John Anthony Henry
Authors: Caroline Richmond
Journal: BMJ (2007)

With his modest manner, John Henry was an internationally renowned expert with a particular interest in rare poisons and the harm caused by street drugs. He was a founder of the poisons unit at Guy's Hospital. He was an expert at the inquest of Leah Betts, who died of water intoxication after taking an ecstasy tablet and drinking seven litres of water at her 18th birthday party. He recognised that the Ukrainian opposition leader Viktor Yushchenko's acne was caused by dioxin poisoning, and he advised the doctors treating Alexander Litvinenko, who died of polonium-210 poisoning.

John was, said Fiona Fox of the Science Media Centre, much loved by the many journalists he had helped over the years. He never failed to return the centre's calls, no matter what time of day or night or how controversial the story. The only time he lay low was after he diagnosed Yushchenko's acne and the centre was besieged with calls from Ukrainian “journalists” asking where he lived.

With Glyn Volans he authored the BMJ's ABC of Poisoning (1985), and he edited the BMA's Guide to Medicines and Drugs, now in its 6th edition. He wrote the chapter on air quality in Panic Nation (2000) edited by Stanley Feldman and Vincent Marks, pointing out that the air we breathe is cleaner than it has been for centuries. He was, said Marks, always helpful and always modest about his knowledge and attainments.

When the tabloid press splashed a story about a planned ricin attack on the London Underground, John defused the hysteria by saying that commuters could sleep or swim in ricin, as it is poisonous only when injected into the blood stream. When campaigners for tougher environmental controls screamed about toxic chemicals found in breast milk and cord blood he patiently explained why this was unscientific scaremongering. What matters, he explained, was the levels at which they were found and whether there was evidence of harm, information that was not forthcoming from campaigners, although he asked for it repeatedly. He commented, “I would have been surprised if they had not found chemicals at that level. You find traces of fire retardant because we have them in our homes. That's why fire deaths have plunged.” He said we should be more concerned about the harmful stuff we put in our bodies every Saturday night than scaring people about unproved risks.

He could tell a story against himself and amazed staff at the Media Centre in admitting that he had been fooled into talking about drugs on the Ali G show. He felt neither angry nor humiliated, adding that dealing with John Humphry or Jeremy Paxman afterwards had been a doddle. He was modest, humorous, and squirmed when anyone tried to pay him a compliment. He called his colleagues “chief,” which became his nickname; to the Media Centre he was “Uncle John.”

John was the son of an Irish-born London doctor, a sportsman who was doctor to Millwall football club. He was evacuated to relatives in County Mayo during the second world war. He was then educated at St Joseph's Academy, Blackheath, and King's College Hospital, passing his conjoint in 1964 and his MB BS a year later. He was a medical registrar at Whittington and University College Hospitals from 1964 to 1967, and then research fellow in clinical rheumatology and nephrology at Barts from 1967 to 1969. During the latter appointment he was warden of Netherhall House, a Catholic student residence in Hampstead.

As a medical student he had consulted a physician at King's about purpuric spots on his legs and was reassured but not given a urine test. Six months later, when having a wisdom tooth pulled, he noted that the urine test had been omitted and did his own: he had marked proteinuria. He had Henoch-Schonlein purpura, and it had damaged his kidneys. In 1968 he had a streptococcal sore throat, which was treated with tetracycline, finishing off his already-damaged kidneys. Advised that he probably had not long to live, he retired from his medical career and from the Catholic residence and received dialysis twice a week, though he remained in touch with medicine and talked to medical students about dialysis. “He counted every day of life as a blessing,” said his colleague Michael Platt, “and was compassionate to all in his care, courageous, and uncomplaining.”

In 1976 he received one of the earliest kidney transplants and returned to clinical medicine as medical registrar at Guy's. He rose to consultant physician in clinical pharmacology, where he worked in the hospital's poisons information service from 1982 to 1997. Then he was headhunted to St Mary's as consultant in accident and emergency medicine by Jane Fothergill and Robin Touquet (he was reassured that he would not have to set any Pott's fractures).

Here he broke new ground on managing poisoning and drug overdose. He introduced the fatal toxicity index for antidepressants, which changed prescribing practice; pioneered α1 glycoprotein as an antidote for cocaine, antidepressant, and other drug toxicity; and introduced a near-patient test for salicylate and paracetamol.

To the surprise of many who knew him, John was a devout Catholic and had been a celibate lay member of Opus Dei since he was 20. He went to mass at 6 30 am every day.

Robin Touquet said that John was always happy to cover for a colleague at short notice. He always carried his air call (it went off at his interview at St Mary's, bemusing Sir Ronald Oxborough, the chairman). He was loved for his personality and admired for his intellectual rigour.

He was a brilliant teacher and clinician who could make on the spot diagnoses. Typically, he spotted cannabis use in a scaffolder with a broken leg and red conjunctivas, and realised that a girl had been given Rohypnol as her urine was green.

He retired in September 2004 but continued researching, and was in demand as an expert witness. In his later years he lived in staff accommodation at Netherhall House, where he was a father figure to the students.

In April the vascular supply to his transplanted kidney failed. He died of internal bleeding after it was removed. He leaves a brother and two sisters.

Professor John Henry, expert toxicologist (b 1939; q King's College, London, 1964; FRCP, FFAEM), died on 8 May 2007.