ChapTer nine
New urban environments,
c.1860–1950
industry and pollution
Although the effects of industrial pollution may have been localized and
limited in the period before c.1860, they became more severe and extensive
thereafter as the scale of industrial production continued to grow. Changes
in the methods of sewage disposal during the second half of the nineteenth
century led to a gradual decline in the amount of effluent flowing directly
into watercourses, but levels of industrial pollution remained high. In 1900
it was said of the Mersey that ‘running as it does for the greater part between
artificial banks and gathering fresh impurities with every mile, it is doubtful
whether the river contains any fish below Stockport’.^1 Research carried out
in the 1970s, when many northern rivers were still extensively polluted,
shows that they carried an impoverished fauna dominated by the louse
Asellus aquaticus, accompanied by small numbers of freshwater shrimps, the
larvae of caddis flies and mayflies, and a fish population largely restricted
to gudgeon (Gobio gobio) and roach (Rutilus rutilus).^2 It was in this period,
moreover, that the effects of airborne pollution on flora and fauna became
serious. Lichens and mosses were seriously affected: most lichens are killed
by levels of atmospheric sulphur dioxide exceeding 150 micrograms per
cubic metre. In urban areas, a variety of foliose lichens declined, and were
subsequently replaced by the green alga Desmococcus olivaceus, first noted
in western Europe in 1860, which is now almost universally found on trees
in towns.^3 But higher forms of vegetation were also increasingly affected.
One observer in 1882 bemoaned how, in south-east Lancashire, ‘fruitful
vales where vegetation flourished, roses grew in abundance, and the most