Indian Journal of Biochemistry & Biophysics Vol. 41, February 2004, pp. 53-56 Biological monitoring of lead and cadmium in human hair and nail and their correlations with biopsy materials, age and exposure Rita Mehra* and Meenu Juneja Department of Pure and Applied Chemistry, Maharshi Dayanand Saraswati University, Ajmer 305 009, India Received 24 March 2003; revised 22 December 2003 Hair and fingernails of exposed and unexposed subjects were analyzed for their lead (Pb) and cadmium (Cd) contents by atomic absorption spectrophotometer with graphite furnace and air- acetylene flame. Hair and nail Pb concentrations in occupationally exposed subjects ranged between 1.020-409.726 and 8.130- 765.306 μg/g and in environmentally unexposed subjects 0.123- 25.160 and 1.076-65.613 μg/g, respectively. Similarly, hair and nail Cd concentrations in occupationally exposed subjects ranged between 0.014-22.086 and 0.214-35.714 μg/g and in environmentally unexposed subjects 0.113-1.627 and 0.028-8.108 μg/g, respectively. A significant correlation was observed between Pb hair and nail concentrations in exposed subjects at P<0.05, as compared to unexposed subjects and Cd hair and nail in exposed, as well as unexposed subjects. With respect to exposure, levels of Pb in hair and nails were found to be significant in exposed subjects, compared to unexposed ones and levels of Cd were significant only in nails of exposed ones. With respect to age, no significant correlation was found between hair and nail Pb and Cd concentrations in both exposed and unexposed subjects. Keywords: Metal body burden, trace/toxic elements, Pb and Cd in hair/nail, biomonitoring Trace elements, even at concentration less than 0.01% of body weight play an important role in the metabolism of living organisms 1 . Urine, hair, nail, teeth and blood have been used as indicators for the estimation of metal levels. Metal body burden of trace/toxic elements is better reflected from trace element contents in hair and nail, than those in the blood, because hair and nail give record of relatively long periods, while blood shows transient levels that change with time. Furthermore, hair and nails are advantageous as they are inert and easier to sample than blood or teeth and can be stored without much technicality. Also, trace metal concentrations in these tissues are reported to be high in earlier studies 2-6 . Determining trace/toxic elements in human hair and nails has importance in biological, medical and environmental studies. Lead is used in smelting and soldering works, painting, manufacture of batteries and motor fuels and is a potential neurotoxin. Its exposure may lead to inhibition of haeme synthesis resulting in anaemia, kidney damage, cerebral oedema, gastro-intestinal, respiratory disorders and nephropathy 7-10 . Cadmium, a highly toxic metal used as antifriction agent in batteries accumulate in the kidney and binds pre- dominantly to metallothionein protein. Its ingestion or inhalation may cause nausea, abdominal cramps, short breath, chocking fits, renal dysfunction and inhibition of iron absorption. Catarrhal and ulcerative gastro- enteritis, congestion, pulmonary infarcts and subdural hemorrhages may be found at necropsy 11-15 . Earlier, we reported studies on Cr, Mn, Ni, Fe, Zn, Ca and Mg 3,4,7,10,16 . In view of the potential of hair and nail for assessing occupational exposure to metals, we determined Pb and Cd concentrations in these tissues in male subjects (18-60 years of age) of roadways workshop, locomotive workshop, and Pb-Cd battery units to examine their differential levels in occupationally exposed individuals and controls. The study was also aimed at investigating whether elevated Pb and Cd concentrations in hair and nail may be used as indicators of occupational exposure to these metals. A possibility of any correlation between Pb and Cd hair and nail concentrations has also been explored. Material and Methods Hair samples (approx. 4-5 cm in length) were collected from the nape of scalp by cutting approximately 2 mm from scalp using a pair of sterilized scissors washed with ethanol 17 , from male subjects working in roadways workshop, locomotive workshop and Pb-Cd battery units, exposed to Pb and Cd in their work environment, in particular. The age of subjects range from 18-60 years. For collection of nail samples, volunteers were asked to wash their hands thoroughly with double distilled water and medicated soap, followed by drying with a clean towel or tissue paper to remove external contamina- tion, if any. Nails were cut from fingers with stainless ________________ *Author for correspondence Fax: 0145-2430225; Tel: 0145-2670366 E-mail: mehra_rita@rediffmail.com