How’d it get in there? Chlorine’s a lifesaver – most treatment plants dose tap water with it to kill dangerous contaminants found naturally in freshwater sources.
Its effects In small doses, chlorine is considered safe to ingest according to Australia’s National Health and Medical Research Centre (NHMRC), over several months, military personnel drank water with chlorine in amounts at least 80 times higher than those found in Aussie water supplies – and they experienced no ill effects.
But you may have heard recent news about SA tap water breaching the NHMRC’s Australian Drinking Water Guidelines or World Health Organization guidelines, oh, about 9298 times from January 2000 to July this year. Friends of the Earth researcher Anthony Amis said the most worrying breaches related to chlorine by-products that some studies found may potentially cause cancer.
One US study, led by Harvard University, linked chlorinated drinking water to bladder and rectal cancers; though the International Agency for Research on Cancer doesn’t classify chlorine as a carcinogen.
SA Health principal water quality adviser Dr David Cunliffe is calling for calm, assuring that SA water is safe, and the public would be notified if there was a health risk.
Take action Chlorine by-products evaporate naturally, so if you’re worried, let your glass sit pretty for five minutes before you take a sip. Another option: get a water filter, like a BPA-free jug, tap attachment or built-in fridge device.
How’d they get in there? In plain English, pathogens are any disease-producing organism, like bacteria and viruses.
“Pathogens can enter the water system either at the source (before treatment) or after treatment (in the pipes delivering it to you) through direct faecal or human contact with the water, sewage leakages, stormwater run-off after rain and animal droppings,” says Dr Helen Stratton, senior lecturer at the Smart Water Research Centre at Queensland’s Griffith University.
Its effects You may recall the most publicised drinking water contamination incident in Australia in 1998, when high numbers of organisms, giardia and cryptosporidium, were reported in Sydney’s treated water – three million residents were advised to boil their water to avoid diarrhoea.
Take action If you have a weaker immune system you may want to boil water for at least five minutes to nix lurgies. “Young children up to
five, chemotherapy patients and the elderly are more at risk, even at very low doses, and should always make sure the water they drink or swim in is safe,” says Dr Stratton.
How’d it get in there? Treatment plants strip out nearly all traces of lead, but just as Black Sabbath can sneak into your Spotify radio, this heavy metal can get back into your drinking water as it flows through your house’s pipes.
If you live in a home built before the 1930s, chances are your pipes contain lead, plus lead-based solders were used on copper pipes until as recently as 1989. But don’t go re-piping your house – the NHMRC says we get more lead from food, dirt and dust than water.
Its effects For some, a small amount of lead is bad news; it’s a cumulative poison that can attack your nervous system, and it’s been linked to things like irritability, anaemia, kidney damage and cancer.
A study in Environment International linked childhood lead exposure to violence in adulthood. If you’re trying to conceive you should also be careful – research over the years has linked lead poisoning to miscarriage and foetal complications.
Take action Run your taps for two minutes each morning to flush out water that’s been stagnating in the pipes, says Dr James Symons, author of Plain About Drinking Water. Use the wastage to water your plants.
How’d they get in there? Every time you pop a pill – contraceptive, antibiotic or painkiller – traces of it come out in your pee. And, sorry to say, that urine can eventually find its way back into our tap water.
“[Water treatment plants have] several options to greatly reduce the levels of drugs in water,” says Dr Frederic Leusch, program leader of Water Quality and Diagnostics at Griffith University.
“These techniques are 99.99 per cent effective, which means that they will remove the great majority of drugs and other chemical pollutants [like pesticides] from water sources, but a tiny little bit will always be left in.”
Its effects The NHMRC says that no definitive link has been established between drug exposure in drinking water and health problems, probably because traces are so low: “For example, [paracetamol] has been detected at up to 45 nanograms per litre in drinking water,” says Dr Leusch.
“At that concentration, you’d have to drink two litres of tap water every day for 30,000 years to get the equivalent of one regular strength Panadol tablet. It’s the same story with all pharmaceuticals… it’s all about the dose.”
Some reports, including one by the University Medical Center Freiburg in Germany, have raised alarm bells over antibiotics in water supplies potentially leading to the development of superbugs, yet the NHMRC says studies are yet to confirm this.
Your action plan Many household filters don’t stop drug residuals, so watch this space: worldwide investigations into drugs in drinking water are ongoing.
If you’re concerned, drink bottled spring water, but make sure you look for the words “spring” or “mineral” water – some companies have admitted to filling bottles with filtered tap water and label it things like “pure”. Sneaky buggers.