Israel's destructive military campaign in Gaza has unleashed a silent killer: asbestos.
The mineral, once widely used in building materials, releases toxic fibers into the air that can stick to the lungs and cause cancer for decades.
Today, its use is banned in most of the world, but it is still present in many older buildings, writes the BBC.
In Gaza, it is mainly found in asbestos roofs used in the territory's eight urban refugee camps, which were set up for Palestinians who fled or were expelled from their homes during the 1948-49 Arab-Israeli war - according to the United Nations Environment Programme (UNEP).
In October 2024, UNEP estimated that up to 2,3 million tons of rubble across Gaza could be contaminated with asbestos.
"The ruins of Gaza are a very, very toxic environment. People will suffer acutely, but also long-term, things that children can carry throughout their lives," says Professor Bill Cookson, director of the National Mesothelioma Research Centre in London.
"The lives lost now will not end here. The legacy will continue," says Liz Darlison, chief executive of Mesothelioma UK.
When asbestos is disturbed by something like an airstrike, its fibers, too small to be seen by the human eye, can be inhaled by those nearby and can then travel to the lining of the lungs.
Over many years, usually decades, they can cause scarring that leads to a serious lung condition known as asbestosis, or, in some cases, an aggressive form of lung cancer called mesothelioma, according to the BBC.
"Mesothelioma is a terrible, incurable disease," says Professor Cookson.
"The really worrying thing is that it's not dose-related. So even small inhalations of asbestos fibers can cause subsequent mesothelioma," he adds.
"It grows inside the pleural cavity. It's extremely painful. It's always diagnosed late. And it's pretty resistant to all treatments."
Typically, those who develop mesothelioma do so 20 to 60 years after exposure, meaning it can take decades before any potential impact is felt across the board. Higher levels or longer periods of exposure are believed to accelerate the progression of the disease.
Dr Ryan Hoy, whose research on dust inhalation is cited by UNEP, says it is extremely difficult to avoid inhaling asbestos fibres because they are "really tiny particles that float in the air and can go very, very deep into the lungs".
They are even harder to avoid, he says, because Gaza is so “densely populated.” The territory is home to about 2,1 million people and is 365 square kilometers (141 square miles), about one-quarter the size of London.
Experts on the ground say people are unable to cope with the risks posed by asbestos or dust inhalation due to the more immediate dangers of the Israeli military offensive.
"At the moment, [dust inhalation] is not something that the population sees as a concern. They don't even have anything to eat, and they are more afraid of being killed by bombs," says Chiara Lodi, medical coordinator in Gaza for the NGO Medical Aid for Palestinians.
"The lack of awareness of the risks of asbestos, combined with the ongoing challenges [people in Gaza] face in trying to rebuild their lives, means they are unable to take the necessary measures to protect themselves," said a spokesman for the NGO SOS Children's Villages in Gaza.
Many "are not fully aware of the harmful effects of dust and debris," they added.
Following the previous conflict in Gaza in 2009, a UN survey of the territory found asbestos in the remains of older buildings, sheds, temporary building extensions, roofs and walls of livestock pens.
There are several types of asbestos, from the so-called "white asbestos", which is the least dangerous, to the "blue", or crocidolite, which is the most. Highly carcinogenic crocidolite asbestos was previously found in Gaza by the UN, according to the BBC.
Globally, about 68 countries have banned the use of asbestos, although some retain exemptions for special uses. The UK banned it in 1999, and Israel banned its use in buildings in 2011.
As well as mesothelioma, asbestos can cause other forms of lung, larynx and ovarian cancer.
A further, lesser-known risk is the risk of silicosis, a lung disease caused by inhaling silica dust, usually over many years. Concrete generally contains 20-60 percent silica.
Dr Hoy says the high levels of dust in Gaza could lead to "an increased risk of respiratory tract infections, upper and lower respiratory tract infections, pneumonia, exacerbations of pre-existing lung diseases such as asthma", as well as "emphysema and chronic obstructive pulmonary disease, which can be exacerbated by lung disease".
For years, health experts have used the September 11 attacks on the World Trade Center in New York as a case study for examining the effects of a large toxic dust cloud on the civilian population.
"The Twin Towers were not in the middle of a war zone, so it was something we could measure and quantify more easily," Ms. Darlison says.
As of December 2023, 5.249 of those enrolled in the U.S. government World Trade Center health program have died from aerodigestive disease or cancer, far more than the 2.296 people killed in the attack itself. A total of 34.113 people have developed cancer during the same period.
The US and a group of Arab states have proposed competing plans for the reconstruction of Gaza. The UN has warned that the process will have to be carefully managed to avoid disturbing vast amounts of asbestos-contaminated rubble.
"Unfortunately, the properties that made us use it so much are the properties that make it difficult to get rid of," says Ms. Darlison.
A UNEP spokesman told the BBC that the debris removal process "will increase the likelihood of asbestos disruption and the release of hazardous fibres into the air".
A UNEP assessment showed that cleaning up all the debris could take 21 years and cost up to $1,2 billion (£929 million).
The Israeli military launched an offensive on Gaza in response to Hamas's attack on Israel in October 2023, in which about 1.200 people, mostly civilians, were killed and 251 people were taken hostage.
The Israeli offensive has killed more than 53.000 Palestinians in Gaza, mostly women and children, according to the territory's Hamas-run health ministry.
The Israel Defense Forces (IDF) did not respond to the BBC's request for comment.
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