Concentration of particulate matter (PM) in Bangkok Metropolitan Region (BMR) is normally higher than the ambient air quality standard of Thailand, especially during winter. However, the linkage between PM and human health in this area is underreported. This study aimed to investigate the relationship between PM and outpatient department (OPD) visits for respiratory diseases among children aged 0–14 years in BMR. OPD visit data were obtained from the National Health Security Office from January, 2015 to December, 2018. Air pollution data, including particulate matter with aerometric diameter up to 2.5 μm (PM_2.5) and 10 μm (PM₁₀), as well as meteorological data were obtained from the Pollution Control Department during the same period. Two-stage approach was used to investigate the association between PM and OPD for respiratory disease among children in BMR. In the first stage, time-stratified case-crossover design with conditional logistic regression model was used to examine province-specific estimate. In the second stage, the province-specific estimate was pooled to derive BMR estimate using random-effect meta-analysis through maximum likelihood estimation. Odds ratio of respiratory OPD among children in BMR per 10 µg/m³ increase in PM₁₀ and PM_2.5 was 1.0256 (95% CI: 1.0160, 1.0325) and 1.0338 (95% CI: 1.0091, 1.0585), respectively. This finding suggests that an increase of PM₁₀ and PM_2.5 was associated with increased risk of OPD for respiratory disease among children in BMR. Therefore, local government should develop and improve the existing air pollution control strategies to reduce PM concentration.

曼谷都会区 (BMR) 的颗粒物 (PM) 浓度通常高于泰国的环境空气质量标准，尤其是在冬季。然而，在这一领域 PM 与人类健康之间的联系却被低估了。本研究旨在调查 BMR 中 0-14 岁儿童 PM 与呼吸系统疾病门诊 (OPD) 就诊之间的关系。OPD访问数据来自国家卫生安全办公室2015年1月至2018年12月。 空气污染数据，包括空气直径达2.5微米（PM _2.5）和10微米（PM ₁₀）的颗粒物)，以及同期从污染控制署取得的气象数据。使用两阶段方法研究 BMR 儿童呼吸系统疾病的 PM 和 OPD 之间的关联。在第一阶段，使用条件逻辑回归模型的时间分层病例交叉设计来检查特定省份的估计。在第二阶段，通过最大似然估计使用随机效应荟萃分析汇总特定省份的估计值以得出 BMR 估计值。PM ₁₀和 PM _2.5每增加10 µg/m ³儿童呼吸 OPD 的比值比分别为 1.0256（95% CI：1.0160、1.0325）和 1.0338（95% CI：1.0091、1.0585）。这一发现表明 PM 的增加₁₀和 PM _2.5与 BMR 儿童患呼吸系统疾病的 OPD 风险增加有关。因此，地方政府应制定和改进现有的空气污染控制策略，以降低 PM 浓度。