London scoping - ukcip

Final Report
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Table 6.4 Potential impacts of climate change on exposure to air pollution
Positive Negative
Reduced exposure to damp conditions indoor due to
being outdoors more often
More circulation of air due to windows and doors being
left open for longer
If more outdoors lifestyles led to a more active lifestyle,
then resistance to respiratory illness would probably be
enhanced.
Increased tropospheric (low-level) ozone (DoH 2002)
Dust mites survive for longer in drier air > asthma
More dust raised in dry air > asthma
Note that most rooms have an air change rate of at least once per hour so that, chemically, most
indoor environments will be similar to that outdoors plus internal sources (moisture, VOCs from
plastics, smoke, etc.). Being outdoors more will not, therefore, contribute to greater exposure to
air pollutants. Greater exposure to air pollution would occur at low level along major roads
(including inside cars and buses) (e.g. see maps of London Health Commission, 2002). Hence,
greater exposure under climate change would be limited to undertaking more journeys along
major roads by car, bus, cycling or walking. More windy weather under climate change would,
on the other hand, cause fewer air pollution episodes arising from the build-up of NOx, PM10s,
VOCs, etc.
People tend to eat more healthily in hotter and drier weather if the evidence of the hot summers
of the mid-1990s is anything to go by, i.e. more fruit and vegetables (Palutikof et al. 1997).
More active lifestyles on the part of children is to be desired given current trends towards
obesity and lack of exercise. If better and hotter weather encouraged this, then there would be a
benefit. If better weather was to improve the prospects of children walking or cycling to school
more, then there would be the added benefit of alleviating traffic congestion during the ‘school
run’ period. Likewise, if better quality and fresher fruit and vegetables were available under
climate change, then benefits would arise, assuming that such foods are accessible.
Unfortunately, there are already wide-spread variations in access to fresh foods in London.
Whilst lower prices would help to make fresh foods more readily accessible, cultural change is
also necessary.
What is more, measures taken to reduce the rate of climate change by reducing greenhouse gas
emissions could produce secondary beneficial effects on health e.g. decreased dependence on
motor transport could encourage walking and cycling - thus improving health. At the same
time, 6.3 in 1000 pedestrians in London are injured in accidents (LHC 2002); over 8,500
pedestrians and 3,500 cyclists in 2000 (ibid.). Clearly, the greater use of bicycles and walking
needs to be facilitated by taking steps to reduce the risks of accidents with vehicles. The risk is
highest in the inner city boroughs of Westminster, Camden and Islington and least in the outer
boroughs. Reducing the combustion of fossil fuels also limits the production of other pollutants
such as SOx, NOx and particulates with potentially significant health benefits.
6.12.5 Case Study: Comparison with Other Cities
An intense summer drought in New York may have contributed to the fatal outbreak of the West
Nile Virus (Rosenzweig & Solecki 2001a).