Aim:The aim of our study was to evaluate the relationship between major urban pollutants and the development of chronic respiratory failure in patients with IPF.

Materials and methods: The probability of presenting chronic respiratory failure was analyzed in 69 patients diagnosed with IPF who were being monitored in our unit of ILD from 2011 to 2020 and were related to the values of the main pollutants (CO, NO2, PM2.5, PM10, O3, SO2 and NOx) in the Comunidad de Madrid in the aforementioned period.

Results: The elevation of the accumulated average values of CO, NO2, PM2.5 and NOx were significantly associated with an increase of the probability of development of chronic respiratory failure in different periods. In the case of CO, an OR 1.62 (1.11-2.36) was observed for each increase of 0.1 mg/m3 (p=0.01) during the three months prior to the event and an OR 1.84 (1.1-3.06) over the previous six months. With respect to NO2, an OR 1.64 (1.01-2.66) (p=0.04) was obtained for six months before the event for each increase of 10 ?g/m3. As for PM2.5, an OR 37.93 (1.6-895) (p=0.02) was achieved over six months before the event for each increase of 10 ?g/m3. Finally, NOx revealed results with an OR 1.11 (1-1.23) (p=0.03), and OR 1.19 (1.03-1.38) (p=0.01) for each increase of 10 ?g/m3 during the three and six months prior to the event respectively. 

Conclusions: There is evidence to hypothesize that cumulative average values of CO, NO2, PM2.5 and NOx could increase the likelihood of developing chronic respiratory failure in patients with IPF