Base cations such as potassium are important in the environment because deposition has an impact upon surface pH, causing an increase in alkalinity, thereby buffering or neutralizing the effects of acidity generated by sulphur and nitrogen. It is for this reason these emissions are of interest, rather than their negative impacts upon human health or ecosystems. It was long assumed that the major source of base cations in the air was dust from soil erosion, but patterns of concentrations in air and precipitation also suggest significant emissions from urban and industrial sources.
Fireworks was the largest source of potassium emissions in 2022, accounting for 4% of total emissions, followed by construction and demolition (20%), iron and steel production (16%) and then domestic combustion of solid fuels (14%). Annual total emissions have decreased by 57% between 1990 and 2022 mainly due to the decline in the use of coal by power stations, industry and the domestic sector. However, domestic sector emissions have increased in recent years due to a rise in wood use, which now accounts for 66% of emissions from the residential sector, compared with just 7% in 1990.