Levels of five metals in male hair from urban and rural areas of Chongqing, China

Selenium and toxic metals in human hair of the Dashan Region, China: Concentrations, sources, and antagonism effect

The Dashan Region was a Se-rich region of China. In this study, 131 residents' human hair samples were collected. The concentrations of Se and toxic metals were analyzed, and the health risk was estimated using the concentration data. Cd and As concentrations were significantly higher than in East China. Se and most toxic metal concentrations increased with age (except for the aged people). Furthermore, gender and smoking habits might have a significant impact on toxic metals and Se levels. Multivariable statistics analysis revealed that Se and toxic metals primarily originate in the environment and are then transferred to the human body via the food chain. Dietary habits had an effect on the Se and As concentrations in hair, according to the results of stable isotope analysis. To assess detoxification ability, the Se/ toxic metal molar ratio was used as an indicator. The results demonstrated that the antagonistic effect of Se and Cd, As, Cr, and Hg (molar ratio > 1) could effectively protect residents in the study area from Cd and As pollution in daily life.

Distribution Characteristics and Influencing Factors of Bio-elements in the Human Hair of Uyghur Communities in an Oasis Area of Xinjiang, China

Located in central Asia, Xinjiang is characterized as a diverse environment in China, consisting of vast deserts, dotted oases, and high mountains. Due to the combined effect of climate conditions under such a diverse environment, there are large differences in human activities, living styles, and eating habits in farmland and grazing pastures between Xinjiang and other regions of China. This study aimed to investigate the variations and mechanisms of elemental distribution in the hair of Uyghur communities among different ages and genders and under different land use backgrounds in an oasis region in Xinjiang. Hair samples from 524 residents from four traditional farmland areas and two grazing pasture areas in Bai Cheng County in Xinjiang were collected, and the levels of thirteen elements were analyzed. The results indicated that the average levels of Cu, Mg, Mn, Zn, Ni, Co, Pb, Fe, Ca, Cd, Cr, As, and Se in the hair of Uyghur communities were within the background levels of Chinese and global residents' hair. Overall, the levels of elements in the hair of women residents were higher than those of men residents. The levels of elements in the human hair of the middle-aged group were higher than those of child and older-aged groups. Elements Cr and Se in the hair of grazing pastures were higher than those of farmland areas. The levels of Cd, Pb, As, and Zn in the hair of farmland areas were higher than those of grazing pasture areas. The levels of Ca, Mg, Cu, and Fe in the hair of Uyghur communities were higher than those of other ethnic groups, while the toxic elements in the hair of residents in Bai Cheng were lower than those in other regions of China. Middle-aged people were exposed to higher levels of toxic elements in their daily activities compared to elderly and child groups. Also, adult groups need much more nutrients for their growth and intellectual development compared to child and elderly groups. The change in land use from grazing pastures to farmland increased the toxic trace element concentration levels in human hair. The significant differences in the overall concentration levels of elements in human hair among the different ethnic groups and regions can be attributed to the differences in lifestyles, cultural customs, dietary habits, and internal and external exposure routes.

Disruption of essential metal homeostasis in the brain by cadmium and high-fat diet

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Whole-life exposure to cadmium leads to elevated metal levels in the brain that further increases in high-fat diet fed mice.

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Female animals accumulate more cadmium in the brain than males, under all treatment conditions.

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Cadmium exposure is associated with changes in the levels of several essential metals.

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Cadmium and high fat diet increase levels of superoxide anion in the cortex, amygdala and hippocampus.

Analyses of human cohort data support the roles of cadmium and obesity in the development of several neurocognitive disorders. To explore the effects of cadmium exposure in the brain, mice were subjected to whole life oral cadmium exposure. There were significant increases in cadmium levels with female animals accumulating more metal than males (p < 0.001). Both genders fed a high fat diet showed significant increases in cadmium levels compared to low fat diet fed mice (p < 0.001). Cadmium and high fat diet significantly affected the levels of several essential metals, including magnesium, potassium, chromium, iron, cobalt, copper, zinc and selenium. Additionally, these treatments resulted in increased superoxide levels within the cortex, amygdala and hippocampus. These findings support a model where cadmium and high fat diet affect the levels of redox-active, essential metal homeostasis. This phenomenon may contribute to the underlying mechanism(s) responsible for the development of neurocognitive disorders.

Human Biomonitoring of Trace Elements in Scalp Hair from Healthy Population of Pakistan

The present study deals with the assessment of essential trace and toxic elements in biological samples (scalp hair) of healthy smoker and non-smoker residents of Lahore (the second most populous city), Pakistan. Human biomonitoring of various trace elements like zinc (Zn), iron (Fe), copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), lead (Pb), and arsenic (As) was evaluated in human hair samples of smokers and non-smokers (males and females) as per IFCC criteria. For the purpose of comparison, scalp hair samples of age- and sex-equivalent healthy persons were also analyzed. The results of this study show that the concentrations (P95 values) of As (0.17, 0.81, and 0.91 μg/g), Cd (2.80, 3.81, and 3.16 μg/g), Cr (4.1, 4.2, and 5.3 μg/g), Cu (20.0, 21.0, and 21.9 μg/g), Ni (3.9, 4.6, and 4.3 μg/g), Pb (4.0, 4.8, and 5.0 μg/g), and Fe (49.0, 49.0, and 59.3 μg/g) were significantly higher in scalp hair samples of smokers than in referents, for various age groups (16-32 years, 33-50 years, and 51-62 years), respectively. The concentrations of Zn (165, 163, and 173 μg/g various age groups, respectively) in similar age group were found lower in the scalp hair samples of smokers than referents. Exposure of high toxic metal level through smoking and deficiency of Zn could be synergistic with the risk factors associated with the use of tobacco. Correlation studies for the elements in cigarette with the elements in scalp hair of male smokers show a highly positive correlation between Cr-Cd, Cr-Ni, Cu-Fe, and Ni-Zn.

Metallic elements in human hair from residents in smelting districts in northeast China: Environmental factors and differences in ingestion media

The health of residents in Huludao City is affected by the emissions of heavy metals from smelting, diet and atmospheric precipitation. This study investigated the concentrations of Hg, Cd, Pb, Cu and Zn in scalp hair samples from 259 residents of different ages and genders from five districts in Huludao City and examined the main factors for heavy metal exposure. Cd and Pb concentrations in hair samples exceeded the normal concentration ranges for human hair (Cd < 0.3 mg/kg; Pb < 9.3 mg/kg), and the highest Pb concentrations were found in subjects in the age range 0-15 years. Samples from men were higher in Cd and Pb compared to those for women. Workers from the Huludao zinc plant (HZP) had higher concentrations of all metals in their hair relative to other occupations except for Cu. Geographically, the highest Cd and Pb concentrations in hair were found for residents living in Daochi district (DCD) and the Zn plant district (ZPD), respectively. In smelting regions, the effects of dust ingestion on heavy metal exposure were more important than in non-smelting regions.

Trace element levels in blood and associated factors in adults living in the metropolitan area of São Paulo, Brazil

This study evaluated blood arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), copper (Cu) and manganese (Mn) levels in a group of residents (n=374) in the metropolitan area of São Paulo (MASP) and investigated the association between trace element levels in blood and sociodemographic and lifestyle factors. Trace elements were measured in specimens by inductively coupled plasma mass spectrometry (ICP-MS). Geometric means were 3.6μg/L, 0.13μg/L, 23.9μg/L, 1.4μg/L, 999μg/L, and 12.5μg/L for As, Cd, Pb, Hg, Cu, and Mn, respectively. As, Pb and Hg levels were associated with education level. Men presented higher blood lead levels (PbB) and lower blood copper levels (CuB) than women. Fish consumption was primarily related to increased blood Hg levels (HgB). Smokers exhibited 1.8 times more blood cadmium levels (CdB) than non-smokers. Only 4% of the study samples exceeded the Pb reference values for the MASP population, and 12% had Hg levels higher than the German HBM-I value (5μg/L for adults).The study group showed slightly higher exposure to As, Hg and Mn and lower Cd than those of European and North American studies.

Occurrence and Distribution of Organophosphate Esters in Surface Soil and Street Dust from Chongqing, China: Implications for Human Exposure

In the present study, the occurrence, concentrations, and distribution of organophosphate esters (OPEs) were studied in surface soil and street dust samples collected from different sites of Chongqing, a metropolitan city in western China. Furthermore, nondietary daily intakes (DIs) of OPEs only through dust ingestion absorption were assessed between toddlers and adults. The ∑OPEs contents ranged from 10.1 to 315 ng/g dw and from 348 to 1369 ng/g dw in surface soil and street dust samples, respectively, with tris (2-butoxyethyl) phosphate (TBOEP), the predominant OPEs in surface soil, whereas tris (chloroethyl) phosphate (TCEP) occupied a relatively high proportion in street dust samples. The mobility of TCEP and tris (2-chloroisopropyl) phosphate (TCIPP) to deeper soil zones with seepage water may play a role in decreasing contents of both compounds in surface soil. Considerably different patterns of pairwise correlations of six OPEs congeners were observed between surface soil and street dust, which could largely relate to the complicated environmental process for tris (1,3-dichloroisopropyl) phosphate (TDCIPP) and TCIPP in surface soil. Analogous sources between surface soil and street dust have been identified through principal component analysis. Compared with adults, the toddlers were more vulnerable to OPEs intake, according to the estimated DI values. For both toddler and adult groups, the estimated exposure values for all OPEs were several orders of magnitude lower than the reference dose (RfD), not suggesting the potential risk to human health.