Association of Protein and Endotoxin in Outdoor Air with Emergency Department Visits for Children and Adults with Asthma in Fukuoka, Japan

We examined the association of biological components in airborne particles, i.e., proteins and endotoxins, in outdoor air with asthma exacerbation in the Fukuoka metropolitan area, Fukuoka, Japan. Data on emergency department (ED) visits for asthma in children (age, 0-14 years) and adults (age, 15-64 years) were collected at a medical center from December 2014 to November 2015. One hundred eighty-one children and 143 adults visited the ED for asthma, and the weekly number of ED visits in children increased in autumn, i.e., September (second week) to November (first week). Fine (aerodynamic diameter ≤2.5 µm) and coarse (≥2.5 µm) particles were collected for 3 or 4 weeks per month, and protein and endotoxin concentrations were analyzed. Protein was largely prevalent in fine particles (0.34-7.33 µg/m³), and concentrations were high in April, May, June, and October. In contrast, endotoxin was mainly included in coarse particles (0.0010-0.0246 EU/m³), and concentrations were high in September (third week), October (first, second, and fourth weeks), February (fourth week), and July (first week). The results of a Poisson regression analysis indicated that endotoxin (in fine and coarse particles alike) was a significant factor for ED visits related to asthma in children, even after adjusting for meteorological factors, i.e., temperature, relative humidity, and wind speed. However, there was no association between environmental factors and ED visits for asthma in adults. These results suggest that endotoxin in outdoor air is significantly associated with an increased risk of asthma exacerbation in children.

Ambient viral and bacterial distribution during long-range transport in Northern Taiwan

Long-range transport (LRT) reportedly carries air pollutants and microorganisms to downwind areas. LRT can be of various types, such as dust storm (DS) and frontal pollution (FP); however, studies comparing their effects on bioaerosols are lacking. This study evaluated the effect of LRT on viral and bacterial concentrations in Northern Taiwan. When LRT occurred and possibly affected Taiwan from August 2013 to April 2014, air samples (before, during, and after LRT) were collected in Cape Fugui (CF, Taiwan's northernmost point) and National Taiwan University (NTU). Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was applied to quantify influenza A virus. qPCR and qPCR coupled with propidium monoazide were, respectively, used to quantify total and viable bacteria. Types and occurrence of LRT were confirmed according to the changing patterns of meteorological factors and air pollution, air mass sources (HYSPLIT model), and satellite images. Two Asian DS and three FP cases were included in this study. Influenza A virus was detected only on days before and during FP occurred on January 3-5, 2014, with concentrations of 0.87 and 10.19 copies/m³, respectively. For bacteria, the increase in concentrations of total and viable cells during Asian DSs (17-19 and 25-29 November 2013) was found at CF only (from 3.13 to 3.40 and from 2.62 to 2.85 log copies/m³, respectively). However, bacterial levels at NTU and CF both increased during FP and lasted for 2 days after FP. In conclusion, LRT increased the levels of influenza A virus and bacteria in the ambient air of Northern Taiwan, particularly at CF. During and 2 days (at least) after LRT, people should avoid outdoor activities, especially in case of FP.