Kinetic of NO2 uptake by Phleum pratense pollen: Chemical and allergenic implications

• Published in: Environment international 2015-01, Vol.196, p.107-113
• Main Authors: Chassard, Guillaume, Choël, Marie, Gosselin, Sylvie, Vorng, Han, Petitprez, Denis, Shahali, Youcef, Tsicopoulos, Anne, Visez, Nicolas
• Format: Article
• Language: English
• Subjects: Air Pollutants - analysis; Air Pollutants - metabolism; Air pollution; Allergens - analysis; Chemical Sciences; Humans; Nitrogen Dioxide - analysis; Nitrogen Dioxide - metabolism; or physical chemistry; Ozone; Phleum - metabolism; Pollen; Pollen allergy; TH1/TH2 balance; Theoretical and; Uptake coefficient
• ISSN: 0269-7491; 0160-4120; 1873-6424
• DOI: 10.1016/j.envpol.2014.10.004

Phleum pratense pollen was exposed to NO2 in a reactor allowing a continuous analysis of NO2 concentration by FTIR. The uptake coefficient of NO2 on pollen was calculated postulating a first order kinetic reaction and a value of (1.1 ± 0.1) × 10−7 was determined. NO2 uptake was faster when the pollen water content was increased and when the pollen was pre-treated with ozone. The effect of NO2 exposure on pollen allergic properties was investigated by quantifying Th2- and Th1-associated chemokines in a model of human dendritic cells. Cellular analysis clearly showed that cells exposed to fumigated pollen favored the production of chemokines known to promote Th2-cell responses. Altogether these data demonstrate that NO2 uptake by pollen directly correlates with increased Th2 response in human cells, and are in favor of the involvement of NO2 pollution in the increase of allergic diseases. •NO2 was captured by the pollen surface with a very low uptake coefficient (∼10−7).•Ozone pre-treatment and a high pollen water content enhanced the capture of NO2.•Exposure to NO2 acidified the pollen surface.•Highly polluted pollen directly correlated with increased allergenicity in human. Irreversible NO2 uptake to pollen and the subsequent chemical and allergenic consequences.