**17. Heavy metals and immunological response**

Various studies had reported effect of heavy metal pollution on immunocompetent cells. Dynamics of environment, administrative method and concentration of heavy metals are indicators with respect to heavy metals toxicity on these cells [75]. Borowska and Pyza [55] examined the activity of heavy metals like cadmium, lead, copper zinc on immune response of *M. domestica* by change in number and morphology of hemocytes such as granulocytes lessened whereas stem cells increased showing the effect on immune cell concentration [55].
