Background

Short- and long-term spatiotemporal variation in exposure to air pollution is associated with respiratory morbidity in areas with moderate-to-high level of air pollution, but very few studies have examined whether these associations also exist in areas with low level exposure.

Objectives

We assessed the association between spatial variation in long-term exposure to PM_2.5 and NO₂ and hospitalisation for all respiratory diseases, asthma, chronic obstructive pulmonary disease (COPD), and pneumonia, in older adults residing in Sydney, Australia, a city with low-level concentrations.

Methods

We recorded data on hospitalisations for 100,084 participants, who were aged >45 years at entry in 2006–2009 until June 2014. Annual NO₂ and PM_2.5 concentrations were estimated for the participants' residential addresses and Cox proportional hazards regression was used to model the association between exposure to air pollutants and first episode of hospitalisation, controlling for personal and area level covariates. We further investigated the shape of the exposure-response association and potential effect modification by age, sex, education level, smoking status, and BMI.

Results

NO₂ and PM_2.5 annual mean exposure estimates were 17.5 μg·m⁻³ and 4.5 μg·m⁻³ respectively. NO₂ and PM_2.5 was positively, although not significantly, associated with asthma. The adjusted hazard ratio for a 1 μg·m⁻³ increase in PM_2.5 was 1.08, 95% confidence interval 0.89–1.30. The adjusted hazard ratio for a 5 μg·m⁻³ increase in NO₂ was 1.03, 95% confidence interval 0.88–1.19. We found no positive statistically significant associations with hospitalisation for all respiratory diseases, and pneumonia while negative associations were observed with COPD.

Conclusions

We found weak positive associations of exposure to air pollution with hospitalisation for asthma while there was no evidence of an association for all respiratory diseases.

中文翻译：

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长期暴露于低浓度的空气污染物中和呼吸系统疾病的住院治疗：澳大利亚的一项前瞻性队列研究

背景

在中等至高水平空气污染地区，空气污染暴露的短期和长期时空变化与呼吸系统疾病的发生有关，但是很少有研究检查在低水平暴​​露地区是否也存在这些关联。

目标

我们评估了居住在澳大利亚悉尼市的老年人的长期暴露于PM _2.5和NO _2的空间变化与所有呼吸系统疾病，哮喘，慢性阻塞性肺疾病（COPD）和肺炎住院的相关性。低浓度浓度。

方法

我们记录了2006年至2009年至2014年6月入院的100,084名年龄大于45岁的参与者的住院数据，直到2014年6月。估计参与者的住所地址的年度NO ₂和PM _2.5浓度，并使用Cox比例风险回归对风险进行建模。空气污染物暴露与住院第一发作之间的关联，控制个人和地区水平的协变量。我们进一步研究了暴露-反应关联的形状以及按年龄，性别，教育程度，吸烟状况和BMI进行的潜在影响修正。

结果

NO ₂和PM _2.5的年平均暴露估计分别为17.5μg·m ^-3和4.5μg·m ^-3。NO ₂和PM _2.5与哮喘呈正相关（尽管不显着）。PM _2.5增加1μg·m ^-3时，调整后的危险比为1.08，95％置信区间为0.89-1.30。NO ₂增加5μg·m ^-3时，调整后的危险比为1.03，95％置信区间为0.88-1.19。我们发现与所有呼吸系统疾病和肺炎的住院均无统计学意义的正相关，而与COPD呈负相关。

结论

我们发现暴露于空气污染与哮喘住院之间存在弱的正相关性，而没有证据表明所有呼吸系统疾病均具有相关性。