Nitrogen dioxide pollution exposure is associated with olfactory dysfunction in older U.S. adults.
Olfactory dysfunction has profound effects on quality of life, physical and social function, and mortality itself. Nitrogen dioxide (NO2) is a pervasive air pollutant that is associated with respiratory diseases. Given the olfactory nerve's anatomic exposure to airborne pollutants, we investigated the relationship between NO2exposure and olfactory dysfunction.



The ability to identify odors was evaluated using a validated test in respondents from the National Social Life, Health, and Aging Project (NSHAP), a representative probability sample of home-dwelling, older U.S. adults age 57 to 85 years. Exposure to NO2pollution was assessed using measurements obtained from the U.S. Environmental Protection Agency (EPA) Aerometric Information Retrieval System (AIRS) ambient monitoring site closest to each respondent's home. We tested the association between NO2exposure and olfactory dysfunction using multivariate logistic regression.



Among older adults in the United States, 22.6% had impaired olfactory function, defined as ≤3 correct (out of 5) on the odor identification test. Median NO2exposure during the 365 days prior to the interview date was 14.7 ppb (interquartile range [IQR], 10.8 to 19.7 ppb). An IQR increase in NO2exposure was associated with increased odds of olfactory dysfunction (OR, 1.35; 95% CI, 1.07 to 1.72), adjusting for age, gender, race/ethnicity, education, cognition, comorbidity, smoking, and season of the home interview (n = 1823).



We show for the first time that NO2exposure is associated with olfactory dysfunction in older U.S. adults. These results suggest an important role for NO2exposure on olfactory dysfunction, and, potentially, nasal disease more broadly.
Pritzker School of Medicine, The University of Chicago, Chicago, IL.
Dara R
DR
Adams
Pritzker School of Medicine, The University of Chicago, Chicago, IL.
Gaurav S
GS
Ajmani
Department of Health Sciences, Bouve College of Health Sciences, Northeastern University, Boston, MA.
Vivian C
VC
Pun
Department of Public Health Sciences, The University of Chicago, Chicago, IL.
Kristen E
KE
Wroblewski
Department of Psychology, Northeastern Illinois University, Chicago, IL.
David W
DW
Kern
Department of Public Health Sciences, The University of Chicago, Chicago, IL.
L Philip
LP
Schumm
Department of Comparative Human Development and the Institute for Mind and Biology, The University of Chicago, Chicago, IL.
Martha K
MK
McClintock
Department of Health Sciences, Bouve College of Health Sciences, Northeastern University, Boston, MA.
Helen H
HH
Suh
Section of Otolaryngology-Head and Neck Surgery, The University of Chicago, Chicago, IL.
Jayant M
JM
Pinto
D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000032:analysis / Q000633:toxicity*; D016017:Odds Ratio; D009812:Odorants; D000857:Olfaction Disorders / Q000139:chemically induced* / Q000453:epidemiology; D055696:Olfactory Perception / Q000187:drug effects*; D014481:United States / Q000453:epidemiology
D000393:Air Pollutants; D009585:Nitrogen Dioxide
aged; air pollutants; air pollution; cross-sectional studies; nitrogen dioxide; olfaction disorders; smell