Airborne- Benzene and Its Effect on Blood Indices of 10-12 Years Old Children in Four Regions of Tehran

There is increasing evidence that environmental pollutants may be contributing to an increase in acute and chronic diseases in a wide range of general population, especially children. Benzene is considered as an important air pollutant of the metropolitan areas. The concentration of benzene was measured in four selected regions of Tehran (Bazaar, Dolat-Abad, Chizar, Gheitarieh & Darabad) during a 6-month period. Ambient concentration of benzene in Tehran was in correspondence to overall pollution levels in the air. Mean exposure levels of benzene for male students (10-12 years of age) of the above mentioned areas were 203, 98, 18, and 15 ppb respectively. This measurement for female students (of the same age group and regions) was calculated as 115, 98, 18, and 15 ppb respectively. Differences of peripheral blood cell parameters between male students in different regions were more significant than the differences among female students and this phenomenon could be attributed to lesser exposure of females to air- borne benzene. In general, correlation of peripheral blood contents of HCT, HGB, RBC and Fe of male group was significant in regard to the amount of airborne benzene in different regions of Tehran. Correlation of immune indicators of blood CD4/ CD8 of female group was also significant in regard to the amount of airborne benzene. Considering the results of this study and ambient standard of benzene in the European countries at 5 ppb, control of air pollution in Tehran should receive special consideration and the health of school children in polluted areas, must be under continuous surveillances. (Tanaffos 2005; 4(13): 47-55)