Ramos-Miras et al. 2023 — PTE concentrations in farmed Pacific White shrimp from Ecuador
This study measured nine potentially toxic elements (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn) in Pacific White shrimp (Litopenaeus vannamei) from indoor cage farming in Ecuador’s El Oro Province, an area with legacy gold mining and associated metal contamination in water and sediments. Measurements were made separately in the cephalothorax (head) and abdominal muscle (tail). The EU regulatory limit for arsenic in seafood cephalothorax (4 mg/kg) was exceeded: head As ranged 3.52–6.11 mg/kg DW. All other PTEs were below applicable EU seafood regulatory limits. Target hazard quotient (THQ) values for muscle tissue (the consumed portion) were below 1 for all elements, indicating no adverse health risk from muscle consumption under the assessed consumption scenarios.
Key numbers
PTE concentrations in shrimp head (cephalothorax), mg/kg DM (range):
- As: 3.52–6.11 (mean 4.63; exceeds EU limit of 4 mg/kg for crustacean hepatopancreas/cephalothorax)
- Cd: 0.02–0.10
- Co: 0.14–0.49
- Cr: 0.23–4.89
- Cu: 99.9–233.0
- Ni: 0.52–1.86
- Pb: 0.24–1.09
- Zn: 51.8–100.5
- Hg: 10.00–66.81 µg/kg DM
PTE concentrations in shrimp tail (abdominal muscle), mg/kg DM (range):
- As: 0.91–3.21
- Cd: 0.01–0.02
- Co: 0.01–0.43
- Cr: 0.01–6.52
- Cu: 20.0–72.44
- Ni: 0.15–2.03
- Pb: 0.01–0.69
- Zn: 31.2–66.1
- Hg: 10.00–67.18 µg/kg DM
Bioaccumulation: PTEs preferentially accumulate in cephalothorax except Hg (mean 40.13 µg/kg DM), which accumulates preferentially in muscle; Hg accumulation in muscle associated with protein and lipid content and total shrimp weight.
THQ values for muscle consumption: below 1 for all elements (no identified health risk from muscle).
Methods (brief)
Pacific White shrimp (Litopenaeus vannamei) raised in 8 cages in a 1-ha indoor pond, El Oro Province, Ecuador (3°23’45”S, 79°57’21”W). Shrimp tissues: aqua regia microwave digestion (ETHOS SEL, Milestone); As, Cd, Co, Cr, Cu, Ni, Pb, Zn by GF-AAS (PerkinElmer). Hg by DMA-80 (Milestone). Certified reference materials CRM 463 and ERMI-CE278 for shrimp tissue validation; recoveries 95–104%. LODs: As 0.05, Cd 0.002, Co 0.2, Cr 0.2, Cu 0.014, Ni 0.07, Pb 0.05, Zn 0.05 mg/kg. All concentrations as mg/kg dry matter. THQ calculated per standard method.
Implications
Certification: Farmed shrimp (Pacific White shrimp) from Ecuador show As in the cephalothorax that exceeds the EU limit; muscle tissue is within limits. For HMT&C purposes, if whole shrimp or shrimp meal is the ingredient, the head fraction drives the As exposure. Shrimp tail/muscle products are within EU regulatory limits for all nine PTEs assessed.
Courses: Good illustration of tissue-specific metal accumulation in crustaceans, and the food-safety distinction between cephalothorax (which consumers sometimes discard) and muscle (the primary consumed tissue). The mining-activity context in Ecuador is relevant for supply-chain origin risk discussions.
App: Shrimp ingredient risk profile: As in shrimp is non-trivial; the edible muscle fraction is lower-risk than cephalothorax; Hg in muscle is associated with protein and lipid content.