Mineral water producers are fuming over a report claiming that tests had found bottled water to be potentially toxic and loaded with heavy metals, firing back with their own research.
Their reaction is in response to results published by the Sefako Makgatho Health Sciences University in Pretoria towards the end of 2022, reports Daily Maverick.
That report, issued on 16 November, noted bottled water was one of the fastest-growing commercial products in both developing and developed countries owing to the belief that it was safe and pure. And yet it said the water tested was anything but safe and pure.
In South Africa, the Sefako report authors wrote, sales of bottled water were driven by the perception that water supplied by the government might not be safe for human consumption.
The study investigated concentrations of trace metals and the physico-chemical properties of bottled water bought from various supermarkets in Pretoria to determine health risks.
Twelve commonly available brands of water were purchased and analysed for trace-metal content. The scientists said three had pH values in the acidic region below the permissible standard of 6.8–8.0 set by the International Bottled Water Association, meaning they were not fit for human consumption. The target hazard quotient calculated for the water samples showed a minimum risk for lead, chromium and nickel.
Chromium is harmful to the skin, eyes, blood and respiratory system. Nickel exposure can harm the lungs, stomach and kidneys, and lead to cancer.
Lead exposure can have serious consequences, especially for children. At high levels of exposure, lead attacks the brain and central nervous system, causing coma, convulsions and even death.
Analysed brands
The brands analysed at by the university team were kept under cool conditions and transported to the laboratory, where they were stored at 4°C until the chemical analysis.
Information on the labels of some of the bottles did not match the chemical make-up of the water they contained, said the research team led by Professor Joshua Olowoyo.
Citing research by Gerassimidou et al, published in May 2022 in the Journal of Hazardous Material, the Pretoria researchers relied on evidence that in certain temperatures, chemicals have the potential to migrate from polyethylene terephthalate (PET) plastic bottles into the water as well as during recycling. It is also possible for the water to be contaminated from the source, due to variations in geological and geographical factors.
Globally, because freshwater quality is deteriorating from human activities such as mining effluent and accidental spills, freshwater systems in most developing countries are under pressure from harmful chemicals.
Municipal water treatment facilities cannot remove these chemicals or other impurities completely from the water because it’s expensive, technology is dated, and there has been an increase in demand for potable water supplies.
The study mapped food-contact chemicals that migrate from PET drink bottles to identify difficulties in closing the plastic packaging loop.
The researchers have called for producers to be monitored for compliance with WHO limits and for suppliers to make analytical reports on water safety available to consumers.
‘Numerous errors’
The subsequent review by Calie Adlem, a former CSRI quality manager, and John Weaver, who has a master’s degree in hydrology, claims to have found “numerous errors and probable incorrect data”, including the use of incorrect units of measure; a lack of clarity about what was being tested/reported; and a lack of interrogation of the results.
Weaver and Adlem have raised objections to the study, saying it errs on three fundamental levels.
They say the authors lack understanding of water chemistry; that they failed to interrogate the results; and that they misunderstood the testing protocols. They have also compared outdated water guidelines, referencing WHO 2007, when there is a free 2017 (4th) version available online.
“Perhaps the most irritating error made by the authors is a conceptual one,” Weaver said. “The WHO guidelines are for drinking water, whereas the waters analysed are bottled water. Bottled water is defined as a foodstuff, thus has separate regulations and standards being, in South Africa, R.718 of 28 July 2006: Regulations relating to all packaged water and SANBWA Packaged Water Standard: Requirements for Source Water, Processing and Packaging 2019. These have been based upon CODEX standards.”
Charlotte Metcalf, the CEO of the South African Bottled Water Association (SANBWA), added: “The data from this coalition and our own routine inspections show a radically different scenario to (the) ‘Toxic in Pretoria’ findings.
“Our members’ results for toxins and heavy metals are historically below the level of detection or very far below the maximum allowable limits. This is due to the diligent process of investigation and protection efforts prior to starting up a water-bottling plant.”
Unsafe sources are not allowed to be bottled in the SANBWA fold, she added.
“We are confident that SANBWA members’ water conforms to all relevant legislation and is safe for human consumption. The best way for consumers to protect themselves from unscrupulous bottlers is to look for the SANBWA logo on a bottle of water.”
South Africa’s bottled water segment is expected to reach volumes of about 2.5m litres by 2027.
Study details
Health Risk Assessment of Trace Metals in Bottled Water Purchased from Various Retail Stores in Pretoria, South Africa
Joshua Oluwole Olowoyo, Unathi Chiliza, Callies Selala, Linda Macheka.
Published in International Journal of Environmental Research & Public Health on 16 November 2022
Abstract
Bottled water is one of the fastest growing commercial products in both developing and developed countries owing to the believe that it is safe and pure. In South Africa, over the years, there has been an increase in the sale of bottled water due to the perceived notion that water supplied by the government may not be safe for human consumption. This study investigated the concentrations of trace metals and the physicochemical properties of bottled water purchased from various supermarkets (registered and unregistered) in Pretoria with a view to determining the health risk that may be associated with the levels of trace metals resulting from the consumption of the bottled water. Twelve commonly available different brands of bottled water were purchased and analysed for trace-metal content using inductively coupled plasma mass spectrometry (ICP-MS). The water samples were also analysed for various physicochemical parameters. The health risk was assessed using the target hazard quotient (THQ). For all the bottled water, the highest concentration of all the elements was recorded for Fe. The values reported for Cr, Ni and Pb were above the limit recommended by World Health Organization. The pH values ranged from 4.67 to 7.26. Three of the samples had pH values in the acidic region below the permissible standard of 6.8–8.0 set by the International Bottled Water Association (IBWA). The target hazard quotient calculated for the water samples showed a minimum risk for Pb, Cr and Ni. The study showed the need to adhere to a strict compliance standard considering the fact that South Africa has rich natural mineral elements, which may have played a role in the high levels of trace metals reported from some of the water samples.
IJIRPH article – Health Risk Assessment of Trace Metals in Bottled Water (Open access)
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SA tap water quality is declining, with DoWS warnings to boil drinking water
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