The given line graph illustrates the levels of air pollution in London, specifically focusing on smoke and sulphur dioxide from 1600 to 2000.
Overall, it is evident that pollution levels caused by sulphur dioxide were consistently higher than those of smoke throughout this period.
The graph indicates that in 1600, the levels of both smoke and sulphur dioxide were relatively low, with smoke measuring around 50 micrograms per cubic meter and sulphur dioxide at approximately 250 micrograms per cubic meter. Between 1600 and 1730, both pollutants gradually increased, reaching levels of 750 micrograms for sulphur dioxide and 230 micrograms for smoke.
Furthermore, the levels of sulphur dioxide and smoke experienced mild fluctuations until 1900, with sulphur dioxide peaking at 850 micrograms per cubic meter in 1850 and smoke reaching 450 micrograms per cubic meter in 1880.
Subsequently, after 1900, the trend for both pollutants sharply declined, with considerable inconsistency, ultimately reaching nearly zero levels, while smoke levels met the sulphur dioxide figures recorded in 2000.