Concentration of Persistent Organic Pollutants in the coastal hydrosphere of Thailand
Ruchaya. Boonyatumanond, Suthib. Srilachai,
Sukanya.Boonchalermkit, Yuwadee In-na,
Environmental Research and Training Center,
Technopolis, Tambon Klong 5, Amphoe Klong Luang,
Pathumthani 12120, Thailand
Department of Environmental Quality Promotion,
Ministry of Natural Resource and Environment
Abstract
The mornitoring program on persistent organic pollutants (POPs) was started from April 2002-March 2003. For forty-eight water samples from 4 main rivers and coastal water along the Gulf of Thailand were analysed for POPs in dry season and wet season by UNU method. The result indicated that the water quality for POPs of river and sea water sample from the coastal area of Thailand is not polluted from POPs. The concentration of POPs residues were detected at the range of 4.2-13.9 ng/L (ppt) with 13C12 recovery 85-95%. The concentration of POPs residues in water samples are lower than Water Quality Standard by Notification of the National Environmental Board, No. 7-8, B.E. 2537 (1994 ).
Introduction
Persistent Organic Pollutants (POPs) are toxic substances of organic (carbon-based) chemical compounds and mixtures. They are dioxin, furans, polychlorinated biphenyls (PCBs), DDT, chlordane, heptachlor, toxaphene, hexachlorobenzene, aldrin, dieldrin, endrin and mirex. These chemicals are products and by-products of human industrial activities that are relatively recent in origin. POPs are persistent in the environment. This means that the substances resist photolytic, chemical and biological degradation . They are general semi-volatile. They are also subject to global distillation. They can travel with the potential to injure human health and /or the environment ( Stephen 1994; Kannon et al., 1994 ; Kannon et al., 1995) . They generally have low water solubility and high lipid solubility. They tend to bioaccummulate in fatty tissues of living organisms. In the environment, concentrations of these substances can magnify by factors of many thousands as they move up the food chain (Sericano, et al., 1995; Boonyatumanond et al., 2000 and 2002; ). These chemical find their way into everything (i.e. air, soil, water and food) (Ogaki et al., 1994; Iwata et al., 1993 ). These facts suggest the significant atmospheric transport tpo persistent organochlorines to the Actric from lower lateitudes. In spites of regulation or prohibition on the chemicals imposed in the most-developed nations since the 1970s , their usage and disposal are still continuing or increasing in developing countries near tropical regions (Forget 1991). ( For the listed POPs pesticides use as alternatives are made available for the small number of remaining recognized uses such as aldrin, dieldrin, chlordane and DDT . For the listed POP industrial chemicals there is need to phase out, over time such as PCBs and HCB.
Polychlorinated Biphenyls (PCBs) used for a variety industrial uses, including in electrical transformers and large capacitors as heat exchange fluid, as paint additives and carbon-free copy and in plastics. The chemical properties primarily responsible for many of the industrial applications of PCBs, that is their inflammability, chemical stability, and miscibility with organic compounds (i.e., lopophilicity), also are the same properties that have contributed to their environmental problems. These compounds preferentially bioaccumulate and biomagnify in higher tropic levels of the food chain. (Hansen ., 1987)
POPs are highly toxic and have the potential to injure human health and the environment at low concentrations. Damage caused to humans and other species by POPs is well-documented and includes the pathologies of cancer and tumors at multiple sites, reproductive disorder, neurobehavioral impairment including immune system dysfunction , lack of development in various body system ( Ohanjanyan et al., 1999).
Thailand has benefited from the availability of the growing pest control chemicals. To support agricultural product in our countries and export product, many kinds of pesticide were imported such as insecticide, fungicide , and herbicide, etc. Because there are resistant chemicals and toxic, the government enforce to decrease and limit using it. In order to understand the distribution of the chemicals residues remain in environment, the fresh water from 4 main river and sea water from the coastal area were analyzed .
Material and method
The monitoring programme started from April-December 2002. Fourty eight samples of water were collected at 24 stations from four main rivers namely, The Chao Phraya river, The Mae-Klong river, The Bang Pa-kong river and The Tha-Chin river including the coastal area along the gulf of Thailand and Andaman sea side as showned in Figure 2, Figure 2 and information of sampling as shown in Table 1.
The Chao Phraya river is the most important river in Thailand, flow through several cities including Bangkok. There are industrial located along the river and a large number of inhabitants live along the river banks. The river, which discharges into the upper Gulf at Samutprakran province, has an average discharge varying from 8,000 x 106 to 34,000 x 106 m3/year. The Bang pakong is the river received domestic sewage from several cities, and effluent from agro-industrials which has a flow of 3,000 x 106 m3/year. The Tha-chin river which flow and discharges into the upper Gulf at Samut Sakhorn at a rate about 1,500 x 106 m3/year. The Mae-kong river which discharges into the upper Gulf of Thailand at Samutsongkram from 9,000 to 16,000 x 106 m3/year. The wastewaters generated from these industries in Chonburi and Samut Prakharn province such as sugar, metal plating, paper mill and food industrial located along the river at a distance about 100 km upstream from the Gulf.
The sample were collected in dry season (April-May) and wet season (October-December) and were analysed for Persistent Organic Pollutants (POPs) namely chlordane hexachlorobenzene, aldrin, dieldrin, endrin and DDT-isomers by UNU method. The water samples were kept at 4 °C
Apparatus
A) Gas-Chromatograph-model 17-A (Shimadzu) equipped with Mass Spectrometer model QP-5050A (Shimadzu )
B) Rotary Vacuum evaporator-type Rotavapor RE-111 (Buchi)
C) Laboratory sharking machine-type Recipro (II-RW)
Figure 1 Map of sampling stations (coastal area)
Figure 2 Map of sampling stations (River Basin)