RESUMEN
The total content of cadmium and its distribution between leaves and roots were investigated for pak choi (Brassica chinensis L.), which was grown in a contaminated area of Hangzhou city, China. Results showed that cadmium concentrations in 90% of samples exceeded the Chinese tolerance limit for food. Although roots of pak choi had a higher concentration of cadmium than leaves, leaf tissue (the edible part) accumulated over 80% (on average) of the whole plant cadmium burden due to the greater biomass in leaf tissue. Since pak choi is the staple vegetable in the study area and of great relevance to human health, the dietary intake of cadmium and calculated risk indexes to local residents through the food chain were determined.
Asunto(s)
Brassica/química , Cadmio/análisis , Contaminación de Alimentos/análisis , Verduras/química , Brassica/toxicidad , Cadmio/toxicidad , China , Ingestión de Alimentos , Humanos , Concentración Máxima Admisible , Hojas de la Planta/química , Raíces de Plantas/química , Salud Pública , Medición de Riesgo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Verduras/toxicidadRESUMEN
Field and retail collections of bivalves from the Pacific Northwest, Canada, were analysed for cadmium concentrations by atomic absorption spectrophotometry (AAS). Both collections of varnish (Nuttallia obscurata) and manila (Venerupis philippinarum) clams contained cadmium concentrations of less than 0.5 µg g(-1), well below international safety guidelines of 1 and 2 µg g(-1) wet weight cadmium for the European and Hong Kong markets, respectively, as well as the 2 µg g(-1) safety guideline set by the Codex Alimentarius Commission (CAC). Cadmium concentrations in retail collections of the Pacific oyster, Crassostrea gigas, were generally above 2 µg g(-1) wet weight (range = 1.5-3.56 µg g(-1)). Retail collections of the mussel, Mytilus spp., contained cadmium concentrations below the 2 µg g(-1) wet weight guideline, but not always the 1 µg g(-1) limit (range = 0.15-1.8 µg g(-1)). However, field collections of Mytilus spp. contained cadmium concentrations between 0.35 and 4.00 µg g(-1) wet weight, and depending on sampling location, concentrations exceeded the CAC guidelines by more than two-fold. Locations where mussels had high cadmium concentrations correlated with regions that had previously reported high values for cadmium in Pacific oysters (r = 0.65; p < 0.05). Of the various shellfish analysed, the four species of scallops, Chlamys hastata, C. rubida, Crassadoma gigantea, and Patinopecten yessoensis, contained the greatest concentrations of cadmium, in excess of 5 µg g(-1) wet weight (range = 4.97-8.98 µg g(-1)) with the greatest concentrations determined for C. gigantea. Cadmium concentrations in shellfish from the Pacific Northwest are greater than values reported for shellfish from other regions of the world and consumers need be aware of Health Canada consumption guidelines for shellfish from this region.