# Atomic Spectroscopy-Based Analysis of Heavy Metals in Seaweed Species
## 3 Conclusions and Future Directions  
From the studies included in this review, it is evident that the determination of heavy metals in seaweed is critical for assessing nutritional composition and identifying contamination sources. In general, the analysis of any food for metals that might be harmful to health is an important part of ensuring food safety. Metals can contaminate raw products through exposure to contaminated environments during growth. During an expert meeting organized by the Food and Agriculture Organization (FAO) of the United Nations, the World Health Organization (WHO) reported on food safety hazards linked to the consumption of seaweed and future work in developing relevant Codex guidance on this subject was recommended [13]. There is a general lack of attention to the evaluation of the role of seaweeds in foodborne illnesses; therefore, close monitoring of the same is advocated [93]. In a scoring matrix developed by [PERSON] et al. to rank 22 food safety hazards in seaweed, the presence of As, Cd, Hg, and Pb was identified as a major heavy metal hazard. The study emphasizes that the occurrence of heavy metal hazards, mainly due to bioaccumulation, require attention in seaweed [94]. Since food safety legislation and related best-practice instruments are based on information on the occurrence of (potential) hazards, documenting and/or screening for the presence of heavy metals and therefore establishing various analysis methods to facilitate heavy metal assessment in seaweed is vital. In order to monitor for food safety hazards, many data are needed for the assessment of heavy metal concentrations per species and per product of raw and processed seaweeds within various national and regional contexts. The sites of wild harvesting as well as seaweed farming have substantial impacts on the final quality and safety of products. Presence of heavy metals is directly corelated with uptake from the environment and accumulation over time. Seaweeds growing in sites close to untreated industrial effluent and run-off and touristic harbors show higher metal bioaccumulation [4]. The longer seaweed stays in a contaminated cultivation environment, especially in the case of wild-harvested seaweed, the greater the exposure and the uptake of metals. Studies suggest that interspecific variations due to differences in morphology, growth rates, and affinity for metals play an important role in the bioaccumulation of heavy metals in seaweed [95; 96]. [PERSON] et al. compiled over 20,000 estimates of trace metal levels in natural seaweeds across the globe. They concluded that brown seaweeds had the highest and that red seaweeds had the lowest accumulation capacities, regardless of sampling location [97]. Similar observations have been reported by other researchers [98]. This review compiles the most widely used techniques for metal measurement in different seaweed species using atomic absorption, emission, and mass spectrometry. The analyte concentration range is an important factor in selecting the atomic spectroscopy technique for analysis. Among the techniques used by most of the studies in this article, GFAAS and ICP-MS can achieve measurements at trace levels (less than 10 ppb) or even ultra-trace levels (ppt). Although GFAAS has lower running costs than ICP-MS, it has the disadvantage of measuring each element separately. In contrast, ICP-MS has the capability to simultaneously measure multiple metal elements, which allows for faster sample processing; in addition, it has a much wider linear dynamic range and fewer interferences. In comparison to GFAAS and ICP-MS, the FAAS and ICP-OES methods are less sensitive and can be used to measure higher levels (more than 10 ppb) of the target elements in samples. Food and environmental industries often use FAAS due to the availability of regulated and standard analysis methods. Since FAAS instrumentation has been used for a longer time compared to other atomic spectroscopies, many well-documented analysis methods have been established, which makes FAAS user-friendly.