Résumé
Potentaillay toxic elements [PTE] like lead, chromium and nickel in suspended paniculate matter [SPM] were evaluated indoor and outdoor at four sites. Two of the sites were offices and the others were homes. The aim of this work was to study the seasonal and annual indoor and outdoor PTE concentrations. The relationship between indoor and outdoor values was studied as well. The results showed seasonal variations. The maximum indoor and outdoor SPM, Pb, Cr and Ni concentrations were recorded during winter season. It was interesting to observe that the annual mean concentration of SPM in both indoor and outdoor [242 and 290 micro g/m[3] respectively] were more than 3.2 times [indoor] and 3.9 times [outdoor] the EPA yearly air quality standard for SPM [75 micro g/m[3]]. In the same way, mean values were more than 2.6 times [indoor] and 3.2 times [outdoor] the Egyptian ambient air quality standardal of 90 micro g/m[3]as annual mean. Also the results showed that the outdoor atmosphere was highly contaminated not only with lead [2.6-0.9 micro g/m[3]] but also with Cr [0.9-0.18 micro g/m[3]] and Ni [2.2-0.37 micro g/m[3]]. Abnormally high metal levels were measured indoor also. In addition, the study showed that the soluble matter of SPM [ammonium, sulphate and chloride] highly exceeded the concentrations found in the atmosphere of other countries. Regarding to indoor/ outdoor [I/O] ratios, the median values of the measured pollutants were observed to be smaller than I. It could be concluded that the above mentioned contaminant concentrations create an appreciable threat lo human health