compare the sources of air contamination in the uk
The given graph depicts 3 sources of air pollutants in the UK over a fifteen-years period starting from 1990.
As can be seen from the graph, it is clearly evident that the total amount of pollutants in the air dropped between these year. The decrease in air pollutant from industrial source was particularly significant.
In 1990, the amount of pollutants from industrial source was about 5.5 million tonnes. There was a slight decrease in that in 1993 and it accounted for 5 million tonnes. From 1993 to 2005, it declined significantly with a particularly sharp fall between 1993 and 1996. In contrast, the amount of air pollutants from transport was relatively constant at 1 million tonnes a course of fifteen years starting from 1990. Last but not least, air pollutants from households saw a decrease from almost 1 million tonnes in 1990 to approximately 0.1 million tonnes by 2005.
Furthermore, the total amount of air pollutants declined rapidly from 1990 to 2005, with a slight drop between 1999 and 2000.
Where's the graph?
As the graph is missing, I will only give some grammatical suggestions for now.
1. it is
clearly evident that ...
"Clearly" is redundant because it means the same as "evident".
2. ... tonnes over a course of ...
Overall, the essay is well structured and I think your choices of word to describe increases/decreases are admirable.