MEXICO CITY -- Mexico City had its cleanest year of the decade in 1999, the government announced in newspaper advertisements Sunday.
According to the city government, smog levels forced declaration of an emergency only three times -- covering five days -- during the year. The best previous year during the decade had been 1996, when there were 10 emergencies covering 34 days.
The worst occurred in 1991, when there were 27 emergencies covering 177 days.
Even so, ozone levels in Mexico City's air were considered "acceptable" only 65 days during 1999, up from 37 in 1990.
The 1999 smog record has political implications because the man who was mayor of Mexico City for most of the past year, Cuauhtemoc Cardenas, recently resigned to run for president.
In full-page newspaper ads, the city government said pollution had been reduced by putting more vapor traps on gasoline pumps, increasing industrial and car inspections and stepping up firefighting and reforestation programs.