The development of assessment procedure for exposure to open rice straw burning emission : a case study of school children in Thailand | |
| Author | Aungsiri Klinmalee |
| Call Number | AIT Diss. no.EV-08-11 |
| Subject(s) | Straw--Thailand Air Pollution--Thailand Burning of land--Thailand Incineration--Thailand |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Technology and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. EV-08-11 |
| Abstract | Thailand is an agricultural country where the paddy rice is the major crop. Currently, most of rice straw is disposed of by open burning which may contribute significantly to the ambient air pollution, personal exposure and consequently health effects. In this study, an integrated monitoring approach consists of the field burning experiment, ambient air monitoring and personal monitoring was conducted to assess the exposure levels and potential health effects in the school children in a rice growing area (Klong Luang, Pathumthani) where open rice straw burning emission would be significant. The smoke samples from open burning fields in Klong Luang were collected and analyzed for potential source signatures. The results show that the rice straw burning emission is characterized by a high fraction of PM2.5 in PMlO, elevated levels of several PAHs (fluoranthene, pyrene chrysene, BbF, BkF and BaP) and higher benzene to toluene ratio. Together with the results from previous study, i.e. high potassium ion (K+) and low BCIOC ratio in PM2.5, a set of source profiles was developed. Ambient air monitoring was done in both intensive burning area and a reference area (National park of Khao Yai) during both dry season (intensive burning season) and wet season for comparison. The rice straw burning signatures were found more pronounced in Klong Luang ambient samples than the reference area samples. Additionally, the characteristic pollutants, e.g. P AHs in Khao Yai and Klong Luang samples were different. P AHs were predominant in gaseous phase in Klong Luang samples similar to the smoke samples, whereas in Khao Yai more particulate P AHs were found. Burning events (hotspot) on MODIS imageries were assessed and the hotspot counts/km2 was higher in the dry season in the burning area. The hotspot counts were also correlated to CO and PM 1 0 measured at an automatic station in the area. Personal exposure monitoring (PEM) was conducted for selected 2 subjects in each area for PM2.5, BTEX, N02 and S02. The exposed levels were higher during the burning season in each area and higher in the burning area as compare to the reference area. Higher K+ and BC were also found in the PEM PM2.5 for Klong Luang subjects than the Khao Yai subjects. The source apportionment of PEM PM2.5 by the Chemical Mass Balance Model (CMB) identified the higher contribution of biomass burning during the dry season in the burning area while in the wet season traffic emission dominated. Simple health effects indicators such as lung functions (measured) and bronchitis score (estimated from the questionnaire survey of 50 school children in each area) were also analyzed which did not show the statistically significant difference between the compared variables. Birth weight records in hospitals show the higher weight of new born infants in the reference area than the burning area. A newly introduced indicator, FEVl/BMI ratio, however was statistically higher in the reference area than the burning area. The results suggest the causative relationships between rice straw emission, ambient and exposure air pollution levels of the children in the burning area. Additional health indicators would be required and the multivariate analysis could be conducted to reveal the effects of the source on the school children health in the burning area. The assessment procedure developed in this study can be applied in other studies to assess the effects of a major air pollution source though further improvement is still required. In particular, some advanced techniques such as biomarkers should be identified and used for the direct link between the source and exposure |
| Year | 2008 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. EV-08-11 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Nguyen Thi Kim Oanh |
| Examination Committee(s) | Visvanathan, Chettiyappan ;Nowarat Coowanitwong |
| Scholarship Donor(s) | Royal Thai Government Fellowship |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2008 |