VOCs Ambient Air Monitoring Report

Transcription

1 VOCs Ambient Air Monitoring Report Pollution Control Department and Department of Environmental Quality Promotion Ministry of Natural Resources and Environment

2 2 List of abbreviations BKK ERTC GC/MS HAP JICA IEAT MTP PCD O 3 µg/m 3 VOCs WHO Bangkok Environmental Research and Training Center Gas Chromatograph Mass Spectrophotometer Hazardous Air Pollutants Japan International Cooperation Agency Industrial Estate Authority of Thailand Maptaphut Pollution Control Department Ozone microgram per cubic meter Volatile Organic Compounds World Health Organization

3 3 List of Working Members Pollution Control Department Dr. Sarawut Thepanondh Ms. Waroonphan Jaruphan Ms. Amornphat Tadsanaprasittipol Ms. Jarinporn Tippamongkol Department of Environmental Quality Promotion Ms. Wanna Laowagul Dr. Hathairattana Garivate JICA Expert Mr. Munehiro Fukuda Mr. Shirane Yoshiharu Dr. Seiji Watanabe Dr. Kiyoshi Imamura

4 4 Section 1: Introduction Background of the project VOCs (Volatile Organic Compounds: VOCs) are defined by WHO (World Health Organization) as organic compounds having boiling point below degree Celsius; under this definition, numerous organic compounds fall into this category. VOCs are released easily from a source to the ambient air and cause air pollution. In recent years, Thailand has faced environmental problems suspected to be caused by VOCs. Hence, understanding the current situation and taking appropriate measures are crucial. Two distinctive characteristics of VOCs should be noted; one being the harmful nature of inhaling the substances (called HAP: Hazardous Air Pollutants) and another being property of being a precursors of ozone and aerosols from photochemical reaction. Hence, a comprehensive and multiple views supported by accumulation of scientific data gathered by monitoring are necessary to establish environmental and emission standards and develop measures to mitigate air pollution caused by VOCs. Under these circumstances, Pollution Control Department (PCD) of Ministry of Natural Resources and Environment has requested Japan technical cooperation to develop environmental and emission standards of VOCs for Thailand. The project has been carried out during March 2006 to February Project activities comprise of establishing of monitoring network, emission inventory and proposing the environmental and emission standard of VOCs. In order to elucidate the status of VOCs pollution in Thailand, the project has collaborated with Department of Environmental Quality Promotion (DEQP) to utilize their monitoring data under the ongoing technical cooperation project with Japan International Cooperation Agency (JICA). This report summarizes the ambient monitoring data of VOCs, measured from these two projects. Concentrations of VOCs, measured in ambient air from several areas such as residential, near source and roadside areas are reported. Spatial and temporal analysis of VOCs concentrations are also carried out to elucidate VOCs situation in the study areas with potential to have high level of VOCs in the country. Objectives 1. To evaluate the ambient concentration of VOCs measuring in urban, near source and residential areas and to establish VOCs monitoring network for Thailand 2. To illustrate the spatial and temporal distribution of VOCs concentration Scope of work The ambient VOCs monitoring program was established in August 2006 as part of the Development of Environmental and Emission Standards of VOCs Project. This monitoring network measures VOCs in the study areas which are Bangkok and vicinity and Rayong. The goal is to investigate air quality related to VOCs in the country's urban, residential and near source areas. Measurement data defines actual air quality impacts of the VOCs. The data is used in the design and management of

5 5 Thailand s air quality, including risk assessment, modeling, planning and trend analysis. A formal quality assurance program is in place to define the data quality of this new database. The program includes quality control of transportation during sampling by using travel blank, precision checking of measurements by collecting and analyzing duplicate samples. The accuracy and validity of the data is maintained by the use of National Institute of Standards and Technology (NIST) traceable calibration standards and comparison of results to other independent toxics monitoring methodologies. Quality assurance results are also a part of this report. One of the characteristics of VOCs in the ambient air is that concentration may fluctuate greatly in both space and time. Concentration of VOCs needs to be discussed with average annual value for considering health effect from long-term exposures. In other words, a large number of data gathered during short term monitoring in many monitoring sites may not be adequate for the evaluation the VOCs situation that area. Consequently, the monitoring sites and monitoring period were selected based on assumption for the area that is most concerned from VOCs pollution. Section 2: Methodology Criteria of sampling site representative Selection of sampling site Monitoring sites were placed in the area of Maptaphut district, Rayong province and in Bangkok and vicinity areas. Sampling locations are selected to represent industrial, roadside, and residential (general) areas. Collections of information, used for site selection were as follows: Residential area: Population of each district in Bangkok Roadside area: Traffic data in Bangkok Near source or industrial area: Odor complain record, initial inventory study, meteorological condition, previous measurement and data related to VOCs There were 6 monitoring sites in Maptaphut area namely Maptaphut Health Center station, Wat Mapchalut station, Watnongfab School station, Maptaphut New Town station, Banplong Community station, and Bantaguan Sanitation Center station. Ambient air samples were taken from these monitoring stations by qualified PCD staff. Location of sampling sites were as shown in Figure 1.

6 6 VOCs Monitoring Site in Maptaphut = Maptaput Health Center 2 = Bantaguan Sanitation Center 3 = New Town Station 4 = Wat Mapchalood 5 = Wat Nongfab 6 = Bannpong Figure 1: PCD ambient VOCs monitoring sites in Rayong province As for Bangkok and vicinity area, there were 17 monitoring sites in total. Seven of them were operated by PCD and were located near the potential emission sources of VOCs. Therefore, these sampling sites were represented near source area. Other monitoring sites (10 sites) were operated by ERTC where ambient air samples were taken in the residential and roadside areas. Locations of monitoring sites in Bangkok were as illustrated in Figure 2 and Figure 3. Details of sampling site were as listed in Table 1.

7 7 Figure 2: PCD ambient VOCs monitoring site in Bangkok and vicinity area Figure 3: ERTC ambient VOCs monitoring sites in Bangkok area

8 8 Table 1: VOCs monitoring sites Sites X(WGS84) UTM Y(WGS84) Roadside (BKK) 1. Donmuang District Office Transportation Department Chokechai 4 Police Station Dindang station Bannhongbon School Residential (BKK) 1. Bangkapisukum school Bordindecha School Watsing School Bangkok Naval base Prachanookoon School City Background 1. Bangna Near source (BKK & vicinity) 1. Wattippawas school (Lad Krabung) Bangpoo North (Ubonsri Village) Bangpoo South (Sodsri House) Chom thong Lad phrao Phaholyothin Intramara Near source (Maptaphut) 1. Maptaphut Health Center Bantaguan Sanitation Center Maptaphut New Town Station Wat Mapchalut Watnongfab School Banplong Community Reference Background 1. Khao Laem Dam Measurement technique VOCs in the ambient air can be sampled by different techniques dependent on the purpose of sampling and availability of analytical instrument. The sampling techniques can be classified into two categories as an active or a passive sampling; the

9 9 presence and absence of a pump in a sampling train. In this study, PCD and ERTC employed the passive sampling of VOCs by using flow control device. Inert surface coated canister is selected for sampling media. Air sample was collected by the difference in pressure between ambient and inside of canister. The advantage of canister system is that it allows the relatively long storage of sampled air for repeat analysis. Stability of VOCs in sample is approximately up to 1 month. Samples were transferred from canister to the a preconcentration unit which concentrating and at the same time minizing sample volume to be injected into a Gas Chromatograph Mass Spectrophotometer (GCMS). Both PCD and ERTC measurement techniques are based on the US.EPA Method TO-15 where PCD using 44-VOCs-mixed standard while ERTC using 77-VOCs-mixed standard. Schematic diagram of VOCs measurement was as shown in Figure 4. Figure 4: Schematic diagram of VOCs measurement In order to assure the quality of data, QA/QC procedures for both sampling and analysis has been set up. This QA/QC criteria will also assure that the data produced using similar QA/QC level will be comparable. Monitoring program Samples were collected once a month since August Samples were taken for 24 ± 1 hours from the start of sampling until the end of sampling on the following day.

10 10 Sampling schedule were set up randomly covering both weekday and weekend. Twelve dataset were collected and were utilized for calculation of annual average concentration. Annual concentration was calculated using arithmetic mean (running average). In this report, 80% completeness of data was used as minimum criteria to calculate the annual concentration of VOCs at each monitoring stations. It should be noted that the requirement of the calculation of the Thai ambient VOCs annual concentration is 12 dataset (100% completeness assuming the same measuring frequency; once a month). Section 3: Results and discussions Twelve months monitoring data were summarized according to their site representativeness as shown in Table 2. Table 2: Summary of VOCs monitoring data Concentration Range (µg/m 3 ) VOCs Rayong Bangkok and vicinity area Industrial Near source Roadside Residential Freon Freon 114 < < < Chloromethane < Vinyl chloride < < < ,3-Butadiene < * < * < Bromomethane < < < Chloroethane < < Freon ,1-Dichloroethylene < < < < Freon 113 < Acrylonitrile <0.01-<0.05 <0.01-< Chloropropene <0.01-<0.04 <0.01-<0.04 Dichloromethane < < ,1-Dichloroethane < < < < cis-1,2-dichloroethylene < < < < Chloroform < < < ,1,1-Trichloroethane < < < < ,2-Dichloroethane < < < < Benzene Carbon Tetrachloride Trichloroethylene < < < ,2-Dichloropropane < < < < cis-1,3-dichloropropene <0.01-<0.04 <0.01-<0.04 < < Toluene trans-1,3-dichloropropene <0.01-<0.04 <0.01-<0.04 < < ,1,2-Trichloroethane <0.01-<0.04 <0.01-< < Tetrachloroethylene < < < ,2-Dibromoethane < < < < Chlorobenzene < < < < Ethylbenzene m-xylene p-xylene m-,p-xylene Styrene < < < < o-xylene

11 11 Concentration Range (µg/m 3 ) VOCs Rayong Bangkok and vicinity area Industrial Near source Roadside Residential 1,1,2,2-Tetrachloroethane < * < * < < Ethyl-4-methylbenzene < * < * 1,3,5-Trimethylbenzene < * < * ,2,4-Trimethylbenzene < * * < ,3-Dichlorobenzene < * < * < < Benzyl Chloride < * < * < ,4-Dichlorobenzene < * < * < < ,2-Dichlorobenzene < * < * < < ,2,4-Trichlorobenzene < * < * < Hexachloro-1,3-butadiene < * < * Propene Freon Isobutene Pentane Methyl-1,3-butadiene Propenal Propanal Iodemethane < < Cyclopentane Methoxy-2-propane Hexane Methacrolein Acetic acid ethenyl ester < Butanal Methylvinyl ketone Butanone Cyclohexane Pentanone < < Pentanal < < Pentanone < < ,4-Dioxane < < Bromodichloromethane < < Methyl isobutyl ketone < < Hexanone < Hexanone < < Hexanal Bromoform < ,2,3-Trimethylbenzene *Values may include some uncertainty. It was found that there were differences of prevalent VOCs compounds according to the type of sampling location. Monitoring result in Bangkok near the traffic curbside area clearly indicated that major VOCs species were those emitted from mobile sources such as 1,3-butadiene and benzene. Concentrations of VOCs were greatly affected by local emission source nearby sampling location. For example, one of the sampling site in Bangkok was located close to the degreasing facility resulted to existing of dichloromethane in that area while concentrations of this compound were found relatively low in Maptaphut area. High concentrations of dichloromethane were also found in monitoring sites, represented residential area in Bangkok. The presence of this compound in such area might be originated from the use of this solvent in the

12 12 household such as for paint remover purpose. On the other hand, vinyl chloride was only found in Maptaphut due to its utilization in this area. Annual VOCs concentrations from measured data were compare with the ambient VOCs standard. Comparison results were as shown in Table 3. Table 3: Comparison of annual average concentration from measurement with annual standard (unit: µg/m 3 ) VOCs Annual MTP BKK* standard Near source Near source Roadside Residential area Benzene ,3-butadiene Chloroform Dichloromethane ,2-dichloroethane ,2-dichloropropane Tetrachloroethylene Trichloroethylene Vinyl chloride Remarks: Data completeness of roadside and residential area in Bangkok was less than 80%. Almost of annual VOCs concentrations measured in Maptaphut area were found below the ambient annual standard except for benzene, 1,3-butadiene and 1,2- dichloroethane. There were 4, 4 and 3 monitoring sites among 6 sampling sites having annual concentration greater than the annual standards of benzene, 1,3-butadiene and 1,2-dichloroethane, respectively. Most of them were located in the northern direction from Maptaphut Industrial Estate. These locations were downwind from the industrial estate which was affected by sea breeze during the daytime. Annual concentrations of 1,3-butadiene were found higher than their annual standards in some areas in Maptaphut and Bangkok. All of the sampling sites in Bangkok area had benzene annual average concentration exceeded annual standard. It was expected that high concentration was attributed from both near source and mobile sources near the sampling site since these 2 compounds were well recognized as pollutants, not only emitted from industry but also emitted from vehicle. This assumption was proven by high concentrations of benzene and 1,3-butadiene in the roadside monitoring stations in Bangkok comparing with other monitor site categories. Monitoring data revealed that annual concentration of tetrachloroethylene, 1,2- dichloropropane and trichloroethylene were relatively low as compared with their annual standards. Section 4: Conclusion and recommendation Measurement of ambient VOCs concentration has been conducted by PCD and ERTC as part of their technical cooperation with JICA. Sampling and analysis of VOCs were developed coupled with data quality control procedures in order to establish reliable

13 13 VOCs database in the country. Measurement program has been set up with an objective to reveal the status of VOCs pollution in Thailand. These data was expected to be used as supporting data to establish the appropriate VOCs management policy including standards and mitigation measures of VOCs in Thailand. Monitoring sites were classified to residential, industrial, and roadside areas. Measurement data were analyzed for their spatial distribution in order to elucidate the prevailing VOCs compounds in each area. Data indicated that most VOCs were sitespecified pollutants in which their concentrations were greatly affected by local emission sources. Annual average concentration of nine VOCs namely benzene, 1,3-butadiene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, tetrachloroethylene, trichloroethylene, and vinyl chloride were compared with Thai annual ambient standard. It was found that an annual concentration of benzene and 1,3-butadiene exceeded ambient air quality standard in some areas in Maptaphut and Bangkok. High concentrations of these compounds were expected not only emission from industry but also emission from mobile source particularly in Bangkok area. Some VOCs that are identified as toxic air pollutants may have caused long-term health impacts on the population living in contaminated areas. Measurements of VOCs are thus necessary for future control efforts to improve the quality of life of people living in polluted areas. Measurement data is one of the crucial tools to evaluate the air pollution problem from VOCs. Therefore, monitoring program need to be continued and expanded to other areas. Development of monitoring techniques as well as capacity building of personnel involved in the process is crucial for enhancing VOCs monitoring network. Reliability and comparability of data are also need to be considered in measurement of VOCs and analysis of data.

14 Acknowledgement The authors would like to express their sincere gratitude to JICA experts; Mr. Shirane Yoshiharu, Mr. Munehiro Fukuda, Dr. Seiji Watanabe, and Dr. Kiyoshi Imamura for their kind support in developing the ambient VOCs measurement at PCD and ERTC. They are thankful to JICA for the technical cooperation and to IEAT for their support to the JICA VOCs project. Special thanks go to the generosity resources both personnel and facilities from Mr. Boonchob Suthamanuswong (ERTC) and Dr. Pornsri Suthanaruk (PCD). Great supports from the entire project member as well as supporting staff are also acknowledged here.