Assessment and bioaccumulation of arsenic and trace metals in two commercial fish species collected from three rivers of Côte d'Ivoire and health risks

Bioaccumulation and health risk of metal contamination from different tiers of food chain in Ennore estuary, Southeast coast of India

The concentration and bioaccumulation of heavy metals were investigated in four distinct components (water, sediment, benthic organisms, and fish) in the Ennore estuary. The average concentration of studied metals in water is 2-5 times higher in the sediment. The geoaccumulation index in the sediment, particularly for Cd, 55 folds greater than WHO and USEPS standards. The indices like MI, Cdeg, PLI, and PERI demonstrated low contamination levels, whereas Igeo and Cf revealed elevated levels of cadmium (Cd), signifying a moderate degree of contamination. Human health indices like Target Hazard Quotation (THQ) values generally fell within permissible limits (<1), except for lead (Pb) and iron (Fe). However, HI values exceeded 1, indicating a non-carcinogenic health risk for consumers. The Target Risk for lead (TRPb) value for Oreochromis urolepis was 1.0 × 10-5, suggesting a significant cancer risk and may leads to other fish species in future if carcinogenic metals bioaccumulation.

Variation in the burden and chemical forms of thallium in non-detoxified tissues of tilapia fish (Oreochromis niloticus) from waterborne exposure

Thallium (Tl) is highly toxic to aquatic ecosystems, but information about its concentration and distribution characteristics in different fish tissues is limited. In this study, juvenile tilapia (Oreochromis niloticus) were exposed to Tl solutions with different sub-lethal concentrations for 28 days, and the Tl concentrations and distribution patterns in the fish non-detoxified tissues (gills, muscle, and bone) were analyzed. The Tl chemical form fractions, Tl-ethanol, Tl-HCl, and Tl-residual, corresponding to easy, moderate, and difficult migration fraction, respectively, in the fish tissues were obtained by sequential extractant approach. The Tl concentrations of different fractions and total burden were determined using graphite furnace atomic absorption spectrophotometry. Exposure-concentration effect determined the Tl burden in the fish tissues. The average Tl-total concentration factors were 360, 447, and 593 in the bone, gills, and muscle, respectively, and the limited variation during the exposure period indicates that tilapia have a strong ability to self-regulate and achieve Tl homeostasis. However, Tl fractions varied in tissues, and the Tl-HCl fraction dominated in the gills (60.1%) and bone (59.0%), switchover Tl-ethanol fraction dominated in the muscle (68.3%). This study has shown that Tl can be easily taken up by fish during 28-days-period and largely distributed in non-detoxified tissues especially muscle, in which concurrent risks of high Tl-total burden and high levels of Tl in the form of easy migration fraction, posing possible risks to public health.

Assessing the risk of human exposure to bioaccessible arsenic from total diet through market food consumption in Chengdu, China

To assess the daily intake of total arsenic (tAs) and arsenic speciation and their potential health risks, different food groups, including vegetables, rice, meat, viscera, freshwater fish, and seafood from Chengdu, China were analyzed. The concentrations of tAs ranged from 41.3 to 1185 μg kg^-1 with a median of 238 μg kg^-1, and 26.0% of tAs in the food groups was of inorganic toxic form. The median concentration of As(V) in rice (184 ± 21.6 μg kg^-1) was approximately 2 to 6 times higher than those in other food groups. The bioaccessible inorganic arsenic (iAs) concentrations of the food items obtained from the local markets of Chengdu ranged from 1.07 to 24.6 μg kg^-1 (mean of 6.04 μg kg^-1). Rice contributed toward the largest amount of daily iAs intake (66.2%). The mean daily iAs intake from vegetable, meat and viscera contributed 10.7%, 12.5% and 6.04% of total iAs intake, respectively. The actual concentration of arsenic in the food exposed to the human body depends on oral bioaccessible fraction. The oral bioaccessibility estimated daily intake (μg kg^-1 bw d^-1) of tAs and iAs for the residents of Chengdu was 0.32 and 0.16. Health risk assessments carried out based on bioaccessible iAs concentrations showed that the food items were safe for consumption from the iAs perspective.

Comparative assessment of human health risk associated with heavy metals bioaccumulation in fish species (Barbus grypus and Tenualosa ilisha) from the Karoon River, Iran: Elucidating the role of habitat and feeding habits

Concentrations of Cd, Ni, and Pb were measured in the liver and muscle tissues of benthic omnivorous (Barbus grypus) and pelagic herbivorous (Tenualosa ilisha) fish collected from two sampling sites along the Karoon River, Khuzestan Province, southwest of Iran. Potential human health risks were evaluated by measuring the estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR). The results highlight the important role of habitat and feeding habits in the uptake of HMs by the two species. The EDI for all HMs exceeded the oral reference doses (RfDo) provided by the USEPA, indicating the two fish species are not entirely safe for human consumption. The THQ values were within the permissible limit (< 1), while HI values (> 1) showed there was non-carcinogenic risk for consumers. The TR values for Pb were within the acceptable range (1.00E-06-1.00E-04) for both species.

Seasonal variations and human health risk assessment of trace elements in the bivalve ecosystem in the Sea of Marmara

Twelve trace elements were studied in four economically important bivalve molluscs (Mediterranean mussel, manila clam, striped venus clam, and truncated wedge clam) from the southern Marmara Sea for seasonal bioaccumulation and human health risk assessment. According to the findings, Fe and Zn were the most accumulative and element concentrations changed considerably (P < 0.05) between seasons and species. Daily, weekly, monthly intake and target hazard quotients of the trace elements were estimated and compared with maximum limits. The results revealed that consuming these bivalve molluscs from the southern Marmara Sea could be considered safe for human consumption. Nevertheless, further monitoring is needed in order to better follow the development in time of elemental pollution due to increasing environmental pressure on the Marmara Sea basin, together with research on other different bioaccumulative organisms.

Arsenic Exposure via Contaminated Water and Food Sources

Arsenic poisoning constitutes a major threat to humans, causing various health problems. Almost everywhere across the world certain “hotspots” have been detected, putting in danger the local populations, due to the potential consumption of water or food contaminated with elevated concentrations of arsenic. According to the relevant studies, Asia shows the highest percentage of significantly contaminated sites, followed by North America, Europe, Africa, South America and Oceania. The presence of arsenic in ecosystems can originate from several natural or anthropogenic activities. Arsenic can be then gradually accumulated in different food sources, such as vegetables, rice and other crops, but also in seafood, etc., and in water sources (mainly in groundwater, but also to a lesser extent in surface water), potentially used as drinking-water supplies, provoking their contamination and therefore potential health problems to the consumers. This review reports the major areas worldwide that present elevated arsenic concentrations in food and water sources. Furthermore, it also discusses the sources of arsenic contamination at these sites, as well as selected treatment technologies, aiming to remove this pollutant mainly from the contaminated waters and thus the reduction and prevention of population towards arsenic exposure.

Hg and 210Po in consumed fish of the Tadjoura Gulf (Djibouti): Levels and human health risk assessment

Hg and ²¹⁰Po were measured in the muscle tissue of commercially important fish species collected in the main coastal cities of the Djiboutian coast (Tadjoura Gulf) to evaluate the potential risk associated with their consumption. The levels of Hg among the different species ranged from 0.02 to 1.69 mg/kg w.w and exceeded tolerable limits as reported by the national regulation (2000-0727/PR/MAEM) and the Codex Alimentarius. The probabilistic distributions of health hazard were evaluated through Monte-Carlo simulation, which confirmed the carcinogenic risk from Hg. The levels of ²¹⁰Po ranged from 4.1 to 134.5 Bq/kg w.w among muscle tissues of the eight commercially important species. The carcinogenic risk was in an unacceptable range and simulation revealed that children were the most vulnerable population. The results obtained confirms that the health impact is reduced when consuming two servings per week.

Effects of heavy metal contamination released by petrochemical plants on marine life and water quality of coastal areas

The present study attempts to assess the threat of water contamination in Persian Gulf by heavy metals (Fe, Cr, Pb, Cu, Zn, Cd, Se, and Ni) and its subsequent effects on five fish species including Scomberomorus guttatus (S. guttatus), Lethrinus nebulosus (L. nebulosus), Brachirus orientalis (B. orientalis), Pomadasys kaakan (P. kaakan), and Scomberomorus commerson (S. commerson). Water and fish samples from fourteen monitoring stations were obtained to determine the concentrations of contaminants in water and fish. Heavy metal pollution index (HMPI) and non-carcinogenic hazard quotient (NHQI) were employed to evaluate contamination level in water and fish muscle. The Kriging geostatistical method was employed to determine the spatial distribution of different heavy metals around petrochemical plants. The highest NHQI values for P. kaakan and B. orientalis species were 1.036 and 1.046, respectively. In both cases, the NHQI values were higher than the maximum allowable value of 1, indicating that both fish species were on the verge of contamination by heavy metals, which in turn makes the consumption of these fish highly hazardous to human health. The lowest NHQI value was observed in S. commerson species at a value of 0.394, indicating its harmlessness to human health. Overall, fish species living within the top 5 m of the water column (S. commerson and S. guttatus) were found to be less contaminated by heavy metals compared to species dwelling near the seafloor (P. kaakan and B. orientalis). Results also indicated the pollution absorption rate in S. commerson and S. guttatus were 0.45 and 3.4 mg/kg-year, while the corresponding values for the B. orientalis and L. nebulosus species were 6 and 2 mg/kg-year, respectively. P. kaakan species showed a pollution absorption rate of 3.2 mg/kg-year. High heavy metal concentrations of 4.8, 10, 9.8, 5.2, 9.4, and 6.7 mg/L were obtained for Cr, Zn, Pb, Ni, Fe, Cu, and Cd, respectively, in water samples obtained from stations nearby petrochemical plants. The HMPI index for the most contaminated stations was ten times that of the maximum allowable limit. Given the intense activity of oil, gas, and petrochemical plants in the Persian Gulf, defining safe fishing areas by management practices similar to contamination zoning maps presented in this study can substantially protect the public health from heavy metal contamination.

Accumulation of Trace Metals in Indigenous Fish Species from the Old Brahmaputra River in Bangladesh and Human Health Risk Implications

In this study, accumulation of the top six most toxic trace metals (Arsenic (As), Cadmium (Cd), Chromium (Cr), Mercury (Hg), Nickel (Ni) and Lead (Pb)) were assessed in six indigenous fish species (Barilius barila, Salmostoma acinaces, Gudusia chapra, Labeo bata, Corica soborna, and Sperata aor) collected from the Old Brahmaputra River in Bangladesh. Human health risk associated with these fish consumption was also evaluated. Metals were analyzed in whole body of fish by an atomic absorption spectrometer (AAS). Mean concentrations of metals (μg/g, wet weight) were in the range of As (< 0.02-0.278), Cd (< 0.002-0.005), Cr (0.239-0.761), Hg (0.008-0.057), Ni (< 0.02-0.044), and Pb (< 0.01-0.038). The metal contents varied significantly among the fishes regarding their feeding habits and living habitats. Concentrations of As, Cr, Hg, and Pb were significantly higher in omnivorous species, whereas the benthopelagic species showed significantly higher accumulation of As (p < 0.05). The target hazard quotient (THQ) for noncarcinogenic risk and target cancer risk (TR) for carcinogenic risk were calculated to estimate the probabilities of experiencing these adverse health effects for the fish consumers. Metal-specific THQ values were all below 1 indicating no potential human health risk. Nonetheless, the hazard index (HI) values to estimate the effects from exposure to all metals collectively elucidated chronic noncarcinogenic health risk particularly from G. chapra consumption. The TR values revealed that there was carcinogenic risk from exposure to As through consumption of the fish. This study finally suggests a systematic and continuous monitoring of trace metal contamination in fishes from the river to ensure the fitness of this food item regarding the safety for human health.

Speciation, contamination, ecological and human health risks assessment of heavy metals in soils dumped with municipal solid wastes

The main aim of this work is to assess the extent of soil contamination, potential ecological and health risks associated with the disposal of municipal solid waste (MSW) near a Ramsar site in Assam, India. Soil samples were collected and analysed for three heavy metals (HMs), namely, chromium (Cr), manganese (Mn) and zinc (Zn). The sources of HMs and their pollution levels were evaluated using different indices. The results demonstrated that Cr contamination was high near the metal scrap segregations unit within the dumping site, otherwise, the ecological risks associated with Zn and Mn were found to be low. The speciation of Cr and Zn were associated with the Fe-Mn oxide bound (F4) fraction, accounting 44.23% and 30.68%, respectively, whereas Mn (52.55%) was associated with the exchangeable fraction (F2). The fate and origin of HMs were assessed using mobility and enrichment factors and 16 out of the 20 sampling sites fell under the category of heavily polluted category for Cr, while others which were nearby the metal segregation units fell under the strongly to extremely polluted category. In few sites, significant enrichment was observed for Zn and minimal to moderate enrichment for Mn, respectively. Health risk assessment results indicated that Cr posed higher threat to human health through ingestion.

Investigation of toxic elements in Carassius gibelio and Sinanodonta woodiana and its health risk to humans

Increasing toxic metal content in aquatic products has become a universal burden due to the risks to aquatic organisms and human health associated with the consumption of these products. In this study, toxic metal distribution and accumulation in the organs of fish and bivalve species of economic and culinary importance from the lower reaches of the Yangtze River are examined, and the corresponding health risks are also investigated. In general, the viscera and gill show higher concentration of metals than other tissues. The order of the accumulation sequence of metals in muscle tissue of fish and bivalve is Zn > Cu > Mn > Cr > As > Hg > Pb > Cd and Mn > Zn > Cu > As > Cr > Pb > Cd > Hg respectively. Maximum accumulation of Mn (507.50 μg g^-1) and Pb (0.51 μg g^-1) in the gill tissues indicates the major uptake of these metals from the water column. According to the Hazard Index (HI) calculations (based on USEPA), the analyzed metals will not cause any harmful health effects to individuals for both normal and habitual fish consumers, except for Hg and As in habitual consumers, if these species are consumed at a larger amount. Compared to the Chinese Food Health Criterion and other international standards (WHO/FAO), metal concentrations in the edible muscle tissues of the studied species are lesser than the acceptable levels and found to be fit for human consumption.