Evaluation of Chemical and Microbial Quality of Bottled Water Available in Sri Lankan Market

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1 Evaluation of Chemical and Microbial Quality of Bottled Water Available in Sri Lankan Market Ellawala, K.C., De Rekha E.P.R., Bandara W.D.L.S., Hasini Kodithuwakku Department of Civil and Environmental Engineering Faculty of Engineering University of Ruhuna Hapugala, Galle SRI LANKA Abstract: Production of bottled water in Sri Lanka has been started in the late 1980`s. Many studies have proved that consumers believe that bottled water is safe and tastes better. However, some studies on bottled water quality have proved that there are many occasions that tap water is safer than bottled water. Therefore, the objective of this study is to analyze the quality of bottled water available in Sri Lankan market. Twenty-five brands of bottled water produced in Sri Lanka (popular brands) has been evaluated for several water quality parameters, namely, ph, alkalinity, hardness, turbidity, conductivity, total dissolved solids (TDS) and total coliforms (TC). ph, alkalinity, turbidity, conductivity and TDS were within the accepted limits in Food (Bottled or Packaged water) Regulations-2005 gazetted by the government. However, it was observed that total coliform count was positive in 4 brands and total hardness exceeded the acceptable level (250 mg/l as CaCO 3) in 4 brands. All the other parameters were in accepted levels in all brands. It can be concluded that all bottled water brands available in Sri Lanka is not meeting the regulations. Keywords: Bottled water, quality, regulations 1. INTRODUCTION 1.1. Bottled Water Drinking water is an essential attribute to sustaining life and health where bottled water is one of the major drinking water sources for human. Improving access to safe drinking water can result in tangible benefits to health. Every effort should be made to achieve a drinking water quality as safe as (Rupasinghe, 2008). Since then the trend of using bottled water is tremendously increased in parallel with the population growth, while new brands were often introduced to the Sri Lankan market. Purchasing of bottled water is popular in Sri Lanka when people are on travel. Hence, as tropical regions, particularly in tourist regions the consumption of bottled water has rapidly increased from 1990s (Calabrase 1997; Misund et al. 1999). In emergency situations, such as natural disasters, bottled water is provided as a safe drinking water supply. Consumers believe bottled water is safe for consumption and free from impurities. Safe, clean drinking water and sanitation is a basic human right to the satisfaction of life. Globally, bottled water is considered as a safer and better source of drinking water over municipal water supplies. Despite this belief, scientific evident has proved that this is not necessarily true (Herath et al., 2012). Organoleptics are very important in the satisfaction of consumers on any kind of drinking water (Doria et al., 2010 ). Moreover, microbial quality is very important for providing safe drinking water. Therefore, this study was focused on measuring several physical and chemical parameters to evaluate whether the quality parameters meet the permitted levels those are important in organoleptics and total coliform count was used to evaluate microbiological quality. 141

2 1.2. Regulations In Sri Lanka bottled water is regulated as a `food`. It is regulated by the Ministry of Health under the Food Regulations, 2005 framed under Food Act No. 26 of It is mandatory to obtain a Certificate of registration from the Chief Food Authority before packaging or importing bottled water. Food (Bottled or packaged water) regulations, 2005 provides physical chemical and microbial requirements of bottled water. 2. METHODOLOGY 2.1. Water Quality Testing Bottled drinking water samples were purchased in Southern province and Western Province of Sri Lanka during the month of September Twenty-five brands of bottled water were included in the analysis; each brand was represented by three bottles of 500 ml volume. Care was taken to purchase bottles from different batches of production. Turbidity was selected as a parameter representing the clarity of water. Conductivity, hardness and total dissolved solids and ph were chosen as parameters those are influential on organoleptic. Microbial quality of water was evaluated using total coliform count. All parameters were measured according to standard methods of analysing water and wastewater (APHA, 1998). 3. RESULTS & DISCUSSION Among the bottled water brands selected for the study, 19 of the brands mentioned their source as tube wells, while 3 each mentioned their source as dug wells and springs. Table 1 shows the district of origin of the analysed brands. 84% of them were bearing registration number issued by the Ministry of Health, Sri Lanka. Only one brand showed the expiry date 2 years after the manufacturing date while the rest had only one year of period for expiring. The range of the shelf life of selected samples for analysis was between one to ten months Chemical Properties of Bottled Water According to physical parameters (Table 1), the average ph of the bottled waters is around neutral (7.2) with the lowest value reported as 6.5 and the highest ph value as 8.2. Twenty-four brands showed accepted permissible ph level given by Sri Lanka Standard Institute (SLS, ), WHO ( ) and EPA ( ). One brand showed slightly higher ph according to WHO showed accepted permissible ph level where it within accepted permissible ph level given by Sri Lanka Standard Institute (SLS) and Environmental Protection Agency (EPA). The average values of EC (102.9 µs/cm) and TDS (79 mg/l) are lower than the accepted permissible levels set by SLS (EC, µs/cm; TDS, mg/l), WHO (EC, <1500 µs/cm; TDS, <1000 mg/l), and EPA (EC, noncorrosive; TDS, <500 mg/l). Based on the study of Dissanayake et al., 1984, Low mineral content in bottled water mainly controlled the aquifer type and origin of the basement rocks around the source groundwater wells. Most of these selected bottled water production areas are located away from the mineralized basement zone. The average value of turbidity (0.88 NTU) was within accepted permissible level given by WHO (<5NTU) and EPA (<5NTU). So all brands showed accepted permissible turbidity level. 142

3 Table 1 Source and measured water quality for different brands of bottled drinking water Water Quality Parameters Brands District of Origin Source ph EC (µs/cm) TDS (mg/l) 1 Colombo Tube well 7.0± ± ±9 2 Gampaha Tube well 7.3± ± ±15 3 Colombo Tube well 6.6± ± ±45 4 Gampaha Tube well 7.4± ± ±54 5 Gampaha Dug well 7.7± ± ±24 6 Kandy Tube well 7.0± ±1.5 25±3 7 Colombo Tube well 7.1± ± ±81 8 Nuwaraeliya Tube well 7.5± ± ±134 9 Matara Tube well 7.4± ±5.7 14±6 10 Colombo Tube well 6.8± ±3.9 16±3 11 Galle Tube well 7.2± ± ±43 12 Kandy Tube well 7.1± ± ±28 13 Colombo Spring 7.2± ± ±3 14 Kalutara Tube well 6.9± ± ±7 15 Badulla Tube well 7.0± ±1.2 18±2 16 Colombo Tube well 7.3± ±6.4 28±4 17 Gampaha Spring 6.8± ±8.3 40±6 18 Colombo Tube well 7.0± ± ±6 19 Gampaha Tube well 7.0± ± ±42 20 Gampaha Dug well 7.8± ± ±2 21 Gampaha Dug well 6.8± ±2.6 36±2 22 Kandy Spring 6.5± ±1.6 46±2 23 Kalutara Tube well 8.2± ± ±5 24 Colombo Tube well 7.6± ± ±5 25 Colombo Tube well 7.5± ± ±3 Table 2 Comparison of some chemical parameters with recent past studies in Sri Lanka Chemical Parameter 2012 Herath et al Udagedra et al Present study ph (Average ± SD) 5.65± ± ± 0.2 EC (Average ± SD) 68± ± ± (µs/cm) TDS (Average ± SD) (mg/l) - 43± ±31.53 According to the comparison of past bottled water related studies has shown that average observed chemical parameter values (ph, EC, TDS and Hardness) are showing an increasing trend with the time of study (Table 2). Except 2012 data, other two studies showed accepted permissible ph level given by Sri Lanka Standard Institute (SLS, ), WHO ( ) and EPA ( ). The average values of EC and TDS for three studies showed lower values than the accepted permissible levels set by SLS (EC, µs/cm; TDS, mg/l), WHO (EC, <1500 µs/cm; TDS, <1000 mg/l), and EPA (EC, noncorrosive; TDS, <500 mg/l). Hence, the present study showed slightly incensement than other two studies. Dissolved minerals contribute to the taste of drinking water to varying degrees (WHO, 2011). There are two types of hardness whereas temporary and permanent hardness. Temporary hardness due to carbonate aquifers is common throughout the terrain of Sri Lanka (Panabokke & Perera, 2005). The two main cations that cause water hardness are Calcium (Ca 2+ ) and Magnesium (Mg 2+ ) based on which water is categorized as soft (<50mg/L), moderately hard (50-100mg/L), hard ( mg/L) and 143

4 very hard (>150mg/L) (Crittenden et al, 2005). In this study 84% brands were on soft water category and 16% brands were on hard water category (Table 3). Table 3 No of brand Water class Sampling location 21 Soft (<50 mg/l) Colombo(7),Gampaha(7), Kandy(3), Galle(1), Matara(1), Badulla(1), Kalutara(1) None Moderately hard ( mg/l) - None Hard ( mg/l) - 4 Very hard (>150 mg/l) Colombo(2),Kalutara(1), Nuwaraeliya(1) Notes: Values (1), (2), (3) and (7) represent number of bottled water samples collected from each district 3.2. Microbiological Properties of Bottled Water Most importantly the presence of total coliforms was found in five brands selected for the study. According to both national and international standards, the Total Coliform count should be zero per 100ml for bottled water as well as drinking water. However, 20% of tested bottled water brands exceeded this required limit with an average count of 3.73 CFU per 100ml. Sasikaran et al. (2012) concluded; more than half of the bottled drinking water brands in Jaffna peninsula were contaminated with aerobic bacteria. Herath et al. (2012) has also observed that bottled water brands available in Sri Lanka have positive values for coliform count, hence supporting the observations made by us. 4. CONCLUSION In this study, the chemical and microbial quality of bottled water brands currently sold in Sri Lankan market was analysed. The results of the current study showed that microbial quality of bottled drinking water available in Sri Lankan market exceed the permissible levels. Other chemical parameters analysed in the water were within standards despite several brands increasing the permissible level for hardness. It indicates that 21 brands are soft water (<50mg/L) and 4 brands are very hard (>150mg/L). Hence the relevant authorities should pay necessary attention in regular monitoring of the quality of the bottled water available in the market. 5. ACKNOWLEDGMENTS This work was partially funded by the University of Ruhuna. 6. REFERENCES American Public Health Association, Standard methods for the examination of water and wastewater, 1998, Washington DC. Calabrase D.M. (1997) Bottled H2O. Better Nutr 59:46 Crittenden JC, Trussell RR, Hand DW, Howe KJ, Tchobanoglous G (2005) Water treatment: principles and design, 2nd edn. Wiley, New York. 144

5 Dissanayake CB, Munasinghe T (1984) Reconstruction of the Precambrian sedimentary basin in the granulite belt of Sri Lanka. Chem Geol 47: Doria M.F., Factors influencing public perception of drinking water quality, Water Policy 12 (2010) 1 19 Herath A.T., Abeysekara T.L., Chandrajith R. and Adikaram N.K.B. Temporal variation of microbial and chemical quality of non carbonated bottled drinking water available in Sri Lankan market, Journal of Food Science, 2012, 77 (3), pp Ministry of Health, Food (Bottled or packaged water) Regulations, Misund A, Frengstad B, Siewers U, Reimann C (1999) Variation of 66 elements in European bottled mineral waters. Sci Total Environ 243: Panabokke C.R, Perera APGRL (2005) Groundwater resources of Sri Lanka. Water Resources Board Sri Lanka Special Report, Sri Lanka, pp Rupesinghe, T., Growing industry - Bottling a life source, Financial Times, Volume 42, No 37, February 10, Sasikaran S., Sritharan K., Balakumar S. and Arasaratnam V., Physical, chemical and microbial analysis of bottled drinking water. Ceylon Medical Journal; 57: Udagedara D. T., Jayawardana D. T. and Pelpitiya S.K., Assessment of chemical variability of major bottled waters in Sri Lanka. Environmental Earth Sciences, Springer-Verlag Berlin Heidelberg. WHO (2008) Guidelines for drinkingaddenda vol 1 recommendations. WHO, Geneva pp WHO (2011) Hardness in Drinking-water Background document for development of WHO Guidelines for Drinking-water Quality. WHO, Geneva. 145