Risk-benefit evaluation of fish from Chinese markets: nutrients and contaminants in 24 fish species from five big cities and related assessment for human health

The Impact of Polychlorinated Biphenyls on the Development of Zebrafish (Danio rerio)

Polychlorinated biphenyls (PCBs) are a group of 209 highly stable molecules that were used extensively in industry. Although their commercial use ceased in 1979, they are still present in many aquatic ecosystems due to improper disposal, oceanic currents, atmospheric deposition, and hydrophobic nature. PCBs pose a significant and ongoing threat to the development and sustainability of aquatic organisms. In areas with PCB exposure high mortality rates of organisms inhabiting them are still seen today, posing a significant threat to local species. Zebrafish were exposed to a standard PCB mixture (Aroclor 1254) for the first 5 days post fertilization, as there is a gap in knowledge during this important developmental period for fish (i.e., organization of the body). This PCB mixture was formally available commercially and has a high prevalence in PCB-contaminated sites. We tested for the effects of PCB dosage (control (embryo water only; 0 mg/L), methanol (solvent control; 0 mg/L); PCB 1 (0.125 mg/L), PCB 2 (0.25 mg/L), PCB 3 (0.35 mg/L), and PCB 4 (0.40 mg/L)) on zebrafish survival, rate of metamorphosis, feeding efficiency, and growth. We found significant, dose-dependent effects of PCB exposure on mortality, feeding efficiency, and growth, but no clear effect of PCBs on the rate of zebrafish metamorphosis. We identified a concentration in which there were no observable effects (NOEC), PCB concentration above the NOEC had a significant impact on life-critical processes. This can further inform local management decisions in environments experiencing PCB contamination.

Fatty acids and organohalogen contaminants in seafood from the Pearl River Estuary, China: Risk-benefit analyses of seafood consumption

Seafood has long been considered a healthy food choice, but it is also an exposure source of contaminants that may bring potential health risks to humans. Here, 80 organohalogen contaminants (OHCs) and 36 fatty acids (FAs) were analyzed in 22 (n = 211) and 19 fishery species (n = 176) from the eastern- and western Pearl River Estuary (PRE), respectively, for risk-benefit analysis. The average concentrations of total FAs in seafood from the eastern- and western PRE were 26.0 ± 2.14 and 21.3 ± 1.66 mg g-1 wet weight, respectively. Seafood from the eastern PRE exhibited higher levels of OHCs than those from the western PRE, highlighting the spatial heterogeneity of OHC contamination within the PRE. Species occupying higher trophic levels (TLs) typically demonstrated higher levels of OHC accumulation, indicating the biomagnification potential of these contaminants in the PRE ecosystem. Significant negative correlations were observed between TLs and the proportions of monounsaturated fatty acids and polyunsaturated fatty acids, presumably attributed to the ability of fish to synthesize these FAs decreases with increasing TLs. Our benefit-risk quotient (BRQ) analyses revealed that, as far as OHCs are concerned, all seafood species had a BRQ∑OHCs value <1, except for one-spot snapper and daggertooth pike conger, which had BRQ values of 1.03 and 1.14, respectively. The findings indicate that most marine species here analyzed may not pose significant health risks to consumers as a result of OHC exposure. However, considering that many other pollutants and nutrients are not analyzed here, the results of our risk assessments should be treated as preliminary, not final. Future data collection is essential to enhance the comprehensiveness of this type of analysis.

Prenatal and concurrent blood mercury concentrations and associations with IQ in canadian preschool children

BACKGROUND

Prenatal and childhood mercury (Hg) exposures have been associated with negative impacts on child neurodevelopment. It is unclear if associations persist at the low Hg exposures typical in Western countries.

OBJECTIVE

To examine associations between prenatal/childhood blood Hg concentrations and child IQ in Canadian male and female children while considering the potential modifying role of prenatal fish consumption.

METHODS

We analyzed data from the Maternal-Infant Research on Environmental Chemicals study. Hg was measured in first trimester (n = 527), cord (n = 430), and child (at 3-4 years of age, n = 355) blood and examined sex-stratified associations between blood Hg and children's Full Scale IQ (FSIQ), Verbal IQ (VIQ), Performance IQ (PIQ), and General Language Composite (GLC) scores (assessed with WPPSI-III). Prenatal Hg analyses were further stratified by prenatal fish consumption (low: 0-2, moderate: 3-7, or high: ≥8 times/month).

RESULTS

Higher cord blood Hg concentrations were associated with lower PIQ (ß = -3.27; 95%CI: 6.44, -0.09) in male children with the lowest prenatal fish consumption. Progressively stronger positive associations were observed with PIQ in male children for moderate (ß = 1.08; 95%CI: 0.10, 2.26) and high (ß = 3.07; 95%CI: 1.95, 4.19) prenatal fish consumption. Cord blood Hg concentrations were positively associated with female children's FSIQ (ß = 1.29; 95% CI: 0.77, 1.81) and PIQ (ß = 2.01; 95% CI: 1.19, 2.83); however, when stratified only in the highest fish consumption subgroup. Among female children, higher child blood Hg concentrations were associated with an approximately 1-point increase in FSIQ, VIQ, and GLC.

CONCLUSIONS

Prenatal exposure to low levels of Hg was associated with lower PIQ scores in male children with low prenatal fish intake. Positive associations between cord and child blood Hg concentrations and IQ were primarily observed in female children and may be due to beneficial effects of prenatal fish intake.

POPs and PAHs in fish oil-based food supplements at the Czech market

The objectives of this study were to assess concentrations of three groups of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in 44 fish oil-based food supplements, to estimate their daily intake by consumers and, to evaluate the compliance of the oil samples with the oil origin declarations (cod liver oil or fish oil). The concentrations of ∑PCBs (7 congeners), OCPs (19 compounds, represented mainly by ∑DDTs), ∑PBDEs (10 congeners), and ∑PAHs (16 compounds) found in samples ranged between 0.15-55.7 µg kg-1, 0.93-72.8 µg kg-1, 0.28-27.5 µg kg-1, and 0.32-51.9 µg kg-1, respectively. Besides, the authenticity of the oils was assessed based on the fingerprints obtained by DART-HRMS, an ambient mass spectrometry technique. Four samples declared as fish oil were probably prepared from cod liver oil, which is much cheaper. Furthermore, these samples contained elevated concentrations of halogenated POPs when compared to supplements produced from fish oil.

Modeling the long-term fate of polycyclic aromatic hydrocarbons (PAHs) and public health risk in Bohai Bay Sea Area, China

The target of this study was to reconstruct the historical concentration, distribution, variation, and exposure risk evaluation for EPA PAHs to the whole sea of Bohai Bay and the coastal population, by employing a specific dynamic multimedia model during 1950-2050. The unsteady-state model, driven by temporal energy activities from 1950 and sustainable scenarios based on socioeconomic development, indicated the annual emission increased by 4.6 times (from 84.8 tons to 391 tons) until 2020 and resulted in concentrations up to 5.2 times in the atmospheric compartment, and 4.9 times in seawater. Two peak concentrations in 1997 and 2014, consistent with total PAHs input revealed significant regional anthropogenic input in northern Bohai Bay (Tianjin) and southern Bohai Bay (Hebei). The peak-to-peak values of the timing concentration revealed a notably alternative increase in the south (+109.4 %-128.6 %), instead of the rapid decline in the north (-21.5 %-44.5 %). The dominant processes at air-seawater interfaces were air-seawater molecular transfer (from 38.4 % to 51.8 %), and wet deposition (from 60.5 % to 47.5 %). Under 5 shared socioeconomic pathways, the optimal scenario (SSP1) achieved a 24.7 % emission decline, an atmospheric decrease of 15.1 %-31.1 %, and 24.8 %-41.2 % mitigation in seawater during 2020-2050, and each pathway exhibited a general lessening concave in the northern developed municipality, compared with convex in the southern developing regions. The inhalation risk assessment evaluated 10 generations living on Bohai Bay coasts, with an acceptable result, while the current sustainable conceive was with meager fruition in reducing risk.

Cooking methods effectively alter perfluoroalkyl substances and nutrients in cultured and wild bullfrogs

The ubiquitous distribution of perfluoroalkyl substances (PFASs) poses a threat to the health of aquatic organisms and humans. Bullfrogs are considered a popular aquatic food product in South China, providing high protein and tasty cuisine; however bullfrogs have been shown to contain significant concentrations of PFASs. However, the risk-benefit ratios of PFASs and nutrient contents in cooked bullfrogs are not well understood. PFASs and nutrients were investigated in raw and cooked specimens of cultured and wild bullfrogs in this study. Novel PFASs showed higher detection levels and accumulation in wild bullfrogs than in cultured bullfrogs. Potential factors such as fat and fatty acid ratio affected PFASs accumulation in different tissues and by different cooking methods of bullfrogs. All cooking methods can reduce PFASs in edible tissues while significantly enhancing the nutritive value index (NVI) compared to raw bullfrogs. Steaming was the most effective way to reduce PFASs (rate of reduction was over 66%) and resulted in a lower risk of contributing to arteriosclerosis than other cooking methods assessed by atherogenicity index (AI) values. Cultured bullfrogs instead of wild bullfrogs were recommended for human consumption, and steaming was regarded as a better cooking method in terms of risk-benefit concerns. Overall, this work provides quantitative analysis of cooking methods that alter PFASs and nutrients in bullfrogs.

Maternal fish and shellfish consumption and preterm birth: a retrospective study in urban China

Preterm birth is the leading cause of perinatal mortality and morbidity. Some prospective cohort studies suggested that fish and shellfish consumption may affect the incidence of preterm birth. However, conflicting evidence exists on the relationship between fish and shellfish consumption and preterm birth. A total of 10 179 women from Gansu province were interviewed after delivery to collect information on their past intake of fish and shellfish using FFQ. Logistic regression models were used to estimate OR and 95 % CI to examine the association between fish and shellfish consumption and preterm birth and its clinical subtypes. Fish and shellfish consumption was associated with reduced risk of preterm birth (OR = 0·65, 95 % CI 0·56, 0·77). Increasing frequency of fish and shellfish consumption, compared with no fish and shellfish consumption, was associated with decreasing odds of preterm birth. Besides, increasing weekly total amount of fish and shellfish consumption, compared with no fish and shellfish consumption, was also associated with decreasing odds of preterm birth. Significant trend effect was also seen between fish and shellfish consumption and very preterm birth (P_{for trend} = 0·001) and spontaneous preterm birth (P_{for trend} = 0·003). Interaction was observed between total fish and shellfish consumption with maternal age (P_{for interaction} = 0·041) and pre-pregnancy BMI underweight (P_{for interaction} = 0·012). Our findings showed that maternal fish and shellfish consumption was associated with lower incidence of preterm birth.We recommend for the national guideline of ≥350 g/week of fish and shellfish consumption among pregnant women.

Exposure to enrofloxacin and depuration: Endocrine disrupting effect in juvenile grass carp (Ctenopharyngodon idella)

This study aimed to determine the effects of Enrofloxacin (ENR) exposure and depuration on the disruption of thyroid function and growth of juvenile grass carp (Ctenopharyngodon idella) as well as to assess the risk of ENR exposure to human health. Juvenile grass carp were treated with ENR solutions at different concentration gradients for 21 days and then depurated for 14 days. The results indicated ENR accumulation in the juvenile grass carp muscles, which persisted after depuration. In addition, exposure to ENR could alter growth by regulating the expression of genes associated with growth hormone/insulin-like growth factor (GH)/IGF) axis and the hypothalamic-pituitary-thyroid (HPT) axis. During ENR exposure, no significant changes in growth hormone levels were observed; however, a significant increase in the growth hormone level was noted. GH/IGF axis-related genes were upregulated after ENR exposure, and their expression levels remained high after depuration. Notably, a significant increase in the serum triiodothyronine (T3) and thyroxine (T4) levels coincided with the upregulation of HPT axis-related genes in both exposure and depuration treatments, and their expression levels remained high after depuration. Therefore, juvenile grass carp exposure to ENR induces physiological stress through HPT and GH/IGF axes that cannot be recovered after depuration. ENR accumulates in the muscles of juvenile grass carp and may pose a threat to human health. Therefore, exposure of juvenile grass carp to ENR results in impaired thyroid function and impaired growth. In addition, consumption of ENR-exposed fish poses human health risks.

Investigating fish contamination scenario and community willingness to adopt consumption advice proposing an advisory option

Consumption advice to ensure the health and safety of fish consumers remains urgent to handle the ever-increasing panic over heavy metal toxicity. Moreover, studies of fish consumption rarely focus on the perceptions and awareness of consumers. Considering this, the present study examines the factors determining the willingness to follow fish consumption advice as well as calculate the risk-benefit ratio and produce the vulnerability map followed by formulating fish consumption advice for consumers of two commercially important fish species, tilapia (Oreochromis niloticus) and mudfish (Ophiocephalus striatus), in the Laguna de Bay area of the Philippines. Primary data on consumers' perceptions were collected through a questionnaire, whereas heavy metal contamination data were compiled from the best available literature. We concluded that people's willingness to adopt consumption advice is mostly dependent on their existing level of fish consumption (P = 0.000). There was no discernible difference in the mean concentration of heavy metals in fish between the dry and wet seasons, with the exception of As concentrations in the samples (t15.75 = 3.72, p < 0.001). The hazard quotient (risk-benefit ratio) for fish consumption (HQefa) was an order of magnitude higher in the mudfish samples (0.05 and 28.28) compared to tilapia (0.04 to 16.02). Binangonan and Taguig from the Northern West Bay (1A, 1B) were clearly recognised on the vulnerability map as the most vulnerable regions in the lake. In general, it was determined that As and Pb were the elements causing consumption restrictions on tilapia collected from various parts of Laguna Lake. As with tilapia, locations with a high-risk advisory for mudfish were identified as the Northern West Bay and Central Bay, with a consumption limit of five meals per month due to excessive mercury pollution. This empirical study can serve as an option for the future development of fish consumption advice in the region.

Persistent and toxic chemical pollutants in fish consumed by Asians in Chicago, United States

Consumption of seafood brings health benefits but may increase the ingestion of contaminants. Compared with other ethnic groups in the U.S., Asians consume seafood more frequently. However, there is little information about how culturally specific fish consumption contributes to exposure to toxicants. In this work, we surveyed fish consumption among Chinese, Korean and Vietnamese communities and purchased 103 seafood samples from local markets in Chicago. Each sample was analyzed for mercury (Hg) and 92 organic chemicals including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and Dechlorane Plus and related compounds (DPs). The rank order of pollutant concentration in all samples was Hg ≫ Σ₆₆PCBs > Σ₁₇OCPs > Σ₈PBDEs > Σ₈DPs. Positive correlations were noted among most contaminant groups. Bluefish, pike and tuna steak had the highest mean Hg (>1 mg/kg). The mean Σ₆₆PCBs was highest in pike and bluefish (>100 ng/g) followed by pollock and mackerel (>40 ng/g). Overall, octopus, shrimp and tilapia were the least contaminated; while pike, bluefish, and pollock were the most contaminated. Omega-3 fatty acids were more strongly affiliated with the organic contaminants than mercury. A risk assessment identified seven types of fish that should have consumption limitations and six that should not be consumed. For these seafoods, consumption advice based on Hg levels would adequately protect health. In the survey participants, 17% of seafood mass consumed is from types of fish that should be limited to 1 or 2 meals/week, while 7% of the seafood mass consumed comes from types that should not be consumed at all. This work adds additional contaminants to the profile of health risks resulting from fish consumption among Asian Americans, which can be used in interventions aimed at conserving consumption of healthy fish while avoiding contaminants.

Chronic chlorpyrifos exposure induces oxidative stress, apoptosis and immune dysfunction in largemouth bass (Micropterus salmoides)

This study was undertaken to (a) evaluate the destructive effects of chronic exposure to low-dose of chlorpyrifos (CPF) on antioxidant system and immune function in largemouth bass (Micropterus salmoides), and (b) to examine whether dietary supplementation of curcumin can mitigate the adverse effects induced by CPF contamination. The experiment consisted of three groups (with three replicates, 30 fish per replicate) which lasted for 60 days: A control group (without CPF exposure or CU application), CP group (exposed to 0.004 mg/L of CPF), and CU group (exposed to 0.004 mg/L of CPF and fed a diet containing 100 mg curcumin per kg feed). The results showed that CPF contamination leads to reduced weight gain, severe histopathological lesions, decreased activity of antioxidant enzymes and down-regulated expression of antioxidant-related genes. Moreover, CPF upregulated the expression of pro-inflammatory genes such as TNF-α, IL-8, IL-15, downregulated anti-inflammatory genes TGF-β1, IL-10, and promoted apoptosis through overexpression of Caspase-3, Caspase-8, caspase-9 and Bax. In addition, curcumin supplementation showed significant improvement in oxidative stress, apoptosis and immune dysfunction, but the improved effect gradually weakened during the exposure last. Gas chromatography-mass spectrometry (GC-MS) analysis for accumulation of CPF in muscle supported the changes of general physiological structure, excessive apoptotic responses, abnormal antioxidant and immune system functions and posed potential human health risks to children based on target hazard quotient. These results suggested that chronic exposure to CPF can cause oxidative stress, apoptosis and immune dysfunction, and that curcumin have the potential to reduce pesticides residues in fish. This also highlights the importance of monitoring pesticides residues in aquatic products and aquaculture aquatic environments.

Human health risk-benefit assessment of fish and other seafood: a scoping review

Fish and other seafood are important sources of nutrients, but they are also sources of chemical contaminants that may cause adverse health effects. This article aimed to identify existing risk-benefit assessments (RBA) of fish, shellfish, and other seafood, compare methodologies, discuss differences and commonalities in findings, and identify limitations and ways forward for future studies. We conducted a scoping review of the scientific literature of studies in all languages published from 2000 through April 2019. We identified 106 RBA of fish and other seafood across Europe, Asia, North America, Africa, and at the global level. Studies were heterogeneous in terms of types of fish and other seafood considered, beneficial and adverse compounds assessed, and overall methodology. Collected data showed that a diet consisting of a variety of lean and fatty fish and other seafood is recommended for the overall population and that women of childbearing age and children should limit the consumption of fish and other seafood types that have a high likelihood of contamination. Our review emphasizes the need for evidence-based, up-to-date, and harmonized approaches in RBA in general.

Thymine-Functionalized Gold Nanoparticles (Au NPs) for a Highly Sensitive Fiber-Optic Surface Plasmon Resonance Mercury Ion Nanosensor

Mercury ion (Hg²⁺) is considered to be one of the most toxic heavy metal ions. Once the content of Hg²⁺ exceeds the quality standard in drinking water, the living environment and health of human beings will be threatened and destroyed. Therefore, the establishment of simple and efficient methods for Hg²⁺ ion detection has important practical significance. In this paper, we present a highly sensitive and selective fiber-optic surface plasmon resonance (SPR) Hg²⁺ ion chemical nanosensor by designing thymine (T)-modified gold nanoparticles (Au NPs/T) as the signal amplification tags. Thymine-1-acetic acid (T-COOH) was covalently coupled to the surface of 2-aminoethanethiol (AET)-modified Au NPs and Au film by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-Hydroxysuccinimide (EDC/NHS) activation effect, respectively. In the presence of Hg²⁺ ions, the immobilized thymine combines specifically with Hg²⁺ ions, and forms an Au/thymine-Hg²⁺-thymine/Au (Au/T-Hg²⁺-T/Au) complex structure, leading to a shift in SPR wavelength due to the strong electromagnetic couple between Au NPs and Au film. Under optimal conditions, the proposed sensor was found to be highly sensitive to Hg²⁺ in the range of 80 nM–20 µM and the limit of detection (LOD) for Hg²⁺ was as low as 9.98 nM. This fiber-optic SPR sensor afforded excellent selectivity for Hg²⁺ ions against other heavy metal ions such as Fe³⁺, Cu²⁺, Ni²⁺, Ba²⁺, K⁺, Na⁺, Pb²⁺, Co²⁺, and Zn²⁺. In addition, the proposed sensor was successfully applied to Hg²⁺ assay in real environmental samples with excellent recovery. Accordingly, considering its simple advantages, this novel strategy provides a potential platform for on-site determination of Hg²⁺ ions by SPR sensor.

Antibiotics in cultured freshwater products in Eastern China: Occurrence, human health risks, sources, and bioaccumulation potential

The adverse effects of antibiotics residues on aquaculture ecosystems and humans raised increasing concerns globally. To assess the occurrence, human health risks, sources, and bioaccumulation potential of antibiotics in cultured freshwater products in Eastern China, 12 and 13 aquaculture ponds were selected in 2018 and 2019, respectively, both covering 8 aquatic species. Concentrations of 12 commonly-used antibiotics were measured in muscle tissue of aquaculture products, water, sediment, and suspended particles. At least two antibiotics were found simultaneously in all muscle tissue samples. The concentrations of most antibiotics in freshwater cultured products were at a medium or lower level in comparison with other studies in China and worldwide, but slightly higher than the concentrations in cultured marine products. The potential risks from the intake of these aquatic products were also evaluated. The results showed limited adverse effects due to the consumption of these products with an exception of fluoroquinolone antibiotics. The bioaccumulation potential from water varied widely in different collection years, but the bioaccumulation factor (BAF) values for antibiotics were all <50 L/kg. BSAF values of antibiotics were all far below 1, except for one site in Zhejiang province in 2018, indicating that the bioavailability from surface sediments was low, in a particular pond environment. The low repeatability of BAF and BSAF calculated in two years indicated a relatively unsteady status in terms of bioaccumulation potential of cultured freshwater ponds yearly.

Tissue distribution and bioaccumulation of legacy and emerging per-and polyfluoroalkyl substances (PFASs) in edible fishes from Taihu Lake, China

Tissue distribution of legacy and emerging per-and polyfluoroalkyl substances (PFASs) in several kinds of edible fishes collected from Meiliang bay of Taihu Lake, China were investigated and the related human health risks were assessed. Perfluorooctanesulfonate (PFOS), perfluorooctanesulfonamide (PFOSA) and 6:2 fluorotelomer phosphate diester (6:2 diPAP) were the most abundant legacy perfluoroalkyl acid (PFAA), PFOS related precursor (PreFOS), and the emerging PFASs in all fish tissues, respectively. Similar to the legacy PFAAs, 6:2 diPAP and 6:6 perfluorophosphinate (6:6 PFPiA) had the highest levels in the fish liver, whereas the highest level of PFOSA was in kidney, which might be due to its intensive transformation in fish liver. The concentrations of PFASs were generally positively correlated with the trophic levels. The profiles of PFASs were significantly different among bitterling, crucian and other fish, which might be related to their different metabolic capacities. Bioaccumulation factors (BAFs) of PreFOSs, 6:2 diPAP, and 6:6 PFPiA were lower than those of PFAAs with the same number of perfluorinated carbons. The calculated hazard ratios (HR) of PFOS (Range: 0.0100-0.655) and perfluorooctanoic acid (PFOA) (<0.00200) in all fish muscles were less than 1.0. However, the HR of the ∑PFASs in crucian muscle was 1.04, which implied that frequent consumption of crucian collected from Meiliang Bay might pose potential risks to human health.

Health effects of nutrients and environmental pollutants in Baltic herring and salmon: a quantitative benefit-risk assessment

BACKGROUND

Health risks linked with dioxin in fish remain a complex policy issue. Fatty Baltic fish contain persistent pollutants, but they are otherwise healthy food. We studied the health benefits and risks associated with Baltic herring and salmon in four countries to identify critical uncertainties and to facilitate an evidence-based discussion.

METHODS

We performed an online survey investigating consumers' fish consumption and its motivation in Denmark, Estonia, Finland, and Sweden. Dioxin and methylmercury concentrations were estimated based on Finnish studies. Exposure-response functions for several health endpoints were evaluated and quantified based on the scientific literature. We also quantified the infertility risk of men based on a recent European risk assessment estimating childhood dioxin exposure and its effect on sperm concentration later in life.

RESULTS

Baltic herring and salmon contain omega-3 fatty acids and vitamin D, and the beneficial impact of these fishes on cardiovascular diseases, mortality, and the risk of depression and cancer clearly outweighs risks of dioxins and methylmercury in people older than 45 years of age and in young men. Young women may expose their children to pollutants during pregnancy and breast feeding. This study suggests that even in this critical subgroup, the risks are small and the health benefits are greater than or at least similar to the health risks. Value of information analysis demonstrated that the remaining scientific uncertainties are not large. In contrast, there are several critical uncertainties that are inherently value judgements, such as whether exceeding the tolerable weekly intake is an adverse outcome as such; and whether or not subgroup-specific restrictions are problematic.

CONCLUSIONS

The potential health risks attributable to dioxins in Baltic fish have more than halved in the past 10 years. The new risk assessment issued by the European Food Safety Authority clearly increases the fraction of the population exceeding the tolerable dioxin intake, but nonetheless, quantitative estimates of net health impacts change only marginally. Increased use of small herring (which have less pollutants) is a no-regret option. A more relevant value-based policy discussion rather than research is needed to clarify official recommendations related to dioxins in fish.

High carbohydrate diet partially protects Nile tilapia (Oreochromis niloticus) from oxytetracycline-induced side effects

Antibiotics used in global aquaculture production cause various side effects, which impair fish health. However, the use of dietary composition such as carbohydrate, which is one of the dominant components in fish diets to attenuate the side effects induced by antibiotics, remains unclear. We determined the ability of high carbohydrate diet to protect Nile tilapia (Oreochromis niloticus) from oxytetracycline-induced side effects. Triplicate groups of thirty O. niloticus (9.50 ± 0.08 g) were fed on medium carbohydrate (MC; 335 g/kg) and high carbohydrate (HC; 455 g/kg) diets without and with 2.00 g/kg diet of oxytetracycline (80 mg/kg body weight/day) hereafter, MCO and HCO for 35 days. Thereafter, we assessed growth performance, hepatic nutrients composition and metabolism, microbiota abundance, immunity, oxidative and cellular stress, hepatotoxicity, lipid peroxidation and apoptosis. To understand the possible mechanism of carbohydrate protection on oxytetracycline, we assessed the binding effects and efficiencies of mixtures of medium and high starch with oxytetracycline as well as the MCO and HCO diets. The O. niloticus fed on the MCO and HCO diets had lower growth rate, nutrients utilization and survival rate than those fed on the MC and HC diets, respectively. Dietary HCO increased hepatosomatic index and hepatic protein content of O. niloticus than MCO diet. The O. niloticus fed on the HCO diet had lower mRNA expression of genes related to protein, glycogen and lipid metabolism compared to those fed on the MCO diet. Feeding O. niloticus on the HCO diet increased innate immunity and reduced pathogenic bacteria, pro-inflammation, hepatotoxicity, cellular stress and apoptosis than the MCO diet. The high starch with oxytetracycline and HCO diet had higher-oxytetracycline binding effects and efficiencies than the medium starch with oxytetracyline and MCO diet, respectively. Our study demonstrates that, high carbohydrate partially protects O. niloticus from oxytetracycline-induced side effects by binding the antibiotic. Incorporating high carbohydrate in diet formulation for omnivorous fish species alleviates some of the side effects caused by antibiotics.

Biomarkers of meat and seafood intake: an extensive literature review

Meat, including fish and shellfish, represents a valuable constituent of most balanced diets. Consumption of different types of meat and fish has been associated with both beneficial and adverse health effects. While white meats and fish are generally associated with positive health outcomes, red and especially processed meats have been associated with colorectal cancer and other diseases. The contribution of these foods to the development or prevention of chronic diseases is still not fully elucidated. One of the main problems is the difficulty in properly evaluating meat intake, as the existing self-reporting tools for dietary assessment may be imprecise and therefore affected by systematic and random errors. Dietary biomarkers measured in biological fluids have been proposed as possible objective measurements of the actual intake of specific foods and as a support for classical assessment methods. Good biomarkers for meat intake should reflect total dietary intake of meat, independent of source or processing and should be able to differentiate meat consumption from that of other protein-rich foods; alternatively, meat intake biomarkers should be specific to each of the different meat sources (e.g., red vs. white; fish, bird, or mammal) and/or cooking methods. In this paper, we present a systematic investigation of the scientific literature while providing a comprehensive overview of the possible biomarker(s) for the intake of different types of meat, including fish and shellfish, and processed and heated meats according to published guidelines for biomarker reviews (BFIrev). The most promising biomarkers are further validated for their usefulness for dietary assessment by published validation criteria.

Benefit-risk assessment of commonly consumed fish species from South China Sea based on methyl mercury and DHA

Even though a growing number of reports indicated favorable health effects with fish consumption, kinds of hazardous substances in fish were detected in fish and to be exceeded advisory limitation. Benefit-risk assessment of commonly consumed fish is urgently needed. We conducted fish consumption survey and fish sampling in the coast of South China Sea to assess benefit-risk effect of commonly consumed fish species. For local residents, weekly methyl mercury (MeHg) exposures from commonly consumed fish species ranged from 0.12 to 2.11 μg/kg bw. Apart from Muraenesox cinereus and Acanthopagrus latus, the rest of 92% (23/25) fish species were at low risk of MeHg exposure. Daily docosahexaenoic acid intakes via consuming specific fish were between 42.18 and 1687.04 mg/day. A total of 72% (18/25) fish species could provide 200 mg/day of DNA for local residents. Benefit-risk assessment assuming intelligence quotient (IQ) score model showed net IQ point gains between 1.53 and 5.65 points with consuming various fish species, indicative of large distinction of health benefit from various fish species. This study suggests commonly consumed fish species from China South Sea could bring much more positive effect than negative effect. Species-specific fish should be considered when providing recommendations of fish consumption. Muraenesox cinereus and Acanthopagrus latus should be minded with risk of MeHg exposure in taking large amounts.

Occurrence, distribution, bioaccumulation, and ecological risk of bisphenol analogues, parabens and their metabolites in the Pearl River Estuary, South China

Bisphenol analogues and alkyl esters of p-hydroxybenzoic (parabens) can be defined as emerging endocrine-disrupting compounds (EDCs) due to their similar characteristics. This study analyzed eight bisphenol analogues, six parabens, and five paraben metabolites in seawater (including aqueous and suspended particle matter (SPM)), as well as organism samples from the Pearl River Estuary, in order to determine their occurrence, distribution, bioaccumulation, and ecological and human health risk in South China's marine environment. The aggregation concentrations of bisphenol analogues, parabens, and paraben metabolites were 106 ng/L, 4.53 ng/L, and 231 ng/L in aqueous samples, 868 ng/g, 173 ng/g, and 9320 ng/g in SPM samples, 41.6 ng/g, 6.46 ng/g, and 460 ng/g in marine organisms, respectively. This study identified significantly higher concentrations of paraben metabolites than their parent parabens in the marine environment, which has not yet been reported in previous studies. These findings call for greater attention on the contamination of paraben metabolites in marine environments. Moreover, the median values of the logarithm of bioaccumulation factors (BAF) for the detected 20 target compounds ranged from 0.11 to 5.07. Bisphenol analogues including bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), bisphenol P (BPP), and Fluornen-9-bisphenol (BPFL) (3.3 < lg BAF < 3.7), and three paraben metabolites including 4-hydroxybenzoic acid (4-HB) (3.3 < lg BAF < 3.7), methyl protocatechuate (OH-MeP), and ethyl protocatechuate (OH-EtP) (Log BAF > 3.7), exhibited varying degrees of potential bioaccumulation effect in the majority of organism samples. Furthermore, all tested chemicals in this study were at low risk quotient (RQ) levels for acute and chronic toxicity in seawater. However, the target hazard quotient (THQ) values of two paraben metabolites, 4-HB and benzoic acid (BA), were higher than 1, which indicates that paraben metabolites have the potential to adsorb into organisms, and their associated human health risks should be of great concern. Overall, the study results suggest that the occurrence and risks of emerging EDCs in coastal waters are deserving of further studies, especially in densely populated regions of the world.

Distribution, bioaccumulation and trophic transfer of trace metals in the food web of Chaohu Lake, Anhui, China

Chaohu Lake is one of the five largest freshwater lakes in China situated in Anhui Province. Water, sediment and aquatic organisms were collected from Chaohu Lake. Trace metals were measured to investigate their bioaccumulation pattern and trophic transfer in the food web as well as potential health risk assessment through fish consumption. Trophic interactions were investigated by stable nitrogen isotope. Linear regression of log metal concentration versus δ¹⁵N was used to determine whether there is biomagnification or biodilution. Results showed that concentrations of trace metals in water were rather low except Hg, some of which surpassed the scope of quality standard. Trace metals in sediment exceeded background values nevertheless within the range for the protection of aquatic life. Therein, geochemical fractionation showed that Cd would pose a considerable potential ecological risk. Trace metals were higher in plankton except for Cu and Zn was higher in shrimp due to metabolic needs. Decreasing trend was observed in Pb, Cr, Cd, As and Hg levels with increasing trophic level whereas increasing trend was observed in Zn. Trace metals in fish were lower than legislation thresholds except for Cr in two samples that exceeded the threshold value. Nonetheless, total target hazard quotient values and target cancer risk were lower than unit and within acceptable range, indicating there was no health risk for inhabitants from trace metals through fish consumption.

Fatty acids, polychlorinated dibenzo-p-dioxins and dibenzofurans, and dioxin-like polychlorinated biphenyls in paired muscle and skin from fish from the Bohai coast, China: Benefits and risks associated with fish consumption

Fish consumption benefits early cognitive development and cardiovascular health because of the n-3 long-chain polyunsaturated fatty acids in the fish, but toxic pollutants in fish, like dioxin-like polychlorinated biphenyls (dl-PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), may decrease or counteract these benefits. In this study, the fatty acids, dl-PCBs, and PCDD/Fs were analyzed in paired muscle and skin from 13 fish and one squid species from the Bohai coast, which have been influenced by serious dioxin pollution from the Bohai Rim Region. The total fatty acid concentrations in the muscle and skin were 2.6-87 and 3.6-156 mg/g wet weight (ww), respectively. The total polyunsaturated fatty acid concentrations were higher in skin than muscle for almost half of the species. The total PCDD/F and dl-PCB toxic equivalents in the muscle and skin were 0.055-0.68 and 0.0099-0.43 pg/g ww, respectively, and were up to five times higher in the muscle than in the skin for eight species. Few benefit-risk studies for fish consumption with and without skin have been performed, so benefit-risk quotients (BRQs) for eating only muscle, only skin, and eating both were calculated. To achieve the recommended 250 mg of EPA + DHA intake, eating only muscle, only skin, and eating both from seven species with BRQs < 1 would cause no significant risk. Removing skin before eating is not necessary for these species. Three fish species had BRQs < 1 for muscle only but BRQs > 1 for skin only. Removing skin before eating would be better for these species. The other four fish species had BRQs > 1 for eating only muscle, only skin, and eating both, indicating the potential risk caused by PCDD/F and dl-PCB. Amounts of the four fish species consumed should be decreased, and other sources of EPA and DHA should be selected.

Tracking pollutants in dietary fish oil: From ocean to table

Dietary fish oil used in aquafeed transfers marine pollutants to farmed fish. However, the entire transfer route of marine pollutants in dietary fish oil from ocean to table fish has not been tracked quantitatively. To track the entire transfer route of marine pollutants from wild fish to farmed fish through dietary fish oil and evaluate the related human health risks, we obtained crude and refined fish oils originating from the same batch of wild ocean anchovy and prepared fish oil-containing purified aquafeeds to feed omnivorous lean Nile tilapia and carnivorous fatty yellow catfish for eight weeks. The potential human health risk of consumption of these fish was evaluated. Marine persistent organic pollutants (POPs) were concentrated in fish oil, but were largely removed by the refining process, particularly dioxins and polychlorinated biphenyls (PCBs). The differences in the POP concentrations between crude and refined fish oils were retained in the fillets of the farmed fish. Fillets fat content and fish growth were positively and negatively correlated to the final POPs deposition in fillets, respectively. The retention rates of marine POPs in the final fillets through fish oil-contained aquafeeds were 1.3%-5.2%, and were correlated with the POPs concentrations in feeds and fillets, feed utilization and carcass ratios. The dietary crude fish oil-contained aquafeeds are a higher hazard ratio to consumers. Prohibiting the use of crude fish oil in aquafeed and improving growth and feed efficiency in farmed fish are promising strategies to reduce health risks originating from marine POPs.

Chronic exposure to low environmental concentrations and legal aquaculture doses of antibiotics cause systemic adverse effects in Nile tilapia and provoke differential human health risk

BACKGROUND

Antibiotics used globally to treat human and animal diseases exist ubiquitously in the environment at low doses because of misuse, overdose and poor absorption after ingestion, coupled with their high-water solubility and degradation resistance. However, the systemic chronic effects of exposure to low environmental concentrations of antibiotics (LECAs) and legal aquaculture doses of antibiotics (LADAs) in fish and their human health risk are currently unknown.

OBJECTIVE

To investigate the in vivo chronic effects of exposure to LECAs and LADAs using oxytetracycline (OTC) and sulfamethoxazole (SMZ) in Nile tilapia (Oreochromis niloticus) and their human health risk.

METHODS

Twenty O. niloticus weighing 27.73 ± 0.81 g were exposed to water containing LECAs (OTC at 420 ng/L and SMZ at 260 ng/L) and diets supplemented with LADAs (OTC 80 mg/kg/day and SMZ 100 mg/kg/day) for twelve weeks. General physiological functions, metabolic activities, intestinal and hepatic health were systemically evaluated. The possible human health risks of the consumption of the experimental Nile tilapia fillets in adults and children were assessed by using risk quotient.

RESULTS

After exposure, we observed retarded growth performance accompanied by reduced nutrients digestibility, feed efficiency, organ indices, and lipid body composition in treated fish. Antibiotics distorted intestinal morphological features subsequently induced microbiota dysbiosis and suppressed intestinal tight junction proteins. Exposure of fish to LECAs and LADAs induced oxidative stress, suppressed innate immunity, stimulated inflammatory and detoxification responses, concomitantly inhibited antioxidant capacity and caused lipid peroxidation in intestine and liver organs. Both LECAs and LADAs enhanced gluconeogenesis, inhibited lipogenesis and fatty acid beta oxidation in intestine and liver organs. The exposure of fish to LECAs and LADAs induced anaerobic glycolytic pathway and affected intestinal fat catabolism in intestine while halted aerobic glycolysis, increased hepatic fat catabolism, and induced DNA damage in liver. The hazard risk quotient in children for fish treated with OTCD was >1 indicating human health risk.

CONCLUSION

Overall, both LECAs and LADAs impair general physiological functions, nutritional metabolism, and compromise fish immune system. Consumption of fish fed with legal OTC provokes health risk in children. Global stringent prohibition policy for use of antibiotics in aquaculture production and strategies to limit their release into the environment are urgently required to protect human health.

Seasonal variation of heavy metals in water, sediment, and highly consumed cultured fish (Labeo rohita and Labeo bata) and potential health risk assessment in aquaculture pond of the coal city, Dhanbad (India)

The extent of heavy metal pollution and their impact on the various component of urban aquaculture pond (India) were investigated on the basis of seasonal variation. The water, sediment, and fish samples (Labeo rohita and Labeo bata) were collected and analyzed to assess the metal toxicity. In the sediment, geoaccumulation index (I_geo), contamination factor (CF), pollution load index (PLI), and ecological risk index (ERI) were calculated. The estimated daily dietary intake (EDI) for As, Cd, Cr, Mn, Pb, and Zn was estimated in adult and children on the basis an average amount of fish consumed by the Indian people and its associated health hazard with was also assessed in terms of target hazard quotients (THQs). The concentration of metals in all the analyzed samples was found higher during pre-monsoon season. While, in case of fish, L. bata species has higher metal accumulation rate during both the seasons than the L. rohita because of their bottom dweller feeding habit. The order of metals in L. bata muscles is Zn > Mn > Pb > Cr > As > Cd. The I_geo value for Zn (2.66 to 3.68) was found to be highest and followed by Cd (1.65 to 3.52) and Pb (1.52 to 2.55) indicating moderate to highly polluted sediment quality. The values of ERI were significantly high during pre-monsoon period and varied from 319 to 557, representing very high metal contamination. From the human health perspective, present study highlighted that the local inhabitants who rely on this valuable pond for fish consumption are exposed chronically to As and Pb pollution due to higher THQ values, especially from the intake of L. bata.

Levels and risk assessment of metals in sediment and fish from Chaohu Lake, Anhui Province, China

Chaohu Lake is the fifth largest freshwater lake in China, which tolerates substantial amount of anthropogenic discharge from surrounding cities that resulting in the degradation of water and damage of aquatic ecosystem. Metal analysis of sediment and aquatic organisms can provide important information on the environmental contamination and potential impact of aquatic food consumption. Thus, the concentrations of Cu, Pb, Zn, Cr, Cd, As, and Hg in sediment and fish from Chaohu Lake were analyzed with inductively coupled plasma mass spectrometry and atomic fluorescence spectrometry. The mean content of Cu, Pb, Zn, Cr, Cd, As, and Hg in the sediment samples were 27.4 ± 6.3, 40.5 ± 12.3, 136.8 ± 65.5, 68.5 ± 9.1, 0.357 ± 0.141, 10.8 ± 1.7, and 0.117 ± 0.049 mg/kg, respectively. The results were compared with background values and evaluation methods, to characterize the potential ecological risk. The concentrations of Cu, Pb, Zn, Cr, Cd, As, and Hg in the fish muscle samples were 1.68-5.31, 0.078-0.31, 15.55-372.98, 0.31-0.93, 0.001-0.033, 0.29-1.03, and 0.04-0.197 mg kg^-1 of dry mass, respectively. Most of the concentrations of the studied metals in muscles were found to be below the safe limits; however, the concentration of inorganic As (10% of total As) in two specimens exceeded the maximum allowance in fish. The ecological risk evaluation showed that the metals in sediment posed low to medium risk. The health risk assessment suggested that the consumption of fish from Chaohu Lake is currently safe with respect to the metals.

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in Zhejiang foods (2006-2015): Market basket and polluted areas

In this study, we measured the levels of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in 620 foods collected during 2006-2015 from Zhejiang market, a municipal waste incinerator (MWI) and E-waste disassembling areas. For market retail foods, the levels of PCDD/F TEQs, PCDD/F plus dioxin-like PCB (DL-PCB) TEQs, and the concentrations of six indicator PCBs were generally below the EU ML. The average TEQ values for the 13 food groups were 42% of EU ML for PCDD/Fs and 32% for PCDD/Fs+DL-PCBs. Some foods of animal origin were close to the corresponding EU ML: pork (PCDD/F TEQ, 79% of ML; PCDD/F+DL-PCB TEQ, 84% of ML); infant formula (90% of PCDD/F ML) and beef (96% of PCDD/F ML; PCDD/F+DL-PCB TEQ, 78% of ML). The estimated dietary intake for the general population was 22.0pgTEQ(kgbody weight (bw))^-1month^-1, which was below the standard of 70pgTEQ(kgbw)^-1month^-1 set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). For the MWI and E-waste disassembling sites, high concentrations of PCDD/Fs and PCBs were measured in all foods tested. The corresponding TEQ in (1) freshwater fish, (2) chicken egg, (3) chicken meat and (4) chicken liver was (1) 1.4-fold (MWI, PCDD/F TEQ), (2) 11.2-fold (MWI,) and 1.6-fold (E-waste disassembling sites), (3) 20.7-fold and (4) 3.3-fold greater than EU ML, respectively. Considering the worst situation (highly polluted foods were consumed), the estimated dietary intake for local residents were 244 (MWI) and 240pgTEQ(kgbw)^-1month^-1 (E-waste disassembling sites), approximately 3.5-fold greater compared to the standard 70pgTEQ(kgbw)^-1month^-1 set by JECFA, indicating high risk could have been imposed on the health of local residents.

Exercise protects against PCB-induced inflammation and associated cardiovascular risk factors

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that contribute to the initiation of cardiovascular disease. Exercise has been shown to reduce the risk of cardiovascular disease; however, whether exercise can modulate PCB-induced vascular endothelial dysfunction and associated cardiovascular risk factors is unknown. We examined the effects of exercise on coplanar PCB-induced cardiovascular risk factors including oxidative stress, inflammation, impaired glucose tolerance, hypercholesteremia, and endothelium-dependent relaxation. Male ApoE(-/-) mice were divided into sedentary and exercise groups (voluntary wheel running) over a 12-week period. Half of each group was exposed to vehicle or PCB 77 at weeks 1, 2, 9, and 10. For ex vivo studies, male C57BL/6 mice exercised via voluntary wheel training for 5 weeks and then were administered with vehicle or PCB 77 24 h before vascular reactivity studies were performed. Exposure to coplanar PCB increased risk factors associated with cardiovascular disease, including oxidative stress and systemic inflammation, glucose intolerance, and hypercholesteremia. The 12-week exercise intervention significantly reduced these proatherogenic parameters. Exercise also upregulated antioxidant enzymes including phase II detoxification enzymes. Sedentary animals exposed to PCB 77 exhibited endothelial dysfunction as demonstrated by significant impairment of endothelium-dependent relaxation, which was prevented by exercise. Lifestyle modifications such as aerobic exercise could be utilized as a therapeutic approach for the prevention of adverse cardiovascular health effects induced by environmental pollutants such as PCBs.

Heavy metals in marine fish meat and consumer health: a review

The numerous health benefits provided by fish consumption may be compromised by the presence of toxic metals and metalloids such as lead, cadmium, arsenic and mercury, which can have harmful effects on the human body if consumed in toxic quantities. The monitoring of metal concentrations in fish meat is therefore important to ensure compliance with food safety regulations and consequent consumer protection. The toxicity of these metals may be dependent on their chemical forms, which requires metal speciation processes for direct measurement of toxic metal species or the identification of prediction models in order to determine toxic metal forms from measured total metal concentrations. This review addresses various shortcomings in current knowledge and research on the accumulation of metal contaminants in commercially consumed marine fish globally and particularly in South Africa, affecting both the fishing industry as well as fish consumers.

Nutrients and contaminants in tissues of five fish species obtained from Shanghai markets: Risk-benefit evaluation from human health perspectives

Shanghai is a Chinese megacity in the Yangtze River Delta area, one of the most polluted coastal areas in China. The inhabitants of Shanghai have very high aquatic product consumption rates. A risk-benefit assessment of the co-ingestion of fish nutrients and contaminants has not previously been performed for Shanghai residents. Samples of five farmed fish species (marine and freshwater) with different feeding habits were collected from Shanghai markets in winter and summer. Fatty acids, protein, mercury, cadmium, lead, copper, polychlorinated biphenyls, hexachlorocyclohexanes, and dichlorodiphenyltrichloroethanes were measured in liver, abdominal fat, and dorsal, abdominal, and tail muscles from fish. Tolerable daily intakes and benefit-risk quotients were calculated to allow the benefits and risks of co-ingesting n-3 long-chain polyunsaturated fatty acids and contaminants to be assessed according to the cancer slope factors and reference doses of selected pollutants. All of the contaminant concentrations in the muscle tissues were much lower than the national maximum limits, but the livers generally contained high Hg concentrations, exceeding the regulatory limit. The organic pollutant and n-3 long-chain polyunsaturated fatty acid concentrations correlated with the lipid contents of the fish tissues, and were higher in carnivorous marine fish than in omnivorous and herbivorous freshwater fish. The tolerable daily intakes, risk-benefit quotients, and current daily aquatic product intakes for residents of large Chinese cities indicated that the muscle tissues of most of the fish analyzed can be consumed regularly without significant contaminant-related risks to health. However, attention should be paid to the potential risks posed by dichlorodiphenyltrichloroethane in large yellow croaker and Hg in tilapia. Based on the results of this study, we encourage people to consume equal portions of marine and freshwater fish.

Effect of eutrophication on mercury, selenium, and essential fatty acids in bighead carp (Hypophthalmichthys nobilis) from reservoirs of eastern China

Analyses of the risks and benefits of consuming fish assess the content of beneficial fatty acids found in fish relative to harmful pollutants such as methylmercury (MeHg). Quantifying the effect of eutrophication on mercury (Hg), selenium (Se) and essential fatty acids (EFAs) in fish is necessary to determine how measures of risk vary with productivity. Total Hg and MeHg, Se and fatty acids, including the EFA eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), were analyzed in Bighead Carp (Hypophthalmichthys nobilis) dorsal muscle tissue from seven subtropical reservoirs of eastern China. Individual elements and fatty acids, as well as derived measures of risk (Se:Hg and hazard quotient, HQ(EFA)) were regressed against indicators of eutrophication, including total phosphorous (TP), chlorophyll-a (chl-a) and phytoplankton species composition. We found low MeHg concentrations (range=0.018-0.13 μg/g ww) and Se concentrations (range=0.12-0.28 μg/g ww), and Se:Hg molar ratios that were well above 1.0, indicating a low risk of Hg toxicity. Bighead Carp had a high content of total polyunsaturated fatty acids (∑PUFAs=44.2-53.6%), which included both EPA (6.9-12.5%) and DHA (16.1-23.2%). However, fish had significantly lower Se:Hg molar ratios in reservoirs with high TP, and lower EPA content with increasing plankton density (i.e. higher chl-a). Phytoplankton species composition predicted Se concentrations, but not Hg concentrations or EFA content. Overall, Hg concentrations in Bighead Carp were very low relative to consumption guidelines, and Se concentrations were adequate to confer protective benefits against MeHg toxicity. Our findings suggest that changes to plankton species composition and density with eutrophication may result in fish of lower nutritional value and thus increase risks to fish consumers by changing the availability of Se and EPA relative to MeHg.

Risk and benefit assessment of potential neurodevelopmental effect resulting from consumption of marine fish from a coastal archipelago in China

The aim of this study was to assess net neurodevelopmental effect via maternal consumption of marine fish. A total of thirty-one species were collected from Zhoushan, China. The net IQ point gain was assessed by FAO/WHO deterministic approach and probabilistic computation (if necessary). Results of the deterministic assessment of two samples belonging to Scoliodon sorrakowah showed negative IQ point gain in both common and extreme consumption scenarios (175 and 450 g/week, respectively); the net IQ gain caused by both consumption scenarios of other species were positive. Both consumption scenarios of Scoliodon sorrakowah showed beneficial neurodevelopmental effect according to probabilistic computation (95% CI for mean of net IQ gain: 0.0536-0.0554 and 0.1377-0.1425, respectively). Except for Scoliodon sorrakowah, this study indicates that both consumption scenarios of other studied species would be recommended according to the FAO/WHO approach. There would be no recommendation of consumption scenarios of Scoliodon sorrakowah for the reason for carefulness.

Organochlorine pesticides in fish from Taihu Lake, China, and associated human health risk assessment

Because contaminants and nutrients always coexist in fish, the risk from contaminants and the benefit from nutrients, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are also concomitant via fish consumption. To investigate the risk and benefit via fish consumption, concentrations of dichlorodiphenyltrichloroethane and its metabolites (DDTs), and hexachlorocyclohexanes (HCHs) in the whole- and portion-muscles of fish from Taihu Lake, China, were measured. Based on the contaminant data and nutrients from our previous study, and the associated risk and benefit via fish consumption were estimated. The concentrations of DDTs and HCHs in the whole-muscles ranged from 7.8 × 10² to 3.4×10³ pg g⁻¹ ww, and from 67.3 to 300 pg g⁻¹ ww, respectively. Of DDTs and HCHs measured, p,p'-DDE and β-HCH were respectively the most abundant pesticides. The composition profiles of DDTs and HCHs suggested that the pesticides were mainly historical residues. The benefit-risk quotient (BRQ) of EPA+DHA vs. POPs (persistent organic pollutants including data of DDTs, HCHs, and those of polychlorinated biphenyls and polybrominated diphenyl ethers cited from our previous study) via consumption of fish from Taihu Lake was calculated. As a result, to achieve the recommended EPA+DHA intake of 250 mg d⁻¹ for a healthy adult, the consumption of most fish species from the lake can cause cancer and non-cancer risks. However, the fish consumption at the rates of 44.9 g d⁻¹ by Chinese would not lead to the risks for most of the species. The results also suggested that the risk of consuming silver carp was generally lower than other fish species, and those of dorsal muscles were lower than ventral and tail muscles.

Trace elements in animal-based food from Shanghai markets and associated human daily intake and uptake estimation considering bioaccessibility

The concentrations of four human essential trace elements [iron (Fe), manganese (Mn), zinc (Zn), chromium (Cr)] and non-essential elements [cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg)] in eighteen animal-based foods including meat, fish, and shellfish collected from markets in Shanghai, China, were analyzed, and the associated human daily intake and uptake considering bioaccessibility were estimated. The mean concentration ranges for eight trace elements measured in the foods were 3.98-131µgg(-1) for Fe, 0.437-18.5µgg(-1) for Mn, 5.47-53.8µgg(-1) for Zn, none detected-0.101µgg(-1) for Cr, 2.88×10(-4)-2.48×10(-2)µgg(-1) for Cd, 1.18×10(-3)-0.747µgg(-1) for Pb, none detected-0.498µgg(-1) for As, and 8.98×10(-4)-6.52×10(-2)µgg(-1) for Hg. The highest mean concentrations of four human essential elements were all found in shellfish. For all the trace elements, the observed mean concentrations are mostly in agreement with the reported values around the world. The total daily intake of trace elements via ingestion of animal-based food via an average Shanghai resident was estimated as 7371µgd(-1) for the human essential elements and 13.0µgd(-1) for the human non-essential elements, but the uptake decreased to 4826µgd(-1) and 6.90µgd(-1), respectively, after trace element bioaccessibility was considered. Livestock and fish for human essential and non-essential elements, respectively, were the main contributor, no matter whether the bioaccessibility was considered or not. Risk estimations showed that the intake and uptake of a signal trace element for an average Shanghai resident via ingestion animal-based foods from Shanghai markets do not exceed the recommended dietary allowance values; consequently, a health risk situation is not indicated.

Immune factors and fatty acid composition in human milk from river/lake, coastal and inland regions of China

Breast milk fatty acid composition may be affected by the maternal diet during gestation and lactation. The influence of dietary and breast milk fatty acids on breast milk immune factors is poorly defined. We determined the fatty acid composition and immune factor concentrations of breast milk from women residing in river/lake, coastal and inland regions of China, which differ in their consumption of lean fish and oily fish. Breast milk samples were collected on days 3–5 (colostrum), 14 and 28 post-partum (PP) and analysed for soluble CD14 (sCD14), transforming growth factor (TGF)-β1, TGF-β2, secretory IgA (sIgA) and fatty acids. The fatty acid composition of breast milk differed between the regions and with time PP. The concentrations of all four immune factors in breast milk decreased over time, with sCD14, sIgA and TGF-β1 being highest in the colostrum in the river and lake region. Breast milk DHA and arachidonic acid (AA) were positively associated, and γ-linolenic acid and EPA negatively associated, with the concentrations of each of the four immune factors. In conclusion, breast milk fatty acids and immune factors differ between the regions in China characterised by different patterns of fish consumption and change during the course of lactation. A higher breast milk DHA and AA concentration is associated with higher concentrations of immune factors in breast milk, suggesting a role for these fatty acids in promoting gastrointestinal and immune maturation of the infant.