survey on the lead concentration of brown rats (rattus norvegicus) and the effect of environmental factors on pb distribution pattern in rural- agricultural areas using gis (golestan and mazandaran provinces)

Heavy metals have contaminated various ecosystems. omnivorous animals such as rodents with high fertility, abundance and low motility can be good indicators for heavy metal contamination of their habitat. rural- agricultural areas around seven cities in golestan and mazandaran provinces were selected to trap five brown rats (rattus norvegicus) from each region. after the preparation of serum samples, pb concentration was measured by atomic absorption spectrometry. also, gis software was used to survey the effect of environmental factors on the pb distribution pattern. the average pb concentration was similar in males and females. the average pb concentrations in rural areas of golestan and mazandaran provinces were 6.7 and 6.3 μg/dl, respectively (p≥ 0.05). the highest average pb concentration (7.55 μg/dl) belonged to rats sampled in areas around ghargomishan road (around neka city), and the lowest average pb concentration (5.20 μg/dl) belonged to rats sampled from kaleh agricultural areas (between bahnamir and babolsar cities). using the sensitivity method of the linear multiple regression model, it was found that the temperature and humidity have the greatest effect and altitude and precipitation have the lowest impacts. the results of this study indicated pb contamination of rural-agricultural areas of golestan and mazandaran provinces and the transmission risk of this hazardous metal to humans and other animals living in these areas. therefore, the communication of information to the authorities and the use of adequate measures to prevent pb entrance to sampled areas seem necessary.