As many studies showed the spatial heterogeneity in the association between particulate matter (PM) air pollution and low birth weight (LBW), few studies focused on the variation of local associations at the national scale and related areal characteristics. This study aimed to explore different approaches to estimating local effects of PM with an aerodynamic diameter ≤ 10 μm (PM₁₀) on LBW across 235 districts in South Korea, to investigate the spatial pattern of local associations, and to examine the relationship with local socio-demographic and environmental characteristics. LBW was identified in 5,692,650 mothers from birth certificate data for 2001-2013. We estimated individual annual-average concentrations of PM₁₀ at centroids of mothers’ residential districts by using a previously-validated prediction model. Then, we estimated district-specific odds ratios of LBW for PM₁₀ using modified geographically weighted logistic regression. Here, we applied four approaches with different neighborhood definitions: the distance-based approach within 20- and 40-km bandwidth and the hybrid approach replacing with adjacent districts for urban districts < 100 km². In addition, we compared district-specific socioeconomic indicators and emission estimates across three groups of districts that showed significantly positive, no, significantly negative associations. Medians of district-specific estimates of four approaches were similar to the global estimate and between each other. However, their variability differed with some unreasonably high estimates when a small distance was applied as the neighborhood definition, although spatial pattern was generally similar among the four. The hybrid approach based on the different neighborhood definition by urban and rural areas provided stable risk estimates. Higher risk districts in rural areas were found in more socioeconomically-deprived areas, whereas urban areas showed higher risk districts when their air pollution emissions were higher. Our approach and findings will help identify high risk areas and enhance understanding of geographic determinants.

由于许多研究表明颗粒物（PM）空气污染与低出生体重（LBW）之间的关联存在空间异质性，因此很少有研究关注全国范围内地方协会的变化以及相关的区域特征。这项研究旨在探索估算空气动力学直径≤10μm（PM ₁₀）的PM对韩国235个地区的LBW的局部影响的不同方法，以调查当地协会的空间格局，并研究与当地社会的关系-人口和环境特征。根据2001-2013年的出生证明数据，在5,692,650名母亲中发现了低出生体重。我们估算了PM _10的年平均浓度通过使用先前验证的预测模型确定母亲居住区的质心。然后，我们使用修改后的地理加权逻辑回归估计了PM ₁₀的LBW的地区特定优势比。在这里，我们采用了四种具有不同邻域定义的方法：20 km和40 km带宽内的基于距离的方法以及针对小于100 km ^2的市区用混合方法替换相邻区域的方法。此外，我们比较了三组地区的特定地区社会经济指标和排放估计值，这些指标显示出明显的正相关，没有显着的负相关。四种方法的地区特定估计值的中位数与全局估计相似，并且彼此之间相似。然而，尽管空间模式通常在这四个区域中相似，但是当以较小的距离作为邻域定义时，它们的变异性以一些不合理的高估计而不同。基于城市和农村地区不同邻里定义的混合方法提供了稳定的风险估计。农村地区的高风险区位于社会经济匮乏的地区，而城市地区的空气污染排放量较高时则显示较高的风险区。