The graph below shows the pollution levels in London between 1600 and 2000.

The graph illustrates the transitions in the amount of

sulphur

dioxide

and smoke emitted in London from 1600 to 2000.

Overall

, the former stands higher than the latter throughout the whole examined period.

According to

the graph, there are generally rising trends in the level of pollution of

sulphur

dioxide

and smoke until 1880.

For example

, the former rises dramatically from 20 in 1580 to 760 micrograms in 1728.

While

it experienced a small decline toward 1750, it continued to surge until 1850 when the largest amount of

sulphur

dioxide

was emitted. Regarding the emission of smoke, it

also

continuously rose to reach nearly 500 in 1880.

However

, the change is less drastic than that of

sulphur

dioxide

. In spite of the upward trends until 1880, both graphs start to fall suddenly. Indeed, the most dramatic fluctuations occurred between 1920 and 1970 as they tended to drop gradually. After that, both graphs fall sharply and eventually hit the bottom at 0 by 2000.