Hugh Brown risks his life to document the men, women and children who mine precious minerals by hand in brutal conditions. He's encountered the "coal mafia", braved the "mountain that eats men" and been interrogated over terrorist links - and he isn't done yet.
"Literally the smell of death was everywhere."
Hugh Brown has recently returned from one of the world's largest silver mines - Bolivia's Cerro Rico. It roughly translates to "rich mountain" but also has a much darker moniker - the "mountain that eats men".
It's an ancient death trap that has claimed the lives of as many as eight million miners in the past 471 years.
"Death is part of working on the mountain. My first fixer, as we were driving through the streets of Potosi, was pointing out 'that woman lost a husband in the mine, that woman lost a husband in the mine'," Brown says.
"It's a town of 150,000, and every single person was related to someone that had died in the mine."
The Perth-based photographer says the 4,824-metre-high mountain in the southern highlands is "like a piece of Swiss cheese" and is "actually physically collapsing in on itself".
"There are so many holes, but the holes haven't all been mapped so nobody knows what holes are where. There are also toxic gases, and people dying in blasts, and people falling off ladders," he says.
"Two men will push these wagons weighing up to two tonnes, and in certain places they get quite a bit of speed up, and if you're caught in the wrong place you can be crushed to death."
Many of those who survive the mountain are struck down with black lung disease.
"Eight years ago they were losing three to five people a day on that mountain. While I was there they were estimating about three to five a month," Brown says.
"Every day you woke up to go into the mountain you thought, am I going to come out today?"
The Cerro Rico miners are among the estimated 30 million men, women and children who mine by hand around the world.
Brown first encountered artisanal miners while travelling through remote parts of Ghana in 2006.
"What they were doing was just fascinating. You hear about the conditions they worked in on the Australian goldfields back in the 1850s, but to see it here in the 21st century blew me away," he says.
Over the past decade, Brown has journeyed to West Africa about 20 times, and has also been to remote and dangerous parts of India, Pakistan and Indonesia.
"In east Java, I spent three weeks living on the side of the Ijen volcano, literally 200 metres from the rim," Brown says.
At the time, the volcano was on its second-highest alert level, with an eruption considered to be imminent.
Miners journey down into the crater of the volcano to collect solidified sulphur. Beneath the tenuous crust is molten sulphur that is somewhere north of 120 degrees Celsius, and could either kill or cause severe burns.
In eastern India, Brown photographed the illegal indigenous Adivasis coal miners, many of whom have turned to mining to survive after being displaced from their traditional lands. At the time, the area was in the midst of a Naxalite insurgency.
"Kidnapping was a significant risk I had to manage," he says.
He then spent three days building trust with the Indian "coal mafia" so he could gain access to another area of the country.
"I know very little about them but I know that if you get on the wrong side of them, it's not good," he says.
"I work in areas that are quite sensitive, because mineral resources mean money, and money funds a lot of things that are not necessarily savoury in the Western world, to put it sensitively. So they don't like photographers sniffing around.
"I had to convince them that I wasn't there for a political purpose, that I was just there to capture a subject that I felt would be historically important in the years to come."
Brown has also spent time among the world's highest altitude miners in the Karakorum Range of northern Pakistan, where some of the world's most beautiful and valuable gems are found.
Towards the end of the trip, while seeking to photograph nomadic gold panners on the Indus River, he was interrogated by civilian and military intelligence agencies who were investigating groups in the region for links to the Islamic State group and the Taliban.
He laughs when asked about the encounter.
"At the end, when he decided I was alright, the military intelligence guy said to me 'have you thought about converting to Islam? I think it's a good idea that you do'," Brown recalls, adding: "That was funny."
The places Brown visits pull together some of humanity's most dangerous - and disturbing - elements: people trafficking, child slavery, insurgency, terrorism, the irreversible destruction of the environment.
"My attitude to a lot of it, which is probably more of a strength now, is that I try not to judge these things," he says.
"It's the yin and the yang. For all the negatives there are good things to come out of it.
"The money that they're making is exponentially greater than what they could earn in the fields or the villages."
In the hardship, he says, the strength of the human spirit shines - as does the universal concept of sacrifice in the name of a better life.
"Back in the Western world, you've got people slogging away in an office doing something they hate, or working a second job, because they think that if they can earn that extra money they will get ahead," Brown says.
"And these miners are no different to that. It's about sacrificing the life that you have for the prospect - and prospect being the key word - of a better life. There's no guarantee, but they're trying.
"And that's what just about every single person on the planet is doing."
Brown says his job makes it "very easy to get killed if you're not careful". He admits the risk to his life is constant, and daily.
"You've got to be on your game. Your senses have to be heightened, you must be aware," he says.
He says the danger is heightened by the fact that he works alone - but quickly adds that he could just as easily be killed in a car accident in Australia.
Where the next part of his project will unfold is, for now, a secret. But he has just finished hostile environment training in preparation.
"I've known what it is like to experience extreme fear. It's not particularly pleasant but you just have to deal with it, and if you can push through that you get to enjoy experiences that enrich your life," Brown says.
"It is in times of difficulty where you learn the most."
Brown can't put a finger on exactly why the project feels so important, but it has a lot to do with creating a place in the history books for the world's artisan miners.
"I could never in my wildest dreams have thought I would be doing something like this," he adds.
