Tuna for dinner — are we eating mercury along with the fish?

Aim of the study: Human consumption of fish protein, including canned tuna fish, is increasing steadily worldwide. However, there are some concerns about the potential exposure to elevated concentrations of metals in canned tuna fish.

Results: For children, they were 7.23E-05 for Al and 2.91E-08 for Cr. THQ and total target hazard quotient (TTHQ) were ≤1.0 for adult and child consumers. The Incremental Lifetime Cancer Risk (ILCR) for As was 3.21E-5 in adults and 4.18E-5 in children. Adults and children who consume canned tuna fish in Iran are not at non-carcinogenic risk but face a carcinogenic risk due to As.

Aim of the study: To balance the risks and benefits of fish consumption, selenium, fatty acids (DHA + EPA), and mercury in fishery products were determined. Analyzed products were canned tuna, frozen tuna (Thunnus albacares), smoked striped marlin (Tetrapturus audax), fresh Pacific sierra (Scomberomorus sierra), fresh dolphinfish (Coryphaena hippurus), fresh tilapia (Gerres cinereus), and fresh bullseye puffer (Sphoeroides annulatus).

Results: EPA + DHA ranged from 1.16 to 10.72 mg g-1. EPA + DHA intake was comparable to or above the recommended daily intake; Hg intake was below the reference dose, but Se intake was below the recommended values for the different population groups. Based on HBVSe, fishery products had positive values; that is, they are healthy foods. Considering the interaction between Hg and Se and the rate of fishery product consumption, the risk to consumers is below one percent.

Aim of the study: The bioaccessible Hg fraction in fish and seafood commonly present in the Mediterranean diet was assessed through three distinct in vitro extraction schemes. Each extraction method provided different results, highlighting the lack of a universal methodology to estimate mercury (Hg) bioaccessibility in those matrices.

Results: Among the three extraction methods tested, the Unified Bioaccessibility Method (UBM) provided the highest estimate of Hg bioaccessibility for consumers. The cooking methods tested (frying, grilling, and steaming) considerably reduced the bioaccessible fraction. Results indicate that bioaccessible Hg in consumed fish and seafood is far below the levels set by current safety risk assessment legislation. These findings highlight the importance of including bioaccessibility measurements in food safety legislation.

Aim of the study: Total mercury (Hg), cadmium (Cd) and lead (Pb) concentrations were determined in canned fish on the Ghanaian market. Total mercury was determined using an automatic mercury analyzer while cadmium and lead levels were determined by flame atomic absorption spectrophotometry.

Results: Total mercury was determined using an automatic mercury analyzer while cadmium and lead levels were determined by flame atomic absorption spectrophotometry. The metal contents in the samples, expressed in μg g(-1) (wet weight), varied from <0.01 to 0.20 with an average value of 0.03 for mercury, from <0.01 to 0.45 with an average value of 0.34 for cadmium, and from <0.01 to 1.44 with an average value of 0.72 for lead. The results indicate that canned fish from the Ghanaian market have concentrations well below the permissible FAO/WHO limits for these toxic metals. Thus, considering the Provisional Tolerable Weekly Intake (PTWI) of Hg, Pb and Cd, the levels obtained in this study are unlikely to constitute significant public exposure through consumption of moderate amounts.

Aim of the study: Histamine is one of the most important health issues associated with consumption of canned tuna because of possible allergic and anaphylactic reactions in consumers. Although the concentrations of histamine in tuna in Iran have been investigated in several studies, definitive conclusions are elusive.

Results: The mean prevalence of histamine was 9.19% (95%; CI, 6.88 to 11.5%). The 95% value of the target hazard quotient for adult consumers was calculated as 0.10. In all studies performed in Iran, the concentration of histamine in canned tuna was lower than the FDA standard. Health risk assessment indicated low histamine risk (target hazard quotient < 1) for adults in Iran from consumption of canned tuna.

Aim of the study: Mercury (Hg) is a toxic element that bioaccumulates in aquatic organisms, posing health risks through seafood consumption. This study quantified total Hg in canned tuna in oil purchased from supermarkets in the Metropolitan District of Quito, Ecuador.

Results: Mean Hg concentrations were 0.22 ± 0.10 mg/kg, 0.63 ± 0.10 mg/kg, and 0.36 ± 0.15 mg/kg for brands A, B, and C, respectively. All values complied with international safety limits; however, the non-carcinogenic risk (HQ > 1) associated with methylmercury exposure from brand C exceeded the reference threshold established by the U.S. Environmental Protection Agency. Recommended weekly intake of tuna to avoid health risks was estimated at 106 g (children) and 512 g (adults) for A; 26 g and 126 g for B; and 64 g and 307 g for C, respectively.

Aim of the study: Despite health benefits, fish consumption poses risks of exposure to toxic substances. Concentrations of toxic metals were determined in 20 fish species available on the Polish market.

Results: Only in tuna was the THQ marker for MeHg twice the recommended safe value. The high methylmercury content and high THQ in tuna indicate that consumption of this fish should be limited. Over the past decade, levels of toxic metals in fish on the Polish market have remained stable. The only significant change was the increase in THg and MeHg in tuna.

Aim of the study: This study evaluated the concentrations of minerals and heavy metals in canned tuna products available on the Turkish market, with a particular focus on the influence of packaging medium (water, oil, and sauce) on elemental distribution. A total of 105 canned tuna samples were collected from Van Province, Türkiye, comprising equal groups (n = 35) of water-, oil-, and sauce-packed products.

Results: Arsenic concentrations ranged from 0.31 to 7.08 mg/kg (overall mean: 1.49 mg/kg) and were frequently detected across all packaging types (74–100% of samples). All samples complied with regulatory limits for lead and tin. Health risk assessment based on estimated daily intake and target hazard quotient indicated a potential non-carcinogenic risk associated with arsenic exposure, while mercury exposure approached the risk threshold, particularly for oil-packed tuna. The ICP-MS method, assessed through certified reference material and quality control procedures, demonstrated adequate sensitivity and reliability for elemental analysis of canned tuna products and supports food safety assessment in the Turkish seafood market.