The determination of essential trace and toxic elements in the biological samples of human beings is an important clinical screening procedure. This study aimed to assess the possible effects of environmental exposure on paralysed male workers (n = 75) belonging to the production and quality control departments of a steel mill. In this investigation, the concentrations of arsenic, cadmium, lead, manganese and zinc were determined in biological samples (blood, urine and scalp hair samples) of exposed paralysis and non-paralysed steel mill workers. For comparative purposes, unexposed healthy subjects of same age group were selected as referents. The elements in the biological samples were measured by atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. The results indicate that the level understudy elements in all three biological samples were significantly higher in paralysed workers of both groups (quality control and production) as compared to referents (p < 0.01). The possible connection of these elements with the aetiology of disease is discussed. The results also show the need for immediate improvements of workplace ventilation and industrial hygiene practices.
"It shows multi-system tissue toxicity, causing neurological, cardiovascular, renal, gastrointestinal, hematologic, reproductive, genotoxic and carcinogenic effects . Thanks to the negative characteristics of lead, it is necessary to monitor its amount in the body [2,3,4,5,6]. Moreover, some complexing agents could enhance or lower toxicity of this metal, thus the effects of such complexes should be considered. "
[Show abstract][Hide abstract] ABSTRACT: The aim of the study was the preparation of a liposome complex with encapsulated lead ions, which were electrochemically detected. In particular, experiments were focused on the potential of using an electrochemical method for the determination of free and liposome-encapsulated lead and determination of the encapsulation efficiency preventing the lead toxicity. Primarily, encapsulation of lead ions in liposomes and confirmation of successful encapsulation by electrochemical methods was done. Further, the reduction effect of the liposome matrix on the detected electrochemical signal was monitored. Besides encapsulation itself, comparison of toxicity of free lead ions and lead ions encapsulated in liposome was tested. The calculated IC50 values for evaluating the lead cytotoxicity showed significant differences between the lead enclosed in liposomes (28 µM) and free lead ions (237 µM). From the cytotoxicity studies on the bacterial strain of S. aureus it was observed that the free lead ions are less toxic in comparison with lead encapsulated in liposomes. Liposomes appear to be a suitable carrier of various substances through the inner cavity. Due to the liposome structure the lead enclosed in the liposome is more easily accepted into the cell structure and the toxicity of the enclosed lead is higher in comparison to free lead ions.
International Journal of Environmental Research and Public Health 12/2013; 10(12):6687-6700. DOI:10.3390/ijerph10126687 · 2.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chronic exposure to heavy metals has long been recognized as being capable of increasing head and neck cancer (HNC) incidence, such as laryngeal (LC) and nasopharyngeal (NPC), among exposed human populations. The aim of the present study was to evaluate the concentrations of arsenic (As) and cadmium (Cd) in the blood of 145 patients (LC and NPC) and 351 controls in order to establish a potential relationship between these factors and the occurrence of LC and NPC. Mean blood levels of As and Cd in patients (5.67 and 3.51 μg/L, respectively) were significantly higher than those of controls (1.57 and 0.74 μg/L, respectively). The blood levels of As and Cd were mostly significantly higher than those of controls (p < 0.05) after controlling the other risk factors of HNC including tobacco smoking and chewing, and alcohol drinking. Cd levels in blood increase significantly with the number of occupational exposure years for patients (p < 0.05). However, seafood was not found to be contributing as an exposure source. Among these risk factors, smoking (>30 pack years) and occupational exposure (>20 years) presented the most significant association with HNC (OR = 10.22 and 10.38, respectively, p < 0.001). Cd level in blood sample of cases that are occupationally exposed/tobacco users (smokers and chewers) were higher than that of non-occupationally exposed/nontobacco users (p < 0.001). The logistic regression model illustrated that HNC (LC + NPC) was significantly associated with blood levels of As (OR = 2.41, p < 0.001) and Cd (OR = 4.95, p < 0.001).
Environmental Science and Pollution Research 09/2013; 21(3). DOI:10.1007/s11356-013-2105-z · 2.83 Impact Factor
"In previous studies (Khlifi and Hamza-Chaffai, 2010; Khlifi et al., 2013), our research group studied the head and neck tract cancer-related data in exposure to heavy metals via occupational exposure and the major mechanisms underlying some toxic metal carcinogenesis. Furthermore, the effects of occupational exposure to cadmium, chromium, arsenic and nickel on diseases and cancer have been confirmed (Grimsrud and Peto, 2006; Chen et al., 2008; Afridi et al., 2011; Feki-Tounsi et al., 2012). Mean and median values of Cd and Cr concentrations in tumor and healthy tissues in farmers, cement workers (bricklayers) and painters are presented in Table 8. "
[Show abstract][Hide abstract] ABSTRACT: Chronic exposure to heavy metals has long been recognized as being capable to increase head and neck cancer incidence among exposed human populations. Head and neck cancer is a significant public health issue in Tunisia. The aim of the present study was to evaluate the concentrations of As, Cd, Cr and Ni in healthy and tumor tissues of head and neck cancer patients. Metal concentrations were determined in tumor and healthy tissues of 101 head and neck cancer patients, using Atomic Absorption Spectrometry. The As, Cd, Cr, and Ni levels in tumor tissues were 3.4, 2.5, 1.3 and 1.5 times higher than those of healthy tissues (p<0.05), respectively. Tumor tissue metal levels were higher in men than in women. As and Cd levels in tumor and healthy tissue samples of patients smokers are significantly higher than those of non-smokers (p<0.05). A strong effect of cumulative smoking as expressed in the number of pack per year, and tumor tissue Cd levels were positively associated with three groups of age (<40, 51-60 and >60years) in both never-smokers and ever-smokers (<20 and ≥20 pack per year). Healthy tissue Cd levels were negatively associated with age in those three groups of smokers. The highest Cd and Cr concentrations among both workers and non-workers were observed in tumor tissues. The Cd and Cr in tissues of farmers, bricklayers and painters were all significantly higher among the workers as compared with the non-workers group. Tissue metal levels have increased due to smoking and occupational exposure. Heavy metal exposure via tobacco smoking and occupational exposures may increase the risk of head and neck in the Tunisian population.
Science of The Total Environment 03/2013; 452-453C:58-67. DOI:10.1016/j.scitotenv.2013.02.050 · 4.10 Impact Factor
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