The line graph illustrates the total volume of air pollutants, measured in million tonnes, emitted by four distinct sectors – Transport, Industry, Households, and the Total amount – in the United Kingdom over a 16-year period, from 1990 to 2005.
Overall, the graph reveals a substantial and consistent decline in total air pollution across the period. Transport remained the largest single source throughout, although the Households sector achieved the most dramatic proportional reduction in emissions.
In 1990, the total air pollution stood at approximately 7.3 million tonnes. This figure then experienced a significant drop, falling steadily to exactly 4.0 million tonnes by 1999 and concluding the period at just over 3.2 million tonnes in 2005. Transport was the main contributor to the overall volume, beginning at 5.3 million tonnes in 1990 before halving to 2.0 million tonnes by the final year.
In contrast, the two smaller sources followed divergent paths. Household emissions started at 0.8 million tonnes and saw a sharp decrease to nearly zero, recording only 0.1 million tonnes by 2005. Emissions from Industry, however, were relatively stable and inconsistent. They began at 0.9 million tonnes, saw a slight peak in 1996, and finished the period slightly higher at 1.0 million tonnes. This stability meant that by 2005, Industry was the second largest source of air pollutants, surpassing Household emissions by a wide margin.