The exponential establishment of cities throughout the globe in the last century is without a doubt a marker of our technological and societal advancements as a human race. Better infrastructure and improved healthcare, are just a few of the many associated benefits of living in a city. At the same time, we cannot ignore the negative impacts of the establishment of cities. In particular, with regards to the realm of life sciences, cities have been a huge curveball for all living beings, the environment, and not forgetting the scientists who study them. Cities have introduced a multitude of new factors for scientists to consider. In epidemiology especially, there are new challenges presented every day to the scientists who already have the difficult task of understanding the complex field of diseases and their transmission. This essay will focus on the challenges and changes that epidemiologists and other scientists in the field, like myself, face as a result of the establishment of cities in the past decade.
In the field of epidemiology, studying the of risk factors of a disease or infection is crucial in understanding its spread. As scientists, we need to be sensitive about the factors that help exacerbate or proliferate diseases and illnesses within a population in order to accurately study its transmission and growth mechanisms. With the rapid establishment of cities in the last century, we have introduced into the equation a completely new set of risk factors– the urban environment and everything else that comes along with it. For instance, the establishment of cities has brought about a change in lifestyle for people, and epidemiologists are seeing an increase in noncommunicable diseases or lifestyle-related diseases as well as mental health issues (Hubacek & et al., 2009). While it is true that cities bring better access to healthcare and technology, this has greatly changed the trends of morbidity and mortality (McKeown, 2009). In many countries with booming cities, there is a sharp rise in the ageing population (World Health Organisation, 2011).
There is extended morbidity despite the lower rate of mortality because people in cities are living longer, but it does not always translate to a better quality of life. In developing countries where more are moving to cities, more elderly are left without informal care from their families or relatives (World Health Organisation, 2011). On the same note, noncommunicable diseases exponentially increase with age, therefore the increasing elderly population in the world is not only a societal and economic burden but a challenge for scientists to keep up with too (Yoshikawa, 2000; World Health Organisation, 2018). Hence, epidemiologists are faced with a new understanding of how cities influence this new age of diseases.
Where there are people, there is a chance to transmit disease; Cities multiply this effect by the hundredfold, by bringing people physically closer together. Generally, cities are characterised to have a higher population density than their rural counterparts. Hence, contact with another person is much more imminent. The high population density in cities increases the propagation of infectious diseases, including those that transmit by air, bodily fluids, water and other vectors (Lee, 1994; Monteiro & et al., 2006). Cities are at greater risk of spreading infectious diseases, not just because of their high population density but their greater connectivity with the rest of the world and other cities (Alirol & et al., 2011). With over 35,000 international flights in a day, Singapore Changi Airport was dubbed the most connected airport in the Asia Pacific region (OAG, 2018). Imagine the scale at which an infectious disease could be spread to the rest of the world from there. It could easily result in a global pandemic, similar to that of the various strains of influenza in the past (Pattemore & Jennings, 2008) and more recently, Ebola virus (Park & et al., 2015). Of course, that is why health organizations and governments worldwide are so wary of such an event happening (Barnes, 2018). The greater the speed of transmission of diseases within cities is important to understand and morphs today’s modern approach to epidemiology. As diseases evolve at a terrifying rate (Leventhal & et al., 2015), scientists need to look closely at cities and how they can more accurately model the transmission of disease based on human networks.
In the face of urbanisation, epidemiologists cannot take for granted the state of affairs when it comes to diseases. Upon reflection, my approach to learning about the transmission of diseases has changed because of the establishment of cities, more so because I live in one. As mentioned previously, there has been a shift in prevailing diseases amongst cities, a rise in noncommunicable diseases and age-related diseases. In Singapore, the ageing population is a real concern. Projections estimate that Singapore may be the fifth most elderly populated country in a matter of almost 30 years (United Nations, 2015). This makes studying the epidemiology of ageing and its associated diseases, even more, relevant for me. I have become more sensitive to the risk factors in urban environments. I have also had to change the way I perceive research and my scientific method when it comes to dealing with the confounding effects of cities on my research in this area. Being in a city, such as Singapore, I get to enjoy the comforts of better infrastructure and in turn, better technology. However, I often do not notice the over-reliance on technology as a scientist in a city. Internet connection is a ‘basic necessity’ nowadays. And as a student, it is hard to imagine a life without it, let alone having to do literature reviews and research without the vast pools of e-libraries and repositories at my fingertips. Moreover, most modern laboratories in cities are well-equipped with air-conditioning and huge freezers to store cell samples, consuming “three to four times more energy than the average building” according to a study by Eades (2018). Therefore, in the laboratory, I try my best to be more energy-saving and environmentally conscious when carrying out my research. Trying as much as possible to use glass-stirrers instead of disposables ones, and doing simples things like turning off the fume hood when not in use, I choose to reduce the carbon footprint of my laboratory.
As much as my research is important, it is just as important to try to reduce the negative impacts brought about by the establishment of cities. If not, scientists would just be adding on to the impacts caused by cities, and we already have enough problems to face as it is. With no sign that the growth of cities is going to slow down any time soon, we should be very aware of the novel challenges that studying diseases in cities pose. I strongly believe that understanding cities is vital to understanding diseases in the 21st century, and eventually how to control them.