Persistent Organochlorine Residues in Household Wells of Java Coastal Urban Areas, Indonesia

INTRODUCTION

The use of pesticides, herbicides and fungicides in Indonesia began when the government launched plantation rehabilitation programme in the 1960`s (Indonesian Pesticide Committee, 1999). Consequently, large-scale application of these toxic materials in agriculture areas can contribute to the presence of those compounds in surface and ground water, lakes, estuary and ultimately in the coastal areas. Most of these compounds are recalcitrant to biodegradation and their entry into the ground water, might be, poses many challenges to the existing of drinking well water from pollution.

Indonesian Pesticide Committee is responsible for the import permission for pesticides, when the government launched plantation rehabilitation programme. The 1974 official list of permitted pesticides contains 94 pesticides, which represent about 76 different compounds. Some of them are brought on the market under different trade names (Hadiwijaya, 1974). Excluded from the list are DDT, Endosulfan, Heptachlor, Aldrin, Dieldrin, Endrin and a number of other persistent chlorinated pesticides. Their use in plantation, aquaculture and agriculture is prohibited (Duursma, 1976). However, DDT is still allowed to be used for domestic and health purposes in particular for fighting the malaria mosquito. Dieldrin and Endrin were previously widely used and in some places old stocks are still available, thus creating the possibility that these pesticides might still be found in the environment (Chozanah, 2007; Watterson, 1999).

Java is by far the most populous island in Indonesia, with approximately 62% of the country`s population and is the most populous island in the world (Calder, 2007). With 130 million inhabitants at 1026 people per km², it is also one of the most densely-populated parts of the world (BPS Statistics Indonesia, 2000; Anonymous, 2001). Jakarta (the capital and largest city of Indonesia), Semarang and Surabaya are located on the Northern coast of Java Island. Like many big cities in developing countries, these cities suffer from major urbanization problems. The cities are highly urbanized, due to the many industries located in the city and as a result, there is also a large slum area. Therefore, there is a require outstretching of existing housing and most importantly water supply. Alternative supply of water for domestic and industrial purposes has been diversified to the area of bore-hole and well drilling, stream and rain water collection and storage.

Clean water is probably the biggest problem in many houses of coastal urban settlement. Based on field investigation, many homes in this region are not connected to the city water supply and wells are often unpredictable. Most houses do not have overhead tanks for catchment or storage but, instead, have large ground storage tanks from which the water is pumped on demand by a small electric pump. The most prevalent of these is the shallow aquifer (dug well) which has become the major source of water in the coastal inhabitants. However, ground waters and surface waters are never pure that probably contain a variety of organic compounds (Fitch and Du, 1996; Nelson et al., 1998; Graber et al., 2001). Organic chemicals such as polychlorinated biphenyls, PAHs and organochlorine pesticides have been identified in the surface water (Jaynes et al., 1999; Louchart et al., 2001; Rupp et al., 2006) and ground water (Muszkat et al., 1993; Barbash et al., 2001; Lapworth et al., 2006). Contaminants from residential areas, industries and agricultural practices through migration and infiltration enter to ground waters (Ilani et al., 2005; Yusuf, 2007). Therefore, a study of the distribution and concentration of organochlorine in the shallow aquifer become the most relevant. This research aims to examine the organochlorine content of the household wells in coastal urban areas and assess how far they conform to the WHO/Indonesia recommendation for drinking water.

Water sample collection: Sampling points were located on coastal urban areas flowing from the west to the east of Java, namely Jakarta, Semarang and Surabaya. Figure 1 shows the sampling sites. Well water samples were collected in polyethylene plastic bottles from 30 different dug wells across those cities during the months of July to August 2007. The water samples were collected in 1000 mL plastic bottles. Then, bottles were properly labeled and tightly sealed. All the water samples were brought to the laboratory for performing organochlorine analyses. The parameters analyzed were psycho-hydrochemical properties and organochlorine contents of shallow ground water. The pH, salinity and temperature were measured at the time of samples collection using pH meter, hand refracto salino meter and a standard centigrade thermometer (Horiba Co. Ltd., Japan).

Fig. 1:	The map of sampling site locations

Sample analysis: The analytical procedure applied was the method of the Standard Method for the Examination of Water and Waste Water (American Public Health Association, 1992), using 15% methylene chloride in n-hexane and capillary columns. One-liter samples were extracted with a solvent mixture and then concentrated in a Kuderna-Danish apparatus. The extracts were cleaned up with Florisil column. The final pesticide extract was obtained in 5 mL of hexane. The samples were then analyzed by gas chromatograph Model Hitachi 163 FPD (Flame Photometer Detector) and nitrogen High Pure (HP) was used as the carrier gas. A 2 m glass column (3 mm ID) packed with 3% Silikon OV1 on 80-100 mesh Supelcon was used. Gasflow at 30 mL min^-1, column temperature at 160-230°C, detector temperature at 290°C and the injector temperature at 290°C were maintained.

Java is an island which administratively divided into four provinces (Banten, West Java, Central Java and East Java), one special region (Yogyakarta) and one special capital district (Jakarta). Jakarta, Semarang and Surabaya are the capital city of Indonesia and Jakarta special district, Central Java and East Java, respectively. These cities were chosen for study because of their representative for the main industrial and human centre of northern coastal urban of Java. Hence, those cities have a great probability for the existence of declining water quality resources.

Pollution of groundwater has been reported for a number of urban throughout the world on a wide range of pollutants, such as organochlorine, heavy metals, nitrate, fecal, bacteria, virus, domestic waste (Mille et al., 1993; Somasundaram et al., 1993; Zhang et al., 1996; Kaçaroğlu and Günay, 1997; Mazari-Hiriart et al., 1999; Reddy and Dunn, 1997; Howard et al., 2003; Timothy et al., 1999; Chrisna et al., 2007; Sabdono et al., 2007). This is mainly due to a higher population density and more intensified agricultural and industrial activities (Baudino et al., 2003; Yusuf, 2007; Fatoki and Awofolu, 2004; Mukherjee and Gopal, 2002). In present study, the results of some physicochemical parameters and selected priority organochlorine in shallow aquifer are preserved in Table 1 and 2, respectively. This study indicated that low variation existed among some physico-chemical parameter temperature, salinity, pH).

Table 1:	Physico-chemical properties of the well water samples in the Java coastal urban area

Table 2:	Range, frequency of occurrence and mean±±standard deviation of organochlorine pesticide residue levels (μg L-1) from Java coastal urban areas
nd = not detected

Colour, taste and odors were detected in water samples. Some of the water samples, particularly some Jakarta and Semarang water samples, did not comply with the standard limits for drinking. The water samples have colour and offensive odour. The water temperature values obtained in this study varied slightly ranged from 28.5-29.5°C with a mean of 28.93°C. This is the most common water temperature in tropical zone. This temperature range of water samples is supposed to be affected by the intensity of the sunlight as temperature rose from 28.5-29.5°C on relatively hot day afternoon. Some workers reported that the temperature of water from tropical climate was little affected by seasonal variations of temperature (Efe et al., 2005; Ravindra et al., 2003). Salinity range was varied from 0 to 9.0‰ with a mean of 2.1±2.51‰. The highest desirable level for pH (7.0) is within the range of 6.5-8.0 values for drinking purposes (WHO, 1993).

Water samples from coastal urban areas of Java showed the presence of selected organochlorine (Table 2). Seventeen out of 30 samples (56.66%) contained residues of heptachlor, ranging from 0.01 to 0.346 μg L^-1, whereas aldrin ranging from 0.007 to 0.013 μg L^-1 was detected in 3 samples (10%). Three samples (10%) showed residues of endosulfan and p,p-DDT and only two samples (6.66%) were found to contain residues of endrin. The ranging of endosulfan, endrin and p,p-DDT was 0.109 to 0.66, 0.648-0.895 and 0.724-1.235 μg L^-1, respectively. Mean values found in positive samples were 0.10±0.10, 0.010±0.003, 0.455±0.30, 0.77±0.17 and 0.934±0.27 μg L^-1 for heptachlor, aldrin, endosulfan, endrin and p,p-DDT, respectively. Comparison of the organochlorine contents in the water sample with World Health Organization (WHO) limits and Indonesian Drinking and Domestic Water Quality Standard for Ground Water showed that some of the household wells were contaminated with organochlorine.

The mean levels of heptachlor and endrin were exceeded the maximum permissible levels for drinking water. However, both aldrin and p,p-DDT were below the maximum allowable concentrations. WHO International Standards for Drinking-water did not refer to endosulfan. Variation in residual levels in these samples could be due to location of the sampling.

Table 3:	Mean±SD and frequency of occurrence of organoch±lorine pesticide residue levels (μg L-1) in household well of Surabaya, Semarang and Jakarta
Note: Mean was calculated for positive samples. Total samples = 10. BD = below detection

The present study sufficiently shows the presence of organochlorine residues in most of the samples. Comparison of data on organochlorine residues of Jakarta, Semarang and Surabaya water samples showed that the highest levels and frequency of occurrence of heptachlor was Jakarta well water (Table 3). Although we have not analysed surface water samples for organochlorine residues in the present investigation, comparing the results reported here with other regional studies on river and sea water contamination (Ratnaningsih et al., 2000), different contamination levels with heptachlor and p,p- DDT were found. Heptachlor was not detected and the mean level of p,p-DDT was lower. It is not known whether this is due to irresponsible insecticide handling practice or groundwater transport processes.

Characteristics of selected physico-chemical parameters and organochlorine pesticide residues in household wells of Java coastal urban areas has been determined in this study. Heptachlor and Endrin only were above the maximum permissible value recommended by WHO and Indonesian Water Quality Standard. As expected, Jakarta coastal urban area was the most contaminated one because of the higher population density and the larger industrial sites. Some of these household wells needs further purification to ensure their sustainability for consumption of coastal urban inhabitants. It is necessary to study further in these areas during the wet and dry period due to fully evaluate the organochlorine impact of pollution on shallow groundwater in seasonal variation.

This study is supported by the grant from Indonesian Ministry of Research and Technology within Incentive Program (Contract No. 41/RD/Insentip/PPK/I/ 2007, 15 January 2007).