Postmortem specimens taken from the 21 teenagers who died at East London's Enyobeni tavern in June did not undergo a critical test needed to establish if methanol poisoning played a role in their deaths.
According to an “unofficial” report by state forensic toxicologist Bronwen Davies to the investigating officer, methanol can neither be blamed nor ruled out as at least a contributing factor in the deaths because “formic acid concentrations were not measured”.
Formic acid is a highly toxic substance that is formed during the body’s metabolism of methanol, itself a highly toxic solvent used in paint thinners, plastics, textiles, dyes, adhesives, antifreeze, cleaning agents and fuels.
In the report Davies describes formic acid as a toxic compound that lowers the pH of blood to make it highly acidic.
Davies is the manager of the forensic toxicology unit in the Western Cape provincial department of health and wellness, and lectures in forensic medicine and toxicology at the University of Cape Town.
Her name appears at the top of an undated, three-page document titled “Toxicological comment on the Eastern Cape deaths”.
Asked about the report, she said in an e-mail on Thursday that “this was an unofficial document and sent in confidence to the investigating officer. I’m not sure why you have seen or had access to it.”
She did not reply to questions about the circumstances that led to her writing and submitting the report.
Davies has previously stated that all forensic analyses of specimens from the victims of the Enyobeni tragedy were performed by the National Health Laboratory Service’s forensic chemistry laboratory (FCL) in Cape Town.
In the document sent to the police, which the Sunday Times has seen, she says her comments are based on the results from the FCL.
The Sunday Times has not seen the detailed FCL test results but Davies’s document gives the key findings, including blood concentrations of methanol, ethanol, carbon monoxide, drugs and pesticides.
The presence of methanol in the youths who died ranged from 0.007g per 100ml to 0.033g/100ml, with an average concentration of 0.012g/100ml. In one case there was not enough blood available for testing.
After a latent phase of six-30 hours (usually 12-24 hours), the individual may become dizzy and drowsy with weakness, headache, vomiting, severe abdominal pain and diarrhoea
— Forensic toxicologist Bronwen Davies
Ironically, the alcohol in such beverages as spirits, beer and cider — ethanol — acts as an antidote to methanol because the two forms of alcohol are metabolised by the same enzyme.
Davies explains that ethanol competes with methanol for these enzymes “and is preferentially metabolised”. If methanol is not metabolised, formic acid is not produced.
Davies says methanol can be present at very low levels in commercially available alcoholic beverages but such instances are seldom relevant from a toxicological point of view, “as the drinks contain enough of the antidote ethanol”. Methanol is also produced within the body’s cells.
“In an average individual, methanol blood concentrations will be less than 0.00015gr/100ml due to these or other sources.”
By contrast, “self-made alcoholic beverages … may lead to accidental poisoning. The acute ingestion of as little as 10ml can cause toxicity and ingestion of 100ml-200ml of methanol is considered fatal in most adults. Toxic doses in children are approximately 0.1-0.15ml/kg.”
Davies says in the report that symptoms of methanol poisoning usually appear well after actual consumption, sometimes only 12-24 hours later. This period “may be longer” if methanol is consumed simultaneously with ethanol.
“Within 30 minutes to two hours of ingestion of methanol, the individual may experience mild drowsiness, confusion and irritability. After a latent phase of six-30 hours (usually 12-24 hours), the individual may become dizzy and drowsy with weakness, headache, vomiting, severe abdominal pain and diarrhoea.
“Extremities become cold and clammy, and tachypnoea [abnormally rapid breathing] develops with deep, laboured breathing. Central nervous system depression with slurred speech, confusion, coma and seizures may also occur.”
Davies says “the onset and progression of toxicity may differ in children as their enzymes are not fully developed, resulting in slower metabolism of methanol to formic acid”.
“The extent of tissue damage and the probability of a fatal outcome due to methanol ingestion are dependent on the amount of methanol ingested, time elapsed since ingestion, co-ingestion of ethanol, aggressive hospital intervention, and the metabolic acidosis established from formic acid accumulation…
“The symptoms experienced by the deceased or those in hospital are unclear, making it difficult to ascertain whether they align with methanol toxicity.”
She suggests investigators should obtain the relevant medical records and treatment details from the hospital where the Enyobeni patients were taken, especially those relating to the tavern patrons who survived, to determine the quantities of certain substances and blood acidity.
On blood-alcohol concentrations, she says the highest levels were 0.26%, 0.22% and 0.18%. “These higher concentrations do suggest high impairment” due to drinking.
Davies says it is “unlikely” that carbon monoxide toxicity — from “cigarette smoke, exhaust fumes and malfunctioning exhaust systems” — was the sole cause of toxicity.
The highest levels of carboxyhaemoglobin — a compound found in the blood when carbon monoxide is inhaled and binds to haemoglobin — were 19.5%, 19.2% and 16.6%. Samples from the rest of the youths who died were below these levels.
No drugs and pesticides were detected, but Davies states “the scope of the analysis performed is unknown”.
Asked if the samples could still be tested for formic acid, a pathologist in private practice who spoke on condition of anonymity said: “Samples are not routinely destroyed after the initial testing. One must accept that samples can deteriorate but the possibility exists that further testing can be done on the samples.”
Ntombizonke Mgangala, the aunt of one of the Enyobeni dead, Sinothando Mgangala, 17, said “there are too many gaps” in the investigation.
She said parents had asked the Eastern Cape health department for a copy of the autopsy results, but nothing had been received by the stipulated deadline. The parents are now consulting lawyers.
Senior researcher and acting head of the Unesco Oliver Tambo chair of human rights at the University of Fort Hare, Siyabulela Fobosi, said there was “some level of incompetence” in how the investigation was being handled.
A “broader investigation” would have examined “where the kids were before they came to the shebeen, what the state of the shebeen is, what plan the owner has for over-crowding”. Alcohol in the shebeen would also have been tested, he said.
Eastern Cape health spokesperson Yonela Dekeda referred queries to the police.
Provincial police spokesperson Brig Thembinkosi Kinana said: “We are not at liberty to make pronouncements on matters that are still subject to a judicial process and which may create or result in uncertainty on the part of those affected by the incident.”
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