Fitness Performance Among Fifth Grade Students and Ambient Fine Particulate Matter, Chemical Constituents, and Sources in California

Abstract

BackgroundChildren are vulnerable to associations between fine particulate matter (PM2.5) and respiratory-related health, such as asthma. A potential explanation is that PM2.5 is associated with a reduced growth of lung function. Because exposure to PM2.5 is tied to lung performance, it may also be linked to reduced physical performance. However, few studies have explored the relationship between PM2.5 and physical performance. We examined the association between PM2.5 and its chemical constituents/sources and physical fitness performance of students in California for 2000-2007.MethodsFifth grade students at California public schools (n=4,041) are required to take a physical fitness test. The aerobic capacity assessment was used as an outcome to represent their cardiorespiratory endurance. The assessment has sex-specific standards, and each school reported the percentage of students who met the standards. Exposure data, including PM2.5, constituents, and sources, were obtained from the chemical transportation model with 4x4 km resolution. Annual averaged pollutant levels were assigned based on the grid of school’s location. A generalized estimating equation was conducted for each pollutant adjusted by year, urbanicity level, obesity rate, and poverty rate of the schools.ResultsOdds of failing the aerobic capacity assessment increased 3.4% (95% confidence interval: 0.3, 6.6) per interquartile range (IQR) increase in PM2.5 (10.8 µg/m3). Similarly, odds increased by 7.8% (4.4, 11.2) and 7.1% (3.3, 10.9) per IQR increase in PM2.5 organic carbon and on-road gasoline vehicles, respectively. We did not observe any notable difference between sexes in stratified analysis.ConclusionsOur study suggests that PM2.5, particularly traffic-related PM2.5, is associated with lowering an achievement of aerobic capacity. This supports previous findings that some PM2.5 constituents and sources are more toxic than other pollutants. Given that few studies have explored the associations between ambient pollution and physical performance among children, further study is warranted to solidify this relationship.