The line graph illustrates the amount of air pollution produced by four different sources in the UK between 1990 and 2005.
Overall, it is clear that air pollution from most sources declined significantly over the period. Industry was the largest contributor at the beginning, but its emissions fell sharply. By contrast, pollution from transport increased gradually and became the main source by the end of the period.
In 1990, industrial emissions were the highest, at approximately 6 million tonnes. However, this figure decreased dramatically over the following 15 years, reaching just over 2 million tonnes in 2005. A similar downward trend can be seen in emissions from electricity generation, which dropped steadily from around 3.5 million tonnes to less than 1 million tonnes.
Pollution from households was relatively low throughout the period and showed a gradual decline, falling from about 1 million tonnes in 1990 to roughly 0.5 million tonnes in 2005. In contrast, emissions from transport rose slightly, increasing from around 1 million tonnes to nearly 2 million tonnes, making it the largest source of air pollution by the end of the period.
In summary, while overall air pollution in the UK decreased between 1990 and 2005, transport became an increasingly significant contributor.