Suspended particulate variations and mass size distributions of incense burning at Tzu Yun Yen temple in Taiwan, Taichung.

Ambient suspended particulate concentrations were measured at Tzu Yun Yen temple in this study. This is characteristic place of incense burning and indoor air pollution sampling site. A universal sampler, micro-orifice uniform deposited impactor (MOUDI) sampler and dry deposition plate were used to measure particulate concentrations. Tzu Yun Yen temple is a typical famous Buddhist-Taoist combined temple, where many pilgrims come from different areas and various belief systems indicating the eclecticism of the temple. The average number of people visiting this temple is above 5000 per day. The PM2.5/PM10 ratios ranged between 31.2 and 87.4% and averaged 69.6+/-12.3% during the incense-burning period, respectively. The results also demonstrated that the fine particulates concentrations (PM2.5) constituted the majority of indoor-suspended particulates at Tzu Yun Yen temple. PM10 concentration was 110.1 microg m(-3) for Zhong Yuan Jie (A festival on the seventh full moon in a lunar year, otherwise known as a summer lantern festival and (or) the commemoration of the dead. Almost all temples have maximum pilgrims for the commemoration of the dead on this day.) and the 1st or 15th of nong li (Nong li is a Chinese lunar calendar system in which 1 year is divided into fixed periods, and the beginning and end of a year is determined. The new moon and full moon are the 1st and 15th, respectively of each month in the Chinese lunar calendar. Many pilgrims appeared at each temple for blessing and good luck for themselves on the 1st and 15th of each Chinese lunar month.) with numbers higher than non-Zhong Yuan Jie and non-1st or -15th day of nong li (average = 85.5 microg m(-3)). In general, the average dry deposition flux (49.4 mg m(-2) day(-1)) in the indoor environment is lower than those measured in the outdoor environment (184.0 mg m(-2) day(-1)) in this study. The mean dry deposition flux of indoor/outdoor ratio was 46.2%. The average mass size distributions were bimodal with the major peaks within 0.56-1 microm and 5.6-10 microm, respectively during non-Zhong Yuan Jie and non-1st or -15th days of each month (Chinese lunar calendar). The average mass size distributions were bimodal with the major peaks within 0.18-0.32 microm and 5.6-10 microm, respectively during Zhong Yuan Jie and the 1st or 15th of nong li of each month (Chinese lunar calendar) at Tzu Yun Yen temple.