P26-11 Assessment of the potential consumer risk from repeated consumption of imported tuna and swordfish containing elevated levels of mercury
Year: 2025
Type: article
Abstract: International food safety alerts regularly indicate elevated levels of mercury in imported fresh or frozen cuts of tuna and swordfish that are above the maximum permitted level of 1.0 mg/kg [1] . The Food Standards Agency performed an assessment to provide context on the potential consumer risk from consuming these fish, to provide guidance for risk managers. A review of international food safety alerts raised between January 2021 and June 2024 was performed. The maximum level of mercury reported in tuna was found to be 2.96 mg/kg and in swordfish it was 4.27 mg/kg. Consumption data was obtained from the UK National Diet and Nutrition Survey [2] . The highest consumers of tuna (not tinned) were adults (19-64) who consume 1.1 g/kg bw/d. The most sensitive consumer population, with respect to risk from mercury, is pregnant women (and those who may become pregnant in the next year) [3] , who are advised in the UK to limit tuna steak consumption to less than two 140g portions per week [4] . Reliable NDNS consumption data are not available for swordfish owing to low numbers of consumers. Online sources showed that a typical swordfish portion was between 110 and 260g. Pregnant women in the UK are advised not to eat swordfish and the general population is advised to limit consumption to one portion per week 4]. Conservative exposure scenarios were considered to determine the maximum level of mercury that would not result in an exceedance of the relevant TWI for that consumer group, if all consumption came from that source, on a long-term basis. For tuna, levels over 0.43 mg/kg led to an exceedance of the TWI for the general population (3.3 µg/kg bw/week [5] ) in the highest consumers. For pregnant women following public health advice, levels of mercury over 0.33 mg/kg exceeded the TWI (1.3 µg/kg bw/week [2] ). For swordfish, it was assumed that a single 200g portion was consumed per week. Based on an adult bodyweight of 70kg [6] , levels of mercury exceeding 1.15 mg/kg would result in an exceedance of the TWI for the general population. The highest levels of mercury reported in international food safety alerts would result in an exceedance of the relevant TWI by approximately 9 and 4-fold, for tuna and swordfish respectively. These scenarios provide context only on the potential consumer risk from tuna and swordfish containing elevated levels of mercury if it were to be repeatedly consumed over a long period of time. They do not make the same refinements as previous consumer risk assessments available for UK consumers and are therefore extremely conservative. It is unlikely that an individual would consume fish containing high mercury levels, on every eating occasion, on a long-term basis. Existing consumer risk assessments performed for UK consumers that considered realistic exposure scenarios have not suggested there is a serious concern from mercury exposure from fish, particularly if public health advice is followed, and these conclusions remain valid 3 , 4 , 5 .
Source: Toxicology Letters
Authors: A. Axon, D. Simitdjioglu, S. Johnston, E. French
Institution: Food Standards Agency
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,270
OpenAlex ID: W4414075827