A. Khalique

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. A strong 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.

Scalp hair metal analysis in the assessment of the occupational exposure of arc welders

Eleven metals (Ca, Mg, Fe, Zn, Cu, Mn, Cd, Co, Cr, Ni and Pb) were estimated in hair samples of metal arc welders and a control group with the same socioeconomic background. Nitric acid–perchloric acid wet digestion procedure was adopted for the estimation of endogenous metal contents by ICP-AE technique. The study exhibited the following increasing order of the metal concentrations: Cd < Co < Cr < Mn < Ni < Cu < Pb < Fe < Zn < Mg < Ca, with average concentrations of 0.54, 0.90, 2.0, 3.0, 3.3, 11.0, 12, 20, 170, 240 and 1050 µg g−1, dry weight, respectively. On average, the levels of Mn, Ni, Pb and Fe were found to be 1.5–2.4 times higher in the hair of welders compared with controls. Besides age and exposure which were strongly correlated, Cu–Mg, Mn–Mg, Ca–Co and Cd–Zn also showed significantly positive correlations. The identification of metal sources, done by cluster and principal component analyses, revealed four factors: age and exposure; Cu, Mg, Mn and Fe; Ca and Co; Cd, Zn, Ni and Pb. High levels of Fe were found to have a depleting impact on Co levels. The arc welders were feared to accumulate heavy metals in their bodies due to long-term endogenous exposure.

Status of Selected Heavy Metal Distribution in Scalp Hair of Traffic Control Personnel Exposed to Vehicular Emissions

ABSTRACT Scalp hair samples of traffic control personnel (n = 71, ages between 25 to 45 years) were analyzed for 11 selected metals by using an Inductively Coupled Argon Plasma Atomic Emission (ICP-AE) technique using nitric acid–perchloric acid based wet digestion method. The observed order of mean concentrations (μ g/g, dry weight) of the metals, in washed hair samples, was: Ca > Mg > Zn > Fe > Pb > Cu > Ni > Mn > Cr > Cd > Co, with corresponding metal levels at 1042.2, 182.4, 169.7, 13.6, 12.4, 11.1, 2.7, 1.9, 1.9, 0.8, and 0.7 μ g/g, respectively. Most of the unwashed samples exhibited 10–15% higher metal levels compared with those in washed samples. A positive metal-to-metal correlation (p < 0.01) was observed for the metal pairs: Ca-Mg (r = 0.737), Pb-Cr (r = 0.441), and Cu-Zn (0.385). Principal Component Analysis (PCA) extracted 6 factors as metals origin using varimax normalized rotation commutatively representing more than 76% of the total variance. Cluster Analysis (CA) showed five strong clusters of selected metals in the hair of the subjects: Age-Exposure, Ca-Mg, Cd-Fe-Mn, Pb-Cr, and Cu-Zn. The results of the current study were compared with those for two other occupationally exposed groups, metal arc welders and autodrivers, using published literature values. The traffic controllers in our study generally, with the exception of Cu, exhibited lower levels of metals in hair samples than did autodrivers and arc welders.

Age and Gender-Based Comparison of Nickel Content of Scalp Hair of Edible Oil- and Hydrogenated Oil-Consuming Populations

ABSTRACT Nickel concentrations (μ g/g, dry weight) in the scalp hair of vegetable oil– and hydrogenated oil–consuming categories of male and female donors, ages between 1–66 years, were estimated by the atomic absorption method to assess the contribution of nickel as a contaminant in the hydrogenated oil. Comparative estimates of hair Ni content revealed enhanced metal levels for donors consuming hydrogenated oil both for male (29.33 μg/g, dry weight) and female (27.09 μg/g, dry weight) population segments, whereas for oil-consuming donors the corresponding levels were 11.51 μg/g and 13.49 μg/g, respectively. The Ni content of hair of elderly donors consuming hydrogenated oil was found significantly higher than that of younger male/female donors. Hair Ni levels as high as 63.59 μg/g and 68.40 μg/g were estimated for hydrogenated oil–consuming males and females, respectively. The Ni concentrations exhibited strong positive correlation with age for the hydrogenated oil–consuming male (r = 0.713) and female (r = 0.707) categories, whereas negative correlations were found for both oil-consuming categories. The regression relationships linking hair nickel content with the donor age of either sex indicated a negative dependence for oil-consuming donors, whereas strong direct dependence was observed for hydrogenated oil-consuming donors. The overall results evidenced an index of elevated nickel levels in the hair of population segment consuming hydrogenated oil, believed to arise from excessive residual nickel in the hydrogenated oil, present at concentrations surpassing the limit recommended by the World Health Organization for the safe ingestion of nickel in food commodities.