Inland southern California is a region of public health concern, especially for children, given the area's perennially poor air quality and increasing sources of local pollution. One elementary school specifically is located only a few hundred yards from the San Bernardino Railyard, one of the busiest goods movement facilities in California, potentially increasing respiratory problems. Through ENRRICH (Environmental Railyard Research Impacting Community Health) Project, we assessed association of proximity to a major freight railyard on adverse respiratory health in schoolchildren. Respiratory screening was provided for children at two elementary schools: one near the railyard and a socio-demographically matched comparison school 7 miles away. Screening included testing for airway inflammation (FE NO), lung function (peak expiratory flow, PEF) and parent reported respiratory symptoms. Parental questionnaires collected additional information. Log-binomial and linear regression assessed associations. Children attending school near the railyard were more likely to exhibit airway obstruction with higher prevalence of abnormal PEF (<80%): prevalence ratio (PR) = 1.59 (95% CI 1.19-2.12). The association with inflammation was less clear. Children at the exposure school, who had lived 6 months or longer at their current address (vs. all children at that school) were more likely to have values suggesting inflammation (FE NO > 20 ppb) (PR = 1.44, 95% CI 1.02-2.02) and present with a trend for increased adverse respiratory symptoms. Children attending school near the railyard were significantly more likely to display respiratory health challenges. Ideally these low-income, low resource communities should be supported to implement sustainable intervention strategies to promote an environment where children can live healthier and thrive.