title: Environmental biomonitoring of essential and toxic elements in human scalp hair using accelerated microwave-assisted sample digestion and inductively coupled plasma optical emission spectroscopy.
abstract: Human scalp hair samples were collected and used to assess exposure to toxic elements and essential elements in the state of North Carolina, USA using accelerated microwave assisted acid digestion and inductively coupled plasma optical emission spectroscopy (ICP-OES). The figures-of-merit of the ICP-OES were appropriate for elemental analysis in scalp hair with detection limits as low as 0.0001 mg/L for Cd, good linearity (R2> 0.9978), and percent recoveries that ranged from 96 to 106% for laboratory-fortified-blanks and 88-112% for sample spike recovery study. The concentrations of essential elements in scalp hair were larger than those of toxic elements, with Ca having the highest average concentration (3080 μg/g, s = 14,500, n = 194). Some of the maximum concentrations observed for As (65 μg/g), Ni (331 μg/g), Cd (2.96 μg/g), and Cr (84.6 μg/g) in individual samples were concerning, however. Samples were statistically analyzed to determine the influence of race, gender, smoking habits, or age on the elemental concentrations in scalp hair. Higher concentrations of essential elements were observed in the scalp hair of Caucasians, females, and non-smokers, and the differences were often significant at a 90% confidence level. Several pairs of essential elements, for example Ca-K, Ca-Mg, and Ca-Zn, were strongly correlated in Caucasian hair but uncorrelated in African-American hair. Similarly, essential elements were strongly correlated in female hair but weakly correlated in male hair. Toxic element pairs (As-Cd, As-Se, Pb-As, and Se-Cd) were strongly correlated in the hair of smokers but uncorrelated in that of non-smokers, suggesting that cigarette smoke is a common source of toxic elements in humans.
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA; Department of Physiology and Pharmacology, Wake Forest University, Winston-Salem, NC, USA.
authors.forename: Hope
authors.initials: H
authors.lastname: Kumakli
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA.
authors.forename: A'ja V
authors.initials: AV
authors.lastname: Duncan
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA.
authors.forename: Kiara
authors.initials: K
authors.lastname: McDaniel
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA.
authors.forename: Tsdale F
authors.initials: TF
authors.lastname: Mehari
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA.
authors.forename: Jamira
authors.initials: J
authors.lastname: Stephenson
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA.
authors.forename: Lareisha
authors.initials: L
authors.lastname: Maple
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA.
authors.forename: Zaria
authors.initials: Z
authors.lastname: Crawford
authors.affiliation: A. R. Smith Department of Chemistry, Appalachian State University, 525 Rivers St, Boone, NC 28608, USA.
authors.forename: Calvin L
authors.initials: CL
authors.lastname: Macemore
authors.affiliation: A. R. Smith Department of Chemistry, Appalachian State University, 525 Rivers St, Boone, NC 28608, USA.
authors.forename: Carol M
authors.initials: CM
authors.lastname: Babyak
authors.affiliation: Department of Chemistry, North Carolina A&T State University, 601 East Market Street, Greensboro, NC 27411, USA.
authors.forename: Sayo O
authors.initials: SO
authors.lastname: Fakayode
mesh_terms: D000328:Adult; D000368:Aged; D053000:Analytic Sample Preparation Methods / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000037:antagonists & inhibitors* / Q000633:toxicity; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D057230:Limit of Detection; D008297:Male; D008872:Microwaves; D008875:Middle Aged; D012535:Scalp / Q000737:chemistry*; D012907:Smoking; D013054:Spectrophotometry, Atomic; D062789:Tobacco Products; D014131:Trace Elements / Q000032:analysis*
chemical_list: D004785:Environmental Pollutants; D014131:Trace Elements
keywords: Environmental-biomonitoring; Human-scalp-hair; Inductively-coupled-plasma-optical-emission-spectroscopy; Inter-element-association; Smoking-habits; Trace-element