MEASUREMENTS OF FORMALDEHYDE AND ACETALDEHYDE IN THE ATMOSPHERE OF MEXICO-CITY

Ambient levels of carbonyls were measured at the University of Mexico campus, Mexico City. Only formaldehyde and acetaldehyde were measured, since aldehydes with higher molecular weight were not detected. The m ost abundant aldehyde was formaldehyde, with an overall ratio CH3CHO/H 2CO of 0.43. Maximum concentrations occurred for formaldehyde at 10:00 h while for acetnldehyde at 8:00 h. Comparing the concentration measu red in this work with those in urban areas it was found that the forma ldehyde and acetnldehyde levels in Mexico City are among the highest r eported in the literature.