The extraction of 21 insecticides and 5 metabolites was performed using an optimized
and validated QuEChERS protocol that was further used for the quantification (GC-MS/MS)
in several seafood matrices (crustaceans, bivalves, and fish-mudskippers). Seven species,
acquired from Hong Kong and Macao wet markets ( a region so far poorly monitored),
were selected based on their commercial importance in the Indo-Pacific region, market
abundance, and affordable price. Among them, mussels from Hong Kong, together with
mudskippers from Macao, presented the highest insecticide concentrations (median values
of 30.33 and 23.90 ng/g WW, respectively). Residual levels of fenobucarb, DDTs, HCHs,
and heptachlors were above the established threshold (10 ng/g WW) for human consumption
according to the European and Chinese legislations: for example, in fish-mudskippers,
DDTs, fenobucarb, and heptachlors (5-, 20- and tenfold, respectively), and in bivalves,
HCHs (fourfold) had higher levels than the threshold. Risk assessment revealed potential
human health effects ( e.g., neurotoxicity), especially through fish and bivalve consumption
(non- carcinogenic risk; Sigma HQ(LT) > 1), and a potential concern of lifetime cancer
risk development through the consumption of fish, bivalves, and crustaceans collected
from these markets ( carcinogenic risk; Sigma TCR > 10(-4)). Since these results indicate
polluted regions, where the seafood is collected/produced, a strict monitoring framework
should be implemented in those areas to improve food quality and safety of seafood
products.
