Introduction

1. Objectives 1. To investigate the spatial variability of outdoor PM and NOx around Taipei basin. 2. To investigate the degree of spatial site representativeness of fixed-site air monitoring stations. 3. To develop a methodology for predicting the level of indoor air pollutants by outdoor concentration. 4. To assess exposure of PM and NOx among housewives in Taipei metropolis. Site Representativeness of Air Monitoring Stations and Indoor/Outdoor Nitrogen Oxide Level around Taipei Metropolis Ruei-Jhao Wong 1;Chang-Chuan Chan 1(1) Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan Figure 1. 2008 wind rose (Taipei station, Central Weather Bureau) Introduction Several studies have already shown that data from fixed-site air monitoring stations can not be representative for personal exposure because human spend about more than 80 % of their time indoors. It tend to conduct microenvironment sampling or personal sampling studies to assess subject’s exposure of pollutants. However, it is necessary to expand the practicability of fixed-site air monitoring stations to human. How can we appropriately utilize the measurement data of fixed-site air monitoring stations to investigate the exposure of occupants living in neighborhood of these stations? If we can use the data of monitoring stations to represent the air quality in outdoor area within a effective distance around a station. Then develop a regression model containing important potential predictor variables to predict indoor concentration of air pollutants by outdoor level. It will be useful when microenvironmental or personal sampling can not be conducted. • Materials and Methods • Measurement instrument: • The data will be collected using DUSTTM check (GRIMM Model 1.108) for particulate matter and portable gas analyzer (Interscan Series 4000) for nitrogen dioxide in indoor microenvironments such as bedroom or kitchen. The air samples will also be collected with Harvard Impactors for particulate matter and Ogawa passive badges for nitrogen oxide. Then analyze collected samples by ultra-microbalance (Mettler Toledo UMX2) and UV-visible recording Spectrophotometer (Shimadzu UV-160A) respectively. In addition, we will also arrange a mobile monitoring station to measure the air pollutants level around three fixed-site monitoring stations. • Site selection: • Firstly, we selected the top 100 villages from Taipei metropolis by a grade containing population density and European Study of Cohort for Air Pollution Effects (ESCAPE) cohort density. Secondly, picked out 40 villages to conform dispersing principal artificially from the top 100. Thirdly, we arrange half of the 40 villages to be traffic type sites and half to be urban background sites. • A street site is a site representing exposure to traffic pollution. Somewhat arbitrarily, a traffic intensity above 10,000 vehicles per day is considered as a traffic site. An urban background site is defined as a site that is not influenced substantially by sources in the ‘direct vicinity’ of the site. In a circle of 50 meter around the site no more than 3000 vehicles should pass daily. • Sampling location: • We will set Ogawa passive badges at the open balconies in 40 households (2nd or 3rd floor) agreeing to enter our study, and set several Ogawa badges outside on different floor of the same buildings. In addition, we will also set Harvard Impactors at the balconies in half of selected households and dispose a mobile monitoring station within several distances around three fix-site monitoring stations (Sin-Jhuang, Gu-Ting, and Si-Jhih). • As for indoor microenvironment, we will put Ogawa in kitchen and bedroom standing for maximum and longest exposure for housewives respectively. Moreover, we will ask several housewives to wear Ogawa badges at breathing zone for two weeks. Furthermore, we will use Dust check monitors and Interscan series 4000 for real-time monitoring in kitchen. Figure 2. 40 selected sampling sites in Taipei metropolis • 1~20: PM + NOX sites • 21~40: NOX only sites • Red color represents street type sites • Yellow color represents urban sites • Green color : • continuous site (Con) • weather station (CWB) Figure 3. Range of mobile monitoring station’s routes around three fix-site monitoring stations Future work Now we have already visited all selected households in the 40 villages. We plan to collect samples from late May to early August for the first season sampling program. All housewives will be asked to fill out a housing and household characteristic questionnaire to control ventilation and burning habits and other biases. In addition to household sampling, we will arrange a mobile monitoring station to park at assigned locations around three fixed-site monitoring stations (Sin-Jhuang, Gu-Ting, and Si-Jhih station). The period is one month per station.