Mercury, Lead, and Cadmium in the Muscles of Five Fish Species from the Mechraa-Hammadi Dam in Morocco and Health Risks for Their Consumers

Overview

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.

Wiki pages updated on ingest

• Mercury
• Lead
• Cadmium
• Fish
• eu-1881-2006

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