There’s a giant landfill site near Maputo, Mozambique’s capital city, that covers 42 acres and rises to 15 metres in height. Young men roam it hoping to find things that are either valuable or can be recycled. These people play an important role in the local economy but they are marginalised by Mozambican society. When I started thinking about photographing the tip roamers, people warned me it would be dangerous: they are “uncivilised”, they said, they would steal my camera, attack me, even kill me. At the beginning of any project, I do lots of research. I need to understand a place and its people, establish contacts who can introduce me to new communities, and build trust with whoever I’m photographing. I don’t work like a photojournalist: I’m not tied to strict deadlines. I like to spend time with the people I photograph. We eat together, play games, get used to each other, so that by the time it comes to shooting, they’re comfortable. Working in the dump was a challenge. It was another world and I was well out of my comfort zone. But I saw it as a privilege. You’re relating to people whom society has judged and excluded. I was a first-hand witness to their lives. The series began in 2015 and took form over several years. I exhibited it, but I didn’t feel like the project was fully over, so I went back a year or two later to see how things had changed. The passage of time fascinates me. I never planned to shoot anything the day this was taken. I was just heading back to the site to see some of the people I had got to know. Early one morning, this guy recognised me and ran over to greet me. There was a broken screen on the ground and he had the idea that he should put his head inside it, like a TV news anchor. He was really enthusiastic – jumping in and out of the screen, mimicking someone presenting the morning news. He was calling the shots. I always try to show the people I photograph the final shot – sometimes as prints, sometimes on my phone or computer. When I showed this guy his image, he laughed a lot. I like to use photography to draw people’s attention to things they’re missing, be it environmental issues, working conditions, or human rights abuses. My own upbringing was not always easy, but it helped me relate to people from different walks of life. I grew up in Mozambique with my mother and two sisters. I was the eldest and the only man in the family, so I was expected to contribute from a young age, and from the age of eight I would go out to look for food and make money where I could. My mother didn’t go to school and couldn’t read. She couldn’t speak Portuguese, which became the official language of Mozambique, so I had to help her communicate. When she got her first mobile phone, she couldn’t use it. She gave it to me so I could keep in touch with people on her behalf. One day, I met a guy with a camera. He knew I was interested in photography and asked if I wanted to buy it. I decided to make a trade: the phone for the camera, and a little cash on top. When I got home, I lied and told my mum someone stole the phone. My earliest photographs were black and white, but once I started working for commercial clients – usually magazines and NGOs – I started shooting in colour. Black and white makes for a stronger connection, though, and I returned to monochrome. It makes an image timeless, almost like a memory. I don’t see my work as documentary photography. I see it as a tool for social intervention. It reveals different things about life, our environment, working conditions, humanity and human rights. I want it to provoke us to think about how we live and how we make decisions. This work is political. Mário Macilau: On Faith is at Ed Cross Gallery, London, 14 June to 5 August. Mário Macilau’s CV Born: Maputo, Mozambique, 1984. Trained: Self-taught. Influences: Willem de Kooning, Samuel Beckett, Ernest Cole, Santu Mofokeng. High point: “Being invited to be a part of the Venice Biennale in 2015.” Low point: “I was deeply affected by the Covid crisis, as the culture sector was shut down and there were a lot of limitations. But I stayed on my path and became stronger.” Top tip: “Photography is like any profession: you need to do it with love, discipline and dedication”