Bioaccumulation and health risk assessment of trace metals in fish from freshwater polyculture ponds in Chengdu, China

Characteristics and correlation analysis of heavy metal distribution in China's freshwater aquaculture pond sediments

The concentration of heavy metals (HMs) in aquaculture pond sediments significantly affects aquatic food safety and environmental quality. The contamination characteristics, drivers and potential sources of HMs in typical bulk freshwater aquaculture pond sediments in major provinces of China were systematically investigated using a variety of methods and models. Specifically, 130 surface sediment samples were collected from the study area, and the geoaccumulation index (Igeo) and potential ecological risk index (RI) were used to jointly evaluate the characteristics of the HMs. Spearman's correlation and redundancy analysis revealed the main drivers of the HMs. Additionally, the positive matrix factorization (PMF) model and absolute principal component score-multiple linear regression (APCS-MLR) model were used to identify the sources of HMs. The results revealed that the pond sediments were safe for fish culture in most of the study areas. Aquafeed protein content is an important driver of HM concentrations in sediments. The total organic carbon (TOC) content, percentage of clay particles, and pH of the aquaculture pond sediments determined the sediment HMs enrichment abilities as 13.6 %, 52 %, and 9.8 %, respectively. Cd, a significantly enriched pollutant, posed a greater ecological risk than the other five HMs (Cr, Cu, Zn, As, and Pb). Three sources of HMs were identified, including agricultural activity (e.g., aquafeeds, pesticides, and fertilizers), industrial production, and natural sources, with contributions of 44.29 %, 36.66 %, and 19.05 %, respectively. This study provides a scientific basis for minimizing the input and accumulation of HMs in freshwater aquaculture pond sediments, and this can provide insights into the prevention and control of the ecological risks posed by HMs.

Hair Heavy Metals and Food Consumption in Residents of Chengdu: Factors, Food Contribution, and Health Risk Assessment

Heavy metal pollution is one of the most pressing issues threatening food security and human health. This study assesses heavy metal (chromium, cadmium, copper, zinc, nickel, and lead) exposure via hair metal concentrations in Chengdu residents, reflecting metal intake from food consumption. From June 2020 to February 2021, a sampling survey was conducted on residents' hair (n=182) and food (n=301) in six main urban areas of Chengdu. The concentrations of heavy metals in hair and food were analyzed by inductively coupled plasma mass spectrometry, and the results showed that the residents of Chengdu City had high hair concentrations of Cd (0.17±0.03 mg kg-1) and Zn (293±21.3 mg kg-1). Gender significantly affected the hair Cr, Zn, and Ni concentrations. Based on the survey results obtained from Chengdu City residents, the habits and diet structure are assessed for the influence of six heavy metals in the hair of the residents. Adolescents' (13-18 years old) hair had significantly higher Pb concentrations than adults (19-59 years old). The concentration of Ni in hair was affected by perming and dyeing habits. For dietary exposure, cereals and meat were the main contributors to the residents' daily intake of heavy metals. The bioaccessibility of Cr, Cd, Cu, Zn, Ni, and Pb in food was 2.45-74.67%, 10.6-78.7%, 13.4-82.5%, 8.89-89.2%, 7.70-85.1%, and 15.4-86.2%, respectively. In health risk evaluation based on the bioaccessible fraction of six heavy metals, the hazard quotient of each heavy metal in food was less than 1, indicating no potential non-carcinogenic risk.

Potentially toxic element bioaccumulation in consumed indoor shrimp farming associated with diet, water and sediment levels

Shrimp production is an important industry for many countries and shrimp consumption is increasing worldwide. Shrimps are a highly nutritional food, but can pose a risk for human health if subject to high levels of environmental contaminants. This work studies the presence of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in shrimps from Ecuador and compares them to such contents noted in other shrimp-production areas in the world to evaluate the possible risks associated with these elements for consumer health, and to relate them to potentially toxic element (PTE) contents in water, sediments and diets, and also to animal biometric parameters. The PTE levels (mg kg-1 DM) obtained are as follows: in the head-As (3.52-6.11), Cd (0.02-0.10), Co (0.14-0.49) Cr (0.23-4.89), Cu (99.9--233.0), Ni (0.52-1.86), Pb (0.24-1.09), Zn (51.8-100.5) and Hg (μg kg-1 DM) (10.00-66.81); in the tail-(0.91-3.21), Cd (0.01-0.02), Co (0.01-0.43) Cr (0.01-6.52), Cu (20.0-72.44), Ni (0.15-2.03), Pb (0.01-0.69), Zn (31.2-66.1) and Hg (μg kg-1 DM) (10.00-67.18). The concentration of all the PTEs is generally lower than the limits set for seafood by European regulations, except for As in the cephalothorax (4.63 mg kg-1). Different behaviours for PTE accumulation in shrimps were found, which preferentially tend to accumulate in the cephalothorax, except for Hg (40.13 μg kg-1 DM), which accumulates in muscle (body) and is associated with contents of proteins, lipids and total shrimp weight. Nonetheless, the target hazard quotient (THQ) values for PTEs indicate that the consumption of shrimp muscles from Ecuador does not pose a human health risk because the values of these indices are below 1 in all cases.

Determination of toxic metals in canned tuna sold in developed and developing countries: Health risk assessment associated with human consumption

This study investigated toxic metal levels in a total of 222 canned tuna sampled from 36 countries (developed and developing) during 2017-2019. For this purpose, four toxic metals (Cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). Under the optimized conditions, the limit of detection (LOD) and the limit of quantification (LOQ) of the instrument ranged from 0.025 to 0.18 and from 0.54 to 0.045 ppb, respectively, with recoveries in the range of 98 %-108 %. Moreover, noncancer risk using the target hazard quotient (THQ) of each of the four toxic metals was assessed, and cancer risk using the target cancer risk (TCR) of inorganic arsenic (iAs) was evaluated. The THQ values of Hg were higher than the limits of safe (THQ ˃1) and TCR showed the carcinogenic risk for iAs for consumers when consuming more than one meal of canned tuna per week.

Heavy Metal Pollution in Aquaculture: Sources, Impacts and Mitigation Techniques

Aquaculture is one of the fastest growing agro-industries as it presently accounts for nearly 50% of all fish for direct human consumption and 43% of total seafood supply. Fish provide about 20% average daily intake of animal protein for about 3.2 billion people globally. The treatment of aquaculture in recent years for the mitigation of heavy metals and other contaminants has been gaining traction due to the benefits of aquaculture to both man and the environment. This paper provides a review of the sources, impacts, and the various methods that have been deployed in recent years by various researchers for the treatment of heavy metal contaminated aquaculture. Related works of literature were obtained and compiled from academic search databases and were carefully analysed in this study. The dangers these metals pose to the sustainability of aquaculture were studied in this review. Studies indicate that some heavy metals, such as mercury, lead, and cadmium, due to their long-term persistence in the environment, allow them to accumulate in the food chain. Mitigation techniques such as adsorption, bio-sorption, and phytoremediation have been deployed for the treatment of heavy metal contaminated aquaculture. Some research gaps were also highlighted which could form the basis for future research, such as research centred on the effects of these metals on the embryonic development of aquaculture organisms and the alterations the metals caused in their stages of development.

Trace elements in seabass, farmed by Turkey, and health risks to the main consumers: Turkish and Dutch populations

Turkey ranked first in sea bass farming in Europe, and almost all extra-EU seabass come from this country. The share of Turkish sea bass in the fish consumption of Europeans has increased significantly, and assessment of potential health risks of trace metals via sea bass, cultured by Turkey, became important. The Netherlands is the main buyer of the Turkish sea bass. Therefore, potential health risks were determined for Turkish and Dutch consumers. In the study, the concentrations of lead (Pb) and mercury (Hg) were below the limits, but the level of cadmium (Cd) was above the guidelines, in spring and winter. Dietary intake and potential health risk were found higher for the Dutch consumer, but all target hazard quotients (THQs) and total THQ (TTHQ) values were well below 1, showing no significant health risk due to the consumption of sea bass, cultured and exported by Turkey. It was determined that these sea basses can be safely consumed in quite high amounts, such as at least 31 meals a month. Se/Hg molar ratios were all above 1 and selenium health benefit values (Se-HBVs) were positive, indicating that selenium (Se) had a protective effect on Hg toxicity and positive health effects. Considering the average annual intake in Turkey and Netherlands, the consumption of sea bass, cultured by Turkey, is safe. Since the risk levels of communities may differ due to their eating habits, it is important to determine the public health impacts of the international fish trade.

Fingerprint characteristics and health risks of trace metals in market fish species from a large aquaculture producer in a typical arid province in Northwestern China

Concentrations of nine metals were measured in eight common cultured fish species obtained from forty-three aquatic product markets across three cities in Xinjiang province, to establish fingerprint characteristics and assess potential human health risks due to the consumption of fish. Metal levels ( μ g/kg, wet weight) in fish muscles were: 1204.88-5113.19 Al, 2.09-12.44 V, 6.10-31.86 Cr, 2368.80-8949.52 Fe, 2.01-10.26 Co, 4082.72-12785.68 Zn, 174.89-763.83 Cu, 0.33-2.24 Cd, and 5.74-9.90 Pb. Fingerprint analysis revealed that the studied fish species from the three cities exhibited a similar pattern of distribution. From the viewpoint of human health, the assessment of non-carcinogenic risk indicated no significant adverse health effects due to consumption of the assessed fish species.