Chemical Senses Advance Access originally published online on December 14, 2005
Chemical Senses 2006 31(1):79-85; doi:10.1093/chemse/bjj019
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Effect of Air Pollution on Olfactory Function in Residents of Mexico City
1 Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, CP 04510 México DF, Mexico, 2 Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Carretera Tlaxcala-Puebla Km 1.5, CP 90070 Tlaxcala, Mexico and 3 Institut für Medizinische Psychologie, Universität München, Goethestrasse 31, D-80336 Munich, Germany
Correspondence to be sent to: Robyn Hudson, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, CP 04510 México DF, Mexico. e-mail: rhudson{at}biomedicas.unam.mx
To our knowledge there has been no study of the effect of everyday air pollution on olfactory function. It was therefore the aim of this study to compare the olfactory performance of long-term residents of Mexico City, an environment with high air pollution, with the olfactory performance of residents of the Mexican state of Tlaxcala, a region geographically similar to Mexico City but with low air pollution. Healthy volunteers [82 Mexico City subjects (MEX), 86 Tlaxcala subjects (TLX)] 20–63 years of age and balanced for age and gender between the two localities were tested for the perception of the odors of everyday beverages presented in squeeze bottles. When tested with ascending concentrations of stimuli in a three-way oddball paradigm, residents of Tlaxcala detected the odors of instant coffee and of an orange drink at significantly lower concentrations than residents of Mexico City. They also performed significantly better in discriminating between the two similar-smelling Mexican beverages horchata and atole in an oddball test. Significant differences between the two populations in overall olfactory performance were apparent in three of the four age classes (20- to 29-, 30- to 39-, and 40- to 49-year-old subjects) but not in the 50–63 years age class. About 10% of MEX subjects compared to about 2% of TLX subjects were judged to have poor olfactory function; all were from the older age classes (mean age: 48.6 years). Thus, air pollution in Mexico City appears to have a substantial impact on olfactory function even in young and middle-aged residents.
Key words: detection threshold, everyday odorants, odor discrimination, olfactory dysfunction