Particulate matter levels and children's lung function in a rural cohort near a drying saline lake

The drying Salton Sea in California is a growing source of wind-blown dust, raising particulate matter (PM) levels in surrounding areas. The impacts of these exposures on children's lung function remain poorly understood. We examined the relationship between PM levels and lung function in children near the Salton Sea.

We enrolled 491 children (mean age: 10.2 years), who were followed over ~1.5 years, contributing 1,269 lung function assessments. Forced expiratory volume in the first second of exhalation (FEV₁) and forced vital capacity (FVC) were measured using a commercial spirometer. Average PM concentrations were estimated for 3 and 12 months preceding each spirometry assessment, using 12 stationary monitors operated by the California Air Resources Board. Analyses were performed using mixed effects linear models adjusting for demographics and underlying health conditions.

Each 1 µg/m³ increase in average PM_2.5 exposure over 12 months before assessment was associated with a 31.5 ml lower FVC (95% confidence interval [CI] = -57.2, -5.9) and a 32.7 ml lower FEV₁ (95% CI = -56.4, -8.9). A 10-µg/m³ increase in average PM₁₀ exposure over 12 months was associated with a 146.6 ml reduction in FVC (95% CI = -230.4, -62.9) and a 122.0 ml reduction in FEV₁ (95% CI = -197.8, -46.2). Associations within a 3-month exposure window showed similar results. PM exposure was associated with impaired lung function in both asthmatic and non-asthmatic children, with a slightly greater impact observed in those with asthma.

PM exposure near the Salton Sea is related to reduced lung function of pediatric residents.