Correlation between arsenic concentration in fish and human scalp hair of people living in arsenic-contaminated and noncontaminated areas of Pakistan

Comparative studies of hair shaft components between healthy and diseased donors

Globally, the rapid aging of the population is predicted to become even more severe in the second half of the 21st century. Thus, it is expected to establish a growing expectation for innovative, non-invasive health indicators and diagnostic methods to support disease prevention, care, and health promotion efforts. In this study, we aimed to establish a new health index and disease diagnosis method by analyzing the minerals and free amino acid components contained in hair shaft. We first evaluated the range of these components in healthy humans and then conducted a comparative analysis of these components in subjects with diabetes, hypertension, androgenetic alopecia, major depressive disorder, Alzheimer's disease, and stroke. In the statistical analysis, we first used a student's t test to compare the hair components of healthy people and those of patients with various diseases. However, many minerals and free amino acids showed significant differences in all diseases, because the sample size of the healthy group was very large compared to the sample size of the disease group. Therefore, we attempted a comparative analysis based on effect size, which is not affected by differences in sample size. As a result, we were able to narrow down the minerals and free amino acids for all diseases compared to t test analysis. For diabetes, the t test narrowed down the minerals to 15, whereas the effect size measurement narrowed it down to 3 (Cr, Mn, and Hg). For free amino acids, the t test narrowed it down to 15 minerals. By measuring the effect size, we were able to narrow it down to 7 (Gly, His, Lys, Pro, Ser, Thr, and Val). It is also possible to narrow down the minerals and free amino acids in other diseases, and to identify potential health indicators and disease-related components by using effect size.

Characteristic features of toxic metal content in hair samples of foreign students at RUDN University from different geographic regions

BACKGROUND

This study explores the regional variations in toxic metal accumulation among RUDN University students from various global regions.

METHODS

This comparative analysis examined hair samples from students hailing from different regions, including Russia, Asia, the Middle East, Africa, and Latin America. The concentrations of Aluminium (Al), Arsenic (As), Cadmium (Cd), Mercury (Hg), Lead (Pb), and Tin (Sn) were measured in the hair samples. The data was then evaluated using regression models to assess the link between the region of residence and toxic metal content in the hair.

RESULTS

The analysis indicated significant regional variations in the levels of toxic metals in the students' hair. The highest content of Al, Cd, and Pb was observed in students from Africa (13.542, 0.028, 0.794 µg/g) and Latin America (9.947, 0.025, 0.435 µg/g). Arsenic levels in students from all regions exceeded that of Russian students by over two-fold. No substantial group differences were found in the Sn content. The regression models suggested that residing in Asia, Africa, and Latin America was a predictor of high Hg levels in hair (0.130, 0.096, 0.227 µg/g). Living in Africa was significantly associated with higher Pb levels (0.794 µg/g), and living in Latin America was close to significantly associated with the Cd level in the hair (0.025 µg/g).

CONCLUSION

This study confirmed an increased accumulation of toxic metals, especially Hg, Cd, and Pb, in students primarily from Latin America and Africa. The findings highlighted the importance of understanding the regional variations in toxic metal accumulation to address associated health risks and the potential impact on students' well-being and academic performance. These insights may guide the development of targeted interventions to reduce exposure to toxic metals in students from various regions around the world.

Concentrations of Lead, Mercury, Arsenic, Cadmium, Manganese, and Aluminum in the Blood of Pakistani Children with and without Autism Spectrum Disorder and Their Associated Factors

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with early onset in utero or childhood. Environmental exposure to six metals (Pb, Hg, As, Cd, Mn, Al) is believed to be associated with ASD directly or interactively with genes. Objective: To assess the association of ASD among Pakistani children with the six metals and genotype frequencies of three GST genes (GSTP1, GSTM1, GSTT1).

METHODS

We enrolled 30 ASD cases, age 2-12 years old, and 30 age- and sex-matched typically developing (TD) controls in Karachi, Pakistan. We assessed associations of ASD status with various factors using Conditional Logistic Regression models. We also used General Linear Models to assess possible interaction of blood Mn and Pb concentrations with the three GST genes in relation to ASD status.

RESULTS

The unadjusted difference between ASD and TD groups in terms of geometric mean blood Pb concentrations was marginally significant (p = 0.05), but for Al concentrations, the adjusted difference was marginally significant (p = 0.06).

CONCLUSIONS

This is the first study reporting six blood metal concentrations of Pakistani children with ASD. Estimates provided for possible interactions of GST genes with Mn and Pb in relation to ASD status are valuable for designing future similar studies.

Zinc application alleviates the adverse renal effects of arsenic stress in a protein quality control way in common carp

The potential antagonistic mechanism between zinc (Zn) and arsenic (As) on renal toxicity was investigated in common carp. The results showed that by increased Zn efflux and retention (as reflected by zinc transporter 1 (ZnT-1), Zrt- and Irt- 1ike protein (ZIP) and metallothionein (MT) expression), Zn co-administration significantly recovered the antioxidant function (catalase, CAT) and the level of renal barrier function (Occludin, Claudins and Zonula Occludens) in comparison to As treatment. Interestingly, Zn co-administration with As resulted in carps undergoing reduction of heat shock response (HSPs), a low induction of autophagy flux (Beclin-1, microtubule-associated protein 1 light chain 3 (LC3) and sequestosome 1 (P62)) and decreased endoplasmic reticulum (ER) stress (activating transcription factor 6 (ATF-6), inositol requiring-1α (IRE1) and PKR-like ER kinase (PERK)) in the aspect of mRNA or protein levels. All these alleviated protein quality control processes induced by Zn under As stress was correlated with the no longer loosen tight connection, less swollen endoplasmic reticulum as well as reduced formation of autophagosomes and autophagic vesicles. Mechanically, post-transcriptional regulated protein quantities compromising phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway was demonstrated true causative forces inside the cell for Zn against As poisoning. In conclusion, we suggested the potential renal protective effect of Zn supplementation against As exposure by the modulation of protein quality control processes.

Toxic Metal Pollution in Pakistan and Its Possible Risks to Public Health

Environmental pollution has increased many folds in recent years and in some places has reached levels that are toxic to living things. Among pollutant types, toxic heavy metals and metalloids are among the chemicals that pose the highest threat to biological systems (Jjemba 2004). Unlike organic pollutants, which are biodegradable, heavy metals are not degraded into less hazardous end products (Gupta et al. 2001). Low concentrations of some heavy metals are essential for life, but some of them like Hg, As, Pb and Cd are biologically non-essential and very toxic to living organisms. Even the essential metals may become toxic if they are present at a concentration above the permissible level (Puttaiah and Kiran 2008). For example, exposure to Zn and Fe oxides produce gastric disorder and vomiting, irritation of the skin and mucous membranes. Intake of Ni, Cr, Pb, Cd and Cu causes heart problems, leukemia and cancer, while Co and Mg can cause anemia and hypertension (Drasch et al. 2006). Similarly, various studies indicated that overexposure to heavy metals in air can cause cardiovascular disorders (Miller et al. 2007; Schwartz 2001), asthma (Wiwatanadate and Liwsrisakun 2011), bronchitis/emphysema (Pope 2000), and other respiratory diseases (Dominici et al. 2006).

Concentrations of arsenic, cadmium and lead in human hair and typical foods in eleven Chinese cities

Concentrations of arsenic (As), cadmium (Cd) and lead (Pb) were determined in 384 human hair samples and 445 purchased food samples from 11 cities in China. The mean concentrations of hair As, Cd and Pb were 0.23, 0.062 and 2.45mgkg^-1, respectively. The As, Cd and Pb concentrations in different foods were lower than the national maximum allowable contaminant levels. By comparison, males had higher hair As concentrations but lower Cd concentrations than females. When the interaction effects of gender and age were considered, males had the higher hair As, Cd and Pb concentrations in the 51-65 year-old age group. Residents of rural areas had higher hair As, Cd and Pb concentrations than people living in urban areas. Further analysis indicates that hair As, Cd and Pb concentrations and their changes with biological and environmental factors cannot be satisfactorily explained by the estimated intakes from purchased food.

Strong positive associations between seafood, vegetables, and alcohol with blood mercury and urinary arsenic levels in the Korean adult population

Blood mercury and urinary arsenic levels are more than fivefold greater in the Korean population compared with those of the United States. This may be related to the foods people consumed. Therefore, we examined the associations between food categories and mercury and arsenic exposure in the Korean adult population. Data regarding nutritional, biochemical, and health-related parameters were obtained from a cross-sectional study, the 2008-2009 Korean National Health and Nutrition Examination Survey (3,404 men and women age ≥ 20 years). The log-transformed blood mercury and urinary arsenic levels were regressed against the frequency tertiles of each food group after covariate adjustment for sex, age, residence area, education level, smoking status, and drinking status using food-frequency data. Blood mercury levels in the high consumption groups compared to the low consumption groups were elevated by about 20 percents with salted fish, shellfish, whitefish, bluefish, and alcohol, and by about 9-14 percents with seaweeds, green vegetables, fruits and tea, whereas rice did not affect blood mercury levels. Urinary arsenic levels were markedly increased with consumption of rice, bluefish, salted fish, shellfish, whitefish, and seaweed, whereas they were moderately increased with consumption of grains, green and white vegetables, fruits, coffee, and alcohol. The remaining food categories tended to lower these levels only minimally. In conclusion, the typical Asian diet, which is high in rice, salted fish, shellfish, vegetables, alcoholic beverages, and tea, may be associated with greater blood mercury and urinary arsenic levels. This study suggests that mercury and arsenic contents should be monitored and controlled in soil and water used for agriculture to decrease health risks from heavy-metal contamination.