The given graph compares how many types of pollutants contaminated the air in the UK during the period of 15 years, from 1990 to 2005.
Overall, it can be seen from the graph that the figures for industry household sources and total air contaminants saw a downward trend while there was a steady leveling out in terms of transportation over the span of the period.
In 1990, total air pollutants indicated the highest rate, with 7 million tons; however, by 1999, that index saw a considerable reduction to 4 million tons. Then, until 2002, there was no change, and at the end of the period, total contaminants decreased significantly to 3 million tons. The figure for transportation stayed constant at 1 million tons during the period from 1990 to 2005.
At the beginning of the period, the industry rate was almost 6 million tons, but after 6 years, that rate registered a significant decline, indicating 3 million tons. Following that, the industry index saw a continuous reduction to 2 million tons in 2005. After that, the figure of households fluctuated between 1 and 0.9 million tons until 1999, and in the following 6 years, that figure decreased substantially to 0 when the period was over.