International Journal of Environmental Research and Public Health Article Application of Positive Matrix Factorization in the Identification of the Sources of PM2.5 in Taipei City Wen-Yuan Ho 1,*, Kuo-Hsin Tseng 1, Ming-Lone Liou 1, Chang-Chuan Chan 2 and Chia-hung Wang 3 1 Department of Environmental Protection, Taipei City Government, 6 Floor, No. 1, City Hall Road, Taipei 110, Taiwan;
[email protected] (K.-H.T.);
[email protected] (M.-L.L.) 2 College of Public Health, National Taiwan University, No. 17, Xu-Zhou Road, Taipei 100, Taiwan;
[email protected] 3 Sinotech Engineering Services, Ltd., 12 Floor, No. 171, Section 5, Nanjing E. Road, Songshan District, Taipei 105, Taiwan;
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[email protected]; Tel.: +886-2-2823-6160 Received: 19 April 2018; Accepted: 15 June 2018; Published: 21 June 2018 Abstract: Fine particulate matter (PM2.5) has a small particle size, which allows it to directly enter the respiratory mucosa and reach the alveoli and even the blood. Many countries are already aware of the adverse effects of PM2.5, and determination of the sources of PM2.5 is a critical step in reducing its concentration to protect public health. This study monitored PM2.5 in the summer (during the southwest monsoon season) of 2017. Three online monitoring systems were used to continuously collect hourly concentrations of key chemical components of PM2.5, including anions, cations, carbon, heavy metals, and precursor gases, for 24 h per day. The sum of the concentrations of each compound obtained from the online monitoring systems is similar to the actual PM2.5 concentration (98.75%).