There is a lack of studies on the impact of very toxic and persistent organic compounds as polychlorinated dibenzodioxins (PCDDs), dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) on the population life expectancy. Preliminary studies on the relations between exposure to PCDD/Fs and dl-PCBs in ambient air and the length of life of residents of 12 cities (2 million people) in the Silesia province has been undertaken. The average length of life of inhabitants in 12 cities of Silesia province was calculated on the basis of register of deaths after excluding deaths caused by external causes and the concentration of PCDD/Fs and dl-PCBs were measured. The studies have shown that inhalation exposure to dioxins, furans and dl-PCBs could be an important factor which may shorten the life expectancy of the population. The results of preliminary studies indicate a strong correlation between the concentration of PCDD/Fs and dl-PCBs in the ambient air and the length of life of women. The conducted analysis of the regression shows that reduction of chlorinated persistent organic compounds of 10fg I-TEQ/m3 could extend life expectancy of women by approximately 4months (0.3years).