Neighborhood Parks and Recreationists' Exposure to Ozone: A Comparison of Disadvantaged and Affluent Communities in Los Angeles, California.

Urban parks are valued for their benefits to ecological and human systems, likely to increase in importance as climate change effects continue to unfold. However, the ability of parks to provide those myriad benefits hinges on equitable provision of and access to green spaces and their environmental quality. A social-ecological approach was adopted in a study of urban park use by recreationists in the City of Los Angeles, contrasting two affluent and two disadvantaged communities situated in coastal and inland zones. Twenty-four days of observations distributed across morning and afternoon time blocks were gathered, with observations in each day drawn from a pair of affluent and disadvantaged community parks. Observers noted location, gender, age, ethnicity/race, and level of physical activity of each visitor encountered during four scheduled observation sweeps on each day of field work. In addition, ozone dose exposure was measured through passive monitoring. Ozone dose exposure was calculated using average hourly ozone in ppb multiplied by METS (metabolic expenditures). Dose exposure was significantly higher in the disadvantaged community parks (with majority Latino use). Findings suggest that additional monitoring in disadvantaged communities, especially inland, may be prudent to facilitate community-based information as well as to assess the degree of potential impact over time. Additionally, mitigative strategies placed in urban parks, such as increased tree canopy may help to reduce the degree of risk and improve community resilience. Future research examining the positive outcomes from physically active use of urban parks may benefit from adopting a nuanced approach in light of the present findings.