Deposition, Transformation, and Remobilization of Soot and Diesel
11
can create new patterns of rain streaking that disfi gure buildings and promote public
disquiet (Grossi and Brimblecombe, 2007).
In the future brownish or yellowish colors may be more dominant and raise
aesthetic issues. Although buildings are currently perceived in terms of grays and
creams (Brimblecombe and Grossi, 2005), yellow colors can derive from sulfation,
oxidation of iron in light-colored stone, surface texture, and the presence of organic
substances (Grossi et al., 2007). As noted earlier, the oxidation of organic rich soot
can produce buildings with a warmer tone.
The patterns of discoloration also affect the appreciation of architecture so it is
important to gain insight into spatial factors that may infl uence the acceptability
of soiling. Those who manage buildings may fi nd it necessary to consider the distribution of soiling in addition to the level of blackening when trying to gauge the
strength of public reaction. They will have to anticipate future blackening patterns,
which will represent a balance between accumulation and redistribution of carboncontaining materials on the surfaces. Climate change means that heavy rainfall and
temperature increases may also encourage the growth of microorganisms, which can
also produce discoloration (Viles, 2002). Public perceptions are not easy to integrate
with considerations such as available fi nance, concerns over physical damage due
to crust buildup, or the importance of having a clean building for specifi c events
or celebrations. Nevertheless, this becomes an increasingly important part of the
management of heritage.
1.10 CONCLUSIONS
In the coming century our buildings will confront great changes in the nature of
the urban atmosphere and climate. Traditional acidic air pollutants will be less
important agents of decay than a range of new pollutants. Carbon-containing particulate material is likely to adhere to and discolor urban surfaces. Additionally,
climate change will mediate the appearances of the deposits on buildings. In the
near future the urban air quality will be better, but still likely to be rich in organic
pollutants, so buildings are likely to take on a warmer tone when these components
undergo transformation. The changes under way have both aesthetic and economic
implications for the cleaning and maintenance of historic buildings. Management
will depend on integrating both the science and the aesthetics. Much has yet to be
learned about the accumulation and removal of particulate matter from complex
architectural geometries. This seems to be a fruitful area for research considering
the wealth of heritage to be managed.
ACKNOWLEDGMENTS
This chapter derives from work within ENV4-CT-2000-0002 CARAMEL and CT2003-501837-NOAH’S ARK funded by DG Research of the European Commission
and has benefi ted greatly from discussions with Alessandra Bonazza.
© 2010 by Taylor and Francis Group, LLC
11
can create new patterns of rain streaking that disfi gure buildings and promote public
disquiet (Grossi and Brimblecombe, 2007).
In the future brownish or yellowish colors may be more dominant and raise
aesthetic issues. Although buildings are currently perceived in terms of grays and
creams (Brimblecombe and Grossi, 2005), yellow colors can derive from sulfation,
oxidation of iron in light-colored stone, surface texture, and the presence of organic
substances (Grossi et al., 2007). As noted earlier, the oxidation of organic rich soot
can produce buildings with a warmer tone.
The patterns of discoloration also affect the appreciation of architecture so it is
important to gain insight into spatial factors that may infl uence the acceptability
of soiling. Those who manage buildings may fi nd it necessary to consider the distribution of soiling in addition to the level of blackening when trying to gauge the
strength of public reaction. They will have to anticipate future blackening patterns,
which will represent a balance between accumulation and redistribution of carboncontaining materials on the surfaces. Climate change means that heavy rainfall and
temperature increases may also encourage the growth of microorganisms, which can
also produce discoloration (Viles, 2002). Public perceptions are not easy to integrate
with considerations such as available fi nance, concerns over physical damage due
to crust buildup, or the importance of having a clean building for specifi c events
or celebrations. Nevertheless, this becomes an increasingly important part of the
management of heritage.
1.10 CONCLUSIONS
In the coming century our buildings will confront great changes in the nature of
the urban atmosphere and climate. Traditional acidic air pollutants will be less
important agents of decay than a range of new pollutants. Carbon-containing particulate material is likely to adhere to and discolor urban surfaces. Additionally,
climate change will mediate the appearances of the deposits on buildings. In the
near future the urban air quality will be better, but still likely to be rich in organic
pollutants, so buildings are likely to take on a warmer tone when these components
undergo transformation. The changes under way have both aesthetic and economic
implications for the cleaning and maintenance of historic buildings. Management
will depend on integrating both the science and the aesthetics. Much has yet to be
learned about the accumulation and removal of particulate matter from complex
architectural geometries. This seems to be a fruitful area for research considering
the wealth of heritage to be managed.
ACKNOWLEDGMENTS
This chapter derives from work within ENV4-CT-2000-0002 CARAMEL and CT2003-501837-NOAH’S ARK funded by DG Research of the European Commission
and has benefi ted greatly from discussions with Alessandra Bonazza.
© 2010 by Taylor and Francis Group, LLC