Abstract: In the period 199121999 w as carried ou t in the Czech Repub lic“Tep lice P rogram ”to evaluate among o thers the impact of air po llu t ion on genet icm aterials and p regnancy ou tcom es. DNA b inding act ivit ies of PM 10 w as stu2 died by an in v itro acellu lar assay coup led w ith 32P2po st labeling and em b ryo tox icity assay u sing Ch ick Em b ryo2 tox icity Screen ing Test (CHEST ). A ll analyses indicate that carcinogen ic PAH s are respon sib le fo r geno tox ic act ivity, con t ribu t ing 45% to 50% of allDNA adduct s induced by comp lex m ix tu res of o rgan ic compounds. In the P regnancy O u tcom e P ro ject w ere analyzed f rom 1994 th rough 1999 app rox. 8 500 p regnancies, u sing in t rau terine grow th retardat ion ( IU GR ) as ou tcom e m easu re. A sign if ican t ly increased risk of IU GR w as es2 tab lished fo r mo thers w ho w ere expo sed to PM 10 levels > 40 Lgöm 3 asw ell as to carcinogen ic PAH s > 15 ngö m 3 du ring the f irst mon th of gestat ion. Thu s, a p rim ary ro le of carcinogen ic PAN s in fetal grow th slow 2dow n w as hypo thesized. P lacen tal bu lky DNA adduct sw ere determ ined by 32P2po st labeling. DNA adduct sw ere relat2 ed to carcinogen ic PAH s expo su re. Resu lt s concern ing the impact of air po llu t ion on p regnancy ou tcom e show ed fo r the f irst t im e that air po llu t ion m ay inf iuence hum an rep roduct ive p rocesses, affect ing fetal grow th. The mo st impo rtan t f indings of Tep lice P rogram are: A ir po llu t ion m ay have an impact on p regnancy ou tcom e, DNA adduct s and som e geno types are sen sit ive b iom arkers of expo su re, PAH s are an impo rtan t sou rce of the geno tox ic and em b ryo tox ic act ivit ies of o rgan ic m ix tu res associated w ich u rban air part icles.