Stray currents, similarly to the noise level or electromagnetic wave emission, belong to physical factors affecting the state of the natural environment. Hazards to the natural environment have been shown, which can be caused by corrosion breakdowns of industrial structures caused by stray currents. Issues connected with stray currents have been discussed. Their sources and the corrosion hazard caused by these currents have been characterised. Anticorrosion protection methods have been presented of metal structures subjected to the harmful interaction of stray currents.