The  use  of biological  tissues  as  diagnostic  tools of trace  element  level for  recognising the disease status  of an exposed human  population is an important  area of investigation. Quantitative analysis of 10  trace  elements  viz  lead, calcium,   magnesium,   chromium,   manganese,  iron, nickel,   copper,  and  zinc  in  the  human  body was  performed  using  hair   as biopsy  material. In the  present  investigation, workers  in a  roadways  workshop,  locomotive workshop  and  Pb battery  units  were  included  as  subjects.  Head  hair  samples  were  collected from the nape region of the skull. Subsequent  to sampling  of hair,  a questionnaire recommended by the  World Health   Organization was  filled  in  order  to obtain  details  about the  subjects  regarding occupation,  duration   of exposure,  medical  history,   etc.  Concentration  of elements  in hair was determined  using  an  atomic  absorption  spectrophotometer. Workers  under  mental  stress were treated  as  cases  and  workers  without  any  symptoms  of mental  stress   were  chosen  as controls.  Significant difference  in  concentration  of lead, calcium,  magnesium,   manganese, nickel,   copper and  zinc  was  found  in  hair   of subjects  with mental  stress   than  those  of controls.  Concentration  of chromium  and  iron  was  found  higher  in  hair   of subjects  with  mental  stress   but  this  difference  was  not  significant  with respect  to controls.