The artwork is made using a new type of concrete material that performs a strange alchemy, hidden within its make up is a catalytic material (nano-crystalline grade of titanium dioxide) that reacts with light to trigger the molecules of air borne pollutants, such as nitric oxides, carbon monoxide and sulphur monoxide to break apart. Daylight initiates a reaction where the active concrete surface converts harmful nitrogen oxides into harmless nitrate this in turn reacts with the calcium hydroxide of the concrete surface and drains off with the next rainfall into soils where plants can use it. This is the first time this material has been used in the UK; the material was originally formulated to be used as paving in congested urban areas to improve air quality.