Several people involved in the film production, and possibly Tarkovsky himself, died from causes that some crew members attributed to the film’s long shooting schedule in toxic locations.
Sound designer Vladimir Sharun recalled: “We were shooting near Tallinn in the area around the small river Jägala with a half-functioning hydroelectric station. Up the river was a chemical plant and it poured out poisonous liquids downstream. There is even this shot in Stalker: snow falling in the summer and white foam floating down the river. In fact it was some horrible poison. Many women in our crew got allergic reactions on their faces. Tarkovsky died from cancer of the right bronchial tube. And Tolya Solonitsyn too. That it was all connected to the location shooting for Stalker became clear to me when Larisa Tarkovskaya died from the same illness in Paris.”
From the Wikipedia article of the stalker movie
The production story of that movie was wild