Reversible Diels-Alder and Michael Addition Reactions Enable the Facile Postsynthetic Modification of Metal-Organic Frameworks.

Functionalization of metal-organic frameworks (MOFs) is critical in exploring their structural and chemical diversity for numerous potential applications. Herein, we report multiple approaches for the tandem postsynthetic modification (PSM) of various MOFs derived from Zr(IV), Al(III), and Zn(II). Our current work is based on our efforts to develop a wide range of MOF platforms with a dynamic functional nature that can be chemically switched via thermally triggered reversible Diels-Alder (DA) and hetero-Diels-Alder (HDA) ligations. Furan-tagged MOFs (furan-UiO-66-Zr) were conjugated with maleimide groups bearing dienophiles to prepare MOFs with a chemically switchable nature. As HDA pairs, phosphoryl dithioester-based moieties and cyclopentadiene (Cp)-grafted MOF (Cp-MIL-53-Al) were utilized to demonstrate the cleavage and rebonding of the linkages as a function of temperature. In addition to these strategies, the Michael addition reaction was also applied for the tandem PSM of IRMOF-3-Zn. Maleimide groups were postsynthetically introduced in the MOF lattice, which were further ligated with cysteine-based biomolecules via the thiol-maleimide Michael addition reaction. On the basis of the versatility of the herein presented chemistry, we expect that these approaches will help in designing a variety of sophisticated functional MOF materials addressing diverse applications.

Zn2+ and Cd2+ assisted photo-catalytic degradation of chlorpyrifos in soil.

The Cd2+ and Zn2+ assisted photo-catalytic degradation of soil incorporated chlorpyrifos (CLP) was reported in current study. The soil samples fortified with CLP and metals were irradiated in photo-reactor for different time intervals to check maximum degradation. Soil samples extracted with acetonitrile were analyzed by HPLC. The results of the study revealed a complete mineralization of insecticide from soil that followed first-order Langmuir-Hinshelwood (L-H) kinetic model. The CLP degradation rate in soil was higher in photoreactor than control with variation in half-life from 41 days to 20 days. The degradation of CLP in photoreactor was 5 fold augmented after Zn2+ fortification of soil while Cd2+ had negligible effect on CLP photodegradation. Thus Zn2+ fortification of soil will not only replenish the important nutrient for plant growth but will also help in alleviating the harmful effects of CLP on soil flora and fauna by enhancing its rate of photodegradation.

Monitoring and distribution patterns of pesticide residues in soil from cotton/wheat fields of Pakistan.

The excessive use of hazardous pesticides for massive cotton and wheat production has deteriorated the quality of Okara district's soil. Thus, in order to sustain the production of good-quality food, it is essential to determine the residue levels of pesticides in the agricultural soil and define their possible sources. Thus, the present study focused on the determination of selected pesticides in the soil samples obtained from cotton/wheat fields by using the modified multi-residue pesticide analysis method based on GCMS and HPLC-UV. Most of soil samples were found to be highly contaminated with imidacloprid, chlorpyrifos, and α-cypermethrin residues. Selected pesticides were significantly correlated with each other at p < 0.05 except imidacloprid, which was negatively correlated with triazophos, MCPA methyl ester, selected pyrethroid pesticides, and their metabolite. Soil pH and phosphate levels were significantly positively correlated while sulfate content was negatively correlated with most of selected pesticides. The varimax normalized factor analysis divides the selected pesticides to the two major factors that explained 87.19% of the total variance which evidenced that pesticide in the same cluster shared a common source in the soil. A significant negative correlation of chlorpyrifos in the second factor pointed towards a source different from other pesticides. Factor and cluster analysis indicated that sulfate levels of soil positively affected the persistence/ mobility of imidacloprid.

Distribution and source apportionment studies of heavy metals in soil of cotton/wheat fields.

Heavy metals enriched agricultural soils have been the subject of great concern because these metals have potential to be transferred to the soil solution and afterward accumulated in food chain. To study the trace metal persistence in crop soil, 90 representative soil samples were collected and analyzed for heavy metal (As, Cd, Cu, Fe, Mn, Ni, Pb, and Zn) and anions (chloride, nitrates, phosphates and sulfates). Cluster and factor analysis techniques were used for the source identification of these excessive heavy metal levels and ecological risk was determined with potential ecological risk assessment. The degree of enrichment of eight studied heavy metals in comparison with the corresponding background levels decreased in order: Cd > Pb > Fe > Ni > Mn > As > Cu ~ Zn. Arsenic and cadmium exhibited 1.30- and 1.64-fold exceeded levels than threshold limits set by National environment quality standards, respectively. Cd in cotton field's soil may lead to higher potential risk than other heavy metals. On overall basis, the cumulative mean potential ecological risk for the district (207.75) corresponded to moderate risk level with higher contributions from As and Pb especially from Cd. Cadmium formed strong positive correlation with phosphate content of soil at p < 0.01. Cluster analysis indicated that Cluster 1 (extremely polluted) probably originated from anthropogenic inputs of phosphate fertilizer and past usage of arsenical pesticides.

Cu(2+) and Fe(2+) mediated photodegradation studies of soil-incorporated chlorpyrifos.

The influences of Cu(2+) and Fe(2+) on the photodegradation of soil-incorporated chlorpyrifos were investigated in the present study. The soil samples spiked with chlorpyrifos and selected metal ions were irradiated with UV light for different intervals of time and analyzed by HPLC. The unsterile and sterile control soil samples amended with pesticides and selected metals were incubated in the dark at 25 °C for the same time intervals. The results of the study evidenced that photodegradation of chlorpyrifos followed the first-order kinetics. The dissipation t0.5 of chlorpyrifos was found to decrease from 41 to 20 days under UV irradiation. The rate of chlorpyrifos photodegradation was increased in the presence of both metals, i.e., Cu(2+) and Fe(2+). Thus, initially observed t0.5 of 19.8 days was decreased to 4.39 days in the case of Cu(+2) and 19.25 days for Fe(+2). Copper was found to increase the rate of photodegradation by 4.5 orders of magnitude while the microbial degradation of chlorpyrifos was increased only twofold. The microbial degradation of chlorpyrifos was only negligibly affected by Fe(2+) amendment. The studied trace metals also affected the abiotic degradation of the pesticide in the order Cu(2+) > Fe(2+).

Photodegradation of α-cypermethrin in soil in the presence of trace metals (Cu2+, Cd2+, Fe2+ and Zn2+).

The influence of trace metals (Cu(2+), Zn(2+), Cd(2+) and Fe(2+)) on the photodegradation of α-cypermethrin (α-CYM) in agricultural soil was studied. The soil samples were spiked with α-cypermethrin with/without the presence of metal ions, irradiated under a UV irradiation chamber for a regular period of time and analyzed by using HPLC. The dark control sterile and unsterile soil samples spiked with α-cypermethrin and selected trace metals were incubated for the same interval of time at 25 °C. The results obtained indicated that α-cypermethrin photodegradation followed biphasic kinetics. α-cypermethrin photodegradation half-lives (t1/2) were increased to 0.71 and. 4.5 hours from 0.64 hours respectively in the presence of elevated Zn(2+) and Cu(2+) concentrations. Fe(2+) and Cd(2+) increased the photodegradation reaction kinetics from -1.078 h(-1) to -1.175 h(-1) and -1.397 h(-1) and varied the t1/2 from 0.64 ± 1.41 to 0.59 ± 2.07 and 0.49 ± 2.01 in the soil. Microbes also affected the degradation of α-cypermethrin in metal contaminated soil. The degradation rate was inhibited in unsterile soil and was found to be in the following order: Cd(2+)< Zn(2+)< Cu(2+)< Fe(2+). The degradation/persistence of α-cypermethrin was affected linearly with the increasing soil metal concentrations.

Orbital mass secondary to acute lymphoblastic leukaemia in a child: a rare presentation.

We report the case of a 3-year-old child, who presented with lid swelling which progressed to proptosis of the left eye. He also had systemic symptoms of fatigue and weight loss. An examination revealed hepatosplenomegaly and lymph node enlargement. Investigations showed a peripheral smear with blast cells, which were also revealed through a bone marrow biopsy. A CT scan showed a mass lesion in the left orbit that had infiltrated into the surrounding tissues. He was diagnosed with acute lymphoblastic leukaemia (ALL) with left-sided orbital mass secondary to it. Haematogenous masses in the orbit are commonly due to granulocytic sarcomas, which are usually associated with acute myelogenous leukaemia (AML), not ALL, and are rare especially when they precede systemic disease.

A phase II randomized placebo-controlled trial of omega-3 fatty acids for the treatment of acute lung injury.

OBJECTIVES: Administration of eicosapentaenoic acid and docosahexanoic acid, omega-3 fatty acids in fish oil, has been associated with improved patient outcomes in acute lung injury when studied in a commercial enteral formula. However, fish oil has not been tested independently in acute lung injury. We therefore sought to determine whether enteral fish oil alone would reduce pulmonary and systemic inflammation in patients with acute lung injury. DESIGN: Phase II randomized controlled trial. SETTING: Five North American medical centers. PATIENTS: Mechanically ventilated patients with acute lung injury ≥18 yrs of age. INTERVENTIONS: Subjects were randomized to receive enteral fish oil (9.75 g eicosapentaenoic acid and 6.75 g docosahexanoic acid daily) or saline placebo for up to 14 days. MEASUREMENTS AND MAIN RESULTS: Bronchoalveolar lavage fluid and blood were collected at baseline (day 0), day 4 ± 1, and day 8 ± 1. The primary end point was bronchoalveolar lavage fluid interleukin-8 levels. Forty-one participants received fish oil and 49 received placebo. Enteral fish oil administration was associated with increased serum eicosapentaenoic acid concentration (p < .0001). However, there was no significant difference in the change in bronchoalveolar lavage fluid interleukin-8 from baseline to day 4 (p = .37) or day 8 (p = .55) between treatment arms. There were no appreciable improvements in other bronchoalveolar lavage fluid or plasma biomarkers in the fish oil group compared with the control group. Similarly, organ failure score, ventilator-free days, intensive care unit-free days, and 60-day mortality did not differ between the groups. CONCLUSIONS: Fish oil did not reduce biomarkers of pulmonary or systemic inflammation in patients with acute lung injury, and the results do not support the conduct of a larger clinical trial in this population with this agent. This experimental approach is feasible for proof-of-concept studies evaluating new treatments for acute lung injury.

Age- and gender-based studies of trace metal levels and various enzymes associated with myocardial infarction.

The present investigation deals with the determination of various serum enzymes known to be elevated during myocardial infarction (MI) and estimation of selected metals like Cu, Cr, Co, Fe, Pb, and Mg by flame atomic absorption spectrophotometry. The data obtained thereby were processed for the determination of correlation coefficient matrix among the cardiac enzymes and the serum metals. The study evidenced the accumulation of Pb during MI and reduction in the level of Fe. A significant negative correlation was observed between Cu and creatine kinase-MB. The data were also segregated into various groups to study the influence of age and gender on the levels of selected parameters. In both the genders, the age of the patients was found to be correlated significantly with various cardiac enzymes. In case of male patients, the most significant correlation was observed between age and blood sugar at random. The other significant correlations among the male patients included Cr-CPK, Cr-creatine kinase-MB, Fe-age, and others. In female patients, the pairs of studied parameters that exhibited significant correlations included age-lactic dehydrogenase, creatine phosphokinase isoenzyme-aspartate aminotransferase, lactic dehydrogenase-creatine phosphokinase isoenzymes, Pb-Fe, and Cu-Co in addition to others.

Distribution, correlation, and source apportionment of selected metals in tannery effluents, related soils, and groundwater--a case study from Multan, Pakistan.

In order to study the distribution, correlation, and apportionment of selected metals, the tannery effluent, related soil, and groundwater samples were collected from Multan, Pakistan, and analyzed on flame atomic absorption spectrophotometer. Among the selected metals, Na, Ca, K, Cr, and Mg revealed dominant concentrations with average values of 5,499, 945, 565, 209, and 107 mg/L and 2,634, 330, 484, 14.1, and 60.5 mg/L in the effluents and groundwater, respectively, whereas the mean metal levels in soil samples were 10,026, 6,726, 9,242, 476, and 9,857 mg/kg. Overall, the mean metal concentrations in the tannery effluents, groundwater, and related soils reveal following order, respectively: Na > Ca > K > Cr > Mg > Ni > Fe > Zn > Co > Pb > Mn > Cd; Na > K > Ca > Mg > Cr > Zn > Ni > Pb > Fe > Co > Mn > Cd; Na > Mg > K > Ca > Cr > Co > Ni > Fe > Pb > Mn > Zn > Cd. Generally, the metal distribution in tannery effluents, soils, and groundwater was found to be random as evidenced by large differences between mean and median values as well as considerably higher standard deviation and skewness values. The selected metal data were also subjected to correlation study to investigate the covariation of metal levels in the three media. The source apportionment of the metal data in the effluents, soils, and groundwater was carried out using principal component analysis in addition to basic statistical and correlation analyses. The source apportionment studies evidenced the gross contamination of groundwater and soils in the vicinity of tanning industrial units in Multan. The current mean metal levels in the soil and groundwater were found to be considerably higher compared with the background concentration levels and WHO guideline values.

Incidence and outcomes of pediatric acute lung injury.

OBJECTIVE: This population-based, prospective, cohort study was designed to determine the population incidence and outcomes of pediatric acute lung injury. METHODS: Between 1999 and 2000, 1 year of screening was performed at all hospitals admitting critically ill children in King County, Washington. County residents 0.5 to 15 years of age who required invasive (through endotracheal tube or tracheostomy) or noninvasive (through full face mask) mechanical ventilation, regardless of the duration of mechanical ventilation, were screened. From this population, children meeting North American-European Consensus Conference acute lung injury criteria were eligible for enrollment. Postoperative patients who received mechanical ventilation for <24 hours were excluded. Data collected included the presence of predefined cardiac conditions, demographic and physiological data, duration of mechanical ventilation, and deaths. US Census population figures were used to estimate incidence. Associations between outcomes and subgroups identified a priori were assessed. RESULTS: Thirty-nine children met the criteria for acute lung injury, resulting in a calculated incidence of 12.8 cases per 100000 person-years. Severe sepsis (with pneumonia as the infection focus) was the most common risk factor. The median 24-hour Pediatric Risk of Mortality III score was 9.0, and the mean +/- SD was 11.7 +/- 7.5. The hospital mortality rate was 18%, lower than that reported previously for pediatric acute lung injury. There were no statistically significant associations between age, gender, or risk factors and outcomes. CONCLUSIONS: We present the first population-based estimate of pediatric acute lung injury incidence in the United States. Population incidence and mortality rates are lower than those for adult acute lung injury. Low mortality rates in pediatric acute lung injury may necessitate clinical trial outcome measures other than death.

Comparative statistical analysis of chrome and vegetable tanning effluents and their effects on related soil.

Two tanning units of Pakistan, namely, Kasur and Mian Channun were investigated with respect to the tanning processes (chrome and vegetable, respectively) and the effects of the tanning agents on the quality of soil in vicinity of tanneries were evaluated. The effluent and soil samples from 16 tanneries each of Kasur and Mian Channun were collected. The levels of selected metals (Na, K, Ca, Mg, Fe, Cr, Mn, Co, Cd, Ni, Pb and Zn) were determined by using flame atomic absorption spectrophotometer under optimum analytical conditions. The data thus obtained were subjected to univariate and multivariate statistical analyses. Most of the metals exhibited considerably higher concentrations in the effluents and soils of Kasur compared with those of Mian Channun. It was observed that the soil of Kasur was highly contaminated by Na, K, Ca and Mg emanating from various processes of leather manufacture. Furthermore, the levels of Cr were also present at much enhanced levels than its background concentration due to the adoption of chrome tanning. The levels of Cr determined in soil samples collected from the vicinity of Mian Channun tanneries were almost comparable to the background levels. The soil of this city was found to have contaminated only by the metals originating from pre-tanning processes. The apportionment of selected metals in the effluent and soil samples was determined by a multivariate cluster analysis, which revealed significant differences in chrome and vegetable tanning processes.

Prospective evaluation of multidetector-row CT angiography for the diagnosis of vasospasm following subarachnoid hemorrhage: a comparison with digital subtraction angiography.

PURPOSE: To evaluate the accuracy of multidetector-row CT angiography (CTA) for the diagnosis of large-vessel vasospasm following subarachnoid hemorrhage by comparison to digital subtraction angiography (DSA). METHODS: Thirty-three patients with acute subarachnoid hemorrhage were enrolled in a prospective study and underwent a total of 40 CTA and DSA examinations within 24 h of each other. Two neuroradiologists reviewed the CTA examinations independently. A third neuroradiologist blinded to the CTA results reviewed the DSA examinations. In each patient, for both techniques, 23 arterial segments were evaluated for their degree of narrowing; the reviewers were asked to attribute every narrowing to 'vasospasm' or 'hypoplasia'. Agreement between CTA and DSA for the degree of narrowing, and agreement between the two CTA readers, were calculated using weighted kappa-coefficients. Sensitivity, specificity, accuracy, positive and negative predictive value (NPV) of CTA to detect large-vessel vasospasm were calculated considering DSA as the gold standard. RESULTS: Substantial correlation (kappa = 0.638) was found between CTA and DSA for the detection of arterial narrowing. Interobserver agreement between the two CTA reviewers for the degree of luminal narrowing was substantial (kappa = 0.712).CTA was 87% accurate for the diagnosis of large-vessel vasospasm; the NPV of CTA was 95%. CTA was more accurate, and interobserver agreement higher, for the proximal arterial segments (basilar and vertebral arteries) than for the distal ones (P2 segments). Using CTA as a screening modality, 83% of unnecessary DSA would have been avoided. CONCLUSION: Compared to the gold standard of DSA, CTA is accurate for the detection of large-vessel vasospasm, and has a very high NPV.

Statistical source identification of metals in groundwater exposed to industrial contamination.

Levels of selected metals Na, Ca, Mg, K, Fe, Mn, Cr, Co, Ni, Cd, Pb and Mn were estimated by flame atomic absorption spectrophotometry in groundwater samples from Kasur, a significant industrial city of Pakistan. Salient mean concentration levels were recorded for: Na (211 mg/l), Ca (187 mg/l), Mg (122 mg/l), K (87.7 mg/l), Fe (2.57 mg/l) and Cr (2.12 mg/l). Overall, the decreasing metal concentration order was: Na>Ca>Mg>K>Fe>Cr>Zn>Co>Pb>Mn>Ni>Cd. Significantly positive correlations were found between Na-Cr (r=0.553), Na-Mn (r=0.543), Mg-Fe (r=0.519), Mg-Cr (r=0.535), Pb-K (r=0.506) and Pb-Ni (r=0.611). Principal Component Analysis and Cluster Analysis identified tannery effluents as the main source of metal contamination of the groundwater. The present metal data showed that Cr, Pb and Fe levels were several times higher than those recommended for water quality by WHO, US-EPA, EU and Japan. The elevated levels of Cr, recorded as 21-42 fold higher compared with the recommended quality values, were believed to originate from the tanning industry of Kasur.

Multivariate analysis of the selected metals in the hair of cerebral palsy patients versus controls.

Seventeen metals were measured in scalp hair samples from cerebral palsy patients (CPPs) and controls. Samples were collected from 95 CPPs and 93 controls. The nitric acid-perchloric acid wet digestion procedure was used for quantification of the selected metals by flame atomic absorption spectrophotometry. The concentrations of Ag, Ca, Cd, Co, Cr, Li, and Mg were significantly higher and those of Cu, Fe, K, Mn, Na, Ni, Pb, and Sb were lower in the hair of CPPs compared with controls. Astrong positive correlation was found between Ca and Mg in the hair of controls but not in that of CPPs. Antimony was found significantly negative in terms of its correlation with Co and Cu in CPPs group but not in the controls. Principal component analysis (PCA) of the data extracted seven factors for CPPs and six factors for controls. Cluster analysis (CA) was also used to support the PCA results. The study evidenced some specific source of Mg and Sb in the hair of CPPs.

Spatial variations in selected metal contents and particle size distribution in an urban and rural atmosphere of Islamabad, Pakistan.

Spatial variations in total suspended particulate matter (TSP) were investigated for distribution of metals and particle size fractions in the urban and rural atmosphere of Islamabad, Pakistan. The metals Na, K, Fe, Mn, Pb, Cd, Cr, Zn, Ni and Co, and the particle fractions <2.5, 2.5-10, 10-100 and >100 microm were included in the study. TSP samples were trapped on glass fibre filters using high volume samplers and quantification of metals was done using Atomic Absorption Spectrometry employing HNO(3) based wet digestion. At the urban site, Na was dominant at 2.384 microg/m(3) followed by K, Fe and Zn with 0.778, 0.667 and 0.567 microg/m(3) as mean concentrations, respectively. The metal levels for the rural site ranged from 0.002 microg/m(3) for Cd to 1.077 microg/m(3) for Na. However, compared with the urban site, mean Pb concentration showed an almost two-fold enhancement, i.e., 0.163 Vs. 0.327 microg/m(3). Metals and particle size source identification was done using Principal Component Analysis and Cluster Analysis. Five sources were traced out for the urban site: industrial, soil, automobile emissions, metallurgical industries and excavation activities. For the rural site, four sources were recorded: agricultural, automotive emissions, excavation activities and metallurgical units. Collectively, for both the sites, PM(10-100) emerged as a major contributor to TSP, followed by PM(2.5-10), PM(<2.5) and PM(>100) in that order. The metals showed in general positive relationship with fine particulate fractions (PM(2.5-10), PM(<2.5)), and negative correlation with coarse fractions (PM(10-100), PM(>100)). Comparison with the corresponding data from various Asian sites revealed that the levels of Na, K, Fe, Mn, Co and Ni for the present study were lower than those reported for grossly polluted cities of the world.

Multivariate analysis of trace metal levels in tannery effluents in relation to soil and water: a case study from Peshawar, Pakistan.

Tannery effluents and relevant ground water and soil samples collected from various tanning industries of Peshawar were analyzed for Na, Ca, K, Mg, Fe, Mn, Cr, Co, Cd, Ni, Pb and Zn by the AAS method. The metal concentration data for the three media are reported in terms of basic statistical parameters, metal-to-metal correlations and linear regression analyses. Metal distributions in the three media were quite divergent and showed non-normal distributions with high standard deviation and skewness parameters. Sodium exhibited the highest mean levels of 1,277mg/L, 881mg/L and 12,912mg/kg in the effluent, ground water and soil samples, respectively. Among other metals, Cr concentrations were 410mg/L, 0.145mg/L, 100mg/kg and Ca, 278mg/L, 64.8mg/L, and 2,285mg/kg in the effluent, ground water and soil samples, respectively. Some significant correlations were observed between effluent and soils in terms of Na, Cr, Ni, Co and Pb. The ground water-soil interrelationship suggested that Na levels in the soil and ground water were significantly correlated with each other (r=0.486, P<0.01). Similarly, Cr in the soil is strongly correlated with Ca in ground water (r=0.486, P<0.01). These results were duly supported by the linear regression analysis of data. The source identification studies conducted using Principal Component Analysis (PCA) and Cluster Analysis (CA) evidenced that ground water and soil were being contaminated by the toxic metals emanating from the tannery effluents.

Multivariate analysis of selected metals in tannery effluents and related soil.

Effluent and relevant soil samples from 38 tanning units housed in Kasur, Pakistan, were obtained for metal analysis by flame atomic absorption spectrophotometric method. The levels of 12 metals, Na, Ca, K, Mg, Fe, Mn, Cr, Co, Cd, Ni, Pb and Zn were determined in the two media. The data were evaluated towards metal distribution and metal-to-metal correlations. The study evidenced enhanced levels of Cr (391, 16.7 mg/L) and Na (25,519, 9369 mg/L) in tannery effluents and relevant soil samples, respectively. The effluent versus soil trace metal content relationship confirmed that the effluent Cr was strongly correlated with soil Cr. For metal source identification the techniques of principal component analysis, and cluster analysis were applied. The principal component analysis yielded two factors for effluents: factor 1 (49.6% variance) showed significant loading for Ca, Fe, Mn, Cr, Cd, Ni, Pb and Zn, referring to a tanning related source for these metals, and factor 2 (12.6% variance) with higher loadings of Na, K, Mg and Co, was associated with the processes during the skin/hide treatment. Similarly, two factors with a cumulative variance of 34.8% were obtained for soil samples: factor 1 manifested the contribution from Mg, Mn, Co, Cd, Ni and Pb, which though soil-based is basically effluent-derived, while factor 2 was found associated with Na, K, Ca, Cr and Zn which referred to a tannery-based source. The dendograms obtained from cluster analysis, also support the observed results. The study exhibits a gross pollution of soils with Cr at levels far exceeding the stipulated safe limit laid down for tannery effluents.

A comparative study based on gender and age dependence of selected metals in scalp hair.

Levels of 10 metals (Ca, Mg, Fe, Zn, Cu, Mn, Cd, Co, Cr and Ni) in the scalp hair of male and female donors, with age groups between 3 and 100 years, were determined by ICP-AES. In total, 58 male and 30 female hair samples were analyzed in triplicate. The donors belonged to the rural area of district Chakwal, a well-known typical non-urban site in Pakistan. Calcium showed the highest concentration of 462 microg/g in the hair of males and 870 microg/g in those of females followed by Zn, at 208 and 251 microg/g for the two sexes. For male donors, Cd showed the lowest concentration (1.15 microg/g) while for female donors Co remained at minimum level (0.92 microg/g). The order of decreasing metal concentration in the hair of male donors was: Ca > Zn > Mg > Fe > Cu > Mn > Ni > Cr > Co > Cd while that for female donors it was: Ca > Zn > Mg > Fe > Cu > Mn > Cr > Ni > Cd > Co. The female group exhibited enhanced levels of all selected metals except Fe and Co in their hair as compared with the male counterparts. A strong bivariate positive correlation was found between Fe and Zn (r = 0.841) for the hair samples from male category while for the female category, strong positive correlations were observed between Ca-Mg (r = 0.617), Ca-Zn (r = 0.569), Ca-Mn (r = 0.565), Mg-Mn (r = 0.655), Cr-Cu (r = 0.655) and Cr-Ni (r = 0.685). The distribution of metals in the hair of donors with respect to different age groups was also investigated for both genders. The study showed that in case of males, the concentration of all selected metals decreased with increasing age except for Cu, Co and Cr. However, for females the hair metal levels increased with age, except for Co for which the concentration decreased with age. No appreciable change in the metal concentration was observed as a function of age for the combined sexes.