Biota-sediment Accumulation Factors Research Articles

Occurrences and ecotoxicological risks of trace metals in the San Benito Archipelago, Eastern Pacific Ocean, Mexico

Trace metal concentrations (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, As, Hg) were determined in water, sediment and biota samples collected from the San Benito Islands off the Pacific Coast of Baja California, Mexico for a geochemical forensic study. Due to the proximity to the continental – oceanic crust interface and high biological endemism, the islands demanded a profound geochemical survey for evaluating the presence and provenance of trace metals. Results suggested that the metals in the region are mainly originated from the geogenic sources (Fe, Mn, Ni, Cr, Cu, Co), deep water circulation (Cd), atmospheric deposition (Pb) and hydrothermal processes (As). Dissolved phase is the major metal carrier of Pb with an average value of 0.182 mg L−1, while Fe (1.60%), Mn (335.42 mg kg−1), Ni (61.77 mg kg−1), Zn (32.36 mg kg−1) and Cr (28.7 mg kg−1) are mainly present in the particulate phase. High values of Pb, As, Cd and Hg in biota with no biological functions are highly toxic and are especially critical to those predators (Sea lions) in the region due to the process of biomagnification. For a qualitative exposure assessment of trace metals, several indices namely Heavy metal Evaluation Index (HEI), Nemerow Pollution Index (NPI), Bioconcentration Factor (BCF) and Biota Sediment Accumulation Factor (BSAF) were calculated. The indices revealed that the overall pollution status of the region is “moderate”. This study advocates a preliminary environmental surveillance in trace metal concentrations for implementing better conservation strategies in maintaining and promoting the ecological richness and endemism of the islands.

Organophosphorus flame retardants in a typical freshwater food web: Bioaccumulation factors, tissue distribution, and trophic transfer

Water, sediment, and wild aquatic species were collected from an electronic waste (e-waste) polluted pond in South China. This study aimed to investigate the bioaccumulation, tissue distribution, and trophic transfer of organophosphorus flame retardants (PFRs) in these aquatic organisms. The concentrations of PFRs detected in the analyzed organisms were between 1.7 and 47 ng/g wet weight (ww). Oriental river prawn and snakehead exhibited the highest and lowest levels, respectively. Tri-n-butyl phosphate (TnBP), tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCPP) and triphenyl phosphate (TPhP) were dominant contaminants, accounting for approximately 86% of the total sum. The mean values of bioaccumulation factors (BCFs) and logarithmic biota-sediment accumulation factors (log BSAFs) for individual PFRs varied from 6.6 to 1109 and from −2.0 to 0.41, respectively. Both log BCFs and log BSAFs of PFRs were significantly and positively correlated with their octanol-water partitioning coefficient (log KOW). The concentrations of PFRs in tissues of large mud carp and snakehead were significantly and positively correlated with the lipid content (each p < 0.05) and the liver, kidney, and gill exhibited high PFR levels. When the concentration was expressed on a lipid basis, liver exhibited the lowest level, indicating the probable effects of metabolism. Significantly positive correlation was also found between lipid content and total PFR concentration in muscle of all aquatic organisms, given the strong correlation between lipid content and the concentration of TnBP. Trophic magnification factors (TMF) of TnBP and TPhP were lower than 1 (0.57 and 0.62), indicating that these PFRs undergo trophic dilution in this aquatic food web.

Relationships between Potentially Toxic Elements in intertidal sediments and their bioaccumulation by benthic invertebrates.

The bioaccumulation of Potentially Toxic Elements (PTEs) by benthic invertebrates in estuarine sediments is poorly understood. We sampled and analysed PTEs in sediments and benthic invertebrates from five sites in the Skeena Estuary (British Columbia, Canada), including sites adjacent to an abandoned cannery and a decommissioned papermill. Our aim was to elucidate baseline levels of PTE concentrations at sites that may be recovering from disturbance associated with prior industrial development and identify organisms that could be used to biomonitor the impact of future industrial developments. There was no indication that sediments of the salmon cannery were polluted, but acidic sediments adjacent to the papermill contained elevated concentrations of Cd, Cr, Hg and Pb. Benthic invertebrate community assemblages confirm that sediments have mostly recovered from prior industrial development associated with discharge of papermill sludge. Overall, we did not observe any relationship between PTE concentrations in the sediment and PTE concentrations in invertebrate tissues. However, we did observe a negative relationship between sediment pH and the Biota-Sediment Accumulation Factor (BSAF) of most PTEs for Oregon pill bugs (Gnorimosphaeroma oregonensis). G. oregonensis, observed at all sites, feeds on the fibers associated with the papermill discharge. Thus, G. oregonensis is a useful biomonitors for quantifying the impact of the decommissioned papermill, and are candidate biomonitors for assessing the impact of similar industrial development projects on intertidal ecosystems.

Pollution Characteristics of Perfluorinated Alkyl Substances (PFASs) in Seawater, Sediments, and Biological Samples from Jiaozhou Bay, China

In order to explore the pollution levels and characteristics of perfluorinated alkyl substances (PFASs), seawater, sediment, and Ruditapes philippinarum samples were collected near the Jiaozhou Bay coast in April 2018. All samples were analyzed by using the high performance liquid chromatography-mass spectrometry method to determine the content of 35 types of PFASs. The results showed that 12 different PFASs were tested in the seawater with ∑PFASs concentrations of 21.1-38.0 ng·L-1; 10 types of PFASs were detected in sediments, with ∑PFASs content (dry weight) ranging from 0.459 to 1.20 μg·kg-1; 19 types of PFASs were measured in Ruditapes philippinarum, with ∑PFASs content (dry weight) of 15.5-27.5 μg·kg-1. Compared with other areas reported in the literature, the total pollution of Jiaozhou Bay was at medium or high levels. In addition, perfluorooctanoic acid (PFOA) was the dominant PFAS in the seawater, sediments, and Ruditapes philippinarum with a detection rate of 100%. 6:2 fluorotelomer phosphate diester (6:2 diPAP) was observed for the first time in seawater and sediments from Jiaozhou Bay and had the highest detection frequency and concentration of the precursor. Perfluorooctanesulfonamide (PFOSA) was the main precursor in Ruditapes philippinarum, of which the detection rate was 93.8%. Moreover, the organic carbon normalized sediment-water distribution coefficient (lg KOC) values were 5.24-6.37 and increased with an increase in carbon chain length. The bioaccumulation factors (lg BAF) and field-based biota-sediment accumulation factors (lg BSAF) were 2.53-4.32 and 1.30-2.50, respectively. The lg BAF values positively correlated with the carbon chain length, whereas the lg BSAF values decreased with an increase in the carbon chain length (C8-C13).

Environmental geochemistry and bioaccumulation/bioavailability of uranium in a post-mining context – The Bois-Noirs Limouzat mine (France)

Knowledge on the bioavailability of trace elements is essential in developing environmental quality standards. The purpose of this study was to explore the relationships between trace elements (in particular Uranium (U)) in sediments, porewater and their bioaccumulation by Chironomus riparius on a uranium mining site and river sediments upstream of the mine. The mobility and speciation of U in sediments was investigated using DGT. Geochemical modelling using CHESS provided insight on sorption behavior of U on ironoxyhydrite (HFO) and aqueous speciation of U.In the upstream site U concentrations found were 0.05 μmol g−1 in surface sediment, 0.84 nmol L−1 in porewater and 2.4 nmol g−1 in Chironomus riparius whereas in the ferrihydrite deposits on the mining sites the concentrations found were up to 9.4 μmol g−1 in surface sediment, 0.37 μmol L−1 in porewater and 0.684 μmol g−1 in in Chironomus riparius. Despite the large differences in concentrations of U between the two sites, sediment to dissolved partitioning coefficients, bioconcentration factor (BCF) and biota sediment accumulation factors (BSAF) were very comparable. In the upstream sediment binding of U to organic matter controls sorption and aqueous speciation of U, whereas in the HFO rich sediments, sorption on HFO and the formation of HFO colloids are the determining factors. The low BSAF factors and high BCF factors indicate that the bioaccumulation is due to uptake from the dissolved phase. The DGT probes with different binding resins provide information on the colloidal nature and lability of the dissolved U species.

Effects of temperature, salinity, and sediment organic carbon on methylmercury bioaccumulation in an estuarine amphipod

Mercury (Hg) is a global contaminant that poses a human health risk in its organic form, methylmercury (MeHg), through consumption of fish and fishery products. Bioaccumulation of Hg in the aquatic environment is controlled by a number of factors expected to be altered by climate change. We examined the individual and combined effects of temperature, sediment organic carbon, and salinity on the bioaccumulation of MeHg in an estuarine amphipod, Leptocheirus plumulosus, when exposed to sediment from two locations in the Gulf of Maine (Kittery and Bass Harbor) that contained different levels of MeHg and organic carbon. Higher temperatures and lower organic carbon levels individually increased uptake of MeHg by L. plumulosus as measured by the biota-sediment accumulation factor (BSAF), while the effect of salinity on BSAF differed by sediment source. Multi-factor statistical modeling using all data revealed a significant interaction between temperature and organic carbon for both sediments, in which increased temperature had a negative effect on BSAF at the lowest carbon levels and a positive effect at higher levels. Our results suggest that increased temperature and carbon loading, of a magnitude expected as a result from climate change, could be associated with a net decrease in amphipod BSAF of 50 to 71%, depending on sediment characteristics. While these are only first-order projections, our results indicate that the future fate of MeHg in marine food webs is likely to depend on a number of factors beyond Hg loading.

Heavy metals and PAHs in an open fishing area of the East China Sea:Multimedia distribution, source diagnosis, and dietary risk assessment.

This study involved a comprehensive investigation of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in seawater, sediments, and seafoods in an important open fishing area connecting China and Japan. Cu, Pb, Cd, Cr, As, and PAHs were detected in all the studied environmental media. Specifically, Pb and low molecular weight PAHs (LMW-PAHs) were observed at high levels, due to intensive ship activities and accidental crude oil spills. Additionally, source diagnosis of PAHs suggested a potential impact from combustion. Bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAF) suggested moderate or low bioaccumulation potentials of the analytes from water and sediments, respectively. Noncarcinogenic risk assessment, based on target hazard quotients (THQs), indicated a potential low risk by consuming the studied seafoods, while the incremental lifetime carcinogenic risk assessment (ILCRs) suggested "acceptable risk" or "potential risk." However, it should be noted that there have been possibilities that the carcinogenic risk could be elevated due to bioaccumulation of the PAHs in the seafoods after long-term exposure. In summary, it is necessary to evaluate the seafood security carefully in this open fishing area due to the potential health risks.

Occurrence and bioaccumulation of persistent toxic substances in sediments and biota from intertidal zone of Abu Ali Island, Arabian Gulf

North Abu Ali Island is contaminated by crude oil from exogenous sources with a variety of persistent toxic substances (PTSs) being input into intertidal sediments. We detected an array of PTSs in sediments and benthic biota off north Abu Ali Island (Arabian Gulf), including 35 polycyclic aromatic hydrocarbons (PAHs), 6 alkylphenols (APEOs), 10 styrene oligomers (SOs), and tributyltin. The PTS concentrations were generally greater than those reported in other areas of Arabian Gulf. PAHs mainly originated from petrogenic sources, and APEOs and SOs seem to be of recent origin. Field-based biota-sediment accumulation factors (BSAF) varied by taxa and compounds, but clearly depended on the log Kow values of individual compounds. Some PTSs exceeded the established guidelines for sediments and biota; we found particularly great BSAFs for alkyl-naphthalenes (C1- and C2-), nonylphenol monoethoxylates, and 2,4,6-triphenyl-1-hexene. Remediation will require on-site clean-up of toxic chemicals together with immediate efforts on preventing input of current pollution sources in the given area.

Distribution, Source and Risk Assessment of Heavy Metal(oid)s in Water, Sediments, and Corbicula Fluminea of Xijiang River, China.

A total of 43 water and sediment samples, and 34 Corbicula fluminea samples were collected in Xijiang River in southern China to determine the spatial distribution and sources of 12 metals/metalloids (V, Co, Cr, Ni, Cu, Mn, Zn, Cd, Pb, As, Sb, and Tl) and to assess the pollution levels and ecological risks of the pollutants. The results showed that the levels of the metals/metalloids (except for Tl) in the river water from almost all of the sampling sites met the Chinese national surface water quality standards. However, the concentrations of the metals/metalloids in the sediments exceeded the background values by a factor of 1.03–56.56 except for V, Co, and Mn, and the contents of Zn, Cd, and Pb in the Corbicula fluminea soft tissue exceeded the limits of the Chinese Category I food Quality Standards. The spatial distribution analysis showed that the concentrations of the contaminants in the lower reaches of Xijiang River were higher than in the upper reaches. The bioaccumulation factor (BAF), biota-sediment accumulation factor (BSF), geo-accumulation index (Igeo), and the potential ecological risk index (RI) were obtained to assess the pollution levels and ecological risks. The results indicated that Cu, Cd, and Zn were the most prone to bio-accumulation in the Corbicula fluminea soft tissue, and the lower reaches showed a much higher pollution level and risk than the upper reaches. The metals/metalloids in the sediments posed serious threat on the aquatic ecosystem, of which Cd, As, and Sb are the most risky contaminants. The results of principal component analysis (PCA) indicated Cr, Ni, Cu, Mn, Cd, Pb, and As in the sediments came from relevant industrial activities, and V and Co originated from natural sources, and Sb from mining activities, Zn and Tl came from industrial activities and mining activities.

Amazon types of waters, BSAF (Biota Sediment Accumulation Factor), biomagnification and bioaccumulation of Hg

Amazonian rainforest aquatic ecosystem is a very unique ecosystem in the Earth, which waters from the Amazon basin have distinct physicochemical and optical characteristics (black, clear and white). In this mini review paper, Amazon status of bioaccumulation and biomagnifications of Hg and MeHg is discussed. Emphasis has been given to understand the effect of BSAF on the aquatic trophic chain (plankton, macroinvertebrates). Keywords: Mercury; Methylmercury; Amazon

Biota-sediment metal accumulation and human health risk assessment of freshwater bivalve Corbicula fluminea in Dongting Lake, China.

In this study, we analyzed the concentrations of metals in sediments and Corbicula fluminea in China's Dongting Lake to assess the suitability of C. fluminea as an effective biomonitor of metal contamination in sediments and food safety. We analyzed the biota-accumulation capacity by calculating the biota-sediment accumulation factor (BSAF) and assessed the potential human health risk of metals exposure via consumption of C. fluminea using the target hazard quotient (THQ) and total target hazard quotient (TTHQ). The results showed that the average concentrations of As (31.93mgkg-1), Cd (5.54mgkg-1), Cr (105.50mgkg-1), Cu (32.53mgkg-1), and Zn (207.89mgkg-1) in sediments were higher than their respective standard set by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. The sediment metals, which were mainly anthropogenic in origin, were at high levels and pose a relatively high ecological risk. Cadium (Cd) showed very high potential ecological risk levels and should be included in the prior pollutants list in the studied area. The mean levels of As (0.81mgkg-1) in C. fluminea were 1.62-times higher than that set by the National Health Commission of the People's Republic of China. BSAF values of the soft tissues of C. fluminea were between 0.05 and 2.14, with higher values for Cu (2.14), Cd (1.77), Zn (1.60), and Ni (1.27). Soft tissues of C. fluminea were able to reflect spatial differences in Sr within sediments around Dongting Lake. The results indicated that C. fluminea could be an potential biomonitor for sediment metals assessment in biomonitoring programs, especially for Cu, Cd, Zn, Ni, and Sr. The mean values for THQ and TTHQ of all the analyzed metals were below 1.0, indicating that the intake of metals via comsumption of C. fluminea does not result in an appreciable risk to human health.

Bioaccumulation and biomagnification of short-chain chlorinated paraffins in marine organisms from the Pearl River Estuary, South China

Short-chain chlorinated paraffins (SCCPs) are a series of new persistent organic pollutants, posing a risk of significant adverse effects to biota. Increasing attention has been paid to SCCP pollution in China as large amounts of chlorinated paraffin (CP) products containing SCCPs have been produced and used there. However, knowledge of the bioaccumulation of SCCPs in marine organisms from the Pearl River Estuary (PRE), Southern China, is still scarce. In this study, SCCP concentrations were measured in seawater, sediments, and marine organisms from the PRE. SCCP concentrations ranged from 180 to 460 ng/L in seawater, from 180 to 620 ng/g dry weight (dw) in sediments, and from 870 to 36,000 ng/g lipid weight (lw) in marine biota samples. C10–11 SCCPs were the predominant homologues in all the samples, with an average abundance of 68% in seawater, 57% in sediments, and 56–77% in marine organisms. However, chlorine patterns of SCCPs in seawater, sediments, and marine organisms were different. Cl8–10 SCCPs dominated in sediments, whereas Cl5–7 SCCPs were the predominant SCCP homologues in water and most organism species. The logarithm bioaccumulation factors (BAFs) of SCCPs ranged from 1.6 to 3.0, and increased significantly with the increase of Kow values for most marine biota species, indicating that Kow was the major factor controlling the bioaccumulation of SCCPs and that SCCPs with higher lipophilicity were more prone to being bioaccumulated from water. Opposite to that observed for log BAFs, biota-sediment accumulation factors of specific SCCPs (range: 0.01–30) decreased significantly with the increase of Kow values. The biomagnification factor of total SCCPs for oyster–mangrove crab was 2.40, implying the potential biomagnification of SCCPs for benthos in the PRE.

ĐÁNH GIÁ ẢNH HƯỞNG CỦA HÓA CHẤT BẢO VỆ THỰC VẬT OCPs ĐẾN SINH TRƯỞNG CỦA CÁ BỚP BOSTRYCHUS SINENSIS NUÔI TẠI CỬA SÔNG SOÀI RẠP - TpHCM

This study was conducted from May to November 2017 to evaluate the accumulation of organochlorine pesticide chemicals (OCPs) in Bostrychus sinensis fish growing at the Soai Rap estuary, Ho Chi Minh City, Vietnam. The pesticide chemicals in the tissues of fish and the sediments of the estuary were analyzed using a gas chromatography method and Varian GC-450 (ECD) instrument. The results showed that in all tissue samples of fish, the content of DDTs was the highest (9.524 ng/g), followed by Aldrin (1.209 ng/g); HCHs (1.972 ng/g); Dieldrin (1.743 ng/g) and Endosunfans (1.053 ng/g), and the lowest values were Heptachlor (0.807 ng/g) and Eldrin (0.715 ng/g). The content of OCPs in all sediment samples from the study area was found to be lower than Vietnamese standard 43: 2012 /MONRE and some other standards in the world. The bioaccumulation factor of OCPs in the tissue of fish was very low level (BAF &lt; 100), for DDTs at low levels (100 &lt; BAF &lt; 500). The Biota-Sediment Accumulation Factor (BSAF) of the seven substances in the sediment was Dieldrin &gt; DDTs &gt; Aldrin &gt; HCHs &gt; Endosunfans &gt; Heptachlor &gt; Endrin.

XÁC ĐỊNH HỆ SỐ TÍCH TỤ HÓA CHẤT BẢO VỆ THỰC VẬT CƠ CLO (OCPs) TRONG MỘT SỐ LOÀI NHUYỄN THỂ HAI MẢNH VỎ Ở KHU VỰC CỬA SÔNG SOÀI RẠP - TpHCM

Deposited sediments contain organochlorine pesticide chemicals which can pollute surface water as well as aquatic ecosystems. In this study, the accumulation of organochlorine pesticide chemicals in the bivalve mollusk group including Pacific oyster (Crassostrea gigas, Thunberg, 1793), green mussel (Perna viridis), blood scallop (Anadara granosa) ), white clam (Meretrix lyrata) and pearl oyster (Pinctada maxima) at Soai Rap estuary, Ho Chi Minh city was selected as subject of this research because of their high bioaccumulation capacity; their sedentary life, organic residue filter feeding habit and the ability to clean the lagoon environment. The pesticide chemicals were analyzed on GC-ECD system. Result of this research shows the different levels of accumulation in meat tissues of 5 species but they are lower than the allowable value of MARD 193:2004 - The bivalve mollusk harvest zone - Conditions to ensure food hygiene and safety. The results of calculating the Bio-Accumulation Factor (BAF) and Biota Sediment Accumulation Factor (BSAF) of the five species have shown that the bioaccumulation of organochlorine pesticides (OCPs) of bivalve mollusks in the area is natural tendency. BAF and BSAF of Crassostrea gigas were 56.672 and 0.429, Perna viridis were 66.730 and 0.608, Anadara granosa were 123.884 and 1.974, Meretrix lyrata were 52.060 and 0.489, Pinctada maxima were 115.176 and 1.076, respectively.

Bioaccumulation of polycyclic aromatic hydrocarbons by arctic and temperate benthic species.

Increasing oil and gas activities may substantially increase chemical stress to benthic ecosystems in the Arctic, and it is necessary to evaluate such environmental risks in these systems. Risk assessment procedures for oil‐related compounds (e.g., polycyclic aromatic hydrocarbons [PAHs]) should address differences in exposure between Arctic and temperate benthos. We compare for the first time the bioaccumulation of PAHs by Arctic benthic invertebrate species with that of temperate species, based on their biota–sediment accumulation factors (BSAFs). Measured PAH BSAFs were generally higher in temperate bivalves (Limecola balthica) than in Arctic bivalves (Macoma calcarea), whereas BSAFs in Arctic polychaetes (Nephtys ciliata) were higher than in temperate polychaetes (Alitta virens). Differences in measured BSAFs were explained by species‐specific feeding modes and traits. However, modeled BSAFs revealed that steady state was not likely to be reached in the 28‐d tests for all PAHs and organisms. Due to the low numbers of individuals, most species‐specific parameters were too uncertain to reveal differences between Arctic and temperate species. The results of the present study suggest that data from temperate species could be used as a surrogate for Arctic species in risk assessment. Environ Toxicol Chem 2019;38:883–895. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Alterations in fingerprints of polychlorinated biphenyls in benthic biota at the Portland Harbor Superfund Site (Oregon, USA) suggest metabolism

In order to understand the sources and fate of polychlorinated biphenyls (PCBs) in several species of benthic biota, including clams (Corbicula fluminea), oligochaetes (Lumbriculus variegatus), and mussels (Margaritifera falcata and Anodonta nuttalliana) at the Portland Harbor Superfund Site (PHSS), their congener fingerprints were examined. First, diagnostic ratios of congeners known to be metabolizable vs. recalcitrant in the cytochrome P450 (CYP) pathway were significantly lower in biota than in its co-located sediment, indicating metabolism may have occurred. Next, the congener patterns were analyzed using Positive Matrix Factorization (PMF). The dominant fingerprint (by mass) in benthic biota is related to Aroclor 1260 but displays differences in the fingerprint that are consistent with weathering via absorption, distribution, metabolism, and excretion (ADME). This fingerprint is similar to one isolated from PCBs in fish from Washington State, indicative of common metabolic pathways and consistent with CYP metabolism. When metabolism is taken into account, the spatial distribution of the PMF-isolated PCB fingerprints in biota matches well with those from co-located sediment samples, suggesting that the same mix of sources at one location partitions into biota and sediment. In accordance to their higher hydrophobicity, higher molecular weight (MW) PCB formulations were proportionately more abundant in biota than in sediment, although low MW PCBs (e.g., PCBs 4 and 11) do bioaccumulate in benthic organisms and should not be ignored in risk assessment efforts. Finally, fingerprinting suggests potential reasons why lab-based and field-based biota-sediment accumulation factors (BSAFs) differ substantially for bivalves.

Assessment of trace elements pollution in the sea ports of New South Wales (NSW), Australia using oysters as bioindicators

In this study Sydney rock oysters (S. glomerata) from six major sea ports of NSW, Australia were used as bioindicators to assess the distribution and levels of trace element accumulation in the ports. Substantial enrichment of Cu, Pb and Zn in the oysters of the sea ports were detected when compared to their background samples and the US Environmental Protection Agency (USEPA) provisional tolerable intake standard. Enrichment of As, Al, Fe, Mn, Br, Sr were also found in the oysters at the port areas. The bioconcentration ratios of the trace elements illustrated significant Fe, Cu, Zn, As, Mn, Al, Pb and Cr accumulation in S. glomerate. The biota sediment accumulation factor suggested Cu, Mn and Zn accumulation at two of the ports (Port Yamba and Botany), indicating availability of these metals in the oysters as strong metal accumulators. In addition, integrated metal contamination illustrated notable Fe, Zn, Cu and Al contamination at port environment, whereas cluster analysis portrayed interconnection between the contaminants and the study sites.

Health Risks of Polychlorinated Biphenyls (PCBs) Levels in Fish and Sediment from River Niger (Onitsha Axis)

ABSTRACTThe health risks of polychlorinated biphenyls (PCBs) levels in fish and sediment from River Niger (Onitsha axis) was investigated. Fish and sediment samples were collected during dry and rainy seasons from upstream and downstream of the river. Extraction was carried out using n-hexane: acetone mixture (50:50) and PCBs were determined using gas chromatography-electron captor detection. Average recovery of 97.67% was obtained for fish and 95.88% for sediment. PCBs concentration and biota-sediment accumulation factor (BSAF) were higher downstream for both seasons. There was no significant difference (P < 0.05) in PCBs concentration between dry and rainy seasons. Concentrations of PCBs in fish were below the Food and Drug Association (FDA, 2018) tolerance level of 2 ppm. Also, noncarcinogenic hazard quotient (HQ) for PCBs congeners in fish samples were ˂1, which indicates no noncarcinogenic health risks from consumption of fish from Niger River. However, carcinogenic HQ for normal fish consumption in children was above 1 in some sample locations but below 1 for adults. Also, carcinogenic HQ for habitual fish consumption was above 1 in some sample locations for both children and adults. There is presence of PCBs in River Niger as a result of anthropogenic activities and industrial discharges, with human risks especially for children.

Bioavailability and biomagnification of organophosphate esters in the food web of Taihu Lake, China: Impacts of chemical properties and metabolism

The bioavailability and biomagnification of organophosphate esters (OPEs) were investigated in a food web in the Zhushan Bay of Taihu Lake, China. The organisms included mainly three biological groups: plankton, invertebrates, and fish, which displayed distinctly different compositional profiles of OPEs. In general, the log BAFs (bioaccumulation factor) of OPEs displayed a significant correlation with their log Kow (octanol-water partitioning coefficient), suggesting that the bioaccumulation was mainly controlled by the hydrophobicity. The log BAFs of the more hydrophobic OPEs in benthic invertebrates were higher than in fish, suggesting that ingesting sediment constituted additional exposure route for benthic invertebrates. The log BSAFs (biota-sediment accumulation factor) in the benthic invertebrates increased with log Kow in the range of 1.44–5.73 and decreased afterwards. The depressed bioavailability of the highly hydrophobic OPEs was attributed to their strong adsorption to the sediment. The biomagnification potency of OPEs was affected by hydrophobicity of the compounds and biotransformation properties in the organisms at different trophic levels. 2-Ethylhexyl diphenyl phosphate biomagnified in the fish food web of Taihu Lake with a TMF (trophic magnification factor) of 3.61, which was due to the combined results of its relatively high hydrophobicity (log Kow of 5.73) and decreased metabolism potential in the high-trophic-level fish. The constant metabolism diminished the biomagnification potency of hydrophobic compounds triphenyl phosphate and tricresyl phosphate in this food web.

Halogenated organic pollutants in sediments and organisms from mangrove wetlands of the Jiulong River Estuary, South China

Eighteen sediments and four biota species were collected from mangrove wetlands of the Jiulong River Estuary (JRE) in South China to investigate the distribution of dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), dechlorane plus (DP) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE). Concentrations of ΣDDTs, ΣPCBs, ΣPBDEs, DBDPE, DP, and BTBPE in mangrove sediments ranged from 21 to 84, 0.52–2.5, 9.0–66, 5.1–32, 0.05–0.14, and 0.03–0.25 ng/g dry weight, respectively. Levels of ΣDDTs, ΣPCBs, ΣPBDEs, DBDPE and DP in mangrove biota ranged from 950 to 30000, 56–400, 8.0–35, nd-20 and 0.44–3.1 ng/g lipid weight, respectively. DDTs were the predominant halogenated organic pollutants (HOPs) in mangrove sediments from the JRE, while PBDEs were the major HOPs in mangrove sediments from the Pearl River Estuary (PRE), suggesting that sediments in JRE and PRE had different sources of HOPs. The dominance of DDTs was found in both mangrove sediments and biota from the JRE, indicating that HOPs in JRE environment mainly come from agricultural sources. The biota-sediment accumulation factors for DDTs and PCBs were significantly higher than those of PBDEs, DBDPE and DP, suggesting high bioavailability of DDTs and PCBs in mangrove biota. Trophic magnification factors for DDTs, PCBs, PBDEs, and DP were 10.5, 3.00, 2.66 and 1.23, respectively, indicating their potential of biomagnification in mangrove food webs.