Relationship of particulate matter and ozone with 3-nitrotyrosine in the atmosphere

Abstract The prevalence of allergic diseases has increased in the past few decades. Bio-aerosol proteins and their chemical modifications, such as 3-nitrotyrosine (3-NT), in the atmosphere have been attracting attention due to their promotive effects on allergies. 3-NT is generated from the amino acid, tyrosine, through a reaction with ozone (O 3 ) and nitrogen dioxide (NO 2 ). However, the underlying mechanisms have not yet been elucidated in detail. Therefore, we measured 3-NT and evaluated the relationships among 3-NT and various pollutants such as sulfur dioxide (SO 2 ), NOx (NO + NO 2 ), ozone (O 3 ), PM 7 , total suspended particulate matter (TSP) containing proteins, humidity, and temperature. 3-NT positively correlated with O 3 , SO 2 , humidity, and temperature, and negatively correlated with NOx. A multiple regression analysis showed that 3-NT positively associated with O 3 , humidity, and PM 7 . O 3 positively associated with 3-NT and PM 7 , and negatively associated with NOx and humidity. These results suggest that 3-NT is generated from PM proteins through a reaction with O 3 under high humidity conditions, and that the measurement of 3-NT is important and useful for the research of O 3 .