Salts of lead and manganese were present in the airborne pollutant particles, and he suggested that these caused the mutation of genes for melanin production but of no others.

It has been impregnated with titanium oxide — a photosensitive air purifier that breaks down the most common airborne pollutants.

Factors such as a citys mean temperature, precipitation levels, geographical location, and airborne pollutant levels can all effect rates of pollution in urban runoff and present unique challenges for management.

They are therefore exposed to a variety of airborne pollutants, from furnishings, plastics and cooking to household dust and (in some of the poorer houses) fungi.

He was particularly interested in airborne pollutants including, for example, sulphur dioxide and the oxides of nitrogen.