Nasal epithelial single cell gel electrophoresis (SCGE)assay and DNA cell cycle analysis in newly arrived adults to Southwest Mexico City (SWMMC)consuming a high fresh fruit and vegetable diet and alpha-tocopherol

Exposure to a polluted urban atmosphere induces DNA nasal strand breaks;adults with poor diets, low in fresh fruits and vegetables have the most DNA nasal damag (EHP 104:160, 1996).We followed 04 healthy,young,nonsmoker males,newly arrived to SWMMC,for 25 days.They kept their previous 2,800 cal well-balanced diet with 14 servings of citrous fruits,10 of seasonal fruits and 24 of fresh vegetables per week.We added a placebo-controlled,randomized,double blind trial with tocopherol 200IU/day.ENT findings,respiratory symptomatology and atmosoheric pollutants were monitored daily.Nasal biopsy samples for the SCGE assay at pH>13 and DNA cell cycle analysis for FCM were taken on days 2,7,14 & 25 after arrival.The volunteers were exposed on their 1st day in the city to 7 03>0.12ppm,a maximal 03 peak of 0.263 ppm and a cumulative 12h 03 of 1.588 ppm and a final 25 day cumulative 03 of 26.98 ppn. The % of DNA nasal damaged cells (SSBś)was on average:40,46,37,43 at days 2,7,14 & 25 respectively for all subjects.The % of S was 7,24,26 & 21 in keeping with the brisk increase in %S associated with exposure to air pollutants(ATS 1997 CGL abstract).There were 10 differences in SCGE results or %S between placebo and Vit E subjects.Moreover,the % of nasal cells with DNA SSBś was well below the rates reported in undernourished subjects(90±6). A diet rich in fresh fruits and vegetables has a protective effect upon the nasal respiratory epithelium of outdoor exercising adults exposed to high ozone concentrations and other pollutsnts.Complementary Vit E 200 IU/day did not improve the midpoint assay results but decrease the incidence of epistaxis,upper respiratory symotoms and the development of squamous metaplastic areas in high flow nasal regions.