Edible Biota Research Articles

Metal bioavailability, bioaccumulation, and toxicity assessment through sediment and edible biota from intertidal regions of the Aghanashini Estuary, India

The sediment cores and edible biota from the intertidal regions of the Aghanashini Estuary were studied for the assessment of metal toxicity. The estuarine sediments received natural input of metals through the weathering of Dharwar and peninsular gneisses, and laterites. The sediments were enriched in Fe, Mn, Zn, Cu, Co and Ni than the upper crustal value. Also, the concentration of Fe, Zn, Cu, Co and Ni was more in the Aghanashini Estuary than other estuaries around the world. The Enrichment Factor (EF) revealed enrichment of Zn, Cu, Co and Ni in sediments, while the Geo-accumulation Index (Igeo) exhibited unpolluted-moderately-strongly polluted class of Fe, Zn, Cu, Co and Ni. The enrichment and pollution of metals in sediments was due to anthropogenic sources (domestic sewage, aquaculture and agricultural discharge) in the estuary. The presence of metals at a high concentration in the residual fraction and at a significant proportion in the bioavailable fractions construed both natural and anthropogenic sources of metal, and their bioavailability in the estuary. The physico-chemical factors (ionic composition, H+ ions, redox potential, and microbial activity) regulated the adsorption and desorption of metals in sediments. The Screening Quick Reference Table (SQUIRT) revealed level of bioavailable Mn and Co higher than the Apparent Effects Threshold (AET) and thus, indicated adverse toxic effects on biota. The Risk Assessment Code (RAC) indicated medium-high-very high risk of Mn, Zn, Co, Cu and Ni to biota. Also, the concentration of Fe, Mn, Zn, Cu and Ni in biota was in excess of permissible limit which pointed to their toxicity to biota and their consumers. The Target Hazard Quotient (THQ) value > 1, and Hazard Index (HI) value > 10 revealed risk of metal toxicity to humans.

Distribution and abundance of microplastics in the water column of Vembanad Lake–A Ramsar site in Kerala, India

The study focuses on the occurrence, abundance and characteristics of microplastics (MPs) in the subsurface and bottom waters of Vembanad Lake, a Ramsar site in the state of Kerala. Even though several studies elucidate the prevalence of microplastic pollution in the surface waters of aquatic ecosystems, a little is known about the vertical distribution of MPs in the water column. Vembanad Lake water is greatly affected by microplastic pollution compared to other Indian lakes as it receive discharges from six rivers; a number of sewage canals and run-off. Ubiquitous distribution of MPs was found in the lake with a mean abundance of 26.79 ± 3.74 items L−1 and 52.70 ± 5.43 items L−1 in subsurface and bottom waters respectively. Fibers, constitute more than half of the total MPs in both subsurface and bottom waters. The dominance of polyamide and polypropylene with most of the MPs being fibers indicate that they originate probably from fishing activities and laundry wastewater. The particles with in the size range 100–500 μm were in excess in the water samples. Further fragmentation, increasing the number of MPs in the lake water was envisaged from the SEM images of MPs showing cracks and crevices. These MPs along with adsorbed contaminants upon ingestion by the aquatic organisms become a threat to the food web of the lake. The local population which depends mainly on the fishes and mussels of the lake for their dietary needs would be greatly affected by the contamination of the lake with MPs. Further research on MPs contamination in edible biota would give more insights on the extent and risks of MPs pollution in the lake.

Lead and Cadmium Levels in Water, Surficial Sediments, and Edible Biota of Urban Rivers in Dar es Salaam, Tanzania, During Two Seasons

This study evaluated levels and seasonal patterns of lead (Pb) and cadmium (Cd) in sediment, water, and mudskippers (Periophthalmus argentilineatus) from urban rivers in Dar es Salaam, Tanzania. The samples were seasonally collected from 15 locations, treated as appropriate, and analyzed instrumentally. The study intended to establish contamination levels, identify hotspots, and assess ecological and human health risks. The results indicated that Cd concentrations were lower than Pb in all the sample matrices. In water samples, Pb levels (0.7 to 24.0 mg/L, n = 30, mean = 7.2 ± 6.5) were higher than both the World Health Organization (WHO) and the Tanzanian Bureau of Standards limits, whereas Cd was below the detection limit. In sediment samples, both the Pb concentrations (9.0 to 159.3 mg/kg, n = 30, mean = 44.7 ± 36.6) and the Cd concentrations (0.03 to 0.82 mg/kg, n = 30, mean = 0.24 ± 0.14) exceeded sediment quality guidelines for the protection of aquatic life. The mudskipper samples contained levels below the Food and Agriculture Organization (FAO) and WHO maximum permissible limits. This indicated that they were safe for human consumption. Metal concentrations in water and sediments were lower during the dry season than in the wet season, probably owing to contaminated runoff from land-use practices during the wet season, whereas the mudskipper samples showed the opposite pattern. Determination of the potential contamination index (PCI) in samples enabled the identification of two hotspots that may need intervention. Evaluation of chronic daily intake (CDI), hazard quotient (HQ), and hazard index (HI) implied minimal health risks. Contamination of the rivers by these toxic metals, be it in low concentrations, is an issue of concern.

The edible biota in irrigated, deepwater, and rainfed rice fields of Asia: a neglected treasure for sustainable food system

Irrigated, rainfed, deepwater rice agro-ecosystems of Asia replete with a suite of edible flora and fauna have provided an alternate and affordable source of essential nutrients apart from the staple. This diverse edible biota once constituted a viable means to supplement the staple and sustained large populations of the rice growing countries of Asia; it is imperative especially in the current crisis of micronutrient deficiency or hidden hunger that afflicts one-third of the global population. In this narrative review, building on secondary literature, we sketch the breadth of the edible biota found in rainfed, deepwater, and irrigated rice fields that have been accepted as food across a large geography of Asian rice-eaters. The nutritional outcome of this edible biodiversity has also been described. We argue that it has been an integral part of the food system that eroded with the intensification of agriculture in recent centuries. Finally, we identify and emphasize on the underlying drivers leading to the fall of this system and suggest a possible way to revive this age-old practice for sustainable agricultural intensification, simultaneously addressing the potential of this system to combat the global health problem of micronutrient deficiency.

Spring-neap tides influence on bioavailability of metals and bioaccumulation in edible biota of the Zuari (tropical) Estuary.

Role of spring and neap tides on metal bioavailability and bioaccumulation in edible biota was studied in the Zuari Estuary. Moderate to very high range of contamination factor for Fe, Mn, Cr, Zn, Cu, Cd, and Pb at one or more stations and tides suggesting their anthropogenic origin. The anthropogenic input of metals was supported by pollution load index. Relatively high bioavailable concentration of Fe, Mn, Cr, Zn, Cu, Cd, and Pb indicated their toxicity to biota. Total metal concentration, viz., Fe, Mn, Cr, Zn, Cu and Cd, and bioavailable content Mn, Cd, and Pb were higher during spring tide than neap tide at one or more stations which revealed their low mobility under flooded conditions. The above observation was well supported by higher concentration of Fe, Mn, Cr, Zn, Cu, and Pb in Polymesoda erosa at the middle estuary during neap tide than subsequent spring tide. Further, an increase in concentration of metals bound to certain bioavailable fractions toward the surface of the cores revealed their possible bioavailability to the biota with changes in the physicochemical properties of the Zuari estuary. Biota sediment accumulation factor revealed macro level accumulation of Cd and suggested its toxicity to marine biota.

Potential health risks of polycyclic aromatic hydrocarbons associated with sediment and seafood from a Ramsar site

Sixteen polycyclic aromatic hydrocarbons were determined in sediments and edible biota from Chilika, the largest brackish water lagoon in Asia. Mean PAH level in sediments was 13,674 ng/g dry weight, higher than reported studies from the region. High molecular weight species dominated total PAH profile indicating pyrolytic origin. Assessment of sediment associated individual PAHs effect on aquatic organisms of the lagoon revealed all the compounds, except naphthalene and anthracene, to be present above the lower range of concentrations related to toxicity. Risk quotient of PAHs revealed that Acenaphthene, Fluorene and Dibenz[a,h]anthracene require priority management concerns. PAH levels in crabs and prawns were 394.4 and 153.0 ng/g d.w., higher than reported studies. BaPeq concentrations were 42.9 and 15.2 ng/g d.w. in crabs and prawns respectively. Carcinogenic PAHs accounted for 33.5% to the total PAHs in edible biota but consumption can be considered safe with respect to lifetime excess cancer risk guidelines.

Potential health risks of polycyclic aromatic hydrocarbons associated with sediment and seafood from a Ramsar site

Sixteen polycyclic aromatic hydrocarbons were determined in sediments and edible biota from Chilika, the largest brackish water lagoon in Asia. Mean PAH level in sediments was 13,674 ng/g dry weight, higher than reported studies from the region. High molecular weight species dominated total PAH profile indicating pyrolytic origin. Assessment of sediment associated individual PAHs effect on aquatic organisms of the lagoon revealed all the compounds, except naphthalene and anthracene, to be present above the lower range of concentrations related to toxicity. Risk quotient of PAHs revealed that Acenaphthene, Fluorene and Dibenz[a,h]anthracene require priority management concerns. PAH levels in crabs and prawns were 394.4 and 153.0 ng/g d.w., higher than reported studies. BaPeq concentrations were 42.9 and 15.2 ng/g d.w. in crabs and prawns respectively. Carcinogenic PAHs accounted for 33.5% to the total PAHs in edible biota but consumption can be considered safe with respect to lifetime excess cancer risk guidelines.

Environmental fates of synthetic musks in animal and plant: An in vivo study

As emerging contaminants, synthetic musks (SMs) cause worldwide concern due to their bioaccumulation in biota. However, the environmental fates of SMs in biota are poorly understood. Here, for the first time, the uptake and elimination behaviors, as well as the transferable capacities, of SMs in living edible biota (fish and aloe) were revealed. Fish muscle was approximately 100–2000 times more efficient in accumulating SMs than was aloe leaf, and nitro musks showed a higher bioaccumulation potential than did polycyclic musks in biota. In addition, the transferable capabilities of SMs by root uptake in aloe were poor. This investigation also showed that both nitro musks and polycyclic musks that accumulated in biota exhibited excellent elimination rates in clean water, and the elimination rates were greater than 78% and 80% in fish (3d) and aloe (2d), respectively. Furthermore, the calculated results suggest that SMs might act as chemosensitizers and enhance the accumulation of normally excluded toxicants in biota in a real aquatic environment.

Polycyclic aromatic hydrocarbons (PAHs) in Crassostrea rhizophorae and Cathorops spixii from the Caroni Swamp, Trinidad, West Indies.

Dietary exposure to polycyclic aromatic hydrocarbons (PAHs) may pose serious threats to human health. However, within the Caribbean, quantitative assessments regarding the risks associated with dietary PAH exposure remain sparse. This study investigated PAH presence in edible biota from the Caroni Swamp and quantitatively assessed the potential health threat to human consumers. Mangrove oysters (Crassostrea rhizophorae) and Madamango sea catfish (Cathorops spixii) collected from seven sites in the Caroni Swamp were analysed for 16 priority PAHs. Total PAH levels ranged from 109 ± 18.4 to 362 ± 63.0 ng/g dry wt. in Crassostrea rhizophorae and 7.5 ± 0.9 to 43.5 ± 25.5 ng/g dry wt. in Cathorops spixii (average ± standard deviation). Benzo[a]pyrene levels in Crassostrea rhizophorae at all sites exceeded international guidelines from British Colombia (Canada) and the European Union (EU). Incremental lifetime cancer risk (ILCR) values based on the ingestion of Crassostrea rhizophorae ranged from 8.4 × 10(-6) to 1.6 × 10(-5) and slightly exceeded the commonly used 1 × 10(-6) acceptable level of risk. Information from this study is important in understanding the potential health risks posed by PAHs, it is critical towards the protection of public health, and it serves as a useful baseline for comparison with future work.

Total and inorganic arsenic levels in some marine organisms from Izmir Bay (Eastern Aegean Sea): A risk assessment

The arsenic compounds in marine biota were evaluated from Izmir Bay (Eastern Aegean) and found that inorganic arsenic occurred as a minor fraction. No information is available on the annual variations of arsenic in important edible biota species from Izmir Bay. Fish and mussel samples were taken from different regions of Izmir Bay between 2009 and 2011 (n=854 individual specimens). The average percentages of inorganic arsenic to total arsenic for all biota samples were 3.43±3.38% with a range of 0.11–11.8%. The importance of speciation analysis for arsenic is supported by our work, because arsenic is ubiquitous in the ecosystem, and flexible toxicity of arsenic is based on chemical form. The average total As levels in Mullus barbatus were 6times higher than Diplodus annularis and Mytilus galloprovincialis. This study also revealed that spatial variation influenced the arsenic levels in the fish samples and the highest concentrations of arsenic were found in Gediz site. Our study showed that estimated daily intakes of arsenic via consumption of flesh fish and shell fish were below the BMDL0.5 values established by FAO/WHO.

Safety assessment of seafood with respect to chemical pollutants in European Seas

Abstract This mini-review discusses the occurrence of chemical pollutants in edible biota from European seas, including the Baltic Sea ecosystem. The bioaccumulation of organic and inorganic pollutants in marine fish and edible molluscs and crustaceans is briefly approached within the context of European Union (EU) food quality standards. The health risks associated with the human consumption of seafood have been assessed mainly by the European Food Safety Authority (EFSA), an independent European agency funded by the EU. The potential health risks arising from the consumption of “frutti di mare” are examined from the standpoint of estimated Provisional Tolerable Weekly Intakes (PTWIs) for toxic pollutants.

Assessment of doses and risk due to natural radionuclides in edible biota of Domiasiat, Meghalaya

A radiation dose assessment exercise was carried out for the edible biota Solanum nigrum, Carica papaya, Raphnus sativum and Phaseolus domesticus due to naturally available radionuclides (40)K, (238)U and (232)Th in the Domiasiat area in Meghalaya, India. The concentration of radionuclides in biota and corresponding soil was measured by the NaI(Tl) detector having a minimum detection limit (efficiency, 32.4%) and machine counting time of 3000 s. The obtained transfer factor for (40)K was 0.3061, 0.7163, 0.1988 and 0.1279, for (232)Th 0.0003, 2.22E-05, 2.71E-05 and 3.45E-05 and for (238)U 1.46E-05, 9.73E-05, 1.46E-05 and 3.11E-05 (ratio) in each biota, respectively. The detailed physiological and morphological study of the biota was carried out. The point source dose distribution (source↔target) hypothesis was applied for the radiation absorbed fraction. The generated data were modelled using FASSET and obtained un-weighted total dose was 1.78E-04, 6.84E-03, 8.46E-03 and 1.73E-04 μGy h(-1), respectively, finally compared with the IAEA and UNSCEAR data set for screening level dose risk assessment.

Baseline assessment of doses and risk due to natural radionuclides in edible biota of Domiasiat, Meghalaya, India

Radiation dose-risk assessment was carried out for cereal species Brassica compestris var. dichotoma, Oryza sativa var. Shalum1, Zea mays, Lactuca indica, Cumunis sativum, and Clocasia esculanta due to naturally available radionuclides 40K, 238U and 232Th in Domiasiat area. The activity in biota and corresponding soil was measured by precipitation method using NaI(TI) detector. Transfer factor (TF) was for Oryza spp. (1.00E−01-40K, 8.76E−05-232Th, and 9.11E−05-238U), for Brassica spp. (5.39E−01-40K, 8.17E−04-232Th and 2.96E−04-238U) and for Zea spp. (3.41E−01-40K, 5.84E−05-232Th, 8.87E−05-238U) etc., respectively. A detailed physio-morphological study of the biota and extensive investigation of ecosystem was carried out for assessment. The data was modeled using FASSET for dose estimation and obtained total dose was 1.58E−04 \( \upmu \hbox{Gy}\,h^{-1} \) in Oryza spp., 2.87E−04 \( \upmu \hbox{Gy}\,h^{-1} \)Brassica spp. and 6.90E−03 \( \upmu \hbox{Gy}\,h^{-1} \) in Zea spp. etc. The dose was compared with the UNSCEAR dataset for screening level dose for biota. Zea spp. was more susceptible for the chronic radiation exposure.

Organochlorine pesticide and heavy metal residues in some edible biota collected from Quanzhou Bay and Xinghua Bay, Southeast China

In order to assess the contamination of edible marine organisms in Quanzhou and Xinghua Bays, Fujian Province, China, concentrations of organochlorine pesticides (hexachlorocyclohexane isomers or HCHs and dichlorodiphenyltrichloroethane isomers/derivatives or DDTs) and heavy metals (Cu, Pb, Zn, As, Cr, Cd, Ni and Hg) in 13 species collected from different sites in the bays were analyzed by GC-ECD and ICP-MS. The concentration of the sum of DDTs exceeded that the sum of HCHs in the samples. Most of the organisms showed higher levels of DDTs than the first level criterion (10 ng/g) for marine biological quality in China (GB 18421-2001) but conformed to the first level criterion (20 ng/g) for HCHs. The estimated mean daily uptake of pesticides was below the level for minimal risk to the consumers. The levels of Cd, As and Pb in most organisms from both bays were markedly elevated and above the recommended legal limits for human consumption. Our results showed the need for routine monitoring of marine species contamination to ensure public and environmental health.

Distribution and bioaccumulation of organochlorine pesticides along the Black Sea coast

Sediment, mussel, and seawater samples were collected three times during 2001-2003 at nine sampling stations along the mid-Black Sea coast of Turkey. The samples were analyzed with GC-ECD for contents of various organochlorine pesticides (OCPs) in the environment. DDT and its metabolites were detected at concentrations significantly above the detection limits. The highest concentrations of DDT metabolites measured in the sediment and mussel samples were 35.9 and 14.0 ng/g wet weight respectively. Considerable levels of aldrin, dieldrin, endrin, heptachlor epoxide, lindane, endosulfan sulphate, and HCB were also detected in the sediment, mussel, or seawater samples. Although these persistent toxic compounds have been banned for some years in Turkey, they may still be used illegally in some regions, contributing to their significant levels in the environment. The biota-sediment accumulation factor (BSAF) estimated for DDT and its metabolites in mussels was 2.9, which is nearly two times higher than the benchmark of 1.7. In spite of such high BSAF values observed for these toxic compounds, their levels in mussels were significantly below the international legal limits recommended by the Food and Agriculture Organization of the United Nations. Edible biota from the waterbodies examined may thus still be considered safe for human consumption at this time. However, as pollutants can biomagnify through the food chain over time, further routine sampling and analysis of biota along the Black Sea coast are warranted in order to better assess the threat of OCPs to public health in the region.

Organochlorine pesticide residues in sediments and biota from the coastal area of Dar es Salaam city, Tanzania

Sediment and biota samples were collected from Msimbazi and Kizinga rivers and from the coastal marine environment of Dar es Salaam during both dry and wet seasons. The samples were analyzed for various organochlorine pesticide residues using GC-ECD and GC-MS. Dieldrin, p, p ′-DDT, p, p ′-DDE, p, p ′-DDD, o, p ′-DDT and γ-HCH were detected at significantly greater concentrations above the method detection limits. Recoveries of pesticide residues ranged 86.5–120% in sediments and 62–102% in biota. The average concentrations of total DDT in sediments for the two seasons were almost the same. Biota samples showed significant difference in levels of residues depending on mode of feeding and age of analyzed biota. p, p ′-DDT to total DDT ratios in all matrices indicated recent use of DDT. The levels of residues in sediments suggest possible adverse effects to humans consuming biota that are directly exposed to the sediments. This effect, which is associated with bio-concentration of residues in the tissues of edible aquatic biota, should not affect wildlife. In spite of concern on the adverse effect to humans posed by pesticide residues in sediments, edible biota from the examined water bodies were found to be safe for human consumption.