Rethinking Infrastructure Design - Rethinking Infrastructure Design for Multi-Use Water Services - page 17

Fig. 18 Picture of a city no tourist would like to take home

4.5 Air Pollution

The air quality in urban areas is in constant degradation in many cities (Fig. 18 ),
much of which is caused by human activities: vehicle and industrial emissions. Air
pollution leads to health problems, degradation of nature and human environment,
has a negative in uence on UHI, causes material degradation and of course reduces

human comfort.
Just as the vegetation on the ground level does, plants on green roofs can remove
several types of air pollutants from the air, such as particulate matter, nitrogenous
compounds and sulphur oxides. And due to the photosynthesis of plants, oxygen is
produced and carbon dioxide in the atmosphere is utilised, which contributes to the
reduction of carbon dioxide. Although vegetation has no magic solutions of heavily
polluted areas, it improves air quality and reduces CO 2 . Indirect bene ts urban

greenery has on air quality are as follows:

Reduced air temperature, which prevents inversion phenomena

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Reduced smog

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Contribution to non-scienti cally proven positive health effect — by reduction of

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anions present

The vegetation cools down cities and helps with reduction of number of days
with inversion, which have direct impact on public health.
Some types of plants and leaf morphology are more ef cient in removing par-

ticulate matter than others are. Thus, the selection on the right plants and their
incorporation into integrated MUS solution for optimisation of bene ts is part of the

innovative planning and quanti cation process.