Cross-sectional investigation of the effects of atmospheric particulate pollutants on pulmonary nodules in Shijiazhuang, China

Lung cancer is the leading cause of cancer deaths in China, and its incidence is closely related to increasing levels of air pollution. The purpose of this study was to investigate the relationship between atmospheric particulate pollutants (including O₃, CO, NO₂, SO₂, PM_2.5 and PM₁₀) of different ages, genders and seasons and pulmonary nodule occurrence in Shijiazhuang city. Using the time series analysis method, focusing on the monthly lag time, the relationship between the concentration of atmospheric particulate pollutants and the incidence of pulmonary nodules was analyzed to understand the effects of pollutants on different demographic and seasonal characteristics. Modest but statistically significant associations were observed between pulmonary nodule detection and atmospheric particulate pollutants. For every IQR increase in monthly concentrations, the relative risks were 1.059 (95% CI 1.006-1.116) for PM_2.5 and 1.117 (95% CI 1.037-1.204) for SO₂, with a 4 month lag. Converting to standardized 10 µg/m² increases, these correspond to 4.8 and 11.6% increases in nodule detection risk, respectively. Slightly stronger associations were observed in women compared to men, and in adults aged 60 and over, though effect sizes were modest with wide confidence intervals. These results suggest potential associations between air pollution exposure and pulmonary nodule detection, though the modest effect sizes and study limitations require cautious interpretation. The observed time-lag patterns and demographic differences may inform future research, but additional prospective studies are needed to establish causal relationships and clinical significance.