Differences in Toxicokinetics and Maternal Transfer between Lipophilic and Proteinophilic Halogenated Organic Pollutants in Laying Hens

In this study,we conducted exposure experiments on egg-laying hens to explore the toxicokinetics and maternal transfer characteristics of lipophilic and proteinophilic halogenated organic pollutants(HOPs).The lipophilic HOPs included polychlorinated biphenyls(PCBs),polybrominated diphenyl ethers(PBDEs),and dechlorane plus(DPs),while the proteinophilic HOPs included perfluorocarboxylic acids(PFCAs).The results revealed that most of lipophilic HOPs exhibit lower depuration rate(kd)than PFCAs.The kd of lipophilic HOPs correlated with the octanol−water partition coefficient(log KOW)values in a V-shaped curve,whereas that of PFCAs correlated with the protein−water partition coefficient(log KPW)values in an inverted V-shaped curve.The depuration rate,rather than the uptake rate,was a leading factor in determining the bioaccumulation potential of HOPs in hens.Although the dominant factors determining the tissue distribution of the two types of compounds were explicit(fats vs phospholipids),chemical-specific tissue distribution was still observed.The egg-maternal concentration ratio was dependent on the exposure status,concentration,and maternal tissue choice.Using a single maternal tissue may not be an appropriate method for assessing chemical maternal transfer potential.PFCAs have a greater maternal transfer potential(>80%of the total body burden)than lipophilic HOPs(approximately 30%for BDE209 and DPs,and less than 10%for the others).Their lipophilic and partly proteinophilic nature makes the toxicokinetics and maternal transfer characteristics of BDE209 and DPs different from those of other lipophilic HOPs.These findings are crucial for enhancing our understanding of the behavior and fate of HOPs in egg-laying hens.

Effect of carcass contamination on necrophagous invertebrate performance

Background:The breakdown of dead organic matter is driven by a diverse array of organisms and is an important process increasingly impacted by a range of contaminants.While many studies have documented how contaminants affect food webs that are fueled by decaying plant litters,much less is known about how contaminants affect organisms that rely on dead animal material.Here,we begin to explore the effects of food contamination—using silver nanoparticles(AgNPs)as a model contaminant—on the carrion beetle Nicrophorus vespilloides that buries carcasses of small vertebrates in soils as food source and larval nursing grounds.Results:Our data show that a single ingestion of a non-lethal dose of 1μg mL^(−1) AgNPs by adult female beetles does not affect overall gut microbial activity but results in shifts in the gut microbial community composition towards pathogens including Alcaligenes,Morganella,and Pseudomonas.While no effects were observed in offspring clutch size,some reductions were visible in clutch weight,number of larvae,and number of eclosing pupae in exposed N.vespilloides in comparison with controls.Repeated ingestion of AgNPs over several weeks led to a decrease in survival of adult beetles,suggesting that more environmentally realistic exposure scenarios can directly affect the success of carcass-feeding animals.Conclusions:Sub-lethal carcass contamination with a model pollutant can affect the gut microbial composition in female beetles and reduce offspring fitness.This encourages consideration of currently overlooked propagation routes of contaminants through necrophagous food webs and inherent consequences for ecological and evolutionary processes.