ABSTRACT
OBJECTIVES: Previous literature has shown that heavy metals (HMs) in cigarette smoke have been overestimated, and second-hand smoke (SHS) has recently raised public concern. This study aimed to review the effects of passive tobacco exposure on lead (Pb) and cadmium (Cd) concentrations of children and women in different biological samples. CONTENT: In this systematic review, two independent researchers assessed different databases/search engines including PubMed, Web of Science, Scopus, and Google Scholar using Mesh terms and Text Words. Studies between January 2000 and May 2022 were included. After quality assessment, studies with sufficient data were included in the meta-analysis. A fixed or random model was used to pool the results in a meta-analysis. Heterogeneity between the studies was assessed by using I-square and Q tests. Forest plots demonstrating the point and pooled estimates were provided. SUMMARY: A total of 976 studies were obtained from different databases and finally 17 studies meet our criteria and were included in our systematic review. Out of 17 studies, six studies had sufficient data for analysis and were included in the meta-analysis. The results of the meta-analysis showed a significant difference in blood lead concentrations (BLC) between the children with SHS exposure and the control group (Hedges' g: 2.44, 95% CI: 1.01-3.86, p<0.05). Also, there were significant differences in hair levels of Cd (Hedges' g: 0.66, 95% CI: 0.04, 1.28, p<0.05) and Pb (Hedges' g: 0.94, 95% CI: 0.05, 1.83, p<0.05) between children with SHS exposure compared to the control group. OUTLOOK: The results of the present meta-analysis showed that passive smokers had higher Pb and Cd concentrations than those who were not exposed to cigarette smoke.
ABSTRACT
Iran is the largest fishery producer in the region reaching nearly 1 million tons. Fish provide a good many nutrients that are beneficial for our health. Due to significant deposits of xenobiotics in the water environments, however, fish may also be a source of non-essential metals, causing a variety of disorders. The main challenges to Iranian fisheries are environmental pollution and quality control, so this study aims to estimate the concentration of cadmium (Cd), mercury (Hg), nickel (Ni), and lead (Pb) in canned tuna fish produced and consumed in Iran. We studied four popular brands (N = 4 × 20) with ICP-MS and then looked at the concentrations and calculated the risk assessment parameters. We found that the lowest concentration was observed for Cd (18 µg/kg) and the highest for Ni (132 µg/kg). Among the brands studied, Pb concentrations differed most (42.0 to 113.3 µg/kg) and Hg levels were more consistent (24.0 and 39.4 µg/kg). The concentrations of Cd, Hg, and Pb in all the brands tested were below EU permissible thresholds. The intake estimation risk assessment parameters (EDI, contribution to PTWI, and CR) and non-cancer risk assessment parameters based on reference doses (THQ and HI) demonstrated the safety of tested products in respect to all metal concentrations studied, while the parameters regarding the toxic effects (MoE, and ILCR) showed that the consumption might cause health risks in terms of Cd (ILCR), Ni (ILCR), and Pb (MoE). The consumption of the canned fish studied should therefore be maintained at a reasonable level (2-5 meals containing fish weekly), so that it may provide necessary nutrients, while avoiding the health risk due to metal content.
