Variation of PM 10 concentration at Kanglung, Bhutan Jigme Thinley 1,2 , Sangay Tenzin 1,3,* , Sherab Jatsho 1,4 1 Student, B.Sc. Physical Science (Physics Chemistry), Sherubtse College, Kanglung, Bhutan 2 Hometown: Sangmari, Lumang, Trashigang. Citizenship ID #: 11506004634 3 Hometown: Bazor, Drametse, Mongar. Citizenship ID #: 10705000139 4 Hometown: Tabi, Kurtoe, Lhuentse, Citizenship ID #: 10604001345 Abstract In this contemporary era, developing nations of the world encounter greater threat on health due to being exposed to polluted air caused by numerous developmental activities. Bhutan as one of the fast developing country cannot be an exception from being exposed to dust. This empirical report based on primary data is an attempt to investigate the production of PM10 by approximately 1500 population dwelling in the vicinity of Sherubtse College. The Respirable suspended particular matter (RSPM) was analyzed using Respirable Dust Sampler (RDS) AMP 460 NL and operated at an average flow rate of 0.9-1.4 m 3 /min free flow. The findings of this report indicate the existence of different proportion of PM10 in different month. This report further substantiates the idea of higher PM10 concentration during dry season and vice versa. The average PM10 concentration was calculated to be 28.48 μg/m 3 . Keywords: Particulate, PM10, Respirable dust, Kanglung, Sherubtse College 1. Introduction 1.1. Background Today, Sherubtse College itself is home to 104 staff and more than 1,100 students. It has been so for years and years back. On top, the college is flanked at the right by College Zangdhog- pelri, Gewog center, Royal Natural Resource Center, hospital, Upper Market, and Kanglung Primary school. Flanked at the left is by public Zangdhogpelri, Lower market, Bhutan Tele- com service, ATM and Jampelyang High School. Enclosing these all are people living on agricultural produces. Passing through Kanglung is Trashigang-Samdrup Jongkhar highway. Justifiable from the above accounts, with lots of amenities crowded to a point, the concern about particulates is inevitable. However, as usually speculated, not all particulates are haz- ardous. Particulates are composite of varying sizes. It was rec- ognized that particulates with aerodynamic diameter below 10 microns which are known as Respirable Dust are that which pose threat to health as they stay suspended in the air and can reach to lungs. These Respirable Dust particulate matters are called PM10. Those above 10 microns are not hazardous as they settle on the ground (DUST MEASUREMENT - BASIC INFORMATION, 2008). Owing to the health hazard of the Respirable dust, it is be- ing measured and studied all over the globe. Today after the limitations of count methods and total mass method, the Res- pirable and size-selective measurement method is being widely implemented. As discussed before, Sherubtse College being the epicenter of Kanglung, the Respirable Dust Sampler Evirotech APM 460 * To whom correspondence should be addressed. Email address: sangay10xin@gmail.com (Sherab Jatsho ) NL was stationed at college with a guarantee of accurate find- ings for Kanglung. Since its installation in 2004, it is still at the same spot i.e. on the rooftop of college cafeteria. 1.2. Objectives This report is compiled with the following objectives: • To get a track of the pattern of change of PM10 over the years • To account on the variation of the PM10 measurement • To gauge the deterioration of air quality of Kanglung • To explore if the PM10 variation is caused by local human activity 1.3. Scope If our report be tailed by same follow-ups, it has scopes to: a) Provide a hard evidence and basis for further studying the ambient air quality b) Be an invaluable testimony for the health state c) Guide the developmental plans of the region 2. Methods 2.1. Selection of station site The machine Respirable Dust Sampler Evirotech APM 460 NL is installed according to the recommendation that it should be at a minimum height of 1.5 m but not exceeding 15 m from the ground level (Yadav, Kumar, Singh, Jain, Sharma, & Zaidi, 2013). Based on above criterion, Respirable dust sampling sta- tion was positioned at the sensitive area, on top of college Cafe- teria exposing to ambient air. This machine was recommended due to the following advantages: c  Sherub Doenme: The Research Journal of Sherubtse College, 2012 Volume 12 Issue 1, ISSN (Print) 1027 0922, (Online) 2308 5452