The graph illustrates the different sources of air pollution in the UK. Overall, total air pollution decreased significantly from seven million tonnes in 1990 to three million tonnes in 2005, with a period of stability between 1999 and 2002.
As can be seen in the figure, in 1990, industry was the dominant source of air pollution, producing around five million tonnes, while transport and residential activities each contributed around one million tonnes. Over the following years, industrial emissions declined sharply, with a particularly sharp decline after 1993. In contrast, pollution from transport remained relatively stable at around one million tonnes throughout the period.
By 2005, these emissions had almost reached zero, marking the most significant reduction of the three sources. Despite the significant decline in industrial emissions, this sector remained the largest contributor of air pollution in 2005. In summary, although all three sectors experienced a decline in air pollution over the 15-year period, the decline was most pronounced in the residential sector, while transport showed minimal change.