FROM the black days of her own menopause to the forensic investigation into the global health crisis caused by the fact 2.5bn people don’t have a toilet, Rose George is fearless in her writing.

As the New York Times reviewer of her book about the latter, The Big Necessity, put it, ‘She’s a nimble writer, one who walks in fear of euphemism or pretension ... She rips open her topics as if they were bags of chips.’

She cut to the chase in Hexham Library on Sunday. She’d been looking at how the lack of toilets in schools could affect pupils in developing countries, when she happened across the fact pubescent girls are routinely pulled out of school the week of their periods.

“I was asked to write a report for the UN,” she said. “I’d spent the previous four years writing about poo after all! ‘Menstrual Health Management’ was the report.

“The level of taboo around periods really bothered me – menstruation impacts on 51 per cent of the population for most of their lives, but I wanted 100 per cent of the population to pick up on it.”

George equally goes the full nine yards in what is her fourth book, Nine Pints: A Journey through the Mysterious, Miraculous World of Blood.

She visited India, Nepal, South Africa and Canadian to look at the varying attitudes to blood.

She investigated reports the wrong type of blood is being used in the treatment of trauma patients, when and why medicinal leeches (which can live to the age of 27) are still used today, and why – just as an official inquiry was finally opened this week – justice is still being sought for the thousands of haemophiliacs given contaminated blood in the 1970s and ‘80s.

George said: “I learned dazzling facts about blood. Every three seconds, a person receives some from a stranger. Our veins and arteries, measured, are 60,000 miles long, or twice the circumference of the earth.

“Every day, our trillion red blood cells travel about 12,000 miles around our bodies. There are more than 300 known blood types, far more than A, B, O, and scientists still don’t know why we have them.”

She turned the spotlight on “a heroine of mine”, Dame Janet Vaughan, the pioneering haematologist who established Britain’s mass blood donation and storage system as the clouds of war loomed in 1938.

And she talked about the history of blood transfusions and the flaws in places such as India and America, where monetary inducements have ushered in ‘bad’ blood.

But British blood isn’t considered safe either, she added. “Our blood isn’t accepted around the world. If you ate a hamburger in the ‘80s, you are a pariah – you could be harbouring mad cow disease.”