The concentrations of 33 elements: Ca, Mg, Na, U, Cu, Zn, P, Fe, Mn, Cr, Se, B, Co, Mo, Si, V, Ni, Be, Hg, Cd, Al, Pb, As, Ba, Au, Pt, Ag, Sr, Sn, Ti, W, Sb and Zr in hair were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Hair samples (n=83) were collected between 1996 and 2003 from inhabitants of city of Wrocław, located in Lower Silesia, south-west Poland (urbanized and industrialized region). Inter-element interactions were studied by evaluation of correlation coefficients between two elements, as well as by multiple regression analysis. The strongest relations found between the elements in the hair were as follows: Mg and Ca, Mn and Ca, Sr and Ca, Sr and Mg, U and Na, Ni and Zn, Mn and Sr, Cd and Ni, Sb and Pt. We obtained also the following essential linear multiple dependences (p<0.05): Al=f(U, P, Mn), As=f(Zn, Fe) (Zn is negatively correlated, β<0), Cu=f(V), Fe=f(Mn, As), Mg=f(Ca), Ca=f(Mg, Ba), Ni=f(Zn, Cd), Sb=f(Pt, Sn, W) and Ti=f(Fe, Co). These relations can be useful in the explanation of relationships among the elements in man.