Assessing Heavy Metal Burden Among Cigarette Smokers and Non-smoking Individuals in Iran: Cluster Analysis and Principal Component Analysis

Heavy metal impacts on antioxidants in cow blood from wastewater-irrigated areas

The aim of the present research was to investigate the presence of heavy metals such as lead (Pb), copper (Cu), chromium (Cr), and cadmium (Cd) in blood samples from cows raised with irrigated wastewater, as well as in the wastewater itself, in the North-western region of Pakistan. A total of 60 blood samples were collected from five different locations in Kohat, namely Tappi Road (TR), Pindi Road (PR), Gul Malik Road (GMR), Markaz Road (MR), and a control group. The samples of both i.e. cow blood and wastewater were analyzed for the concentrations of heavy metals. The highest concentration of Cd was detected in the MR site with a mean value of 0.03 mg/L, and the highest concentration of Cu (0.04 mg/L) was recorded in the TR site, while the lowest level was found in the control group with a mean of 0.002 mg/L in blood samples. The highest Cr and Pb concentrations were found at the PR site, with mean values of 0.03 and 0.07 mg/L, respectively, whereas the control group had the lowest concentrations, with mean values of 0.002 and 0.01 mg/L. Similarly, heavy metal concentrations were analyzed in wastewater used for irrigation in the study area. Results indicated elevated concentrations of Cu and Cr in wastewater, although they remained below the World Health Organization (WHO) recommended values except for Cr (0.13 mg/L) in the GMR site, which exceeded permissible limits. Cd and Pb concentrations in wastewater were relatively low, but Cd concentration surpassed WHO limits, particularly with a mean concentration of 0.08 mg/L in the TR site. Comparison between heavy metal concentrations in blood and wastewater revealed higher values of Cd and Pb in blood samples than in wastewater, while Cu and Cr concentrations were higher in water compared to blood. Additionally, elevated levels of Super Oxide Dismutase (SOD), antioxidant enzyme Catalase (CAT), and oxidative stress marker malondialdehyde (MDA) were detected in blood samples. Cluster and principal component analyses were employed to assess heavy metal toxicity among the groups, indicating potential long-term adverse health effects on animals, transfer to humans, and toxicity in living organisms.

Trace Element Concentrations in Autopsied Heart Tissues from Patients with Secondary Cardiomyopathy

Cardiomyopathies (CMP) represent a significant health problem as they have a poor long-term prognosis and often require transplantation. Heavy metals are known to have cardiotoxic effects and some of them, such as cadmium (Cd), are found to be elevated in the urine and blood of individuals with heart diseases; nevertheless, direct measurement of metals (e.g. zinc (Zn) which is necessary for normal heart function), in the myocardium of individuals with CMP has not been performed. Here, we aimed to analyze the levels of a group of metals in the myocardium of the left ventricle in individuals with CMP. At the Institute of Pathology, we collected 52 samples of left ventricle post-mortem, out of which 19 subjects had been diagnosed with CMP (mean age: 72 y ± 10), and 33 subjects had not suffered from any heart disease (mean age: 67 y ± 15). We found out that individuals with CMP had a significantly higher concentrations of lead, nickel, manganese and copper than non-CMP subjects (p = 0.002, p < 0.001, p = 0.011, and p = 0.002). Interestingly, zinc was significantly lower in CMP subjects than in n-CMP individuals (p = 0.017). Our results indicated the involvement of an increased lead, nickel, copper and manganese heart load in individuals with CMP coupled with lower concentrations of zinc.

Association of environmental tobacco smoke (ETS) with lead and cadmium concentrations in biological samples of children and women: systematic review and meta-analysis

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.

Comparison of Heavy Metals in Urine Samples of Smoker and Non-smoker Persons

In this study, the concentrations of heavy metals such as cadmium (Cd), chromium (Cr), and lead (Pb) in the two groups of cigarette smokers and non-smokers in five age range groups were measured. Heavy metal concentrations were collected in participants' urine samples and analyzed using atomic absorption spectrophotometry (AAS). The results showed that the concentrations of these metals in the urine of smokers were higher than in non-smoker subjects. The mean concentration of Cd, Cr, and Pb for smokers were 1.188 ± 0.931, 1.929 ± 0.940, and 0.069 ± 0.023, respectively, while the mean concentration of Cd, Cr, and Pb for non-smokers were 0.151 ± 0.165, 0.203 ± 0.218, and 0.037 ± 0.030, respectively. The results revealed statistically significant differences when comparing the samples of smokers to the control group in all heavy metals in the present study. Also, the results revealed statistically significant differences in Cd, Cr, and Pb when comparing the samples of smokers to age groups. The trend of metals in urine samples in two groups (smokers and non-smokers) is as follows: Cd > Cr > Pb. The concentration of Cd, Cr, and Pb in all samples of the present study was higher than the biological limit, according to ACGIH. Therefore, Cd, Cr, and Pb were the most critical metals accumulated in the urine of cigarette smokers.

Associations of five blood heavy metals with hepatitis B virus infection and immunity in adults: a cross-sectional study

BACKGROUND

Heavy metal pollution has emerged as a significant concern for human health, prompting increased awareness of its potential adverse effects. While previous research has established a connection between heavy metals and liver function biomarkers, the specific relationship between heavy metals and HBV infection remains unexplored. This cross-sectional study aims to investigate the potential correlations between five blood heavy metals - lead, cadmium, mercury, manganese, and selenium - and the presence of HBsAg, HBsAb, and HBcAb in adults.

METHODS

The study utilized data from NHANES 2007-2018. Participants were classified into four groups based on their infectious status, and the association between heavy metals and HBV infection was analyzed using multiple logistic regression and stratification analysis.

RESULTS

A total of 8431 participants were included, with 5 436 classified as Susceptible, 1 765 as Vaccinated, 865 as Natural Infection, and 103 as Acute/Chronic HBV Infection. The Vaccinated group exhibited a lower mean age (34.52 ± 14.16 years) compared to the other groups. Statistically significant differences in heavy metal concentrations (except selenium) were observed among the groups (P < 0.001). After adjusting for covariates, lead was significantly associated with HBV infection (Q2: OR 2.37, 95%CI 1.04-5.39; Q3: OR 2.34, 95%CI 1.01-5.40), and positive trends were observed for high blood concentrations of mercury (Q4: OR 3.03, 95%CI 1.31-7.04) and manganese (Q4: OR 2.52, 95%CI 1.20-5.28). Furtherly, the presence of lead reduced the protection of HBsAb (Q2: OR 0.84, 95%CI 0.73-0.97; Q3: OR 0.77, 95%CI 0.66-0.90; Q4: OR 0.83, 95%CI 0.70-0.98). Subgroup analysis indicated that cadmium was associated with an increased risk of HBV infection in Asians (OR 1.36, 95%CI 1.03-1.78) and individuals with a BMI range of 25 to 30 (OR 1.60, 95%CI 1.17-2.18).

CONCLUSIONS

The study's findings suggest a correlation between elevated blood Pb concentrations and reduced immunization rates against hepatitis B. Individuals with a positive HBsAg exhibit lower blood Se concentrations and higher blood Hg and Mn concentrations.

Cadmium as an ovarian toxicant: A review

Cadmium (Cd) is a ubiquitous heavy metal toxicant with no biological function in the human body. Considerably, because of its long biological half-life and very low excretion rate, Cd is inclined to accumulate and cause deleterious effects on various body organs (e.g., liver, kidney, and ovary) in humans and animals. Ovaries are the most vulnerable targets of Cd toxicity. Cd has been shown to induce oxidative stress, follicular atresia, hormonal imbalance, and impairment of oocyte growth and development. Moreover, Cd toxicity has been associated with increasing incidences of menstrual disorders, pregnancy loss, preterm births, delayed puberty, and female infertility. Therefore, it is crucial to understand how Cd poisoning impacts specific ovarian processes for the development of preventive interventions to enhance female fertility. The current review attempts to collate the recent findings on Cd-induced oxidative stress, follicular apoptosis, steroid synthesis inhibition, and teratogenic toxicity, along with their possible mechanisms in the ovarian tissue of different animal species. Additionally, the review also summarizes the studies related to the use of many antioxidants, medicinal herbs, and other compounds as remedial approaches for managing Cd-induced ovarian toxicity.

A review on the potential risks and mechanisms of heavy metal exposure to Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease that affects patients as well as the health and economic stability of society as a whole. At the same time, heavy metal pollution is widely recognized as having a possible impact on the environment and human health. Therefore, these diseases have become important global public health issues. In recent years, researchers have shown great interest in the potential association between heavy metal exposure and the development of COPD, and there has been a substantial increase in the number of related studies. However, we still face the challenge of developing a comprehensive and integrated understanding of this complex association. Therefore, this review aimed to evaluate the existing epidemiological studies to clarify the association between heavy metal exposure and COPD. In addition, we will discuss the biological mechanisms between the two to better understand the multiple molecular pathways and possible mechanisms of action involved, and provide additional insights for the subsequent identification of potential strategies to prevent and control the effects of heavy metal exposure on the development of COPD in individuals and populations.

Selenium and zinc alleviate quaternary metal mixture -induced neurotoxicity in rats by inhibiting oxidative damage and modulating the expressions of NF-kB and Nrf2/Hmox-1 pathway

Background

This study evaluated the potential protective effects of Zn and Se in the cerebellum and cerebral cortex, two fundamentally important brain regions, in albino rats that were exposed to heavy metals mixture (Al, Pb, Hg and Mn).

Methods

Animals were divided into five groups of seven animals per group with following patterns of exposure, controls group 1 were orally treated with deionized water for 60 days; group 2 was exposed to heavy metal mixture (HMM) with following concentrations (20 mg·kg^-1 of Pb body weight; 0.40 mg·kg^-1 of Hg; 0.56 mg·kg^-1 of Mn; and 35 mg·kg^-1; of Al), while groups 3,4 and 5 were exposed to HMM and orally co-treated with zinc chloride (ZnCl₂; 0.80 mg/kg), sodium selenite (Na₂SeO₃;1.50 mg/kg) and zinc chloride plus sodium selenite (ZnCl_0.2 + Na₂SeO₃) respectively.

Results

Exposure to HMM depressed cellular antioxidant apparatus, induced generation of lipid peroxidation markers (Malondialdehyde and NO), downregulated expression of transcription factors (Nrf2, and NF-kB) and upregulated Caspase 3 levels. HMM potentiated acetylcholinesterase activity and induced moderate histopathological alterations. Nevertheless, Zn, Se and in particular Zn + Se had recovering effects on all mentioned hazardous effects produced by HMM exposure in the cerebral cortex and cerebellum.

Conclusions

Selenium and zinc exert neuroprotection via Nrf2/NF-kB signaling pathways against quaternary heavy metal mixture-induced impairments in albino Sprague Dawley rats.

Exposure of environmental trace elements in prostate cancer patients: A multiple metal analysis

Prostate cancer (PCa) is the second leading cause of cancer-related deaths among men. To elucidate the connection between trace elements (arsenic: As, cadmium: Cd, lead: Pb, chromium: Cr, and nickel: Ni) and the risk of PCa, we analyzed trace element levels in the serum, urine, and tissues of PCa patients, while also examining their smoking status. We correlated these levels with their smoking habits. Notably, levels of Cd (P ≤ 0.05) and As (P ≤ 0.01) were significantly higher in the tumor tissue than in adjacent tissues. No significant differences were observed in the levels of Pb, Cr and Ni. Additionally, urinary Cd levels in 70% and arsenic levels in 2.3% of the PCa cohort were markedly higher than the CDC-reported cutoff (Cd ≤ 0.185 μg/L & As ≤100 μg/L). None displayed elevated levels of urinary Pb, Cr, and Ni. Conversely, in serum samples, the concentration of arsenic exceeded the CDC-determined limit (As ≤1.0 μg/L) in 31.69% of PCa patients. However, only 7.04% of patients had higher serum Cd levels than the CDC standard values (Cd ≤ 0.315 μg/L), while all PCa patients exceeded the Cr CDC limit (Cr ≤ 0.16 μg/L) and the Ni CDC limit (Ni ≤ 0.2 μg/L). On the contrary, no significant differences were observed in serum Pb (Pb ≤ 35.0 μg/L). Our findings establish a positive link between Cd and arsenic tissue concentrations and the risk of PCa. Subsequent studies are essential to determine whether elevated trace element levels pose a risk for the development of prostate carcinogenesis. Interestingly, among the PCa cohort comprising smokers, notably higher Cd levels were observed only in tumor tissues (P ≤ 0.01) and urine (P ≤ 0.05) compared to other elements or in other specimens.

Exploring the association of metal mixture in blood to the kidney function and tumor necrosis factor alpha using machine learning methods

This research aimed to approach relationships between metal mixture in blood and kidney function, tumor necrosis factor alpha (TNF-α) by machine learning. Metals levels were measured by Inductively Couple Plasma Mass Spectrometry in blood from 421 participants. We applied K Nearest Neighbor (KNN), Naive Bayes classifier (NB), Support Vector Machines (SVM), random forest (RF), Gradient Boosting Decision Tree (GBDT), Categorical boosting (CatBoost), eXtreme Gradient Boosting (XGBoost), Whale Optimization-based XGBoost (WXGBoost) to identify the effect of plasma metals, TNF-α, and estimated glomerular filtration rate (eGFR by CKD-EPI equation). We conducted not only toxic metals, lead (Pb), arsenic (As), cadmium (Cd) but also included trace essential metals, selenium (Se), copper (Cu), zinc (Zn), cobalt (Co), to predict the interaction of TNF-α, TNF-α/white blood count, and eGFR. The high average TNF-α level group was observed among subjects with higher Pb, As, Cd, Cu, and Zn levels in blood. No associations were shown between the low and high TNF-α level group in blood Se and Co levels. Those with lower eGFR group had high Pb, As, Cd, Co, Cu, and Zn levels. The crucial predictor of TNF-α level in metals was blood Pb, and then Cd, As, Cu, Se, Zn and Co. The machine learning revealed that As was the major role among predictors of eGFR after feature selection. The levels of kidney function and TNF-α were modified by co-exposure metals. We were able to acquire highest accuracy of over 85% in the multi-metals exposure model. The higher Pb and Zn levels had strongest interaction with declined eGFR. In addition, As and Cd had synergistic with prediction model of TNF-α. We explored the potential of machine learning approaches for predicting health outcomes with multi-metal exposure. XGBoost model added SHAP could give an explicit explanation of individualized and precision risk prediction and insight of the interaction of key features in the multi-metal exposure.

Non-Uniform Bioaccumulation of Lead and Arsenic in Two Remote Regions of the Human Heart's Left Ventricle: A Post-Mortem Study

The extent of heavy-metal-induced cardiotoxicity is proportional to the levels of metal bioaccumulation, and it was previously assumed that heavy metals accumulate uniformly in the myocardium. Therefore, the aim of this study was to investigate concentrations of metals and metalloids in two distant regions of the left ventricle (LV), the base of the LV, and apex of the LV using inductively coupled plasma mass spectrometry (ICP-MS). We also examined the potential correlation between metal levels and the thickness of the interventricular septum in twenty LV specimens (ten from the base of LV and ten from the apex of LV) from 10 individuals (mean age 75 ± 6 years). We found significantly higher concentrations of arsenic and lead in the LV apex compared to the base of the LV. We also found a positive correlation between the concentrations of arsenic in the myocardium of LV and the thickness of the interventricular septum. Our results indicate that arsenic and lead accumulate to a higher extent in the apex of the LV compared to the base of the LV. Therefore, future studies designed to measure levels of metals in heart muscle should consider non-uniform accumulation of metals in the myocardium.

Current Levels of Environmental Exposure to Cadmium in Industrialized Countries as a Risk Factor for Kidney Damage in the General Population: A Comprehensive Review of Available Data

The growing number of reports indicating unfavorable outcomes for human health upon environmental exposure to cadmium (Cd) have focused attention on the threat to the general population posed by this heavy metal. The kidney is a target organ during chronic Cd intoxication. The aim of this article was to critically review the available literature on the impact of the current levels of environmental exposure to this xenobiotic in industrialized countries on the kidney, and to evaluate the associated risk of organ damage, including chronic kidney disease (CKD). Based on a comprehensive review of the available data, we recognized that the observed adverse effect levels (NOAELs) of Cd concentration in the blood and urine for clinically relevant kidney damage (glomerular dysfunction) are 0.18 μg/L and 0.27 μg/g creatinine, respectively, whereas the lowest observed adverse effect levels (LOAELs) are >0.18 μg/L and >0.27 μg/g creatinine, respectively, which are within the lower range of concentrations noted in inhabitants of industrialized countries. In conclusion, the current levels of environmental exposure to Cd may increase the risk of clinically relevant kidney damage, resulting in, or at least contributing to, the development of CKD.

Effect of Arsenic Exposure and Cigarette Smoking on Total and Cause-Specific Mortality: An Occupational Cohort With 27 Follow-up Years

BACKGROUND

The relationship between arsenic exposure and all-cause mortality and the joint effects of arsenic exposure and smoking have been poorly described in previous studies.

METHODS

After 27 years of follow-up, a total of 1738 miners were included in the analysis. Different statistical methods were used to explore the relationship between arsenic exposure and smoking and the risk of all-cause mortality and various causes of death.

RESULTS

A total of 694 deaths occurred during the 36,199.79 person-years of follow-up. Cancer was the leading cause of death, and arsenic-exposed workers had significantly higher mortality rates for all-cause, cancer, and cerebrovascular disease. All-cause, cancer, cerebrovascular disease, and respiratory disease increased with cumulative arsenic exposure.

CONCLUSIONS

We demonstrated the negative effects of smoking and arsenic exposure on all-cause mortality. More effective actions should be taken to reduce arsenic exposure in miners.

The association between blood manganese and liver stiffness in participants with chronic obstructive pulmonary disease: a cross-sectional study from NHANES 2017-2018

BACKGROUND

To explore the relationship between blood manganese and liver stiffness in the United States among participants with chronic obstructive pulmonary disease (COPD).

METHODS

All data were obtained from the 2017-2018 National Health and Nutrition Examination Survey database (NHANES). A total of 4690 participants were included in the study. All participants included complete information on COPD, liver stiffness, and blood manganese. Liver stiffness (kPa) was measured from "Examination Date" and blood manganese (ug/L) was obtained from "Laboratory Data". A multiple linear regression model was used to assess the correlation between blood manganese and liver stiffness.

RESULTS

Among the 4690 participants, blood manganese was lower in the COPD group but liver stiffness was higher (p < 0.05). There was a positive correlation between blood manganese and liver stiffness (β = 0.08, 95% CI 0.03, 0.12). This positive association was more pronounced in COPD participants (β = 0.25, 95% CI 0.08, 0.42) and there was a non-linear relationship, which was more significant when blood manganese exceeded 14.43 ug/L (β = 1.76, 95% CI 1.10, 2.41).

CONCLUSIONS

The association between blood manganese and liver stiffness was positive, which was more apparent in COPD patients.

Zinc in Prostate Health and Disease: A Mini Review

Introduction-With the high global prevalence of prostate cancer and associated mortalities, it is important to enhance current clinical practices for better prostate cancer outcomes. The current review is towards understanding the value of Zn towards this mission. Method-General information on Zn in biology and multiple aspects of Zn involvement in prostate health and disease were referred to in PubMed. Results-The most influential feature of Zn towards prostate health is its ability to retain sufficient citrate levels for a healthy prostate. Zn deficiencies were recorded in serum, hair, and prostate tissue of men with prostate cancer compared to non-cancer controls. Zn gut absorption, albumin binding, and storage compete with various factors. There are multiple associations of Zn cellular influx and efflux transporters, Zn finger proteins, matrix metalloproteinases, and Zn signaling with prostate cancer outcomes. Such Zn marker variations associated with prostate cancer recorded from biological matrices may improve algorithms for prostate cancer screening, prognosis, and management when coupled with standard clinical practices. Discussion-The influence of Zn in prostatic health and disease is multidimensional, therefore more personalized Zn requirements may be beneficial. Several opportunities exist to utilize and improve understanding of Zn associations with prostate health and disease.

Examining of Heavy Metal Concentrations in Hookah Smokers

Hookah smoking has been spreading around the world, especially among young adults. The current study aimed to investigate the concentration of heavy metals and elements and clinical symptoms in hookah users in comparison with non-users. To the best of our knowledge, the present study represents the first scientific contribution indicating levels of several heavy metals and elements in urine and blood in hookah users and non-users as well as evaluating clinical symptoms. This research was implemented in Iran among 100 males divided into two groups (50/group): control and hookah users. Heavy metal contamination (lead, cadmium, arsenic, thallium, zinc, and copper) in blood and urine samples was assayed by graphite furnace atomic absorption spectrometry (GFAAS). Duration of hookah use was 7.06 ± 4.57 years. The mean ± SD of lead, arsenic, and thallium concentrations was 3.77 ± 2.22, 8.50 ± 4.34, and 4.22 ± 2.69 μg/L. The mean levels of blood for lead, arsenic, and urinary thallium in hookah users are significantly higher than the control group (p < 0.05). The most frequent clinical symptoms in hookah smokers were constipation and fatigue. Findings from this study might guide the development of policies to regulate hookah smoking and prevent adverse health effects associated with hookah smoking.

Passive Smoking Is Associated with Multiple Heavy Metal Concentrations among Housewives in Shanxi Province, China

Background: Passive smoking may increase the content of heavy metals in housewives. However, this association remains a subject of debate. Female passive smoking is widespread, particularly in Chinese rural areas. Objective: This study aimed to assess the association between heavy metal accumulation and passive smoking status among rural housewives. Methods: 405 women were recruited in Shanxi Province of Northern China, and 384 (94.8%, 384/405) participants were included in the final study, of whom 117 women were exposed to passive smoking. The information on their basic characteristics was collected via a structured questionnaire. We used inductively coupled plasma mass spectrometry (ICP-MS) to analyze the concentrations of nine heavy metals, including cadmium (Cd), germanium (Ge), arsenic (As), lead (Pb), titanium (Ti), copper (Cu), iron (Fe), cobalt (Co), and chromium (Cr), in hair samples. Results: The results indicated that higher As, Ge, Ti, and Fe concentrations were significantly associated with passive smoking. After adjusting for potential confounders, the adjusted odds ratios and the 95% confidence intervals of As, Ge, Ti, and Fe were (1.80 (1.13–2.90),p = 0.028), (1.78 (1.14–2.80), p = 0.007), (1.70 (1.09–2.67), p = 0.019), and (1.67 (1.07–2.63), p = 0.035), respectively. The statistically significant linear trend of the adjusted odds ratios at different levels further supported their association. Conclusion: Our research concluded that exposure to environmental tobacco smoke might contribute to As, Ge, Ti, and Fe accumulation among housewives.

Spatial distribution and source apportionment of heavy metal(loid)s in urban topsoil in Mianyang, Southwest China

Spatial distributions and sources of some commonly concerned heavy metal(loid)s (HMs, As, Ba, Cr, Co, Cu, Ni, Pb, Mn, Zn, and V) in topsoil of Mianyang city, a typical medium-sized emerging industrial city in Southwest China, were determined to explore the influences of anthropogenic activities on the urban environment. The contents of the 10 HMs in 101 topsoil samples were analyzed using an X-ray fluorescence spectrometer, and their sources were analyzed by positive matrix factorization and statistical analysis. The spatial distributions of the HMs and the source contributions were mapped using GIS technology. The results showed that the mean contents of Ba, Cr, Cu, and Zn in the topsoil were significantly higher than their background values. Industrial activities resulted in high contents of Ba, Zn, Cu, and Cr. As, Co, Ni, and V that primarily came from natural sources; Pb, Cr, Cu, and Zn were chiefly derived from a mixed source of industry and traffic; and Ba and Mn primarily originated from industrial sources. Natural sources, mixed sources, and industrial sources contributed 32.6%, 34.4%, and 33.0% of the total HM contents, respectively. Industrial sources and mixed sources of industry and traffic were the main anthropogenic sources of HMs in the urban topsoil and should be the focus of pollution control.

Smoking is associated with altered serum and hair essential metal and metalloid levels in women

The objective of the study was to evaluate the association between smoking and essential metal (Co, Cr, Cu, Fe, Mn, V, Zn) and metalloid (Se) levels in hair and serum of adult women using inductively coupled plasma-mass spectrometry (ICP-MS). In this cross-sectional study, a total of 344 women 20-70 years old including 199 smokers and 145 non-smoking women were enrolled. Serum Cu, Fe, and Zn levels in smoking women were found to be 6%, 8%, and 3% lower of levels in non-smokers, respectively. In contrast, circulating Mn, V, and especially Cr concentrations in smoking women exceeded the respective values in non-smoking women by 5%, 14%, and 54%. Hair Fe and Se levels in smoking women were 17% and 23% lower as compared to non-smoking controls, respectively. In multiple regression models, smoking severity was inversely associated with serum and hair Se concentrations, whereas the relationship to serum and hair Cr was positive. In addition, serum Zn and hair Fe levels were found to be inversely associated with the number of cigarettes per day. These findings hypothesize that health hazards of smoking may be at least in part be mediated by alteration in essential metal and metalloid metabolism.