really about”: residents' experiences with the planned introduction of a new high-voltage power line

Cases of strong local opposition to the planned introduction of new high-voltage power lines (HVPLs) have been documented in the past. During and after the planning process for a new HVPL, local residents will be informed about the siting process and its outcomes. Although it has been suggested in the literature that this communication plays an important role in residents' responses to a new HVPL, it has been rarely empirically studied. In this qualitative study, we conducted in-depth interviews with 15 residents about their experiences with the planned introduction of a new HVPL near their homes. Thematic analysis revealed that residents' experiences were centred around negative expectations of living near the new HVPL and perceived injustice of the planning process and its outcomes. Residents' perception that communication was not tailored to their information needs played a significant role in these negative experiences. Suggestions for improving communication will be discussed.