Invisible Demons review – apocalypse now for pollution nightmare in Delhi

Environmental doom is coming: as the planet heats up, it’s all going to get much worse. Nothing new there – but, terrifyingly, this depressing snapshot of severe pollution in Delhi gives us a vision of apocalypse now. It’s a follow-up by Rahul Jain to another haunting documentary, Machines, about a Gujarat textile factory. Here he has captured some nightmarish images that genuinely look as if they could have been staged for a sci-fi film: patients in a hospital gasping into oxygen masks like victims of a chemical attack; streets engulfed by brown smog; waves of toxic white foam bobbing along a river.

This is a despairing handwring of a film. In a voiceover at the start Jain admits his own privilege, explaining that he “grew up in an air-conditioned world”. What the rest of the film demonstrates is the environmental injustice of India’s economic growth, how the poor are bearing the brunt. Clips from the TV news fill in the details: a 49C heatwave in Delhi (eight degrees higher than expected June temperatures). A news anchor explains that toxic air pollution is the third biggest killer in India, more deadly than smoking and terrorist attacks.

But mainly the voices we hear are of ordinary people suffering from stinging eyes, breathing difficulties and nausea. And then there are the images: a huge pipe pumping filthy black water into a river, cows chomping plastic bags. A drone shot of a great river of rubbish flowing through the city like some feature of the landscape is grotesquely beautiful. I have to admit I was holding out for a little uplift at the end, some hopeful little shred to cling to in this sea of despair: a crusading politician maybe? Fat chance. Air pollution particles might be the invisible killers of the title – but politicians are nowhere to be seen.

• Invisible Demons is released on 30 September in cinemas and on 4 October on Mubi.