Ambient Viral and Bacterial Distribution during Asian Dust Storm in Taiwan

Abstract

Objectives: To evaluate the impacts of the occurrence and type of long-range transportation (LRT) on the distribution of virus and bacteria in Northern Taiwan by quantifying the levels of enterovirus influenza A virus and bacteria in ambient air on the days before during and after LRT and background days Also this study preliminarily investigates the relationships between the ambient bacterial concentrations with air pollutants and meteorological factors Methods and Materials: The present study monitors the Asian Dust Storm (ADS) events from September 2013 to April 2014 When ADS occurred in the desert and possibly affect Taiwan daily air samples were collected on the days before during and after ADS Also during this period a continuous 3-days sampling were performed in the second week of each month to take daily air samples for background days Two sampling stations located in Northern Taiwan were adopted: Cape Fukuei (CF Shimen District New Taipei City) and National Taiwan University (NTU Daan District Taipei City) Cassettes with 37-mm Teflon filters (0 2 ?m) were utilized to capture ambient enterovirus influenza Avirus and bacteria Daily filter samples were collected using vacuum air pumps for 24 hr After sampling reverse transcription quantitative PCR (RT-qPCR) was applied to quantify enterovirus and influenza A virus and qPCR and propidium monoazide coupled with qPCR were respectively used to quantify total and viable bacteria We would confirm whether the LRT belongs to ADS and its effect on Taiwan based on the data of meteorological conditions (temperature and wind speed from Taiwan Centeral Weather Bureau (Taiwan CWB)) and air pollutions (PM10 and PM2 5 from Taiwan Environmental Protection Administration (Taiwan EPA)) the source of air mass (48-hr backward trajectory produced by HYSPLIT model) and satellite images of MODIS sensor Spearman Correlation Coefficient was used to analyze the relationships that viable and total bacteria have with air pollutants (PM10 PM2 5 NO2 NO NOX CO O3 and SO2) and meteorological factors (temperature RH wind speed and cumulative rainfall) Results and Discussion: A total of two ADS (11/17/2013-11/18/2013 11/25/2013-11/29/2013) and three frontal pollution cases (FP) (09/16/2013-09/17/2013 10/12/2013-10/13/2013 01/03/2014-01/05/2014) were identified in this study Influenza A virus only detected in the samples collected on the days before and during the FP (1/3-1/5 2014) with concentrations of 0 87 and 10 19 (copies/m3) respectively In term of bacteria on background days the trend of cell concentrations at CF and NTU stations was similar showed without geographic difference However ADS affects the distribution of bacterial concentrations in the atmosphere at two stations in different levels The total (1 40 log copies/m3) and viable (0 85 log copies/m3) concentrations of bacteria during ADS days at CF station were higher than those detected after ADS (0 23-0 41 log copies/m3) For NTU station the total (1 44 log copies/m3) and viable (0 77 log copies/m3) concentrations of bacteria before ADS were the highest and followed by those found on the days during ADS (1 25 and 0 45 log copies/m3 for total and viable cells respectively) In term of FP events the impacts of FP were observed at not only CF station but also NTU station The days during and/or after FP have higher bacterial concentrations than the days before FP In FP event occurred in January the respective concentrations of total and viable bacteria were 0 60-1 62 and 0 34-0 78 log copies/m3 for the days during FP as well as 1 05-1 90 and 1 19-1 23 log copies/m3 for the days after FP which were more abundant than those quantified from the days before FP (0 57-1 19 and 0 17-0 80 log copies/m3 for total and viable cells respectively) Surprisingly this study found the bacterial viability were greater than 34% during the event days regardless LRT types showing the LRT can carry bacteria that are viable and may have adverse health effects The results of correlation analyses show that PM10 levels significantly and positively correlated with total (r=0 56 p

Date of Award	2015 Feb 17
Original language	English
Supervisor	Huey-Jen Jenny Su (Supervisor)