The graph compares the pollution indexes in London between 1550 and 2000. The report takes into account two kinds of pollutants: smoke and sulphur dioxide. The results are given in micrograms per cubic metre.
From an overall perspective, it can be seen that the problem of surphur dioxide in the air was more serious than that of smoke during the whole period given. Despite the significant growth in both figures, the pollution level began to decrease by 2000.
Regarding surphur dioxide, it was on the constant rise since the beginning, reaching 720 micrograms per cubic metre after 1700. Then, it fell below 500 micrograms and soared again in 1790th before peaking at approximately 1,000 in the middle of the nineteenth century. Nevertheless, 1900 saw its decline, which continued up to 2000.
With respect to smoke, its figures did not fluctuate so much and were below 250 until 1800. However, later, they rose to almost 500 around 1900, which was the highest but not long-lasting result. The same year smoke pollution indicators started dropping, finishing at 0 micrograms in 2000.