RESUMO
The generation of electricity through the use of radioactive material at the nuclear power plant is inevitably associated with the production of wastes, some of which have potential impact on the biosphere. The objective of the present investigation was to provide information for evaluating the presumed impact of the Mexican Nuclear Power Plant "Laguna Verde" on the natural populations. Two sibling species that live in the immediate vicinity, Drosophila melanogaster and D. simulans have been studied for several traits in a long term study. The present study describes results for the desiccation resistance (DR) trait obtained during the period from 1995 to 2002. Flies were collected at two sites, one near the reactors and another farther away. The data obtained confirmed that D. melanogaster had higher DR values than D. simulans at both sites. The analysis of the results obtained from both species of the site closer to the reactor indicated that the values of the DR in the operational stage did not change, compared with those in the preoperational stage previously analyzed. Therefore, the significant differences found between the monitored sites did not seem to be associated to the operation of the reactors.