Jørgensen Jeanette Therming, Johansen Martin Søes, Ravnskjær Line, Andersen Klaus Kaae, Bräuner Elvira Vaclavik, Loft Steffen, Ketzel Matthias, Becker Thomas, Brandt Jørgen, Hertel Ole, Andersen Zorana Jovanovic
Centre for Epidemiology and Screening, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Danish Centre for Cancer Research, Danish Cancer Society, Copenhagen, Denmark.
Neurotoxicology. 2016 Jul;55:122-130. doi: 10.1016/j.neuro.2016.06.003. Epub 2016 Jun 2.
Air pollution has been considered a potent environmental risk factor for neuropathology through neuroinflammation and oxidative stress, which might also cause brain tumour formation. However, epidemiological evidence on the association between air pollution and brain tumours in humans is sparse, with no data on exposure to particles. In this study we aim to examine associations between long-term exposure to ambient air pollution and risk for development of brain tumours.
We used the Danish Nurse Cohort with 28,731 female nurses (age≥44years) recruited in 1993 or 1999 when self-reported information on lifestyle was collected. We obtained data on the incidence of brain tumours until 2013 from the Danish Cancer Register, and estimated annual mean concentrations of particulate matter with diameter<2.5μm (PM2.5), particulate matter with diameter<10μm (PM10), nitrogen oxides (NOx) and nitrogen dioxide (NO2) at the residence since 1990 using an atmospheric integrated chemistry-transport models system, and examined the association between the 3-year running mean of pollutants and brain tumour incidence using time-varying Cox regression, separately for total brain tumours, and for tumour subtypes by location (brain or meninges), and by malignancy (malignant or benign), and estimated hazard ratios and 95% confidence intervals per increase in interquartile range of exposure.
Of 25,143 tumour-free nurses at recruitment, 121 developed brain cancer during 15.7 years of follow-up. We found a weak positive association between total brain tumours and PM2.5 (1.06; 0.80-1.40 per 3.37μg/m(3)), NO2 (1.09; 0.91-1.29) per 7.5μg/m(3), and NOx (1.02; 0.93-1.12 per 10.22μg/m(3)), and none with PM10 (0.93; 0.70-1.23 per 3.31μg/m(3)). Associations with PM2.5 and NO2 were stronger for tumours located in meninges than in brain, and for benign than for malignant tumours. Finally, association of total brain tumours with PM2.5 was modified by BMI, and was statistically significantly enhanced in obese women (2.03; 1.35-3.05).
We found weak evidence for association between risk of brain tumours and long-term exposure to air pollution in women older than 44 years. However, we present novel results that obese women may be susceptible, as well as a positive tendency towards elevated risk for meninges and benign tumours, which require further investigation.
空气污染被认为是通过神经炎症和氧化应激导致神经病理学的一个强大环境风险因素，这也可能导致脑肿瘤形成。然而，关于空气污染与人类脑肿瘤之间关联的流行病学证据很少，且没有关于颗粒物暴露的数据。在本研究中，我们旨在探讨长期暴露于环境空气污染与脑肿瘤发生风险之间的关联。
我们使用了丹麦护士队列，该队列由1993年或1999年招募的28731名年龄≥44岁的女性护士组成，当时收集了她们关于生活方式的自我报告信息。我们从丹麦癌症登记处获取了截至2013年的脑肿瘤发病率数据，并使用大气综合化学传输模型系统估算了自1990年以来她们居住地直径<2.5μm的颗粒物（PM2.5）、直径<10μm的颗粒物（PM10）、氮氧化物（NOx）和二氧化氮（NO2）的年平均浓度，并使用时变Cox回归分别研究污染物3年移动平均值与脑肿瘤发病率之间的关联，分别针对总的脑肿瘤、按位置（脑或脑膜）以及按恶性程度（恶性或良性）划分的肿瘤亚型进行分析，并估计每增加一个四分位数间距暴露的风险比和95%置信区间。
在招募时无肿瘤的25143名护士中，有121名在15.7年的随访期间患了脑癌。我们发现总的脑肿瘤与PM2.5（每3.37μg/m³为1.06；0.80 - 1.40）、NO2（每7.5μg/m³为1.09；0.91 - 1.29）和NOx（每10.22μg/m³为1.02；0.93 - 1.12）之间存在微弱正相关，与PM10（每3.31μg/m³为0.93；0.70 - 1.23）无关联。与位于脑膜的肿瘤相比，PM2.5和NO2与位于脑的肿瘤之间的关联更强；与恶性肿瘤相比，与良性肿瘤的关联更强。最后，总的脑肿瘤与PM2.5之间的关联受到BMI的影响，在肥胖女性中统计学显著增强（2.03；1.35 - 3.05）。
我们发现44岁以上女性脑肿瘤风险与长期暴露于空气污染之间存在关联的证据较弱。然而，我们呈现了新的结果，即肥胖女性可能易感，以及脑膜和良性肿瘤风险升高的积极趋势，这需要进一步研究。
