A human risk assessment by heavy metal and pesticide exposure by fish consumption at the Galápagos islands
Nezami, C. (2022). A human risk assessment by heavy metal and pesticide exposure by fish consumption at the Galápagos islands. MSc Thesis. Universiteit Antwerpen/Ghent University/Vrije Universiteit Brussel: Antwerpen/Gent/Brussel. 30 pp.
Galapagos archipelago is not immune to global and regional pollution. A diverse range of contaminants have been found in marine biota. The present work reports the determination of pesticides and mercury in three different species of fish swordfish (Xiphias gladius), Galapagos mullet (Mugil galapagensis) and Thoburn’s mullet (Xenomugil thoburni). The objectives were to assess: (a) the feeding habits of local people on Santa Cruz Island; (b) the levels of persistent organic pollutants and Hg in muscle and liver; (c) the potential human health risk exposure to Hg through a human health risk assessment. The outcome of this study could serve as a baseline for future studies to implement a food safety regulation in Ecuador to avoid possible health risks caused by the ingestion of pesticides and heavy metals. The mercury quantification was performed using the DMA method which allows limits of detection of 0.005ng. For the quality control, we used a certified reference material (SRM DORM – 4: Fish protein certified reference material for trace metals, National Research Council of Canada (NRC - CNRC). Regarding the pesticide analysis, the LC-MS/MS pesticides were processed with the QuEChERS method and the (GC-ECD) with an Agilent Technologies 6890N gas chromatograph equipped with an Agilent Technologies 7683 Series autosampler injector. The mercury concentration expressed as wet sample weight varied from 0.010 ug g -1 to 1.168 ug g -1. After performing the health risk assessment indices for mercury concentration (EWI) and the calculation of the risk to our data our results explained no risk to human health of the local population on Santa Cruz Island. The results showed no presence of pesticide residues in the samples. The survey results showed no frequent consumption of mullet and swordfish within the Santa Cruz community. People preferred the yellowfin tuna as a food source.
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