Scientists at the University of Peradeniya’s Postgraduate Institute of Science have uncovered troubling revelations about the release of trace elements, heavy metals, and antimony from Polyethylene Terephthalate (PET) bottles commonly employed in the production of Bottled Drinking Water (BDW).
The study, conducted by Asanka Vishwanath and A.C.A. Jayasundera, reveals significant gaps in existing regulations, particularly in Sri Lanka’s Food Act No.26 of 1980, SLS 894 (BDW standard), and SLS 1336 (PET packaging standard).
The research highlights a lack of comprehensive coverage for trace elements, excluding copper (Cu), manganese (Mn), and zinc (Zn), in the current regulatory framework, indicating a potential unawareness of the leaching risks associated with these metals. Notably, the study emphasises that the parameters outlined in the existing documents do not accurately reflect the true requirements for ensuring water quality in BDW.
Furthermore, the researchers point out that SLS 1336, designed to regulate PET bottle quality, lacks specific details on trace metals. The absence of regulations for antimony (Sb) in the BDW section of the Food Act raises concerns, as PET bottles could be a potential source of metal contamination.
PET is widely used for BDW packaging, and the study highlights the crucial importance of health and safety considerations in relation to PET-made bottles. Certain catalytic metals, including Zn, Mn, cobalt (Co), Cu, germanium (Ge), titanium (Ti), and antimony (Sb), used during the PET synthesis process may leach into the water, posing potential health risks to consumers.
Recommendations
The study recommends a comprehensive amendment to the existing standards, calling for the inclusion of major trace elements to ensure continuous quality management in the BDW industry. Researchers emphasise on the need for future studies on migration levels of catalytic metals and their toxic effects to establish maximum permeability levels.
Despite the substantial financial investment in the national PET requirement, the research points out a lack of investigations into the trace element composition of PET resins and questions the credibility of the current regulatory framework.
Environmental contamination
Meanwhile, in another recent study jointly conducted by researchers from the University of Peradeniya and the Rice Research and Development Institute (RRDI), the critical issue of environmental contamination stemming from heavy metals has taken centre stage.
The collaborative effort involves the expertise of R.W.W.K.A.D. Rajapaksha, S. Tharanya, D.M.J.B. Senanayake, and N.U. Jayawardana from the Department of Agricultural Biology at the Faculty of Agriculture, University of Peradeniya and the RRDI in Bathalagoda.
Heavy metals, natural components of the environment, have faced disruptions in their cycles and biochemical balance, primarily attributed to indiscriminate human interventions, such as those seen in agriculture and related industries. Excessive exposure to heavy metals has been established to cause adverse effects on both plant life and human health.
The study, based on current research evidence, delves into reported levels of toxic heavy metals – including cadmium (Cd), lead (Pb), arsenic (As), nickel (Ni), zinc (Zn), copper (Cu), mercury (Hg), manganese (Mn), and chromium (Cr) – in the Sri Lankan geo-environment.
One notable aspect highlighted is the estimated groundwater potential of Sri Lanka – approximately 780,000 hectares per year. Anthropogenic activities, such as the application of agrochemicals, manure, and sewage sludge, are identified as potential contributors to alterations in the natural concentrations of heavy metals.
Adhering to Sri Lankan standards and World Health Organization (WHO) guidelines, the study emphasises on the maximum allowable levels of arsenic (As) in drinking water set at 0.01 ppm. A 2012 research revealed that As concentrations were within the acceptable limit in groundwater across various zones in Sri Lanka.
Examining the maximum concentration of heavy metals in well water across 25 districts, the study revealed that in 2018, no district exceeded the allowable levels of cadmium (Cd) and chromium (Cr). However, Galle District stood out with an alarming concentration of lead (Pb) at 288 μg/L, surpassing the permissible level.
Water sources
Addressing Sri Lanka’s common disposal method of municipal solid waste in open dumps or landfills, the study sheds light on the potential threat posed by landfill leachate containing heavy metals, which can contaminate groundwater.
The study highlights the importance of artificial water structures, such as reservoirs, in serving as crucial ecological and economic sources for drinking water and agriculture. In the dry zone, where cascade irrigation systems with small tanks are prevalent, a 2003 study linked 90-94.5% of Chronic Renal Failure (CRF) patients to farming communities under the Mahaweli irrigation scheme.
As concerns rise over heavy metal contamination, this comprehensive study calls for increased awareness, further research, and potential regulatory measures to safeguard Sri Lanka’s environmental health and ensure the well-being of its communities.
Concerns over potential health issues
However, when contacted by The Sunday Morning, Friends of the Earth International Chairperson and Centre for Environmental Justice Senior Advisor Hemantha Withanage expressed concern over the unspecified standards of SLS and the health issues it would lead to.
Withanage said that from 2013 to 2017, multiple studies had been conducted based on this contamination and the damage it would cause to people’s kidneys. Heavy metals such as chromium, nickel, and cadmium were found in drinking water, in amounts exceeding normal percentages.
This, however, wasn’t only limited to bottled water, but was also observed in products such as rice. He noted that, in general, Sri Lanka’s soil contained excessive amounts of heavy metal.
Withanage said that the root cause of these problems was mainly based on pesticides and weedicides used for agriculture. The use of such chemicals is a primary cause of such contamination, while sometimes, it is an issue with the soil itself. He added that there was scientific research confirming that these substances inflicted damage on our kidneys, further pointing to their own study on mercury levels in places like Meegama and Puttalam.
“This debate concerning heavy metal in water has been happening for a while in Sri Lanka,” he said. “Typically, in Sri Lanka, we sell purified well water. We also have mineral water, which, for the most part, is taken from water springs and its quality is different.”
Further, he addressed ozone treatment for water contamination. Ozone is an oxidising and highly reactive gas. Two kinds of ozone are naturally found in the atmosphere, while man-made ozone products also exist today. It is most commonly used in water treatment, to purify drinking water, bottled water, and groundwater (during remediation), industrial wastewater cooling towers, and swimming pools. Although this method is highly effective and chemical free, allowing for cleaner and safer water, it is costly.
Withanage added: “A primary issue we have with water, currently, is the high chloride levels in water found in the dry zone, along with these heavy metals. In Colombo, we cannot drink groundwater, because it is not in a condition suitable for that.”
According to him, most of the groundwater in Sri Lanka is unusable and water resources are diminishing. With no awareness of this, people in relatively rural areas often use this non-potable water.
Moreover, with the prevailing weather conditions causing issues such as floods, the spread of bacteria (such as E.coli) in such water sources too poses health hazards. Drainage systems and industrial waste also contribute to the contamination of both surface and groundwater while natural standards such as the hardness of water render it unusable. For example, in places like Hambantota, the chloride content of water is high, making it not suitable for consumption.
Currently, there is no proper study conducted regarding well water in Sri Lanka. Withanage noted that it was less safe than it used to be, owing to pollution.
“In the water sanitation project, we focus on ‘leaving no one behind’. Here, we focus on water quality related problems, where pipe-borne water is what we have as the safest option,” he stated.
Pipe water, supplied by the National Water Supply and Drainage Board (NWSDB) remains the safest source of water by far. However, only 60% of Sri Lankans have access to pipe-borne water. Thus, the remaining population faces the brunt of these issues regarding contamination, further burdened by prolonged bouts of drought and other precarious situations. Withanage added that there were very few people who consumed surface water found in sources such as water springs.
Meanwhile, repeated attempts by The Sunday Morning to contact Sri Lanka Standards Institution (SLSI) Chairman Dr. Asanga Ranasinghe, Director General Dr. Siddhika Senaratne, and Consumer Affairs Authority (CAA) officials, including its Chairman Shantha Niriella and Director – Consumer Affairs and Information Asela Bandara proved futile.