- Bottled water industry needs close supervision by competent authorities
Since certain bottled water brands are unsuitable for drinking in accordance with the Health Ministry regulation and the Sri Lanka Standards Institution (SLSI) as they exceed the permitted levels for one or more of the prescribed parameters, the bottled water industry needs to be closely supervised by competent authorities.
These findings and recommendations were made in a research article on the "Evaluation of the microbiological quality of commercially available bottled drinking water in the Colombo District'' authored by D.D.N. Perera, J.L.P.C. Randika, H.A.D. Ruwandeepika and R.G.U. Jayalal (all four attached to the Sabaragamuwa University's Applied Sciences Faculty's Natural Resources Department), and A.T. Herath (attached to the Open University's Natural Sciences Faculty's Botany Department) and published in the Ceylon Journal of Science' 52nd Volume's Second Issue in June, 2023.
Bottled water, according to a Trinidad study, is currently known as a billion Dollar global business, and the human consumption of bottled water has largely increased due to successful promotions done by water bottle manufacturers highlighting characteristics of bottled water including their safety, purity, and cleanliness. B. Rani, R. Maheshwari, A. Garg and M. Prasad's "Bottled water - A global market overview" notes that many types of bottled water such as mineral water, purified water, sparkling water, sparkling mineral water, flavoured water, near water, and functional water are available all over the world.
Alternative water source
The bottled water concept was established in Sri Lanka in the late 1980s , per C. Sevigny's "The success of bottled water: The hidden costs hurt us and the environment". Although new brands of bottled water are introduced to the market constantly, it is still questionable as to whether these water related products are safe for drinking. However, the local demand for bottled drinking water has drastically increased due to reasons such as the tourism industry development, natural disasters, health related problems due to unsafe drinking water, the improved living standards of the people, increasing surface and groundwater pollution, branding, and terrorist activities. Bottled drinking water is believed to be a healthy alternative to tap water, thus, per H.M.R.W. Piyarathna, M.S.C. Perera, M.P. Karunanayaka, S.S. Ekanayaka and S.P.R. Udara's "Sri Lankan bottled water industry overview", leading to the flourishing of this industry in the country. According to the 2019 list of the Food Control Administration Unit of the Ministry, there are 178 local bottled water brands and three imported brands (from France, Japan, and Italy) available in Sri Lanka. Further, in Sri Lanka, it is essential to certify the manufacturing or importing process of bottled water by the Sri Lanka Standard Institute (SLSI). To obtain the SLS certificate, the water source must be set up as a spring, tube well, or dug well. However, bottled water brands are available in the Sri Lankan market without SLS standards, quality packaging, and standard water quality related information.
The concern about the microbiological quality of bottled water has grown over the years, according to studies in Canada and Ethiopia, and B. Gautam's 'Microbiological quality assessment (including antibiogram and threat assessment) of bottled water". The detection of coliforms (bacteria) and heterotrophic (organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter) bacteria in bottled water in counts that far exceeded national and international standards set for potable water for human consumption has been documented. M.E.Z. Da Silva, R.G. Santana, M. Guilhermetti, I.C. Filho, B.P.D. Filho and C.V. Nakamura's "Comparison of the bacteriological quality of tap water and bottled mineral water", A.T. Herath, C.L. Abayasekara, R. Chandrajith and N.K.B. Adikaram's "Temporal variation of microbiological and chemical quality of non-carbonated bottled drinking water sold in Sri Lanka" and A.T. Herath and C.L. Abayasekara's "A monthly evaluation of the microbiological and chemical quality of bottled drinking water" reported that bottled water is not sterile as it may contain various pathogens such as Escherichia coli or other coliforms, Pseudomonas spp., Campylobacter, or even Mycobacterium. Bottled water has, per H. Leclerc, D. Mossel and C. Savage's "Monitoring non-carbonated (‘still’) mineral waters for aerobic colonisation", also been a vehicle for the transmission of disease causing microorganisms such as Vibrio cholerae and Staphylococcus aureus.
In Sri Lanka, regarding the quality of bottled water, it has been recorded that they have exceeded the levels permitted by the SLSI for the presumptive total coliforms. Further, A.T. Herath, C.L. Abayasekara, R. Chandrajith and N.K.B. Adikaram's "Pseudomonas aeruginosa (bacteria) in bottled drinking water in Sri Lanka: A potential health hazard" revealed that there was Pseudomonas aeruginosa in the bottled drinking water. S. Sasikaran, K. Sritharan, S. Balakumar and V. Arasaratnam's "Physical, chemical and microbial analysis of bottled drinking water" which was conducted in the Jaffna Peninsula showed that the bottled water contained Escherichia coli and Klebsiella spp. and some fungal contaminants.
Strict regulations
Though the bottled water industry has improved world-wide, strict regulations have been established in many countries to regulate the quality of bottled water in many countries. General guidelines for the quality of water used for human consumption have been recommended by the World Health Organisation (WHO) and the European Economic Community. Per the WHO, Escherichia coli and thermotolerant coliform bacteria should be zero in any 100 millilitres (ml) of a drinking water sample and the heterotrophic plate count limits at 50 colony forming units per ml (cfu/ml) of drinking bottled water. According to SLS 894: Part Two: 2020, and the Health Ministry regulation (Gazette, 1420/4, 21 November, 2005), the total coliform and fecal coliform counts should be zero per 100 ml and the aerobic plate count should be less than one into 103 colony forming units per a ml of bottled water.
Considering the urbanisation rates in Sri Lanka, Colombo is one of the most highly urbanised cities. More than 10% of the population of Sri Lanka lives in the Colombo District. As mentioned in C.P. Liyanage and K. Yamada's "Impact of population growth on the water quality of natural water bodies", 81% of the water demand in Colombo is fulfilled by the Kelani River and it is a primary source of drinking water. According to the Food Control Administration Unit, 26 brands of bottled water are available in the Colombo District markets. The bottled water manufacturers in Sri Lanka mostly use dug wells, tube wells, and springs as a water source for bottling and most bottled water contains purified underground water. Some of those bottled water manufacturers use underground water from the Kelani River basin to fill the bottled water. M. Mahagamage, S. Chinthaka and P.M. Manage's "Assessment of water Lanka" explains that the groundwater in the Kelani River basin is poor for drinking purposes and according to observations, the reason is the inappropriate construction of toilets nearby the River basin, causing fecal coliform contamination of the groundwater. Further, the bacteriological and chemical parameters of the bottled water could be changed during the storage of bottles under ambient conditions.
Studying on illegally bottled water
However, there is a doubt that many illegal bottled water brands are coming into the market due to the increasing demand in the market. Already used bottles are refilled by some manufacturers with unhygienic water sources.
Hence, Perera et al., to determine the microbiological quality, collected three bottles from each of the 26 (currently available bottled water brands in the Colombo District) different brands of bottled water, randomly from local markets covering several parts (supermarkets, groceries, hotels, bus stands, and juice bars) of the Colombo District. The date of expiry and the protective polythene seal on the lid were carefully checked before the collection. All bottles were stored under ambient temperature (27 ºCelsius) until the time of analysis. All 26 brands were analysed in triplicate, for each analysis. The shelf life of the bottled water is one year and all the testing was done within the shelf life.
According to the information given on the bottled water labels, natural springs, dug wells, shallow wells, and deep tube wells were widely used for bottling purposes in Sri Lanka. Water sources had been mentioned in all the brands collected. Some sources were from the central highlands and some were from the Kelani River basin. Accordingly, some sources were dug wells and it was 15% while 78% of the brands’ sources were tube wells and deep tube wells, 4% were from shallow wells and another 4% were from springs.
SLS certifications were there on the label of all the bottled water and the Ministry registration numbers were also incorporated. Other standards such as the International Organisation for Standardisation and the Hazard Analysis and Critical Control Point had been obtained by the manufacturing companies and such information was mentioned on the label. Some brands (12%) have mentioned the water purification processes such as filtration, reverse osmosis, and activated carbon filtration. The polythene seal on the lid should be there in every water bottle and it is one of the Ministry regulations. However, 15% out of the 26 brands did not have the polythene seal on the lid. According to the SLS and Ministry regulation, the total coliform and fecal coliform should be absent per 100 ml of bottled drinking water. However, this study showed that 50% of the brands have exceeded the presumptive total coliform level (average colony count = 21.95) and 23% of the brands have exceeded the presumptive fecal coliform level (average colony count = 1.875) of the SLSI, the Ministry regulation and the WHO.
In the current study, 35% of the samples, out of the 26 brands investigated showed high heterotrophic plate counts which exceeded the WHO quality guidelines of 50 cfu per ml for bottled drinking water.
A total of 85% of the bottled water samples were contaminated with fungal species. Among the fungal species isolated, Aspergillus spp., Trichoderma sp. and Rhizopus sp. were the dominant genera. In addition, Mucor sp. was identified.
Algae were observed in 8% (two brands) out of the 26 bottled water brands tested. The algae species was identified as Chlorella vulgaris. One of the brands which recorded algae has mentioned that they have done many kinds of filtrations such as active carbon filtration and reverse osmosis.
Standards differ
Every country has its drinking water related standards that prescribe which substances can be in drinking water and their maximum concentrations. The standards are called maximum contaminant levels. They are formulated for any contaminant (whether it is a substance or a foreign bacterial, viral, or fungal element or a chemical substance) that may have adverse effects on human health, and each company that prepares drinking water has to follow the stipulated standards, per the WHO's "Guidelines for drinking water quality". The Ministry and the SLSI have stipulated the standards for drinking water in Sri Lanka.
The bottled water should be kept in places avoiding direct sunlight and in a cool, dry place. Coliform organisms have long been recognised as a suitable microbial indicator of drinking water quality, largely because they are easy to detect and enumerate in water. In drinking water from municipal supplies, the coliform test can be used as an indicator of treatment efficiency and the integrity of the distribution system. Although coliform organisms may not always be directly related to the presence of fecal contamination, the presence of coliforms in drinking water suggests the potential presence of pathogenic enteric microorganisms such as Salmonella spp., Shigella spp., and Vibrio cholera, which could give rise to human diseases.
According to the results obtained, most of the bottled water brands exceeded the permitted level in the number of colonies presumed to be total coliforms and fecal coliforms. Earlier research done in Sri Lanka indicated that 63% of the bottled water brands tested, exceeded the thresholds permitted by the SLSI for presumptive total coliforms while 97% of the brands exceeded the WHO permitted limit.
Further, 30% of the brands exceeded the limit for presumptive fecal coliforms (zero cfu per 100 ml in compliance with the WHO permitted standards, the SLSI, and the Ministry regulation). K. Ragila, P. Abiman, A.C. Thavaranjit and P. Iyngaran's "Quality analysis of bottled drinking water in the Jaffna Peninsula" revealed that the microbiological levels of four of the eight brands analysed were unfit for human consumption. Another study done in the Jaffna Peninsula found fungal and coliform bacterial contamination in 14% and 9% out of the 22 bottled water brands, respectively, and Escherichia coli and Klebsiella spp. were found in the water brands that had fecal contamination.
Therefore, it is also noticed that the presence of coliforms and heterotrophic bacteria in bottled water is a major public health concern.
Studies in Tanzania, Nigeria, Bangladesh and Lesotho have revealed that total coliforms and fecal coliforms were reported in the bottled water brands and that the majority of the bottled water tested violated the manufacturer’s safety criteria. Further, according to the findings, it showed that the filtration systems of the water samples similarly performed poorly and provided low drinking water quality and that the existence of indicator organisms may indicate a lack of sanitation during processing.
In the environment, total coliforms are present in plants, soil, etc. Consequently, the number of total coliforms should be higher than fecal coliforms, usually as fecal contaminants. Coliform organisms have long been acknowledged as a good microbiological indicator of drinking water quality, owing to their ease of detection and quantification in water.
The fecal coliforms count rather than the total coliforms count is, per F.P. Downes and K. Ito's "Compendium of methods for the microbiological examination of foods", a reliable measure of the pollution of water from fecal origin. The presence of fecal coliforms in the samples studied is an indicator of the fecal contaminants that may lead to human diseases, such as Salmonella spp., Shigella spp., Vibrio cholerae, and other pathogens. Therefore, the positive results, particularly the presumptive fecal coliform counts in some brands investigated in the current study indicate concern over the microbiological quality of bottled water in Sri Lanka.
C.M. Manaia, O.C. Nunes, P.V. Morais and M.P. Da Costa's "Heterotrophic plate counts and the isolation of bacteria from mineral waters on selective and enrichment media" and a Nepali study have identified several heterotrophic bacteria as being common in bottled water; these included genera such as Achromobacter, Acinetobacter, Aeromonas, Alcaligenes, Arthrobacter, Caulobacter, Corynebacterium, Flavobacterium, and Pseudomonas. Some of these genera contain species that have been known as opportunistic pathogens. In the present study, 35% of the brands tested had a higher heterotrophic plate count and WHO quality guidelines of 50 cfu per ml for bottled drinking water. A total of 19% of the brands were too numerous to count. The presence of a high number of heterotrophic bacteria in bottled water is probably due to the natural microbial flora of the source waters.
Although heterotrophic plate count bacteria have been considered harmless, P.A. Rusin, J.B. Rose, C.N. Haas and C.P. Gerba's "Risk assessment of opportunistic bacterial pathogens in drinking water" and D. Pavlov, C.M.E. De Wet, W.O. Grabow and M.M. Ehlers's "Potentially pathogenic features of heterotrophic plate count bacteria isolated from treated and untreated drinking water" suggested the potential health risk associated with heterotrophic plate count bacteria present in drinking water, which comply with water quality standards.
Some of the fungi isolated from bottled water samples are species commonly found in the environment while some of these fungi can cause diseases in humans, per M.T. Hedayati, A.C. Pasqualotto, P. Warn, P. Bowyer and D.W. Denning's "Aspergillus flavus: human pathogen, allergen and mycotoxin producer". While filamentous fungi in water do not usually pose possible problems for public health, certain fungi are isolated from mineral water. Penicillium citrinum and Alternaria alternata have some toxic potential and can pose a health risk. D.A. Cabral and V.F. Pinto's "Fungal spoilage of bottled mineral water" advises to count fungal propagules and lay down basal lines. There are several algal species in water bodies. The term ‘algae’ is used for some lower plants and many, often unrelated groups of microorganisms that can perform photosynthesis. One algae species was observed in two brands (8%) out of the 26 bottled water brands. The algae species was identified as Chlorella vulgaris which is one of the common species found in freshwater. The bottled water brand where the algae were found has mentioned that they have done many kinds of filtrations such as active carbon filtration and reverse osmosis.
Exceeding permitted levels
According to the results of the analysis of the water sources, the dug wells, tube wells, and springs did not show any significant difference in terms of fecal coliform and the total coliform levels in the samples. Moreover, spring water in the Knuckles Mountain Range, the main source of water for the bottling industry in Sri Lanka, exceeded the permitted level of coliform bacteria according to the Ministry regulation, the SLS and WHO guidelines. Further, the heterotrophic plate count and the algae levels are significantly higher in tube wells compared to dug wells and springs.
Considering the overall presence of microorganisms in bottled water, other than the contaminants of the source water, there is also a possibility that the plastic bottles may have been contaminated with bacteria and fungi before filling. M. Yoshimatsu's "Environments for mineral water production in factories" observed that microbial contamination can sometimes be seen in the processes of filling and capping bottles. A Japanese study noted that in some bottling plants, plastic bottles are not handled or stored in sterile conditions before filling, resulting in contamination. Besides, the methods of the elimination of the contaminants of the source water adopted during bottling (ultra violet and filtration) may not be sufficient for the removal of microorganisms.
According to the results, bottled water under some brands were unsuitable for drinking in accordance with the Ministry regulation, and the SLSI as they exceeded the permitted levels for one or more prescribed parameters viz; heterotrophic plate count, presumptive total coliform, and fecal coliform. This study revealed the importance of public awareness regarding the quality and potential health risks associated with the consumption of bottled water in Sri Lanka. Therefore, the bottled water industry needs to be closely supervised by competent authorities so as to ensure that customers in Sri Lanka have safe bottled drinking water.