What we know
The media reports that water passing through the tap has up to 15 times the lead levels allowed in Australian drinking water (maximum 0.01 milligrams per litre). Queensland Health’s Forensic and Scientific Services conducted the tests, so the results are credible.
What we don’t know
We don’t know how extensive the contamination is. So far, only one tap has been tested and I haven’t seen the actual results. So, we need a larger sample of taps to determine if this was a one-off contamination (unlikely) or represents a wider problem.
Aldi confirmed the taps were tested by a National Association of Testing Authorities accredited laboratory and passed Australian standards for lead leakage into water before going on sale. But it is not clear why the current tested tap exceeds the Australian standards by so much.
Is it a problem with a particular batch? Or did substitution of high lead components occur after the first samples were tested as some media reports claim? Australia permits higher levels of lead in brass used in Australia’s plumbing fittings than the US, for example. However, the reported lead levels seem too high for this to explain the current situation.
Aldi has suspended sales of the tap and is currently having the taps tested at an independent accredited laboratory. Answers to the questions should be available by the end of the month.
Another issue is the report of “up to 15 times the permitted lead level”. We don’t know if the level of lead is declining with each use of the tap, or if this is just simple assay variability. If the levels decline over time the risk to consumers are less (but still concerning).
What is the risk if I have one of these taps?
While the levels involved are substantially higher than the Australian guideline, they are still low and not likely to cause acute lead poisoning. One or two glasses will not poison you.
But lead is a cumulative toxin. Continued consumption of low levels of lead (over weeks, months and years) can have adverse effects.
The major concern is in babies, young children and unborn babies. Babies and young children absorb more lead than adults, with significant effects on their developing bodies. Effects include disruption of red blood cell production, kidney damage, behavioural disturbances and other nervous system effects. The behavioural and nervous system effects are of most concern.
Exactly which effects occur will depend on how long and how much water has been consumed (and whether the reported lead levels are typical). For adults, anaemia, high blood pressure, tremor, tiredness, sleeplessness, irritability, headache and joint pain may be signs of long-term exposure to low levels of lead.
What should I do if I have one of these taps?
Until it is determined if other taps of this brand are similarly contaminated (again, previous test samples had complied with Australian regulations) people who have bought these taps should not use water from them for drinking or cooking.
Anyone who has any health concerns should consult their doctor.
Aldi confirmed the taps were undergoing independent testing, which is expected to be completed by 31 July. “If these results present any indication that a health risk exists for our customers, we will take appropriate action,” a company statement said.
In the meantime the company recommends customers who have bought the taps register their product to receive updates and the results of the testing.
Ian Musgrave receives funding from the National Health and Medical Research Council to study adverse reaction to herbal medicines and has previously been funded by the Australian Research Council to study potential natural product treatments for Alzheimer's disease. He has used workshops on lead contamination as a teaching tool for environmental toxicology.
Authors: Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide