胃癌（GC）仍然是中国甘肃省的一个重大健康问题，其发病率和死亡率超过全国平均水平。尽管公认的健康风险与空气动力学直径＜1μm (PM1) 的环境颗粒物相关，但 PM1 暴露与 GC 发病率之间的关系尚未得到广泛研究。 2013 年至 2021 年胃癌病例数据收集自中国甘肃省 262 家医院。同时收集归一化植被指数（NDVI）、国内生产总值（GDP）、饮酒和吸烟行为指数（DSBI）、PM1、PM2.5和PM2.5-1的数据。利用贝叶斯条件自回归 (CAR) 结合广义线性模型 (GLM) 和准泊松回归，我们评估了 PM1、PM2.5、PM2.5-1、NDVI、DSBI 和 GDP 对 GC 发病率的影响，同时调整潜在的混杂因素。我们的分析表明，在总体年龄标准化发病率 (ASIR) > 40 的地区，PM1 (μg/m3) 暴露与 GC 发病率呈显着正相关（相对风险 [RR]：1.023，95% 置信区间 [CI， 1.007, 1.039]），男性 ASIR >50（RR：1.014，95% CI [1.009，1.019]），女性 ASIR >20（RR：1.010，95% CI [1.002，1.018]）。在研究地区，PM2.5、PM2.5-1、DSBI 和 GDP 与 GC 发生率呈正相关，而 NDVI 呈负相关。我们的研究结果证明，在干旱地区的胃癌高危地区，PM1 暴露与胃癌发病率呈正相关。需要进一步的研究来阐明环境因素与 GC 之间复杂的非线性关系。这些见解可以为甘肃及类似地区改善胃癌控制和预防的策略提供参考。© 2024 UICC。

Gastric cancer (GC) remains a significant health concern in Gansu province, China, with morbidity and mortality rates surpassing national averages. Despite the recognized health risks associated with ambient particulate matter with an aerodynamic diameter <1 μm (PM1), the relationship between PM1 exposure and GC incidence has not been extensively studied. Data on GC cases from 2013 to 2021 were gathered from 262 hospitals in Gansu, China. Concurrently, data on the normalized vegetation index (NDVI), gross domestic product (GDP), drinking and smoking behavioral index (DSBI), PM1, PM2.5, and PM2.5-1 were collected. Utilizing a Bayesian conditional autoregressive (CAR) combined generalized linear model (GLM) with quasi-Poisson regression, we evaluated the impact of PM1, PM2.5, PM2.5-1, NDVI, DSBI, and GDP on GC morbidity while adjusting for potential confounders. Our analysis indicated that exposure to PM1 (μg/m3) is significantly positively correlated with GC incidence in regions with an overall age-standardized incidence rate (ASIR) >40 (relative risks [RR]: 1.023, 95% confidence intervals [CI, 1.007, 1.039]), male ASIR >50 (RR: 1.014, 95% CI [1.009, 1.019]), and female ASIR >20 (RR: 1.010, 95% CI [1.002, 1.018]). PM2.5, PM2.5-1, DSBI, and GDP were positively correlated with GC incidence, while NDVI was negatively correlated in the study regions. Our findings provided evidence of a positive correlation between PM1 exposure and GC incidence in high-risk areas of GC within arid regions. Further research is warranted to elucidate the complex nonlinear relationships between environmental factors and GC. These insights could inform strategies for improving the control and prevention of GC in Gansu and similar regions.© 2024 UICC.