Pyrene Bioaccumulation, Effects of Pyrene Exposure on Particle-Size Selection, and Fecal Pyrene Content in the Oligochaete Limnodrilus Hoffmeisteri (Tubificidae, Oligochaeta)

Abstract

The oligochaete Limnodrilus hoffmeisteri Cleparéde was exposed to sediment-amended pyrene (0-1,196 nmol/g dry wt) for 2, 5, and 10 d to investigate sediment particle-size preference, tissue pyrene bioaccumulation (using biota-sediment accumulation factor, BSAF), fecal pyrene concentrations (using fecal-sediment accumulation factor, FSAF), and pyrene biotransformation. In non-pyrene-amended sediment, L. hoffmeisteri preferentially ingested finer sediment particles (< 3.5 microns). However, pyrene concentrations > 199 nmol/g dry weight resulted in a decreased preference for finer particles, presumably reducing pyrene exposure. Particle selectivity also changed with time such that after 10 d, worms showed an increased preference for finer particles. At high pyrene exposure, tissue pyrene concentrations rapidly attained equilibrium (maximum body residue 4.4 mumol/g wet wt, close to values cited for hydrocarbon critical body residues). Levels of biotransformation were low (mean 14%) and independent of time or pyrene concentration. Biota-sediment accumulation factor showed a negative relationship with sediment pyrene concentration; this trend may be due to reduced availability at high sediment pyrene concentrations or due to reductions in both ingestion rate and selectivity for fine, pyrene-rich particles. Fecal pyrene concentrations were depleted compared to sediment levels, suggesting removal of pyrene during gut passage by absorption. Fecal-sediment accumulation factor showed a negative relationship with increasing sediment pyrene levels.

Influence of bioturbation on bioavailability and toxicity of PAHs in sediment from an electronic waste recycling site in South China

“…The results revealed that sublethal effects to the worms occurred due to the high worm densities, which was consistent with previous studies (Lotufo et al, 2000;Millward et al, 2001;Mäenpää et al, 2009). Similar to the present study, sublethal toxicity was believed to be the reason for the decrease in bioaccumulation of pyrene in the oligochaetes Limnodrilus hoffmeisteri and L. variegatus (Millward et al, 2001;Mäenpää et al, 2009). Lotufo et al (2000) reported worms at high density were more susceptible to toxicant effects on their growth, and they suggested competition for food sources may be one of the reasons.…”

“…Although reproduction was noted in some cases, survival of the worms was all close to 100 percent, thus reproduction was not the reason for the decline in worm weights in the present study. These results, which are consistent with the literature (Lotufo et al, 2000;Millward et al, 2001;Mäenpää et al, 2009), indicated that overcrowding may change organism susceptibility to contaminants, which in turn may alter sediment toxicity. Thus, future studies should take this into consideration when analyzing the effects of bioturbation on bioavailability of contaminants in sediments.…”

Effects of sedimentary sootlike materials on bioaccumulation and sorption of polychlorinated biphenyls

“…Input parameters were sediment-water distribution coefficients (K d ϭ f TOC ·K OC , with total organic carbon-normalized sediment-water distribution coefficient (K OC ) values estimated from logK OC ϭ logK OW Ϫ 0.21 [35]); coal and charcoal-water distribution coefficients (K S ) from Jonker and Koelmans [13]; and bioconcentration factors (estimated as BCF ϭ f lipid ·K OW ). Although Limnodrilus indeed probably has a slight preference for fine, low-density, organic carbon-enriched particles [36], incomplete gut clearance cannot have substantially contributed to the elevated BSAFs. After exposure, concentrations of several PCBs in worms inhabiting charcoalcontaining sediment should therefore be less than 10 g/kg (concentrations in extracts just above detection limits).…”

Bioavailability of Hydrophobic Organic Contaminants in Sediment with Different Particle-Size Distributions

“…Although the role of organic carbon (OC) and other sediment composition factors, such as black carbon and sedimentary plant-derived carbon, have been well studied with respect to bioavailability (Rochne et al 2002;Cornelissen et al 2005;Kukkonen et al 2005;You et al 2006;Yang et al 2008), few studies have investigated the role that physical properties, such as sedimentary particle-size distribution, may play in this estimation (Cornelissen et al 1999;Millward et al 2001;Laak et al 2007). …”

“…Moreover, selective ingestion of fine sediment by benthic organisms also make particle-size distribution an important factor affecting bioavailability of HOCs in sediment (Millward et al 2001). In addition, particle sizes equate to particle transport rates in the aquatic environment.…”