Don’t Grow Your Kombucha in a Ceramic Pot!

 Elizabeth O’Brien, Manager of the Lead Advisory Service (NSW)

The Lead Advisory Service (NSW) recently had an enquiry from an elderly couple and follow up of the case included the hospitalisation of the couple. They required chelation treatment for severe lead poisoning: the wife had a blood lead level of 5.9 µmol/L (122 µg/dL) and the husband’s level was 4.5 µmol/L (93 µg/dL). Through the blood lead notification system a home assessment was done by the local Public Health Unit and it revealed one likely source of lead was a ceramic pot. The couple had drunk kombucha tea stored in the ceramic pot every day for six months. The ceramic pot was imported by the couple from Spain and has "a shiny painting inside and outside".

 Kombucha tea is an alternative therapy favoured (unusually) by older people. The culture becomes extremely acidic when fermented, sometimes reaching a pH as low as 2.7 [Ref.: How to Make Kombucha – at a Glance, by Gunther Frank, internet site http://w3.trib.com/~kombu/]. A warning from the US journal Morbidity and Mortality Weekly Report (Dec 8th 1995) says "Because of the acidity of Kombucha tea, it should not be prepared or stored in containers made from materials such as ceramic or lead crystal, which both contain toxic elements that can leach into the tea".

 Unfortunately, only some of the sets of instructions on how to prepare the tea that are in circulation contain this warning. The kombucha fungal and bacterial culture used to make the tea, is usually shared among friends, rather than purchased. The consequent difficulties of spreading the warning notice before someone dies of lead poisoning have inspired a haematologist at the local hospital to write up the cases for eventual publication in a medical journal.

 As well as the established need to warn people that kombucha tea stored in ceramic or lead crystal can be a dangerous source of lead, these cases raise the question of lead stored in the bones being released by the action of Kombucha tea. An Internet site on Kombucha says "…When examining body fluids such as urine, it has been shown that people who drink Kombucha on a regular basis will excrete any toxins [sic] that have either built up internally as a result of illness or been absorbed from the environmental [sic]. Specific toxins which have been successfully isolated as being effectively purged from the body are: caesium, mercury, lead and benzol". [Ref.: internet site www.kombu.com/kombu/ by Kombu International in Queensland.]

 As 95% of an adult’s total body burden of lead is typically stored in the bones, it needs to be considered in examining the above 2 cases whether the action of the kombucha tea internally also contributed to the high blood lead levels, or whether simply drinking an acidic fluid from an inadequately glazed ceramic pot was sufficient to explain the poisoning. The wife’s small body size could be relevant to her extremely high blood lead (if they drank the same volume each day) but also the fact that the husband used lead solder throughout his working life in telecommunications could explain some of his very high blood lead level.

 LAS made inquiries on this issue to Australian Customs Service and to the Australian and New Zealand Food Authority (ANZFA). Customs advised us to write and suggest that a Customs (Prohibited imports) Regulations may need to be formulated which ensures that individual importers of less than 1000 ceramic items be advised at the customs check that the ceramic they are importing could possibly contain lead or other toxic heavy metals. ANZFA responded that they only regulate what is put in food (eg food additives) but they don’t regulate food. If Kombucha contains toxic substances it could be prohibited as a "Prohibited Botanical".