Potential exposure to airborne pesticides in homes : a case study in Bangkok Metropolitan Region, Thailand | |
| Author | Prapat Pentamwa |
| Call Number | AIT Diss. no.EV-08-13 |
| Subject(s) | Air--Pollution--Thailnd--Bangkok Pesticides--Environmental aspects--Thailand--Bangkok |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. EV-08-13 |
| Abstract | The overall goal of this study is to provide a comprehensive assessment of the pesticide levels and potential exposure to pesticides in homes in the Bangkok Metropolitan Region (BMR), Thailand. A comprehensive survey for of 280 representative households in urban (l08), suburban (l02) and rural (70) areas of BMR was conducted to produce a database on the types, active ingredients and application methods. Most households indicated that mosquitoes were the main indoor nuisance (71.1 %). Of 22 different available commercial products containing 12 different active ingredients the pyrethroids pesticides, rating moderate toxicity, are the most common. The levels of 41 target chemicals in selected 8 homes of BMR were characterized during the dry season of 2006-2007. These include 25 organochlorine pesticides (OCP), of which 17 are persistent organic pollutant (POP) pesticides, 7 pyrethroids pesticides and 9 polychlorinated biphenyls (PCBs). Airborne samples were taken over 24-h and analyzed by GC-ECD following US EPA TO-lOA method. Indoor air concentrations are higher than the outdoor levels for most chemicals hence the 1/0 ratios are mostly above 1.0. Among the OCPs, heptachlor was found at the highest concentrations for urban homes (5.2±3.1 ng/m3 indoor and 2.6±OA ng/m3 outdoor). PCBs profiles are dominated by the lighter congeners with the highest levels found for PCB31 (lOA nglm3 indoor of urban homes). Both children and adults in the participating 8 homes spent on average, 83.3% of their time indoors at home and other indoor places. The estimated potential absorbed doses by inhalation exposure route for children were greater than adults for most of OCPs and PCBs compounds about 2 times. The potential absorbed doses of children and adults for the maximally detected heptachlor compound was still significantly lower than the acceptable daily intake value. To study the possible pathways of pesticides applied indoors, a household insecticide containing permethrin and cyfluthrin as active ingredients was sprayed in a closed room of 22.5 m3 (W 2.9m x L 3.35m x H 2.32m). The spray was done for 15 seconds as recommended in the label instruction of the container. The airborne insecticides were peaked right after the spraying, i.e. around 20 minutes (permethrin at 40.7 !lg/m3 and cyfluthrin at 2.9 !lg/m3) and dropped dramatically after one hour following the application. During the first 20 minutes after the application, a large portion of those chemicals were depleted or lost (>47%). Thus, the total amount found in indoor air, wall, floor and ceiling compartments consisted of less than 53%. Eight days after applications, none of these chemicals were detected in any sampling matrices. The half life of both chemicals is likely to be in the same ranged (0.93 to 1.04 hours) in the room. One day after application of the pesticides (permethrin and cyfluthrin) in a closed room is a safe enough period for the occupants to re-enter homes |
| Year | 2008 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. EV-08-13 |
| 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 and Management (EV) |
| Chairperson(s) | Nguyen Thi Kim Oanh; |
| Examination Committee(s) | Preeda Parkpian ;Perera, L. A. S. Ranjith; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2008 |