Beware toxic trace metals in some bottled waters

A variety of branded bottled waters was tested by scientists in Pretoria with shocking results. Ivo Vegter explored the topic, first published in the Daily Friend. At least three of the brands were declared to be unsafe for human consumption as they contained high levels of harmful trace metals. So think carefully before you automatically reach for a bottle of water. Perhaps a glass of tap water is the way to go after all. – Carmen Mileder

Regulatory failure: toxic water

By Ivo Vegter

Fifteen years ago, Regulation 718 (R718) came into force. Promulgated under the Foodstuffs, Cosmetics and Disinfectants Act number 54 of 1972, this placed bottled water under regulation by the Department of Health.

The problem had been that anyone could stick any water into a bottle, and as long as it didn’t actually stink or appear discoloured, consumers would be none the wiser. Scammers and frauds were coining it.

R718 defined what bottled water is, and split it into three categories: ‘natural water’, ‘water defined by origin’ (iceberg, snow, stream, rain, river, mist, spring, glacier and sea water), and so-called ‘prepared water’.

For prepared water, anything goes. It can be tap water, as long as it has undergone any treatment acceptable for bottled waters, such as filtration, and remains within the general requirements for bottled waters on chemical composition, microbiological safety, packaging and labelling.

Water defined by origin can be processed in any number of ways, including disinfecting and changing its chemical composition. Despite the label, you’re not likely to get what actually comes out of that glacier or spring.

Natural water is heavily restricted, however. It must be bottled at source, and may not undergo any treatment beyond filtering and adding or removing carbon dioxide. Natural water is supposed to be the real deal.

Seventy percent of all South Africa’s bottled water is marketed as natural water, and is obtained from underground aquifers.

All hail natural water

Natural water, of course, is assumed to be healthy. Natural is good! Natural is better than prepared water! If only we only consumed more natural stuff, we’d all be healthy and cancer-free and live to 120.

Turns out, this is false. Natural water contains loads of trace minerals and metals that can be toxic to humans.

Researchers from the Sefako Makgatho Health Sciences University in Pretoria, led by Joshua Oluwole Olowoyo, collected samples of 12 branded bottled waters of all three categories – natural, defined by source, and prepared – from both formal and informal retailers. They subjected these bottled waters to chemical analysis.

The results, at first glance, appear to be moderately alarming. In a paper published in the International Journal of Environmental Research and Public Health, they reported that three of the 12 samples ‘may be considered unsafe for human consumption due to the levels of toxic trace metals present in the samples’.

Another three (two of the above plus one other) were quite acidic, with pH levels ranging from 4.65 to 4.79.

The authors muse that ‘[some] reports from literature have suggested that changes in water pH may affect the gut microbiota composition and the host metabolism while others have suggested an increase in the incidence of diabetes, especially from drinking water with low pH’.

I wouldn’t worry too much about that, however. Most people who don’t already suffer from things like gastritis, stomach ulcers or gastro-œsophageal reflux disease can consume acidic fruit juices, vinegary pickles and modest amounts of wine just fine without dramatically increasing their risk of grave medical consequences.

They are right, however, that acidic water is able to leach more minerals and metals out of the rock and soil in which it is found.

Toxic metals

The real problems start with the chemical composition of the water. The conclusion that three of the 12 brands were unsafe for consumption was based on a detailed risk assessment conducted by the authors.

Considering only the levels of metals present in the water, however, suggests that the real situation is even worse than this.

Every single one of the samples had chromium levels three to four times the 50µg/l limit recommended by both R718 and the World Health Organisation (WHO). Although R718 allows up to 100µg/l before deeming it ‘contaminated or injurious to health’, none of the samples came in below that level, either.

Out of the 12 samples, nine had lead levels higher than the limit of 10µg per litre recommended by both R718 and the WHO. One was dramatically higher at 123.5µg/l, and it was one of three that exceeded the levels of 50µg/l above which R718 deems it contaminated or injurious to health.

The WHO and R718 both recommend a limit of 20µg/l of nickel, but all the samples came in between about 75µg/l and 90µ/l. However, unlike with chromium, these levels are below the 150µg/l at which it deems the water to be unsafe.

The other trace elements tested for, namely iron, copper, manganese, vanadium, titanium, molybdenum and cadmium were below WHO guidelines in all samples, according to the paper.


I double-checked this claim. R718 sets no limits on iron, vanadium, titanium or molybdenum. Of these, the WHO sets a guideline only for molybdenum, of 6µg/l, which all samples met.

For manganese, however, the WHO recommends 80µg/l, which seven of the samples exceed. R718 is plagued with a typo, setting a recommended maximum level of 500µg/l and an acceptable range of up to 100µg/l. One assumes the first of these is supposed to be 50µg/l. Still, six of the samples exceeded 100µg/l above which R718 deems it to be contaminated or injurious to health.

Copper levels in all the samples do come in under the 2 000µg/l guideline set by the WHO, but 11 of the 12 samples exceed the limit of 100µg/l above which R718 considers water to be unsafe for consumption. Let’s be gentle and blame R718 for this, though.

Finally, for cadmium, the WHO guideline is 3µg/l, as is the R718 guideline, although the latter allows up to 5µg/l before deeming the water to be unsafe. All of the samples exceeded these limits, by a factor of three or four. One exceeded it by a factor of 13.

In reality, therefore, every single one of the sampled brands of bottled water in the Olowoyo study exceeds the safety limits set by South Africa’s Regulation 718. Perhaps we should panic just a little, after all.

Naturally occurring minerals

The authors have a lot to say about where the contamination might have come from, but little about where it does come from. Given the location of the water sources, around Pretoria on the Witwatersrand, we can probably blame naturally occurring minerals and possibly acid mine water pollution.

Perhaps ‘natural water’ dug from a well in some Pretoria backyard isn’t quite as pure as Alpine spring water, after all. There’s probably a reason why the original mineral waters were tapped from high mountain springs: there, snow-melt is filtered by the soil, but the water probably contains far fewer toxic metals than groundwater in industrialised valleys.

Regulatory failure

This raises serious questions about the effectiveness of government regulation. The study authors point to the inconsistency between the chemical analysis R718 requires water vendors to put on the labels, and the actual chemical content of the water they tested.

It isn’t clear why R718 distinguishes between ‘natural water’ and ‘water defined by origin’, as if, say, spring water isn’t ‘natural’. It doesn’t allow any treatment (beyond filtering and (de-)carbonisation) for natural water, but does allow for treatment of water defined by origin, both for microbial decontamination and to reduce elements originally present in excess of acceptable levels.

Perhaps as a consequence of this ban on treatment, some water sold as ‘natural water’ violates the rule that no bottled water shall contain substances or emit radioactivity in quantities that may be injurious to the health of the consumer.

It is also clear from this research that many, if not most, water bottlers fail to conduct accurate chemical analysis to print on their labels, and fail to meet the required standards to be considered safe for consumption.

The regulation of bottled water by the Department of Health, in short, has been exposed as a miserable failure.

The voluntary private association of water bottlers, the South African National Bottled Water Association(SANBWA), maintains a standard that includes R718, but also covers other requirements and global best practices. It also has strict requirements for membership.

Sadly, the Olowoyo paper does not identify the 12 brands it analysed, so it is impossible to tell whether any of them were members of the SANBWA.


One would hope not, since in the absence of effective regulation by the Department of Health, consumers will have to rely on the good name of SANBWA members to be sure the water they drink isn’t toxic.

Either way, consumers will have to be far more vigilant in future. Buy only from reputable, established brands that have a reputation to protect. Be fussy about the source. Water from boreholes in mining territory, or bottled by fly-by-nights, is far more likely to be contaminated with heavy metals and minerals at potentially unsafe levels.

We’re often told that government regulations are necessary to protect consumers and keep them safe from opportunistic capitalists. Why we should trust government to perform this function, however, will remain a mystery.

I’m as cynical about government competence as anyone, and even I’m surprised that 15 years after imposing health regulations on bottled water, a survey by scientists found literally every bottle they tested to be at least somewhat unsafe for human consumption.

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The views of the writer are not necessarily the views of the Daily Friend or the IRR

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