Mahjoub et al. 2021 — Mercury, lead, and cadmium in five fish species from a Moroccan dam, with health risk assessment
This study measured total mercury (tHg), lead (Pb), and cadmium (Cd) in the muscle tissue of five fish species collected from the Mechraa-Hammadi Dam in Morocco, a drinking water and irrigation reservoir. Analytical methods used were GF-AAS (graphite furnace atomic absorption spectrometry) for Pb and Cd, and CV-AAS (cold vapor atomic absorption spectrometry) for Hg. All measured metal concentrations in fish muscle were below the limits established by EC Regulation N° 1881/2006 for food safety. A target hazard quotient (THQ) analysis was performed to characterize non-cancer health risk for consumers. This study provides food-chain-relevant metal occurrence data for freshwater dam fish in North Africa and a regulatory compliance comparison against EU standards.
Key numbers
Five fish species measured (species identities in source). Metals: tHg (CV-AAS), Pb and Cd (GF-AAS). Matrix: fish muscle tissue. All values below EC N°1881/2006 maximum limits. THQ analysis performed for human health risk. Jurisdiction: Morocco (MA). Publication: Journal of Toxicology 2021;8865869. License: CC BY.
Methods (brief)
Sampling from Mechraa-Hammadi Dam reservoir in Morocco. Fish muscle dissected and analyzed for tHg by CV-AAS and Pb/Cd by GF-AAS. Regulatory comparison against EC N°1881/2006 maximum levels. Health risk assessed using target hazard quotient (THQ) per USEPA methodology. Limitation: single sampling event from one reservoir; seasonal and inter-annual variation not captured.
Implications
Certification: Freshwater dam fish from Morocco comply with EU food safety limits for tHg, Pb, Cd; provides North Africa regulatory compliance context. Courses: Illustrates freshwater fish as a food-chain pathway for metal exposure and the use of THQ methodology in consumer health risk assessment. App: Freshwater fish from reservoirs in North Africa carry lower Hg burden than oceanic predatory fish; risk below EU regulatory thresholds.