Implications of the COVID-19 pandemic for urban informal housing and planning interventions: Evidence from Singapore.

The outbreak of the COVID-19 pandemic revealed the crucial role of social distancing and hygiene practices in reducing virus transmission and thus revealed the high risk of infection in urban informal housing. Through an empirical study of Singapore's infectious situation and antiepidemic measures, this paper shows that the number of infected migrant workers living in dormitories was three hundred times greater than the number of infected local urban residents, not only because of the migrants' 'vulnerable' position but also because their living conditions fostered widespread transmission of the virus. The dwelling conditions of migrant dormitories, such as overcrowded living spaces, widely shared sanitation facilities, and poor hygiene practices, present great challenges to standard prevention strategies and control measures. Adverse health impacts resulting from the lockdown of dormitories during the COVID-19 pandemic suggest the importance of planning intervention in the dwelling conditions of informal housing, and indicate a need for the governments' active reforms of building codes and health care systems to promote the health of disadvantaged groups and then create more inclusive and healthy cities for all the society.

Introduction

The outbreak of the 2019 novel coronavirus disease (COVID-19) has caused approximately five hundred million infections and over six million deaths (https://covid19.who.int/, accessed April 14, 2022), and the number of infected cases is still increasing daily. The public health emergency has not only brought incalculable devastation to international social and economic development but also raised wide concern about controlling and preventing pandemics in the urban context (Allam & Jones, 2020). Since the COVID-19 pandemic is predominantly caused by direct contact and droplet transmission through coughing and sneezing, maintaining social distance and improving hygiene practices have been globally accepted as the principal approaches to reducing the risks of infection (Corburn et al., 2020). Additionally, community lockdown and self-quarantine for a certain period have played key roles in curbing the spread of the pandemic. Therefore, both indoor conditions and outdoor exposure confront great challenges that point to an increasingly critical domain at the intersection of urban planning and public health (Megahed & Ghoneim, 2020). It is therefore necessary to understand how the living environment affects urban public health based on the lessons of COVID-19 as well as what planning interventions are urgently needed for city governments to prevent the spread of infectious diseases.

One of the greatest concerns, which has been emphasized in several previous studies (Parikh et al., 2020; Wilkinson, 2020), is the high infection risk in urban informal housing and residents of such facilities regarding COVID-19 transmission pathways and control measures. The substandard dwelling conditions of informal housing, including unclean water and overcrowded spaces, create hotbeds for the drastic spread of infectious agents (Corburn et al., 2020; Martinez et al., 2008). More importantly, these dwelling conditions make the application of standard precautions and control measures implausible in informal housing (Tavares & Betti, 2021). Without specific considerations and planning interventions, restrictive control measures imposed by a number of countries could possibly generate adverse health outcomes rather than the impact of the disease itself (Wilkinson, 2020). Corburn et al. (2020) even claimed that any COVID-19 responses that neglect the living conditions of people in informal housing will further jeopardize the survival of a considerable proportion of the world population. Nevertheless, empirical evidence about the COVID-19 pandemic in urban informal housing is still far from sufficient to generate effective planning interventions to protect and promote the health of those who dwell in such communities.

Research on the impact of informal housing on urban public health is significant, especially in developing countries facing escalating population density and inadequate provision of living infrastructure and necessary services (Fox, 2014; Mahabir et al., 2016). Notably, over the past 50 years, an increasingly rapid urbanization process has taken place in the Global South, characterized by massive rural-to-urban migration and increasingly unplanned urban growth (Ezeh et al., 2017). Informal housing has emerged and proliferated in many low- and middle-income countries, providing an important form of shelter for low-income migrants and the urban poor (Soyinka & Siu, 2018). However, informal housing and its residents have often been stigmatized and blamed for public health problems that they are unable to control, as they are often subjected to institutions and regulations that are unaffordable or unfeasible for them (Wilkinson, 2020). While the current literature has uncovered much information about the health problems of informal housing dwellers and how economic, social, and health service conditions affect their health (Ghosh et al., 2020; Tavares & Betti, 2021), we still know little about the political and sociocultural reasons underlying the mismanagement of high population density and limited resources. This is nevertheless an urgent issue in Global South countries challenged by the dynamism of continuing urbanization (Garcia Ferrari et al., 2022; Zhu, 2020).

Regarding the widespread transmission of COVID-19 across the world, this paper calls for a focus on the essential risks of wholesale infections within informal housing and planning interventions in dwelling conditions. We conducted a case study of Singapore to investigate the critical role of informal housing in the spread of COVID-19. Singapore has long been famous for its living environment, social security, and efficient government. The planning strategy of the so-called City in a Garden and the inclusive public housing scheme are often cited as a successful case of managing a large population in a situation of land scarcity (Bocquet, 2015; Glass & Salvador, 2018). However, the outbreak of COVID-19 and the country's antiepidemic measures revealed the ignorance of dwelling conditions in informal housing and governing policies that excluded the dwellers, which caused undesirable outcomes for both urban public health and social equity. The case of Singapore could offer a warning about urban planning strategies exclusive of informal housing regarding public health issues, since many countries in the Global South confront even more challenging situations in relation to increasing population density and inadequate living infrastructure.

Understanding the public health risks of urban informal housing and the importance of planning interventions

Public health risks of urban informal housing: A multidimensional issue

Urban informal housing refers to unplanned housing areas or housing that violates building codes within the urban context (Balise and Ehlenz, 2020; Zhu, 2020). Roughly one-quarter of the global population lives in informal housing areas, such as slums, urban villages, self-built housing, and clustered dormitories, making the health risks of informal housing an important public issue (UN-Habitat, 2015). Most previous studies on the public health risks of urban informal housing have focused on analysing the dwellers’ socioeconomic and living conditions. By investigating the socioeconomic status of the dwellers of such housing, one stream of the literature has focused on how sociospatial segregation has led to health disparities between urban informal housing and formal residential sectors. According to Soyinka and Siu (2018), dwellers of informal housing have been found to suffer disproportionately from social exclusion from urban advantages such as public housing schemes and social welfare systems, and this exclusion prevents them from achieving health security. Bolt et al. (2010) and Parks (2014) have indicated that people living in urban informal housing are trapped in a vicious cycle of poverty since they also experience cumulative disadvantages, such as limited job opportunities, poor social networks, and constrained local resources. To sustain their livelihood, dwellers of urban informal housing are forced to be more frequently exposed to a high risk of infection, leading to much worse health outcomes than those confronting formal residential communities (Ezeh et al., 2017).

The other stream of the literature has been more concerned about the building forms and living conditions of informal housing, which potentially cause deteriorated dwelling conditions and health risks. Zhu (2012) indicated that informal housing in the form of high-plot-ratio and high-site-coverage buildings, which have been widely identified in high-population-density countries across Asia, has resulted in a deficiency of open space, which causes hazards in case of fires or natural disasters. As urban densification continues, some scholars have pointed out that land holdings will become increasingly fragmented by informal housing and that dwelling conditions will deteriorate quickly. (Tian, 2008; Zhu, 2020). Parikh et al. (2020) claimed that deteriorating dwelling conditions could easily exacerbate the spread of infectious diseases and worsen health conditions in informal housing, which urgently needs responsive strategies and should become a research focus of urban public health.

The absence of effective planning interventions from city governments has commonly been identified as the main driver of the public health risks of informal housing (Fekade, 2000; Rydin et al., 2012). However, it is worth unpacking the political and sociocultural reasons behind the mismanagement of increasing housing demands. First, there is usually a two-way compromise between city governments and low-income migrants regarding the presence and development of urban informal housing. On the one hand, a number of city governments regard this type of settlement as a workable solution to accommodate a large proportion of the fast-growing urban population (Fox, 2014; Wang et al., 2010). On the other hand, to reduce living costs, low-income migrants prefer to live in urban informal housing and tolerate poor dwelling conditions and residential segregation, which has further encouraged city governments to ignore planning controls for informal housing developments (Rydin et al., 2012). In a number of city contexts across Asia and Africa, few reliable data on the numbers and health conditions of people living in urban informal housing are available in official records due to the illegal or informal status of these residents (Wilkinson, 2020). This may create uncertainties in policy responses regarding the suffering of informal housing dwellers and subsequently impede planning interventions. As a result, city governments continue to largely overlook the public health risks of informal housing, although poor living conditions and negative health impacts have been exposed (Parikh et al., 2020).

Vulnerability of urban informal housing to pandemic transmissions

The spread and impacts of COVID-19 have revealed multiple vulnerabilities within urban informal housing (Mishra et al., 2020). Based on the transmission pathways and symptomatic characteristics of COVID-19, there are two major vulnerabilities concerning the infection risks and health burdens of urban informal housing. The first is transmission vulnerability, which plays a more critical role than epidemiological vulnerability in increasing the infection risk of dwellers of urban informal housing. Specifically, although the fatality rate is related to people's physical condition (Jain & Yuan, 2020), COVID-19 is highly infectious among certain population groups regardless of age, sex, and comorbidities (World Health Organization, 2020). The dense living environment and highly shared infrastructure of urban informal housing, which considerably increase the frequency and duration of face-to-face contact among dwellers over short distances or in confined spaces, essentially stimulate the spread of the virus and enhance the risk of infection (Parikh et al., 2020). That is, the living environment makes residents much more vulnerable to the spread of COVID-19 than their physical condition (Dietz et al., 2019).

Second, urban informal housing and its residents are extremely vulnerable to control measures because of substandard dwelling conditions and an insecure health system (Wilkinson, 2020). Globally accepted measures to control and prevent the transmission of COVID-19, such as social distancing and self-quarantine, commonly assume basic dwelling conditions (e.g., isolated living space and sanitation facilities) and access to essential services (e.g., water supply and waste disposal). However, it is nearly impossible for residents of informal housing to maintain physical distance and reduce their exposure to risks owing to the use of shared sanitation facilities and overcrowded living spaces (Tavares & Betti, 2021). The dwelling conditions of informal housing also do not allow individuals carrying the virus to self-isolate with separate toilets and hygiene facilities. Under these circumstances, precautions (e.g., temperature checks and nucleic acid tests) and swift quarantine measures are urgently needed before widespread transmission occurs within informal housing areas. Unfortunately, existing studies have indicated that dwellers of urban informal housing suffer from inadequate or inappropriate health care as well as financial and institutional barriers to access to health resources (Sverdlik, 2011). The risk of clusters of infections is thus greatly enhanced, and COVID-19 in urban informal housing will produce unimaginable burdens on the urban health system if the state continues to ignore these dwelling conditions and simply applies standard controlling measures (Wilkinson, 2020).

Planning interventions for urban public health

The history of planning interventions for infectious disease1 indicates that policy measures and planning interventions by city governments can promote and maintain the urban advantage in terms of public health (Cutler et al., 2006). With regard to today's cities, building forms and residential environments can vary substantially, and low-income migrants usually live in informal housing characterized by substandard dwelling conditions (Howden-Chapman et al., 2008). Because of the vulnerabilities of urban informal housing to the spread of COVID-19, planning interventions are supposed to prioritize improving the dwelling conditions of informal housing within cities, and the key role of local government through active reforms and institutional changes is necessary (Basile & Ehlenz, 2020; Wilkinson, 2020).

Currently, basic building standards and regulations are far from sufficient to guarantee the dwelling quality of informal housing within cities (Rydin et al., 2012). For instance, Gulyani and Bassett (2010) pointed out that there is a lack of clear rules for determining the point at which overcrowding occurs at the unit level. Moreover, although meeting plot ratio and site coverage government building codes, informal housing tends to sacrifice the housing floor area per capita and the provision of basic infrastructure in favour of additional economic gain, leading to overcrowded living spaces and highly shared sanitation facilities (Zhu, 2012). Therefore, the standards by which residential buildings are planned and constructed need improvements to create healthier dwelling conditions and more resilient living environments. In particular, it is necessary to take housing floor area and sanitation facilities per capita into account in strict planning standards to make social distancing and self-isolation practical in future pandemics.

Regarding long-term projections for urban public health, more importantly, institutional efforts and policies need to be tailored and enforced by local governments to match the political and sociocultural contexts (Wilkinson, 2020). As both city regulators and policy makers, local governments play an important role in providing and protecting urban public health through local support structures (e.g., health services, social assistance, and affordable housing). The vulnerabilities of informal housing and its residents indicate deficiencies in support structures that exclude certain groups and households. To fill these gaps and mitigate negative health impacts, it is necessary for local governments to collaborate with key stakeholders (e.g., local residents, employers, and social organizations) who are much more familiar with local detailed infrastructure to obtain more information and data on urban informal housing and basic needs of the dwellers (Wilkinson, 2020). This is crucial to better public health interventions for migrant labourers and informal housing, such as the monitoring of changes, relief, and responses.

The dwelling conditions of migrant workers in relation to the spread of COVID-19 in Singapore

Social segregation: health care and dwelling conditions for migrant workers

Singapore is a densely populated city-state with approximately 5.704 million inhabitants in a land area of 648 km2. As one of the most open economies in Asia, it relies heavily on foreign labourers, who are stratified as foreign talent, with professionals and skilled workers at the upper level, and low-skilled migrant workers at the bottom. Low-skilled migrant workers engage mainly in labour-intensive industries that are essential to Singapore's economy, such as construction, shipping and foreign domestic services. These migrant workers come predominantly from South Asian countries such as Bangladesh and India as well as countries of Southeast Asia and China. By the end of 2010, the estimated number of foreign labourers had reached 1,113,200, accounting for nearly 20% of the total population and 35% of the whole workforce in Singapore. Among the foreign labourers, 685,400 were semiskilled and low skilled, including 293,400 in construction and 131,000 in the shipyard sector (Lee et al., 2014). According to the report by Global-Is-Asian Staff (2019), these low-skilled workers are usually poorly paid, with a monthly salary as low as US$250, which is much lower than a typical monthly salary of $500 to $600 in Singapore.

Low-skilled migrant workers live at the bottom of society, suffering from institutional discrimination that constrains their capability to pursue a contented and healthy life in Singapore. First, there is a dual-track foreign labour policy that differentiates the entitlements between low-skilled workers and foreign talent. To attract the latter to support Singapore's efforts to upgrade to a knowledge-based economy, privileged measures are applied, such as liberalized immigration policies, easier requirements for permanent residence and citizenship, permission for family members to accompany them, and an attractive tax regime (Chia, 2011). Although the country also needs low-skilled workers to help contain business costs to keep it economically competitive and provide cost-effective domestic services to the increasing middle class and ageing population, the number of these workers is controlled to protect jobs for local workers, who are usually unwilling to perform the low-paid jobs (Chia, 2011). Control measures, such as work permits, quotas and levies, are adopted. Work permit holders cannot change employers, cannot bring their families, and must depart from the country immediately once their employment is terminated. The number of work permit holders that a firm can hire is subject to a quota that is a proportion of the firm's total workforce. In addition, employers must pay levies for hiring work permit holders, which narrows the gap between domestic wage levels and migrant workers' reservation wage. The low wage has therefore become a financial barrier that makes it difficult for these workers to improve their living conditions in Singapore.

Second, as is common worldwide, foreign labourers in Singapore are excluded from government-supported social entitlements that are available only to local Singaporeans and permanent residents. Among the social entitlements, health care and dwelling conditions are two vital aspects of foreign labourers' quality of life. In terms of health care, foreign labourers are not eligible for subsidized health care but are covered by medical insurance that is purchased by their employers (Sadarangani et al., 2017). The insurance covers inpatient and day surgery fees but not outpatient fees for services such as outpatient treatment and rehabilitative, preventive or mental health services (Yi et al., 2020). Receiving outpatient services is subject to foreign labourers’ own ability to pay; thus, these services are affordable for foreign talent but usually not for low-skilled migrant workers.

In terms of dwelling conditions, the situation is similar to that of health care, which shows a large difference across social groups. Aiming to provide decent homes equipped with modern amenities for all those who need them,2 Singapore has created a housing system in which government-subsidized public housing accounts for nearly 80% and the remaining part is private housing (Lum, 2002; Phang, 2001). The former consists of flats with 1–5 rooms and executive flats and is allocated to eligible Singaporeans and permanent residents with household incomes under a regulated ceiling. Except for a small proportion of minimum-standard housing held for local and foreign workers to lease, each kind of public flat is allocated to households in accordance with predesignated household income intervals (Phang, 2001). The income ceiling is frequently reviewed, and nine out of every ten Singaporeans is eligible for public housing (Lum, 2002). The private sector targets the group with incomes in the top decile. The entire residential property market is thus arranged in a unique pyramid structure with the lowest and largest stratum comprising households living in low-end public housing; above that in ascending order are larger and newer public units, entry-level private housing such as condominiums, medium-level private housing such as terraced houses and finally landed properties (Lum, 2002; Sing et al., 2006). Community residential quality has been increasing over time, as is evidenced by the gradual increase in the proportion of the private sector on the one hand and the increase in the ratio of larger public flats3 on the other (Phang, 2001; Lum, 2002; Sing et al., 2006).

In contrast to residents living in public and private housing communities with increasing housing quality, low-wage migrant workers are widely excluded from the housing system, with the notable exception of a small number who qualify for rental public housing. The majority, at a rough estimation currently more than 323,000, live in 43 migrant dormitories built and operated by commercial operators. The migrant dormitory has long been regarded as a practical type of settlement for housing migrant workers in land-scarce Singapore. However, the dwelling conditions of migrant dormitories are frequently reported to be extremely poor, as is manifested by high population density, low housing floor area per capita, and highly shared public facilities.

For example, S11, which operates many such utilitarian housing blocks on the city fringes, advertises ‘the cheapest dormitories in Singapore’. One migrant dormitory site can house up to 14,000 workers in four-story buildings covering an area of 5.8 ha (see Fig. 1 and Fig. 2 ). The population density of a migrant dormitory can be as high as 241,379 persons/km2, which is nearly 3 times the average population density of Singapore (8900 persons/km2). In particular, there are commonly 12 to 20 bunkbeds per room in a dormitory. Fig. 3 presents a typical room layout of a 20-person dormitory, exhibiting the overcrowded space and inadequate sanitation facilities. One dining table and three suites of bathroom facilities are shared by 20 persons, and each person has an average living space of 4.529 m2 with less than 2.5 m2 for him- or herself. This is in sharp contrast to the living conditions of local communities, which have an average housing floor area per capita of 69 m2 in a 3-room public flat (Sing et al., 2006). While the housing floor area per capita in the layout meets the minimum living space required by the government (4.5 m2), the reality is that commercial operators have strong incentives to overlook migrants' dwelling conditions in order to gain further profits. Global-Is-Asian Staff (2019)reported that two directors of construction firms were fined in 2019 due to illegal overcrowding in a dormitory with a housing floor area per capita of only 2.57 m2. According to Dutta (2020), one hundred migrant workers shared a block of five toilets and five shower stalls in many Singapore dormitories. Overall, without appropriate health care services and dwelling conditions, these migrant workers are the most marginalized and vulnerable social group in outbreaks of infectious diseases (Lee et al., 2014; Global-Is- Asian Staff, 2019).

Fig. 1

A site plan of the S11 dormitories

Source: http://www.singapore-dormitory.com.sg/facilities.htm.

Fig. 2

S11 dormitories

Source: http://www.singapore-dormitory.com.sg/index-2.html.

Fig. 3

A layout of a typical dormitory room

Source:Transient Workers Count Too.

Antiepidemic measures in transition

Regarding the outbreak and spread of COVID-19, the antiepidemic measures of Singapore can be divided into three stages to the end of September 2020. The first stage was from January 23, 2020, when the first imported case was detected, to the implementation of the ‘circuit breaker’ on April 7, 2020, when a partial lockdown was imposed. This stage was characterized by a mild and reactive government coping strategy, with a peak in daily increases of imported cases on March 23 followed by the peak in community cases on April 7. Because of the reactive response, the quarantine rules were initially lax. In addition to the cases detected through surveillance, which were isolated immediately, persons with a potential risk of infection entering the country, including those from Wuhan, were only issued a stay-at-home notice. This notice was then applied to all people entering after March 20, after which the entry rules became stricter. As most newly detected imported cases were those isolated before detection, the imported COVID-19 pandemic was gradually brought under control with the tightening of the entry rules.

Due to the initial lax entry rules and quarantine measures, local communities began to respond to infection cases on February 4, 2020, nearly two weeks after the report of the first imported case. Relying on the strategy of aggressive contact tracing followed by quick identification and isolation, the cases of infection in local communities reached a daily increase of ten or fewer cases before mid-March. However, this situation changed in the period from March 24 to April 8, when community cases increased rapidly and the peak of daily increase reached 64. The government strategy of aggressive contact tracing and the policy of stay-at-home isolation generally functioned well in the first stage. Singapore recorded fewer than 600 cases during this period and was once praised as a shining star of handling COVID-19 without affecting the normal socioeconomic order.

The second stage did not start until the peak of community cases and the fuelling of COVID-19 in migrant dormitories at the beginning of April (see Fig. 4 and Fig. 5 ). To curb the rapid spread of COVID-19 across the city-state, the government initiated an active antiepidemic policy with a partial lockdown on April 7, including the closure of schools and most workplaces in addition to essential sectors such as logistics, transportation, and telecommunications. The government directed all labourers living in dormitories to stop working and imposed a stay-at-home order on approximately 180,000 foreign workers in the construction sector. As a result, an apparent downwards turn of the daily increase in community cases occurred immediately, but the outbreak of COVID-19 spread in migrant dormitories at the same time.

Fig. 4

Epidemic curve

Source: Ministry of Health, Singapore.

Fig. 5

Epidemic split curve

Source: Ministry of Health, Singapore.

Indeed, the government took preventative measures in dormitories for migrant workers in January, including advising dormitory operators to monitor workers for fever, encouraging personal hygiene and limiting mingling in common areas. The implementation of the suggestions, however, was left to each dormitory operator. Fingerprint scanners for entry and exit were added in some dormitories to strengthen management, but temperature checks were rare. The limited number of imported and local community infection cases led most dormitory operators to believe that those precautions were sufficient. The fact that there was only one reported dormitory case on February 9 and another on February 11 further led all relevant groups to be careless about the health risks of migrant dormitories. Consequently, the infectious conditions for COVID-19 in migrant dormitories were exacerbated after March 26, when dormitory infection was reported again, and thereafter, the public health emergency rapidly became uncontrolled. On April 5, the daily increase in reported infections in dormitories exceeded infections outside, and the rate of infections continued to accelerate until mid-April. In response, government-ordered quarantine was applied to dormitories where infection was reported. Migrant workers were confined to their rooms, except to use the bathrooms, and meals were delivered in these dormitories. Once an individual felt feverish, he or she was tested. If the test was positive, he or she was then moved to ‘community care beds’ in facilities that were either converted from public buildings or temporarily constructed as new facilities to house patients with mild symptoms. Testing, conducted after the appearance of symptoms, was generally reactive at the beginning of the quarantine.

Unfortunately, associated with the quarantine of dormitories and reactive coping measures, there was a surge of infections in the quarantined dormitories, and quarantine was then applied to more dormitories. The daily reported cases of infection jumped from 60 on April 5 to 1397 on April 20, and the number of quarantined dormitories increased from 19 on April 6 to 25 on April 28. After a short period of successful pandemic control, Singapore had become the worst-hit country in Southeast Asia since mid-April, forcing the city-state to impose stricter quarantine measures and to take more active precautions. On April 21, it expanded the lockdown to almost all of Singapore and extended it to June 1 from the initial ending date of May 4. The main target was to decrease community cases decisively and ensure that infections in migrant dormitories would not spread into local communities. At the same time, the government started to gradually expand the scale of testing in dormitories, from testing just people who felt feverish to including all suspected cases. The daily testing number reached 3000 migrant workers at the beginning of May. Moreover, the city-state endeavoured to provide more isolation facilities for those who were symptomatic, even without a confirmed COVID-19 test. According to the official report released in May 2020, there were 10,000 community care beds, which would expand to 20,000 by mid-June. Finally, the city-state started to rehouse some migrant workers to reduce population density. On May 15, it was reported that additional housing for approximately 60,000 migrant workers would be created by the end of 2020. The change in coping strategies from reactive to active had taken effect, as was shown in the slow decrease in daily reported cases in dormitories after April 20.

After the end of the lockdown on June 1, Singapore started a new stage of antiepidemic measures. In the third stage, the city-state maintained an active response. Passengers at entry points into the country were strictly surveilled, isolating all imported infection cases before detection. The daily number of newly reported community cases experienced two waves of fluctuations, one immediately after the end of the lockdown and the other between late June and late July. There was a progressive decrease in the daily number of dormitory cases from the reopening of the country to July 10, which was then followed by a new rebound. After mid-August, the virus spread was under control, with a steady decline in the total number of cases.

Poor dwelling conditions and exclusive antiepidemic policies

Singapore had successfully controlled COVID-19 once again. However, it is necessary to consider why local communities and migrant dormitories showed two extremes in terms of the spread of COVID-19. For the local communities, the transmission of the virus was generally controllable by the city-state throughout the whole period. Stay-at-home isolation based on aggressive contact tracing was the main countermeasure applied by the government to these communities. Through the conscious isolation of community residents, the government was able to handle the virus in those areas with a reactive response based on its disease outbreak response system4 and risk management capacity that had been established in combating SARS in 2003 and H1N1 in 2009 (Lai and Tan, 2012, Lin et al., 2020). This clearly shows that the vast majority of infected cases were detected through surveillance and that the minority were isolated by the government before detection. Facing the sharp rise in community cases in early April 2020, the lockdown strategy functioned quickly and efficiently. Although there were two fluctuations after reopening, the situation was easily controlled. In contrast, mass quarantine as an unprecedentedly strict countermeasure was applied to clustered dormitories, causing a sharp surge in infections even during the lockdown period. The results imposed great challenges on the health care system, the government and even the whole city-state.

COVID-19 is a respiratory disease that spreads through droplets from the nose or mouth by coughing and sneezing and by people coming into contact with contaminated surfaces before touching their nose, mouth or eyes. In particular, an infected person, even without any symptoms, is highly infectious, making it very difficult to detect the source of infection. Once a person tests positive, he or she may have already infected close contacts and left COVID-19 in the air, on surfaces and in other places to infect his or her contacts. That is, in addition to the predicable isolation of suspected and infected persons and even their close contacts, some efficient precautions are necessary, including wearing a mask, maintaining social distance, reducing the sharing of facilities and space to reduce contact frequency, and timely disinfection.

Considering the characteristics of COVID-19 spread and necessary precautions, the differentiated dwelling conditions between local communities and dormitories may be a crucial reason for the two extremes. As mentioned before, the living conditions of public housing and condominiums are of good quality in Singapore, with an average floor area per capita of over 30 m2 as well as an excellent residential environment. This provides good conditions for community residents to take precautions, such as stay-at-home isolation, maintaining social distance, and following strict hygiene rules. Therefore, the city-state reactive coping strategy based on contact tracing, quick identification and isolation of new cases functioned well in local communities.

However, Singapore's reactive containment effort adapted to the communities had a weak link with migrant dormitories that featured extremely high population density, low housing floor area per person and highly shared facilities. The overcrowded living conditions and inadequate provision of basic infrastructure made the enforcement of social distancing implausible. Once infections existed in the dormitories, the quarantine aimed at protecting the rest of the city actually placed the migrant workers at higher risk of person-to-person direct transmission. Due to the high population density, the sanitary conditions of migrant dormitories are usually difficult to guarantee, and they are further worsened by the high degree of sharing of facilities and space. If the quarantine is applied and disinfection practices cannot compensate for poor sanitary conditions, the results will be more contaminated surfaces and air, which are highly infectious. The highly shared facilities additionally increase the frequency of contact with contamination, making the unhygienic dormitories a hotbed for COVID-19 infection.

The relationship between the dwelling conditions of migrant dormitories and high risk of COVID-19 spread is empirically evidenced in two ways. First, the local communities saw an absolutely low infection rate of COVID-19 after the start of the outbreak, while the rate within dormitories increased rapidly (see Fig. 6 ). On April 17, before which the communities had experienced a hard hit, the infection rate of COVID-19 in local communities was 0.0225%, which was much lower than the total infection rate of 0.09% in Singapore. However, the infection rate of migrant workers living in dormitories reached 1.01%, which was 44.89 times the rate of local communities. By June 1, when the lockdown was initiated, the infection rate of local communities had increased to 0.03%, while the rate of dormitories had increased by nearly 10 times to 10.23%, which was 341 times the rate of the former. By September 25, the infection rate of the dormitories had reached 16.82%, which was as much as 420.5 times the infection rate of local communities (0.04%). Second, how the city-state took measures to successfully handle COVID-19 after its drastic spread within dormitories illustrated the key role of dwelling conditions in the process of virus transmission. After the quarantine, residents were confined to their rooms, and sanitary conditions worsened quickly, which made it difficult for them to maintain social distancing and follow strict hygiene rules. Moreover, shared facilities such as bathrooms, toilets, and laundry rooms significantly stimulated the spread of COVID-19. Mass quarantine without predictable precautions directly leads to a sharp surge in infections. After specific responses such as extensive testing, isolation, rehousing migrants to reduce the residential density, and improving sanitary conditions, the severe situation was alleviated.

Fig. 6

Sum of community, dormitory and imported cases

Source: Source: Ministry of Health, Singapore.

Aiming to improve migrant workers’ dwelling conditions

Warnings about the overcrowded and unsanitary living conditions of the dormitories in relation to infectious diseases such as SARS, H1N1 and the Zika virus were documented before COVID-19 (Lee et al., 2014; Tam et al., 2016). In response to these warnings, the authorities gradually updated the requirements under the Foreign Employee Dormitory Act, such as setting the minimum living space per resident and requiring the provision of facilities such as sick bays and isolation rooms in each dormitory and contingency plans in case of a pandemic. However, in reality, the poor living conditions in dormitories have not changed substantively over the years. It is not uncommon for the construction of dormitories not to comply with government specifications. Despite their compliance, the dormitories that were built to meet the basic needs of workers during normal times were far from meeting the requirements of effective precautions and resistance to the pandemic, such as sufficient social distancing.

Despite the constant avowal of the authorities that they would thoroughly promote better living standards in dormitories whenever the country expressed sympathy for migrant workers after experiencing a major incident, real progress still lagged behind expectations and was subject to complex interactions among stakeholders, namely, workers, employers, dormitory operators, the authorities, and the public. Without any opportunities to obtain permanent residency, low-wage migrant workers usually live frugally to save money for their future livelihood or their family in their country of origin. Therefore, trading health for wealth, they are incapable of bearing any additional costs upon their reservation wage (Hsu & Dastidar, 2009). Their accommodation is by law the responsibility of their employers, who lease rooms for them from the dormitory operators. The increased costs of raised living standards would be imposed directly on employers and dormitory operators, who are unwilling to shoulder all the additional costs. When it is impossible to reduce migrant workers’ wages to keep jobs attractive to them, the increased costs are then partially passed on to the public as consumers, reflecting higher prices for the services and products produced by migrant workers. The unwillingness of consumers to pay increasing costs is imaginable, especially when a significant proportion of local residents have negative perceptions of migrant workers and there is decreasing support for them (International Labor International Labour Organization, 2020). When high reliance is placed on the market to ensure the welfare of migrant workers, the authorities, as regulators, must balance raising living standards against objections from market forces and the public.

The outbreak of COVID-19 among migrant workers at such a scale offered Singapore, the well-known ‘Garden City’, an unprecedented lesson and forced it to reexamine how to treat this overlooked population and make substantive changes. On the one hand, it showed the above stakeholders that promoting living standards is not only the right thing to do but also in their interests and the interests of society as a whole; on the other hand, the city-state started to make short-, medium- and long-term plans. In the short term, alternative accommodations have been gradually provided for people in the hardest-hit dormitories to reduce the residential density. Testing new standards, including increasing the living space per resident, decreasing the number of beds per room, reducing the number of people sharing a toilet and bathroom, and building new permanent dormitories according to the new standards, is part of the medium plan. In addition, an increasing number of voices are appealing to the government to adjust development strategies to reduce the reliance on low-skilled migrant workers and to take a more direct role in supplying accommodations for migrant workers. Suggestions such as upgrading technology to add more automation to traditionally labour-intensive industries, increasing the productivity of local residents, and having dormitories owned by the government and managed on a competitive basis by private companies, have also been proposed and discussed by scholars and the public as long-term countermeasures.

Discussion and conclusion

As economic growth is unable to bring all urban populations into a zone of better health conditions, continuing urbanization is unable to allow more people to enjoy urban advantages in terms of improved health conditions in cities. To date, the COVID-19 pandemic is still damaging the health conditions of millions of residents in cities such as New Delhi, Mexico City, and Rio de Janeiro, where social distancing orders are difficult to follow and the basic living infrastructure is severely inadequate because of dense informal housing. Although providing a key form of shelter for low-income migrants and the urban poor, informal housing and the concomitant sociospatial exclusion have trapped dwellers of such housing in a vicious cycle of poverty. Owing to the potential health risks of these dwelling conditions, moreover, informal housing has gradually become an essential threat to urban public health that urgently needs effective planning controls from city governments.

This empirical study of Singapore regarding urban public health problems revealed during the COVID-19 pandemic has obviously highlighted the importance of considering informal housing in strategies and measures to control and prevent infectious diseases. The fluctuating outcomes of antiepidemic measures taken by the Singapore government further call for planning interventions in dwelling conditions of informal housing and health security of those dwellers. Therefore, we argue that a more inclusive planning strategy for urban public health must seriously take the dwelling conditions of informal housing into account, as these conditions involve one-quarter of the world's population. Particularly, the healthy dwelling conditions require sufficient housing floor area and basic infrastructure per capita to guarantee sanitation and hygiene standards, since improved hygiene and maintaining physical distancing are principle measures for reducing the infection risks of COVID-19 in any context. Almost one hundred and fifty years ago, the Public Health Act in the United Kingdom triggered the application of plot ratio and site coverage in the domain of modern urban planning. With regard to sustainable urban public health, cities in the twenty-first century also need a baseline of living space and sanitation infrastructure per capita as a strict planning standard to safeguard the dwelling conditions of urban residents.

The accessibility of adequate sanitation facilities should be regarded as a basic human right to prevent disease and protect privacy and dignity. The market mechanism is able to provide private goods (e.g., personal health) and club goods (e.g., public health in gated communities) with little consideration of the overall health outcomes of cities and society. Urban public health and social equity, however, are public goods that are necessarily provided by city governments (Zhu, 2020). Along with the rapid urbanization process, intervention in public health must be balanced with social and economic interventions, especially in relation to low-income migrants and their settlements, to sustain livelihoods. The role of city government should not be limited to urban regulators to maintain socioeconomic order; instead, city governments must actively engage in reforms and actions to improve the living standards of urban residents in terms of equal access to health resources and consistent planning of residential environments. This is further relied on a baseline understanding of populations within cities and be able to monitor changes, which requires more data and information on the physical and socioeconomic conditions of urban dwellers (Wilkinson, 2020). It is therefore imperative for local governments to actively involve and strengthen connections among key stakeholders who have much more knowledge on locally social and spatial infrastructure, such as local residents, employers, and nongovernmental organizations.

Author statement

Jiren Zhu (First Author): Conceptualization, Theoretical analysis, Writing - Original Draft, Jieming Zhu: Conceptualization, Supervision, Writing - Review & Editing, Yan Guo (Corresponding Author): Conceptualization, Data Curation and Visualisation, Empirical analysis, Writing - Original Draft.

Declaration of competing interest

None.