Han C, et al. J Korean Med Sci. 2018 Jun;33(30):e193. https://doi.org/10.3346/jkms.2018.33.e193

Although several studies have evaluated the association between fine particulate matter (PM_2.5) and acute lower respiratory infection (ALRI) in children, their results were inconsistent Therefore, we aimed to evaluate the association between short-term exposure to PM_2.5 and ALRI hospitalizations in children (0–5 years) living in seven metropolitan cities of Korea. The ALRI hospitalization data of children living in seven metropolitan cities of Korea from 2008 to 2016 was acquired from a customized database constructed based on National Health Insurance data. The time-series data in a generalized additive model were used to evaluate the relationship between ALRI hospitalization and 7-day moving average PM_2.5 exposure after adjusting for apparent temperature, day of the week, and time trends. We performed a meta-analysis using a two-stage design method. The estimates for each city were pooled to generate an average estimate of the associations. The average PM_2.5 concentration in 7 metropolitan cities was 29.0 μg/m³ and a total of 713,588 ALRI hospitalizations were observed during the 9-year study period. A strong linear association was observed between PM_2.5 and ALRI hospitalization. A 10 μg/m³ increase in the 7-day moving average of PM_2.5 was associated with a 1.20% (95% CI: 0.71, 1.71) increase in ALRI hospitalization. While we found similar estimates in a stratified analysis by sex, we observed stronger estimates of the association in the warm season (1.71%, 95% CI: 0.94, 2.48) compared to the cold season (0.31%, 95% CI: −0.51, 1.13). In the two-pollutant models, the PM_2.5 effect adjusted by SO₂ was attenuated more than in the single pollutant model. Our results suggest a positive association between PM_2.5 exposure and ALRI hospitalizations in Korean children, particularly in the warm season. The children need to refrain from going out on days when PM_2.5 is high.

The effects of climate change and air pollution on health have become major topics of discussion and conducting an assessment on the vulnerabilities of climate change is essential to providing a solution for it. This study assesses human vulnerability to the health effects of climate change and ozone. We classified 27 detailed vulnerability indicators into eight categories and assessed the vulnerability of 249 jurisdictions in South Korea by applying the Fuzzy Technique for Order Preference by Similarity to Ideal Situation method. The results indicated that metropolitan and major urban areas were more vulnerable than other areas. Furthermore, factors such as air pollution, meteorological conditions, a vulnerable environment, the distribution of disease, health/medical capacities, and air pollution control had a significant impact on vulnerability. A validity analysis was on the vulnerability assessment results and the number of new patients diagnosed with diseases associated with the cardiovascular system; the results indicated a 66.9% correlation, signifying a considerably high validity. The proposed method for assessing vulnerabilities in terms of the health effects of air pollution is objective and based on data; thus, it is expected to present a high degree of applicability. The results can also be a critical foundation upon which to establish health policies.

Ozone concentrations have increased in recent decades, and several studies have reported that long-term exposure to ozone increases the mortality risk induced by respiratory conditions. However, research on cause-specific mortality related to ozone exposure and respiratory diseases remains scarce. We constructed a retrospective cohort of 5,360,032 adults aged ≥ 65 years from the National Health Insurance Service of Republic of Korea, and death certificates were obtained from Statistics Republic of Korea to determine the cause of death between 2010 and 2019. The daily maximum 8 h average levels of ozone during the warm season annually (May–September) and other air pollutants were determined for the residential district. We analyzed the data using a time-varying Cox proportional hazards model with individual- and district-level covariates, incorporating a competing risk framework to address deaths from causes other than chronic obstructive pulmonary disease (COPD) and asthma. In our single-pollutant model with a 3-year moving average, a 1 ppb increase in ozone exposure was associated with a hazard ratio (HR) of 1.011 (95% confidence interval [CI]: 1.008–1.013) for COPD mortality and an HR of 1.016 (95% CI: 1.011–1.022) for asthma mortality. In our model adjusted for the presence of underlying diseases and district-level variables, the HRs were 1.009 (95% CI: 1.008–1.014) for COPD and 1.017 (95% CI: 1.011–1.023) for asthma, respectively. These associations remained robust in our two-pollutant model, except for NO₂ and COPD. A linear concentration–response relationship was identified between ozone concentration, COPD, and asthma mortality. In this large nationwide cohort study, long-term exposure to ozone was associated with an increased risk of death from COPD and asthma in older Korean adults.