Average Bioconcentration Factors Research Articles

Metallic trace elements in marine sponges living in a semi-enclosed tropical lagoon.

The ability of marine filter feeders to accumulate metals could help monitor the health of the marine environment. This study examined the concentration of metallic trace elements (MTE) in two marine sponges, Rhabdastrella globostellata and Hyrtios erectus, from three sampling zones of the semi-enclosed Bouraké Lagoon (New Caledonia, South West Pacific). MTE in sponge tissues, seawater, and surrounding sediments was measured using inductively coupled plasma with optical emission spectroscopy. The variability in sponge MTE concentrations between species and sampling zones was visually discriminated using a principal component analysis (PCA). Sponges showed Fe, Mn, Cr, Ni, and Zn concentrations 2 to 10 times higher than in the surrounding sediments and seawater. Hyrtios erectus accumulated 3 to 20 times more MTE than R. globostellata, except for Zn. Average bioconcentration factors in sponge tissues were (in decreasing order) Zn > Ni > Mn > Fe > Cr relate to sediments and Fe > Ni > Mn > Cr > Zn relate to seawater. The PCA confirmed higher MTE concentrations in H. erectus compared to R. globostellata. Our results confirm that marine sponges can accumulate MTE to some extent and could be used as a tool for assessing metals contamination in lagoon ecosystems, particularly in New Caledonia, where 40% of the lagoon is classified as a UNESCO World Heritage Site.

Accumulation of nutrients and potentially toxic elements in plants and fishes in restored mangrove ecosystems in South China.

Mangroves are highly dynamic ecosystems that offer important services such as maintaining biodiversity, filtering pollutants, and providing habitats for fishes. We investigated the uptake and accumulation of nutrients and potentially toxic elements in mangrove plants and fish to better understand the role of mangrove restoration in maintaining mangrove biota quality. In mangrove plants, the average bioconcentration factors of nutrients and potentially toxic elements were in the order P > Pb > Mn > Mg > Se > Zn > Hg > Cu > Cd > As > Co > Cr > Ni > Fe > V > Sb, where only P (all plant species) and Pb (Sonneratia apetala Buchanan-Hamilton) had a BCF > 1.0 in mangrove plants. In general, Sonneratia spp. had better performances than Kandelia candel (Linn.) Druce, Aegiceras corniculatum (Linn.) Blanco and Acanthus ilicifolius L. Sp. in terms of nutrient uptake and toxic metal(loid)s accumulation, and the best uptake capacity was found in S. apetala. Fast growth and easy adaptation make S. apetala suitable for a restored mangrove ecosystem, but continual management is needed to prevent its suppression of mangrove species diversity. The concentration of As, Cd, Hg, Cu, Cr and Pb in the mangrove sediment were 30-220% higher than the Chinese National Standard of Marine Sediment Quality Class I limits, suggesting that the sediments were unsuitable for aquaculture and nature reserves. Although a higher toxic metal(loid)s concentration in the sediment was found, the target hazard quotient (THQ) of this toxic metal(loid)s in 5 mangrove habitat fishes was <1.0, except THQ of Pb in Boleophthalmus pectinirostris Linnaeus was 1.17, and THQ of Cr in Bostrychus sinensis Lacépède was 1.12. The low THQ (less than 1.0) of mangrove habitat fishes suggested that the restored mangrove system could alleviate the bioaccumulation of toxic metal(loid)s in mangrove fish.

Assessment of Heavy Metal Uptake in Potatoes Cultivated in a Typical Karst Landform, Weining County, China.

The average content of heavy metals in Weining soil of karst landforms is generally higher than that of other agricultural regions. The aim of this study was to evaluate the heavy metal content in potatoes from Weining county and to analyze the correlation between the content of heavy metals in potatoes planted in the soil of karst landform and the soil’s environmental factors (soil heavy metals, soil pH, soil organic matter, altitude). Weining county (Guizhou province, China) is a typical karst landform, and has a potato production yield of 2.7 million tons. In this study, 56 soil and potato samples were collected from Weining county and the heavy metal content in the soils and potatoes was detected by inductively coupled plasma atomic mass spectrometry (ICP-MS). The content of Cr, Ni, and As in the soil was found to be higher, with almost half of the samples exceeding the maximum allowable levels. A total of 9 of the 56 samples tested had pollution load index values greater than 1.0, which indicates serious soil pollution. It was found that the ability of the potato to absorb heavy metals from the soil was very low, with the average bio-concentration factors of the metals Zn, Cu, Pb, Cr, Ni, and As being 0.087, 0.088, 0.0028, 0.0034, 0.0066, and less than 0.001, respectively. The content of the six heavy metals in the potatoes were all lower than the maximum permissible limit. The results show that a high As content in the soil could increase the content of Pb in potatoes, that a lower pH was beneficial to the bioaccumulation of Cr and Ni in potatoes, and that a high altitude is detrimental to the bioaccumulation of zinc and copper in potatoes. The HRI ranged between 1.12 × 10−2 and 5.92 × 10−2.

Periphyton bioconcentrates pesticides downstream of catchment dominated by agricultural land use

Periphyton provides important ecosystem services in aquatic environments, including supporting diverse consumers. We studied pesticide bioconcentration in periphyton in a coastal marsh on Lake Erie. The marsh is within a protected area (Rondeau Provincial Park) but receives discharge from tributaries draining intensively farmed land. Periphyton bioconcentrated 20 pesticide chemicals above levels observed in adjacent water or sediment. Average bioconcentration factors ranged from 12 times for the herbicide dicamba to 6864 times for the fungicide boscalid on a dry-weight basis. Bioconcentration factors were not linearly related to pesticides’ log Kow, log Koc, or water solubility (simple linear regressions, p > 0.43). The removal of pesticides from ambient water represents another valuable ecosystem service provided by periphyton. However, we caution that bioconcentration of pesticides in periphyton provides a mechanism through which contemporary and legacy pesticides may enter wetland food webs.

The accumulation and distribution of five antibiotics from soil in 12 cultivars of pak choi

There is a lack of understanding about the potential accumulation of antibiotics in plants exposed to low-dose contaminated soil. 12 Brassica rapa subsp. chinensis cultivars were used to investigate the different accumulation capacities of sulfamethoxypyridazine, tetracycline, ofloxacin, norfloxacin and difloxacin from the soil. The results showed a significant variation (p < 0.05) among the 12 cultivars in the accumulation of antibiotics. Cultivars Y1 and Y2 had the highest accumulation capacity with average concentrations of 3.26 and 3.00 μg kg−1, respectively, while cultivars Y4 and Y9 had the lowest accumulation capacity with average concentrations of 0.83 and 0.89 μg kg−1. The average antibiotic concentration in all edible part samples (2.74 μg kg−1) of the treatment group was about 3.0-fold of that of the control group (0.93 μg kg−1). The average bioconcentration factors of sulfamethoxypyridazine, tetracycline, ofloxacin, norfloxacin and difloxacin were 0.051, 0.031, 0.017, 0.036 and 0.034, respectively, indicating a higher uptake of sulfamethoxypyridazine compared to ofloxacin. And the mobility of antibiotics in soil is a main factor affecting the bioavailability for plants. The average concentration of antibiotics in edible parts of cultivar Y12 on the 25th and 45th day were 1.52 and 1.73 μg kg−1 and that of the roots were 3.73 and 6.61 μg kg−1, respectively. The concentrations of tetracycline and difloxacin in the edible parts and roots significantly increased with growing time, while the concentration of sulfamethoxypyridazine and ofloxacin changed little throughout the growing period. The potential risks of antibiotics in vegetables on human health cannot be ignored. Overall, attention should be paid to the translocation of antibiotics from soil to plants.

Urea increased nickel and copper accumulation in the leaves of Egeria densa (Planch.) Casp. and Ceratophyllum demersum L. during short-term exposure

In the present study, two fresh water plant species Egeria densa (Planch.) Casp. and Ceratophyllum demersum L. were subjected to separate and combined action of urea (2mМ) and metals (Ni and Cu, 10μM) to investigate the phytoremediation potential of these two submerged macrophytes during short-term experiments (48h). Both submerged macrophytes demonstrated high accumulative potential for Ni and Cu (average bioconcentration factors were 2505 for Ni and 3778 for Cu). The urea (2 mM) was not significantly toxic for studied plant species. Futhermore, urea worked as an additional source of nitrogen and stimulated some metabolic processes such as the synthesis of photosynthetic pigments, soluble proteins, non-enzymatic antioxidants, and activated some enzymes. Adding urea to the metals increased their accumulation in both macrophytes (on average by 35% for Ni and 15% for Cu). Combined action of urea and Ni did not have a significant effect on antioxidant response, but caused a sharp increase of urease activity (4 folds on an average) in both plants. The copper exerted a stronger toxic effect on both studied macrophytes compared to nickel. Adding urea to copper in some cases diminished the toxic action of this metal. Study concludes that the responses of E. densa and C. demersum to urea and metal action (separate and combined) were depended on the type of pollutant and the activity of antioxidant defence system. Therefore, the studied aquatic macrophytes found to be potential phytoremediators of water bodies, the addition of an organic nitrogen source in the form of urea in environmentally relevant concentration will increase the efficiency of phytoextraction of metals.

Toxicity-based toxicokinetic/toxicodynamic assessment of bioaccumulation and nanotoxicity of zerovalent iron nanoparticles in Caenorhabditis elegans.

Elucidating the relationships between the toxicity-based-toxicokinetic (TBTK)/toxicodynamic (TD) properties of engineered nanomaterials and their nanotoxicity is crucial for human health-risk analysis. Zerovalent iron (Fe0) nanoparticles (NPs) are one of the most prominent NPs applied in remediating contaminated soils and groundwater. However, there are concerns that Fe0NP application contributes to long-term environmental and human health impacts. The nematode Caenorhabditis elegans is a surrogate in vivo model that has been successfully applied to assess the potential nanotoxicity of these nanomaterials. Here we present a TBTK/TD approach to appraise bioaccumulation and nanotoxicity of Fe0NPs in C. elegans. Built on a present C. elegans bioassay with estimated TBTK/TD parameters, we found that average bioconcentration factors in C. elegans exposed to waterborne and food-borne Fe0NPs were ~50 and ~5×10−3, respectively, whereas 10% inhibition concentrations for fertility, locomotion, and development, were 1.26 (95% CI 0.19–5.2), 3.84 (0.38–42), and 6.78 (2.58–21) μg·g−1, respectively, implicating that fertility is the most sensitive endpoint in C. elegans. Our results also showed that biomagnification effects were not observed in waterborne or food-borne Fe0NP-exposed worms. We suggest that the TBTK/TD assessment for predicting NP-induced toxicity at different concentrations and conditions in C. elegans could enable rapid selection of nanomaterials that are more likely to be nontoxic in larger animals. We conclude that the use of the TBTK/TD scheme manipulating C. elegans could be used for rapid evaluation of in vivo toxicity of NPs or for drug screening in the field of nanomedicine.

APPLICATION OF FLY ASH-STABILIZED MUNICIPAL SEWAGE SLUDGE ON GROWTH OF Brassica chinensis AND HEAVY METAL TRANSFER IN POT EXPERIMENT WITH A BARREN SOIL

Pot experiments were performed with a barren soil amended with fly ash stabilized municipal sewage sludge to cultivate Brassica chinensis. Accumulation and transformation of heavy metals in the tested soil-plant system were investigated. The results showed that appropriate application of fly ash-sludge mixture could improve the growth of Brassica chinensis. The plants cultivated in F30 treatment, which contained 14% (volumetric) sludge and 6% (volumetric) fly ash, presented the highest yield and nutrients and better physiological characteristics. The average bioconcentration factors (BCFs) of the studied heavy metals in the Brassica chinensis cultivated in F30 treatment decreased in the order of Sb (8.05) > As (1.50) > Zn (0.84) > Cu (0.44) > Mn (0.16) > Ni = Cr (0.10) > Pb (0.07) > Co (0.06) > Cd = Ti (0.05) > Fe = V (0.02). The concentrations of Cd, As, Ni, Pb, Cr, Cu and Zn in the cultivated Brassica chinensis were lower than the maximum permissible concentrations for the vegetables in China. Planting Brassica chinensis could reduce the availability of Cu, Zn, Ni, Cr, Mn, Co, As and Sb in the fly ash-sludge amended soil. The long-term effect of repeat application of the fly ash-sludge mixture on soil and plants require further field investigation.

Occurrence of perchloroethylene in surface water and fish in a river ecosystem affected by groundwater contamination.

Long-term monitoring of the content of perchloroethylene (PCE) in a river ecosystem affected by groundwater contamination was performed at a site in the Czech Republic. The quality of surface water was monitored quarterly between 1994 and 2013, and fish were collected from the affected ecosystem to analyse the content of PCE in their tissue in 1998, 2011 and 2012. Concentrations of PCE (9-140 μg/kg) in the tissue of fish collected from the contaminated part of the river were elevated compared to the part of the river unaffected by the contamination (ND to 5 μg/kg PCE). The quality of surface water has improved as a result of groundwater remediation during the evaluated period. Before the remedial action, PCE concentrations ranged from 30 to 95 μg/L (1994-1997). Following commencement of remedial activities in September 1997, a decrease in the content of PCE in the surface water to 7.3 μg/L (1998) and further to 1 μg/L (2011) and 1.1 μg/L (2012) led to a progressive decrease in the average concentration of PCE in the fish muscle tissue from 79 μg/kg (1998) to 24 (2011) and 30 μg/kg (2012), respectively. It was determined that the bioconcentration of PCE does not have a linear dependence because the decrease in contamination in the fish muscle tissue is not directly proportional to the decrease in contamination in the river water. The observed average bioconcentration factors were 24 and 28 for the lower concentrations of PCE and 11 for the higher concentrations of PCE in the river. In terms of age, length and weight of the collected fish, weight had the greatest significance for bioconcentration, followed by the length, with age being evaluated as a less significant factor.

Pesticides in Water, Fish and Shellfish from Littoral Area of Lake Biwa

A survey of 29 pesticides were performed for water, fish and shellfish from two littoral areas of Lake Biwa and Yanamune River in 2007. Three insecticides, 5 fungicides and 13 herbicides were detected in the water from the sampling locations, but the insecticides and fungicides were not and the only 9 herbicides were detected in the fish and shellfish from the locations. Bioconcentration factors (BCF) of the 9 herbicides in the fish and shellfish were calculated by the field data obtained from the survey. The average field BCF values of the herbicides in the fish were 8 and 25 for molinate, 5-23 for bromobutide, 4 and 10 for simetryn, 100-214 for esprocarb, 15-41 for pretilachlor, 148 for anilofos, 14 and 79 for mefenacet and 78 for cafenstrole. Those in the shellfish were 6 and 13 for bromobutide, 4 and 8 for simetryn, 67 and 135 for esprocarb, 2 for pretilachlor, 117 for pyributicarb and 57 and 139 for mefenacet. The field BCF data in the fish were evaluated by laboratory BCF data from literatures for molinate, bromobutide, pretilachlor, simetryn and mefenacet.

Mineralization and plant uptake of 14C‐labeled nonylphenol, nonylphenol tetraethoxylate, and nonylphenol nonylethoxylate in biosolids/soil systems planted with crested wheatgrass

Microcosm experiments (duration, 150 d) were conducted to evaluate the mineralization and plant uptake of [14C]nonylphenol (NP), [14C]nonylphenol tetraethoxylate (NPE4), and [14C]nonylphenol nonylethoxylate (NPE9) in a soil/biosolids (99.5:0.5 w/w) environment planted with crested wheatgrass (Agropyron cristatum). Three initial nominal concentrations (6, 24, and 47 mg/kg dry wt) each of NP, NPE4, and NPE9 were examined along with unplanted and unplanted poisoned controls. Phenol (22 mg/kg) also was evaluated as a more degradable reference compound. The biosolids were obtained from a municipal treatment plant, and the loamy sand soil was freshly collected. Mineralization ranged from 7% for NP to 53% for phenol, and no enhancement was observed in the planted systems. For NP, NPE4, and NPE9, 14C foliar tissues concentrations were proportional to exposure concentrations but were 10-fold lower than the root concentrations and two- to threefold lower than the soil concentrations. Bioconcentration factors (BCFs) based on 14C measurements ranged from 0.31 (mg compound/kg dry plant/ mg compound/kg dry soil) for systems spiked with NP to 0.52 for systems spiked with NPE9. Results of the NP analysis (initial concentration, 47 mg/ kg) showed a 90% decrease in the soil concentration and an average BCF of 1.0. The lower BCF calculated from the 14C analysis likely resulted from the presence of NP transformation products in the soil that are less available or are translocated by the plants but quantified by the combustion/liquid scintillation counting procedure.

Effects, transfer, and fate of RDX from aged soil in plants and worms

The objectives of this study were to provide data that can be used to predict exposure-based effects of RDX in aged soil on multiple endpoint organisms representing two trophic levels. These data can be used for defining criteria or reference values for environmental management and conducting specific risk assessment. Dose–response experiments formed the basis for the evaluation of toxic effects and transfer of contaminants from soil into two trophic levels. Long-term exposure tests were conducted to evaluate chronic, sublethal, toxicity and transfer of aged soil-based explosives, with RDX as main contaminant. In these tests, plants were exposed for 55 days in the greenhouse, biomass was determined and residues of explosives parent compounds and RDX metabolites were analyzed using HPLC techniques. Worms were exposed for 28 days ( Eisenia fetida) and 42 days ( Enchytraeus crypticus) in the laboratory, biomass and number were determined, and tissues were analyzed for explosives compounds. The plants tolerated concentrations up to 1540 mg RDX kg −1 soil-DW. Biomass of Lolium perenne was not significantly related to soil-RDX concentration, while biomass of Medicago sativa significantly increased. No screening benchmark for RDX in soil for plants was calculated, since concentrations up to 1540 mg kg −1 soil failed to reduce biomass by 20% as required for a LOEC. RDX, RDX-metabolite MNX, and accompanying HMX concentrations in plants were significantly related to concentrations in soil after 55 days of exposure (RDX: R 2 = 0.77–0.89; MNX R 2 = 0.53–0.77; HMX: R 2 = 0.67–0.71). The average bioconcentration factors (BCF) were for RDX 17 in L. perenne and 37 in M. sativa, and for HMX 2 in L. perenne and 44 in M. sativa. The worms also tolerated concentrations up to 1540 mg RDX kg −1 soil-DW. Biomass of E. fetida adults decreased with soil-RDX concentration, and a LOEC of 1253 mg kg −1 soil-DW was estimated. RDX concentrations in E. fetida were significantly related to concentrations in soil after 28-day exposure ( R 2 = 0.88). The average BCF in E. fetida for RDX was 1. Because in response to exposure to RDX-contaminated soil the RDX concentrations in plants increased initially and decreased subsequently, while those in worms increased continuously, RDX in worm tissues may accumulate to higher concentrations than in plant tissues, regardless of the low average BCF for worms.

The bioconcentration and metabolism of chlorpyrifos by the eastern oyster,Crassostrea virginica

Eastern oysters (Crassostrea virginica) were exposed to [14C]chlorpyrifos (O,O-diethyl-O-[3,5,6-trichloro-2-pyridyl] phosphorothioate) at an average measured seawater concentration of 0.6 microg/L under flow-through conditions for 28 d. The compound O,O-diethyl-O-(3,5-dichloro-6-methylthio-2-pyridyl)phosphorothioate (DMP) was extracted and identified as the single metabolite observed, and this metabolite constituted the majority of the total [14C] activity in the oyster at all sampling times. Once oysters were exposed to clean water, both chlorpyrifos and DMP residues cleared rapidly from whole oysters, with elimination half-lives of <3 d. A simple two-compartment uptake/elimination model was adequate to describe total [14C] activity in whole oysters, edible tissue, and oyster liquor. The average bioconcentration factors (BCFs) for total [14C] activity in whole oysters, edible tissue, and oyster liquor were 565, 1,400, and 35 ml/g, respectively. The parent [14C]chlorpyrifos accumulated to a peak residue concentration of 135 microg/kg in whole oyster tissue, representing an empirical [14C]chlorpyrifos BCF value in the oyster of approximately 225 ml/ g; the BCF value for [14C]chlorpyrifos was lower than the BCF for total [14C] activity in whole oysters and edible tissue because of extensive metabolism to DMP and oyster elimination processes.

Contribution of dietary bacteria to metal accumulation in the slipper limpet

Recent studies have shown that dietary ingestion can be an important source for metal accumulation in aquatic animals. Whether bacteria can contribute significantly to the overall metal accumulation in these animals remains little known. In this study, we used the kinetic modeling approach to examine the relative contribution of the aqueous phase, bacteria, and phytoplankton, as sources for Cd, Cr, and Zn accumulation by the slipper limpet Crepidula onyx, a suspension feeder that can capture bacteria efficiently. Metal uptake rate constants measured in C. onyx were 0.200, 1.232, and 1.294 l g–1 d–1 for Cd, Cr, and Zn, respectively. The assimilation efficiency (AE) of metals from ingested phytoplankton (11 to 44% for Cd, and 31 to 41% for Zn) was comparable to AEs of metals from ingested bacteria (21 to 42% for Cd, 35 to 47% for Zn), whereas the AEs of Cr from ingested phytoplankton (10 to 22%) were lower than from ingested bacteria (44 to 59%). The AEs of Cr from different phytoplankton and bacterial diets were related to its distribution in the cytoplasm of cells and its passage time across the animal’s guts. The limpets filtered the bacteria at rates (17 l h–1 g–1) 1.3 to 1.9× lower than the filtration rate on different phytoplankton diets (22 to 33 l h–1 g–1). The estimated average bioconcentration factors of metals by 2 bacterial strains were 2 to 6 × 105 for Cd, 1 to 7 × 105 for Cr, and 1.5 to 7 × 105 for Zn. The kinetic model predicted that uptake from dietary phase dominated metal accumulation in the slipper limpets (87% for Cd, 72% for Cr, and 83% for Zn). Ingestion of bacteria contributed 23% for Cd, 27% for Cr, and 17% for Zn accumulation in the limpets under typical conditions for the limpets. Our study therefore highlights bacteria as a potentially important source of metal accumulation in this filter-feeding mollusc.

Accumulation and excretion of pesticides used as insecticides or fungicides in agricultural products by the willow shiner Gnathopogon caerulescens

The average bioconcentration factors (BCF) in the whole body of willow shiner ( Gnathopogon caerulescens) after 24–336 hr exposure were 810 for chlorpyriphosmethyl, 802 for vamidothion, 110 for edifenphos, 25 for ethoprophos, 83 for bendocarb, 39 for pirimicarb and 114 for methyl parathion. The correlations between a logarithm of 48 hr- Lc 50 to carp (log Lc 50 and the parameters (a logarithm of n-octanol-water partition coefficiens (log P ow) and log BCF in willow shiner) were investigated for the pesticides studied here and already reported. The correlation factor ( r) was −0.136 ( N = 21) for log Lc 50 vs log P ow and 0.039 ( N = 24) for log Lc 50 vs log BCF. The excretion rate constants ( k) from the whole body of the fish were 0.01 hr −1 for chlorpyriphosmethyl, 0.03 hr −1 for vamidothion, 0.11 hr −1 for edifenphos, 0.27 hr −1 for ethoprophos, 0.18 hr −1 for bendiocarb, 0.01 hr −1 for pirimicarb and 0.08 hr −1 for methyl parathion. The correlation between log k and log BCF was investigated for 22 pesticides already reported and studied here. The r value was not so high (−0.537, N = 22) but higher (−0.672, N = 2) in the case of excluding simetryne.

Accumulation and excretion of chloroanilines by carp

Accumulation and excretion of chloroanilines were studied for carp ( Cyprinus carpio L.). The average bioconcentration factors (BCF) in the whole body of the fish after 24 – 336 hr exposure were 2.0 and 3.7 for o-chloroaniline. 0.8 and 2.2 for m-chloroaniline and 0.8 and 1.7 for p-chloroaniline at high and low concentrations of the chemicals, respectively. The excretion rate constants (k) from the whole body of the fish were 0.19 hr −1 for o-chloroaniline, 0.21 hr −1 for m-chloroaniline and 0.16 hr −1 for p-chloroaniline. The experimental data on the accumulation and excretion of the chloroanilines were consistent with the field data.

Accumulation and excretion of organophosphorous pesticides by carp Cyprinus carpio

1. The average bioconcentration factors (BCF) in the whole body of carp ( Cyprinus carpio L.) after 24–168 hr exposure were <0.5 for dichlorvos, 7.4 for salithion, 29 for phenthoate, 2.8 for methidathion, 4.7 for pyridaphenthion, 26 for fenthion and 1.7 for phosmet. Further, the BCF value of EPN after 168 hr exposure was 85. 2. The correlation between n-octanol-water partition coefficients ( P ow) and BCF in carp was investigated for 13 pesticides studied here and already reported. The correlation factor ( r) was not very high (0.5139, N = 13) but higher (0.7005, N = 12) in the case of excluding captan. 3. The excretion rate constants ( k) from the whole body of carp were 0.54 hr −1 for salithion, 0.52 hr −1 for phenthoate, 0.54 hr −1 for methidathion, 0.43 hr −1 for pyridaphenthion, 0.34 hr −1 for fenthion and 0.18 hr −1 for EPN.

Accumulation and excretion of organophosphorous pesticides by willow shiner

Bioconcentration and excretion of 8 organophosphorous pesticides were studied for willow shiner ( Gnathopogon caerulescens ). The average bioconcentration factors (BCF) in the whole body of the fish after 24 – 168 hr exposure were 0.8 for dichlorvos, 76 for salithion, 18 for methidathion, 29 for pyridaphenthion, 481 for fenthion and 36 for phosmet, Further, the BCF values of the other pesticides after 168 hr exposure were 713 for phenthoate and 1682 for EPN. The correlation between n-octanol-water partition coefficients (P OW) and BCF in willow shiner was investigated for 19 pesticides studied here and already reported. The correlation factor (r) was not so high (0.6819, n=19) but higher (0.9085, n=18) in case excluding captan. The excretion rate constants (k) from the whole body of willow shiner were 0.20 hr −1 for salthion, 0.05 hr −1 for phenthoate, 0.27 hr −1 for methidathion, 0.20 hr −1 for pyridaphenthion, 0.07 hr −1 for fenthion, 0.04 hr −1 for EPN and 0.28 hr −1 for phosmet.

Accumulation and excretion of pesticides used in golf courses by carp ( Cyprinus carpio) and willow shiner ( Gnathopogon caerulescens)

1. The average bioconcentration factors (BCF) in whole body of willow shiner ( Gnathopogon caerulescens) were 3.9 for simazine, 18 for chlorothalonil and 350 for captan. 2. The average BCF values in whole body of carp ( Cyprinus carpio L.) were 220 for tolclofos-methyl, 460 for chlorpyriphos, 20 for flutolanil, 27 for isoprothiolane, 25 for chlorothalonil, 100 for captan, 440 for isoxathion and 360 for iprodione. 3. The correlations between n-octanol-water partition coefficients ( P ow) and BCF in willow shiner and carp were investigated for the pesticides studied here and already reported. Correlation factors ( r) except captan were 0.9391 ( N = 10) for willow shiner and 0.7747 ( N = 15) for both fishes. 4. The excretion rate constants ( k) from whole body of willow shiner were 0.77 hr −1 for simazine, 0.04 hr −1 for chlorothalonil and 0.02 hr −1 for captan. 5. The k values from whole body of carp were 0.04 hr −1 for tolclofos-methyl, 0.02 hr −1 for chlorpy-riphos, 0.12 hr −1 for flutolanil, 0.19 hr −1 for isoprothiolane, 0.01 hr −1 for captan and 0.03hr −1 for isoxathion.bl]

Accumulation and excretion of tri- n-butyltin chloride and triphenyltin chloride by willow shiner

1. The bioconcentration factors (BCF) of both Bu 3SnCl and Ph 3SnCl via gill intake of willow shiner ( Gnathopogon caerulescens) reached plateaus after 28 days of exposure. The average BCF values of Bu 3SnCl and Ph 3SnCl ( N = 2) were 3620 and 2300, respectively, after 28–35 days of exposure. 2. The BCF values by oral intake of willow shiner reached plateaus after 42 days for Bu 3SnCl and probably after the same period for Ph 3SnCl. The average BCF values of Bu 3SnCl and Ph 3SnCl ( N = 2) were 0.08 and 0.10, respectively, after 42–49 days of exposure. 3. The order of these compounds (Bu 3SnCl > Ph 3SnCl) in the accumulation potential via gill intake was reversed compared with that by oral intake.