Cellular and Molecular Research Center, Sabzevar University of Medical Sciences, Sabzevar, Iran.
ISGlobal, Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
Sci Total Environ. 2020 Jun 20;722:137933. doi: 10.1016/j.scitotenv.2020.137933. Epub 2020 Mar 14.
Exposure to air pollution is associated with adverse health effects; however, the available evidence of its association with telomere length (TL), an early marker of ageing, in children is still scarce with no study available for preschool children. This study aimed to investigate the association of exposure to air pollution and traffic indicators at home and kindergarten with relative leukocyte TL (LTL) in preschool children. This cross-sectional study included 200 preschool children (5-7 years old) recruited from 27 kindergartens in Sabzevar, Iran (2017). Outdoor annual average levels PM, PM, and PM at residential address and kindergartens were estimated applying land use regression (LUR) models. Moreover, indoor levels of PMs at kindergartens were measured for four days in each season resulting in a total of 16 days of measurements for each kindergarten. Total streets length in different buffers and distance to major road were calculated as traffic indicators at residential address and kindergartens. We applied quantitative real-time polymerase chain reaction (qRT-PCR) to measure relative LTL in blood samples obtained from children. Mixed linear regression models were developed with qPCR plate and kindergarten as random effects, to estimate association of each pollutant and traffic indicator with LTL, controlled for relevant covariates. Higher concentrations of outdoor PM, PM, and PM, at home and kindergartens were associated with shorter relative LTL. Similarly, increase in indoor PM concentrations at kindergartens was associated with shorter relative LTL (β = -0.18, 95% CI: -0.36, -0.01, P-value < 0.01). Moreover, higher total street length in 100 m buffer around residence and lower residential distance to major roads were associated with shorter relative LTL (β = -0.25, 95% CI: -0.37, -0.13, P-value < 0.01, and 0.32, 95% CI: 0.20, 0.44, P-value < 0.01, respectively). Overall, our study suggested that higher exposure to air pollution and traffic at kindergarten and residential home were associated with shorter relative LTL in preschool children.
空气污染暴露与不良健康影响有关；然而，目前关于其与端粒长度（TL）的关联的证据仍然很少，TL 是衡量衰老的早期标志物，且针对学龄前儿童的研究尚不存在。本研究旨在调查家中和幼儿园空气污染和交通指标暴露与学龄前儿童相对白细胞 TL（LTL）的关系。本横断面研究纳入了 200 名来自伊朗萨卜泽瓦尔的 27 家幼儿园（2017 年）的学龄前儿童。采用基于土地利用的回归（LUR）模型估算了家庭住址和幼儿园的 PM、PM 和 PM 年平均室外浓度。此外，每个季节在幼儿园内测量了 PM 的室内浓度，每个幼儿园总共测量了 16 天。计算了不同缓冲区的总街道长度和到主要道路的距离作为家庭住址和幼儿园的交通指标。我们应用定量实时聚合酶链反应（qRT-PCR）测量了从儿童采集的血液样本中的相对 LTL。采用混合线性回归模型，以 qPCR 板和幼儿园为随机效应，估计每个污染物和交通指标与 LTL 的关联，同时控制了相关协变量。家庭住址和幼儿园中 PM、PM 和 PM 浓度升高与相对 LTL 缩短有关。同样，幼儿园内 PM 浓度升高与相对 LTL 缩短有关（β=-0.18，95%CI：-0.36，-0.01，P 值<0.01）。此外，家庭住址 100m 缓冲区总街道长度增加和家庭住址距主要道路距离减小与相对 LTL 缩短有关（β=-0.25，95%CI：-0.37，-0.13，P 值<0.01，和 0.32，95%CI：0.20，0.44，P 值<0.01）。总体而言，我们的研究表明，幼儿园和家庭住址空气污染和交通暴露增加与学龄前儿童相对 LTL 缩短有关。
