Personal Exposure to Black Carbon at School and Levels of Fractional Exhaled Nitric Oxide in New York City.

BACKGROUND

Schools are often located near traffic sources, leading to high levels of exposure to traffic-related air pollutants, including black carbon (BC). Thus, the school environment could play in a significant role in the adverse respiratory health of children.

OBJECTIVES

Our objective was to determine associations between personal BC levels at school and airway inflammation [i.e., fractional exhaled nitric oxide (FeNO)] in school-age children. We hypothesized that higher school BC (SBC) would be associated with higher FeNO.

METHODS

Children 9-14 years of age in New York City (NYC) () wore BC monitors for two 24-h periods over a 6-d sampling period, repeated 6 months later. SBC was defined as the average personal BC concentrations measured during NYC school hours (i.e., 0830-1430 hours). FeNO was measured following each 24-h BC monitoring period. Multivariable linear regression in generalized estimating equation models were used to examine associations between SBC and FeNO. Results are presented as percentage difference (PD) in FeNO.

RESULTS

Personal BC at school was associated with higher FeNO ( higher FeNO per BC (95% CI: 1.31, 13.9), ]. Compared with BC exposure during school, a smaller PD in FeNO was observed in association with BC exposure while commuting to and from school [ (95% CI: 0.70, 13.3), ]. Personal BC in non-school environments and residential BC were not associated with FeNO (). A significant association between personal BC at school and FeNO was observed among children with seroatopy who did not have asthma [ (95% CI: 4.81, 40.9), ].

DISCUSSION

Schools may be important sources of BC exposure that contribute to airway inflammation in school-age children. Our results provide rationale for interventions that target improved air quality in urban schools and classrooms. https://doi.org/10.1289/EHP8985.