Urban humans as new hosts: continuous wild habitat fragmentation will accelerate the conditions for future epidemics
June 25, 2020
Olivia Duncan
Architect, MSc Sustainable Urban Development, University of Oxford
On behalf of the Oxford COVID-19 Evidence Service Team
University of Oxford
Correspondence to oliviaduncan@gmail.com
VERDICT
A ‘coalition’ approach among urban strategists is a key element to mitigate the current COVID-19 crisis, and future epidemics. Each urban context with differing population and building densities requires specific context-sensitive mitigation approaches, including a recognition of the urban impact on the natural or biophysical environment. COVID-19, combined with the negative impacts of widespread habitat fragmentation resulting from urbanisation patterns, now demand a reform of urban development expertise. Collaborative approaches to protect humans from future epidemics is essential for ‘urban futures’;
Further research and experimentation in biomimicry present major opportunity to mitigate surface contamination.
CONNECTING RAPID URBANISATION, FRAGMENTED HABITATS AND THE POST-COVID BUILT ENVIRONMENT
The current pandemic and the transmission routes of SARS-CoV-2 are still being researched globally, and the denser and poorer Global South cities are most likely to be the most affected. Amidst high uncertainty, a recently published study recognises that although the virus’ transmission routes are not well characterised, research suggests that its spread happens via physical contact, droplet and airborne routes. Considering the majority of humans are now urban, and generally spend over 90% of their time in indoor environments – with the remaining time assumed to be spent in shared public spaces – an enquiry into the urban environment’s role in supporting or suppressing the spread seems inevitable.
When presented with the advent of an infectious disease, the most appropriate concern of any municipal government, first and foremost, is likely to be to control the spreading of that disease. Human history provides insight to previous approaches for controlling the extensive spread of unknown infections; and our medieval counterparts encountered a more devastating pandemic than our present COVID-19’s, known as the Black Death, as there is evidence that the European population was almost disseminated by it.
Most current suppressing and mitigating strategies require a testing period, and rigorous monitoring of unfamiliar viral behaviour. In this context, urban strategists and epidemiologists could form a coalition group of ‘herd immunity’ enthusiasts and strict suppression supporters, depending on their urban densities and level of economic development. It is well recognised that given the high mortality rate of COVID-19 compared to influenza, an early adoption of ‘herd immunity’ strategy – where population level immunity would be attained organically -would mean that around 0.8% of the total population will likely be killed before a vaccine is accessible to the community, excluding the excess mortality resulting from any healthcare system’s ability to cope with the high number of infections.
From historical to current scholarship, there is much evidence of successful and futile methods for combating infectious disease at the city level: mass sanitisation programmes; urban waste management; natural cross ventilation in buildings, as well as behavioural measures such as quarantining; strict social distancing; curfews, and the enforced use of facial masks.
Since the 1970s, there has been increased attention towards the role of urbanisation in disrupting natural habitats, generating global pollution, and subsequently, its contribution to the emergence of pandemics. Irrespective of warnings and validation across research initiatives on the impact of climate change on the planet, cities continued to grow and encroach on biophysical ecosystems causing, amongst other negative consequences, habitat fragmentation, and the destruction of animal and plant varieties harbouring potential viruses. For example, urbanisation in China increased exponentially from 17.92% to 52.57%, in the period between 1987 and 2013 and it is predicted to increase to 70% by 2030. This rapid urbanisation is evident in the city of Wuhan, marked by its deterioration in vegetation cover and growth of impervious areas as a result of residential land development between 1991 and 2013. Amongst many indicators, the claim that Wuhan was the source of SARS-CoV-2’s first human infection, makes it fitting that this event would prompt the rethinking of not only the economic growth paradigm, but the profound need of a multi-disciplinary approach to urban expansion, integrating research in the medical sciences with sustainable urban development. The need for collaboration between planetary health professionals, epidemiologists, anthropologists, and urban community activists in the urban planning process seems unquestionable.
At an architectural level, the demand for infrastructure to support optimal air quality inside buildings, and to promote uncontaminated surfaces calls for further investigation and innovative solutions. HVAC (Heating, Ventilation and Air Conditioning) management strategies combined with pioneering biomimicry-inspired surface coating play an important role in protecting a building’s occupants from exposure to infectious aerosol, and contact transmission. Healthcare buildings seem to be the focus of HVAC scientific literature, and generally support the proposal that a mix of airflow, sensitive room pressurisation, and appropriate ventilation designs, together with temperature and relative humidity controls are effective at controlling transmission. While the commercially available SharkletFilm surface skin, provides bacterial inhibition on high-tough environmental surfaces supporting reduction of chemically-based surface disinfection; the development of an anti-viral universal solution for surfaces is still to be attained.
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Disclaimer: the article has not been peer-reviewed; it should not replace individual clinical judgement and the sources cited should be checked. The views expressed in this commentary represent the views of the authors and not necessarily those of the host institution, the NHS, the NIHR, or the Department of Health and Social Care. The views are not a substitute for professional medical advice.
AUTHOR
Olivia Duncan is an architect and urbanist holding a MSc in Sustainable Urban Development from the University of Oxford. With a wide range of international experience in architecture, urban planning and design, Olivia is concerned with the built environment, wellbeing, and community participation in urban development projects.
