A population assessment of mercury exposure from two cities of Pakistan with respect to freshwater and marine fish consumption.

In this study, we aimed to estimate the level of mercury (Hg) in scalp hair samples of human subjects and its association with consumption of sea- and freshwater fish species. The scalp hairs were collected from both genders (male and female) aged between 15 and 50 years (n = 200), living in coastal areas of Karachi, who mostly consumed sea fish species, referred to as exposed subjects. For comparison purposes, scalp hair samples of both genders (n = 160) were collected from the inhabitants of Karachi and Hyderabad cities who consumed freshwater fish species termed as referent subjects. The frequently consumed fresh and marine fish species were also collected. The level of Hg was determined in fish and scalp hair samples by cold vapor atomic absorption spectrometry, prior to ultrasonic-assisted acid digestion in a mixture of nitric acid and hydrogen peroxide. The validity of methodology was checked by certified reference material (CRM) BCR 397 (human hair) and DORM-2. The concentrations of Hg in sea- and freshwater fish were found in the range of 1.47-2.09 and 0.402-0.676 µg/g, respectively. The exposed subjects had significantly elevated levels of Hg in scalp hair samples (1.8-4.3 µg/g) as compared to referent subjects (0.87-1.95 µg/g) (p < 0.001). A significant positive correlation was obtained between the concentration of Hg in hair and age of study population. Exposed and referent female subjects had higher levels of Hg in scalp hair than that in males of both study groups (p = 0.02-0.031).

Evaluation of calcium, magnesium, potassium, and sodium in biological samples (scalp hair, serum, blood, and urine) of Pakistani referents and arthritis patients of different age groups.

BACKGROUND: Rheumatoid Arthritis is a chronic inflammatory disease resulting in joint inflammation (particularly joints of hands, wrists, feet, knees, ankles, and shoulder) that is manifested by swelling and functional impairment. METHODS: This study was designed to compare the levels of calcium (Ca), magnesium (mg), potassium (K), and sodium (Na) in four biological samples (scalp hair, serum, blood, and urine) of patients with rheumatoid arthritis (RA) as compared to referent subjects of both genders who do have not arthritis problems. All patients and referents were divided in two age groups, (46-60) and (61-75) years. A microwave assisted wet acid digestion procedure was used for acid digestion of biological samples. The digests of all biological samples were analysed for Ca, Mg, K, and Na by flame atomic absorption spectrometry (FAAS). The proposed method was validated by using conventional wet digestion of the same sub samples and certified reference samples of hair, serum, blood, and urine. RESULTS: The results indicated significantly lower levels of Ca, Mg, and K in the biological samples (blood, serum, and scalp hair) of male and female rheumatoid arthritis patients when compared to referents of both genders, whereas the levels of Na were found to be high in blood and urine samples of patients as compared to nonrheumatic referents. CONCLUSIONS: These data represent a guide for clinicians and other professionals who will be investigating the deficiency of essential micronutrients in biological samples (scalp hair, serum, and blood) of rheumatoid arthritis patients.

Evaluation of zinc, copper and iron in biological samples (scalp hair, blood and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients.

BACKGROUND: The consequence of a deficiency in trace elements has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between low scalp hair and blood zinc, copper, and iron concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). METHODS: The study was performed on sixty two male HIV+ patients (HIV-1) from different cities in Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea and high fever). The biological samples (scalp hair, blood, and urine) were collected from AIDS patients. For comparative study, 120 healthy subjects (males) of the same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials (CRMs) and values obtained by conventional wet acid digestion method of the same CRMs. RESULTS: The results indicated significantly lower levels of Fe and Zn and high levels of Cu in the biological samples (blood and scalp hair) of male HIV-1 patients compared with control subjects. It was observed that the low levels of zinc and iron may be predictors for secondary infections in HIV-1 patients. There was a significant decrease in mean values of Fe and Zn in whole blood and scalp hair samples of three groups of AIDS patients as compared to a control healthy male group (p < 0.001). CONCLUSIONS: Deficiency of Zn and Fe might play a role in the development of AIDS in the subjects of this study.

Effects of selenium supplementation on iodine and thyroid hormone status in a selected population with goitre in Pakistan.

BACKGROUND: Selenium (Se) has an essential role in thyroid hormone metabolism. It has the potential to play a major part in the outcome of iodine (I) deficiency The aim of the present study was to evaluate the Se and I status of biological samples (serum and urine) of 160 goitrous male (GMPs) and 195 female patients (GFPs). The supplemental effects of Se (200 microg/day) and I (100 - 125 microg/day) were evaluated after 6 months. For comparison purposes, non-goitrous subjects of both genders (n = 440) with same age group and socioeconomic status were also selected. METHODS: Hydride generation atomic absorption spectrometry (HGAAS) was used to investigate the Se concentration in the biological samples, prior to microwave assisted acid digestion. Quality control for the methodology was established by comparing the results obtained with certified samples with those obtained by conventional wet acid digestion method on the same CRMs and real samples. RESULTS: The mean serum Se concentration was significantly lower, while urinary Se was higher in GMPs and GFPs as compared to control subjects (p < 0.005 and < 0.007, respectively). The levels of I, free tri-iodothyronine, and thyroxin were found in goitrous patients of both genders were low compared to age matched healthy controls (p < 0.015, < 0.006, and < 0.002, respectively). On the other hand, high levels of thyroid stimulating hormone were observed in GMPs and GFPs (p < 0.009). CONCLUSIONS: It was observed that Se in biological samples of hypothyroid patients can play an important role in determining the severity of the hypothyroidism associated with iodine deficiency. A wide-scale epidemiological study is recommended together with the examination of the potential preventive role of Se supplementation in endemic goiter regions.

Evaluation of status of calcium, magnesium, potassium, and sodium levels in biological samples in children of different age groups with normal vision and night blindness.

BACKGROUND: The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization (WHO) estimates 13.8 million children have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological sample composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. METHODS: This study was designed to compare the levels of magnesium (Mg), calcium (Ca), potassium (K), and sodium (Na) in scalp hair, serum, blood, and urine of night blindness children in two age groups, (1-5) and (6-10) years, of both genders comparing them to sex- and age-matched controls. A microwave assisted wet acid digestion procedure was developed as a sample pretreatment for the determination of Mg, Ca, K, and Na in biological samples of children with night blindness. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, serum, blood, and urine. The digests of all biological samples were analysed for Mg, Ca, K, and Na by flame atomic absorption spectrometry (FAAS) using an air/acetylene flame. RESULTS: The results indicated significantly lower levels of Mg, Ca, and K in the biological samples (blood, serum, and scalp hair) of male and female children with night blindness and higher values of Na compared with control subjects of both genders. CONCLUSIONS: These data present guidance to clinicians and other professionals investigating deficiency of essential mineral elements in biological samples (scalp hair, serum, and blood) of children with night blindness.

Evaluation of calcium, magnesium, potassium, and sodium in biological samples of Pakistani viral hepatitis (A-E) patients and controls.

BACKGROUND: The aim of the present study was to compare the level of calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) in biological samples (serum, blood, urine, and scalp hair) of patients suffering from different types of viral hepatitis (A, B, C, D, and E; n = 521) of both genders, ages ranged between 31-45 years. For comparative study, 255 age-matched subjects of both genders, residing in the same city, were selected as controls. METHOD: The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and values obtained by conventional wet acid digestion method on the same CRMs. RESULT: The results of this study showed that the mean value of Na was higher in blood, sera, and scalp hair samples of hepatitis patients, while Ca, Mg and K levels were found to be lower than age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p < 0.05). CONCLUSIONS: These results are consistent with data reported in literature, confirming that the deficiency of essential mineral elements and sodium overload can directly cause lipid peroxidation and eventually hepatic damage.

Case-control study of male cancer patients exposed to arsenic-contaminated drinking water and tobacco smoke with relation to non-exposed cancer patients.

The investigated data indicated that inorganic arsenic in drinking water is associated with increased mortality from different types of cancers. In the present study, biological samples (blood and scalp hair) of male subjects having lung and bladder cancers and non-cancerous subjects belonging to arsenic (As)-exposed area of southern parts of Pakistan were analysed for As contents. The As levels in drinking water of understudy area showed that sections of understudy population are exposed to arsenic concentrations, which was 3-15-fold higher than the permissible level (<10 µg/L). For comparative purposes the biological samples of matched male cancer patient, as referent patients belonging to big city (Hyderabad) who had used municipal treated water with low arsenic levels <10 µg/L, were also collected. The exposed cancer patients have 2-3-fold higher level of As in both biological samples compared to non-exposed case-matched cancerous male subjects. This study is compelling evidence in support of positive associations between arsenic-contaminated water, food and cigarette with different types of risks of cancer.

Levels of arsenic, cadmium, lead, manganese and zinc in biological samples of paralysed steel mill workers with related to controls.

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.

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

The effects of arsenic (As) toxicity due to frequent consumption of arsenic-contaminated fish was estimated by the analysis of scalp hair of adult males, living near arsenic-contaminated area of Pakistan. For comparison purposes, scalp hair samples were also collected from the inhabitants of Hyderabad city consuming fish species with low levels of As, collected from Indus River. Concentration of As in scalp hair samples was analyzed by using hydride generation atomic absorption spectrometry (HG AAS), after microwave-assisted acid digestion. The accuracy of the As measurement was tested simultaneously analyzing certified reference material. The concentration of As in muscle tissues of fish species were found in the range of 2.11 to 14.1 µg/g and 1.92 to 12.2 µg/g, collected from arsenic-contaminated and noncontaminated areas, respectively. Exposed subjects had significantly elevated levels of As in scalp hair samples (0.72-4.94 µg/g) as compared with referent subjects (0.21-1.484 µg/g; p < 0.01). The As levels in scalp hair was positively correlated with As levels in fish.

Evaluation of zinc in scalp hair and blood samples of tuberculosis and diarrhea male human immunodeficiency virus patients.

BACKGROUND: The consequence of zinc (Zn) deficiency has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. METHODS: This study examined the association between low scalp hair and blood Zn concentrations and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on sixty two male HIV+ patients (HIV-1) from different cities in Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, and high fever). The biological samples (scalp hair and blood) were collected from AIDS patients, and for comparative study, 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. RESULTS: The Zn in biological samples was determined by flame atomic absorption spectrometry prior to microwave assisted acid digestion. The proposed method was validated by a certified sample of human hair BCR 397 and Clincheck control-lyophilized human whole blood. It was observed that the low levels of Zn may be predictors for secondary infections in HIV-1 patients. There was a significant decrease in mean values of Zn in whole blood and scalp hair samples in both groups of AIDS patients as compared to a controlled healthy male group (p < 0.001). CONCLUSIONS: Deficiency of zinc might play a role in the development of AIDS in the subjects of this study.

Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant.

The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V(5+) species from soil, vegetable and grass samples using Na(2)CO(3) in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V(5+) and V(4+) determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 µg/g in test and control soil samples, respectively. The contents of V(5+) and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 µg/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P<0.01). Statistical evaluations indicate that the sum of concentrations of V(5+) and V(4+) species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence.

Determination of arsenic in scalp hair samples from exposed subjects using microwave-assisted digestion with and without enrichment based on cloud point extraction by electrothermal atomic absorption spectrometry.

A simple and rapid cloud point extraction (CPE) procedure was applied for preconcentration of trace quantities of arsenic (As) in scalp hair samples. The samples were subjected to microwave-assisted digestion in a mixture of nitric acid and hydrogen peroxide (2 + 1, v/v) prior to preconcentration by CPE. The As in digested samples was complexed with ammonium pyrrolidine dithiocarbamate (APDC), and the resultant As-PDC complex was extracted by a nonionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114). After centrifugation, the surfactant-rich phase was diluted with 0.1 M HNO3 in methanol and analyzed by electrothermal atomic absorption spectrometry. The experimental parameters, i.e., amount of APDC, concentration of Triton X-114, equilibrium temperature and time, were optimized. For validation of the proposed method, a certified reference material (CRM) of human hair (BCR 397) was used. No significant difference (P > 0.05) was observed between the experimental results and certified values of the CRM (paired t-test). The LOD and LOQ obtained under the optimal conditions were 0.025 and 0.083 microg/kg, respectively. The developed method was applied for the determination of As in scalp hair samples from male and female subjects of two villages of Khairpur Mir's, Pakistan.

Comparative study of liver cancer patients in arsenic exposed and non-exposed areas of Pakistan.

The investigated data shows that arsenic (As) in drinking water is associated with increased mortality from different types of cancers including liver cancer. In this study, blood and scalp hair samples of male liver cancer patients and healthy referents belonging to As exposed areas of Sindh Pakistan were analyzed for As contents. The As levels in drinking water of understudy area showed that sections of this population was exposed to 3-15-folds higher concentrations of As than permissible limit. For comparative purposes, blood and scalp hair samples of matched cancerous patient as referent patients belonging to big city (Hyderabad) who have used municipal treated water with low As levels <10 µg/L were also collected. The results of this study showed that the average As concentration was higher in the blood and scalp hair of exposed and non-exposed referent cancer patients as compared to referents (p < 001). The exposed cancerous patients have twofolds higher As level in both biological samples as related to non-exposed case matched cancerous male subjects.

Distribution of copper, iron, and zinc in biological samples (scalp hair, serum, blood, and urine) of Pakistani viral hepatitis (A-E) patients and controls.

The aim of the present study was to compare the level of copper (Cu), iron (Fe) and zinc (Zn) in biological samples (serum, blood, urine, and scalp hair) of patients suffering from different viral hepatitis (A, B, C, D, and E; n = 521) of both gender age ranged 31-45 years. For comparative study, 255 age-matched control subjects, of both genders residing in the same city were selected as referents. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cu and Fe were higher in blood, sera, and scalp hair samples of hepatitis patients, while Zn level was found to be lower than age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p < 0.05). These results are consistent with literature-reported data, confirming that the deficiency of zinc and hepatic iron and copper overload can directly cause lipid peroxidation and eventually hepatic damage.

Chromium and manganese levels in biological samples of normal and night blindness children of age groups (3-7) and (8-12) years.

This study was designed to compare the levels of chromium (Cr) and manganese (Mn) in scalp hair, blood, and urine of night blindness in children age ranged (3-7) and (8-12) years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure, was developed as a sample pretreatment, for the determination of Cr and Mn in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood and urine. The digests of all biological samples were analyzed for Cr and Mn by electrothermal atomic absorption spectrometry. The results indicated significantly higher levels of Cr, whilst low level of Mn in the biological samples (blood and scalp hair) of male and female night blindness children, compared with control subjects of both genders. These data present guidance to clinicians and other professional investigating deficiency of Mn and excessive level of Cr in biological samples (scalp hair and blood) of night blindness children.

Evaluation of essential trace and toxic elements in biological samples of normal and night blindness children of age groups 3-7 and 8-12 years.

The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization estimates 13.8 million children to have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial, and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological samples composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of Zn, Mg, Ca, K, Na, As, Cd, and Pb in scalp hair, blood, and urine of night blindness children age ranged 3-7 and 8-12 years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment, for the determination of As, Ca, Cd, K, Pb, Mg, Na, and Zn in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The results of this study showed that the mean values of As, Cd, Na, and Pb were significantly higher in scalp hair, blood, and urine samples of male and female night blindness children than in referents (p < 0.001), whereas the concentrations of Zn, Ca, K, and Mg were lower in the scalp hair and blood but higher in the urine samples of night blindness children. These data present guidance to clinicians and other professional investigating deficiency of essential mineral elements in biological samples (scalp hair and blood) of night blindness children.

Status of toxic metals in biological samples of diabetic mothers and their neonates.

The mechanism of transport of trace elements from the mother to the newborn is still not well known. The aim of present study was to compare the status of trace toxic elements, arsenic (As), cadmium (Cd), and lead (Pb) in biological samples (whole blood, urine and scalp hair) of insulin-dependent diabetic mothers (age ranged 30-40) and their newly born infants (n = 76). An age and socioeconomics matched 68 nondiabetic mothers and their infants, residing in the same locality, who were selected as referents. The elemental concentrations in all three biological samples were determined by an electrothermal atomic absorption spectrometer, prior to microwave-assisted acid digestion. The mean values of As, Cd, and Pb in all biological samples of diabetic mothers and their infants were significantly higher as compared to the referent mother-infant pair samples (p < 0.01). The high levels of As, Cd, and Pb in biological samples of diabetic women may play a role in the pathogenesis of diabetes mellitus and impacts on their neonates.

Interactions between cadmium and zinc in the biological samples of Pakistani smokers and nonsmokers cardiovascular disease patients.

The pathogenesis of some cardiovascular diseases (CVDs) has been altered with changes in the balance of certain trace and toxic elements. The aim of the present study was to assess the role of zinc (Zn) and cadmium (Cd) in smoker and nonsmoker male CVD patients (n = 457) of two age groups (31-45) and (46-60). The both elements were determined in biological samples (scalp hair, blood, and urine) of CVD patients and healthy referents for comparison purpose. The concentrations of Zn and Cd were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. It was observed that the mean values of Cd were significantly higher in the biological samples of smokers CVD as compared to nonsmoker CVD patients, while the level of Zn was lower in both smoker and nonsmoker patients. The concentrations of Zn in whole blood and scalp hair samples were lower in CVD patients as compared to referents (p > 0.001). Results showed significant changes of levels of Cd and Zn in blood and scalp hair samples of CVD patients when compared with healthy referents, while reverse in the case of urine samples. It was observed that low Zn levels were associated with both smoker and nonsmoker CVD patients, while increased cadmium accumulation was observed in smoker patients as compared to nonsmoker patients (p > 0.025).

Evaluation of status of trace and toxic metals in biological samples (scalp hair, blood, and urine) of normal and anemic children of two age groups.

Anemia affects a substantial portion of the world's population, provoking severe health problems as well as important economic losses to the region in which this condition is found. This study was designed to compare the levels of essential trace and toxic elements in scalp hair, blood, and urine samples of anemic children (n = 132) with age range 1-5 and 6-10 years of both genders. For a comparative study, 134 non-anemic age- and sex-matched children as control subjects, residing in the same city, were selected. The metals in the biological samples were measured by flame atomic absorption spectrophotometry/electrothermal atomic absorption spectrometry prior to microwave-assisted acid digestion. The proposed method was validated using certified reference samples of hair, blood, and urine. The results indicated significantly lower levels of iron, copper, and zinc in the biological samples as compared to the control children of both genders (p = 0.01-0.008). The mean values of lead and cadmium were significantly high in all three biological samples of anemic children as compared to non-anemic children of both age groups (p = 0.005-0.001). The ratios of essential metal to toxic metals in the biological samples of anemic children of both age groups were significantly lower than that of controls. Deficiency of essential trace metals and high level of toxic metals may play a role in the development of anemia in the subjects under study.

Association of environmental toxic elements in biological samples of myocardial infarction patients at different stages.

The exposure of toxic elements may directly or indirectly associate with different pathogenesis of heart diseases. In the present study, the association of arsenic (As), cadmium (Cd), cobalt (Co), lead (Pb), and nickel (Ni) in biological samples (whole blood and urine) and mortality from myocardial infarction (MI) patients at first, second, and third heart attacks was carried out. Both biological samples of 130 MI patients (77 male and 53 female), with ages ranging from 45 to 60 years, and 61 healthy persons (33 male and 28 female) of the same age group were collected. The elements in biological samples were assessed by electrothermal atomic absorption spectrophotometer, prior to microwave-assisted acid digestion. The validity of methodology was checked by the biological certified reference materials. During this study, 78% of 32 patients aged above 50 years, registered after third MI attack, died. In these subjects, the levels of As, Cd, Co, Ni, and Pb in blood samples were higher in MI patients as compared with referents (p < 0.05), while increased by 11.7%, 12.2%, 5.55%, and 7.2%, respectively, in the blood samples of those patients who tolerated the third MI attack (p = 0.12). The high level of understudied toxic elements may play a role in the mortality of MI patients.