Radon is the main source of natural radioactivity, and its measurement is considered extremely important in radioprotection, given its relationship with the occurrence of lung cancer. In the last two years, measurements of this radioactive gas were carried out in Lima considering a grid of 5 km${}^2$ and the population density to determine the number of measurements to be carried out. Cellulose nitrate nuclear track detectors exposed in bare mode and diffusion chamber mode were used to estimate ${}^{222}$Rn concentrations. In diffusion chamber mode, non-commercial monitors and commercial monitors were used. The monitoring results are presented for 43 districts of the Lima Province whose population is approximately ten million inhabitants occupying a total area of 2655.15 km${}^2$. Measurements were made obtaining an average concentration of 49 Bq·m${}^{-3}$ using bare detectors and 66 Bq·m${}^{-3}$ using non-commercial diffusion chambers. Average concentrations obtained by both detector exposure modes were below the maximum concentration recommended by the WHO. A radon (${}^{222}$Rn) map was also obtained as a visual representation of the ${}^{222}$Rn levels in the Lima province using inverse distance weighting (IDW) interpolation.

El objetivo de la presente investigación fue medir las concentraciones de radón en las viviendas de los distritos de la Provincia de Lambayeque mediante detectores LR-115 Tipo II en modo descubierto. Se utilizó detectores de trazas nucleares de estado sólido (SSNTDs), películas de nitrato de celulosa LR 115 tipo II. El número de detectores se determinó por distrito considerando la densidad poblacional y tratando de cubrir tanto la zona urbana como rural. Los detectores fueron expuestos en modo descubierto, en el interior de las viviendas durante 90 días; el procedimiento de grabado y la lectura de los detectores se realizaron en el Laboratorio de Huellas Nucleares de la PUCP. Los resultados muestran que el 15 % del total de viviendas muestreadas sobrepasaron el límite máximo permisible por la normativa nacional establecida por el IPEN, encontrándose concentraciones altas de Radón en los distritos de Lambayeque, Túcume y Chóchope.