EN
Influence of the lead on the biology of Nippostrongylus brasiliensis was examined. N. brasiliensis larvae exposed to the action of 200 ppm lead during 9 days were used to infect rats. The first group of the rats were infected with 1000 larvae kept in the solution of PBS whereas the larvae contaminated with the lead were given to the second group of rats. Capability to invasion of the contaminated larvae decreased by 28.7-57,2%. Reproductiveness of the N. brasiliensis decreased by 40.6% and the maximum point of production of the eggs was moved back by one day.