2. Background
Construction Workers have been called upon to play a special role in Australia’s economic recovery from the pandemic [
1]. At the outset, a range of fiscal policies were deployed to stimulate activity throughout the sector, including fast-tracking public works and direct payments to homeowners for renovations. Throughout the crisis. works on site were allowed to continue despite little knowledge of the disease and its long-term effects. Unlike workers in healthcare, defense, education and aviation, construction workers were initially exempt from mandatory vaccination for reasons that appeared to be more ideologically driven than based on medical facts.
The Delta Variant of Sars-CoV-2 was first detected in the affluent suburbs of Sydney’s east due to critical failures in the state’s international quarantine system [
5] before spreading to the working-class suburbs of the west. This prompted closures of state and Local Government Area (“LGA”) borders to stem the spread of disease. Amid growing concerns, construction workers were a factor behind the spread of the virus among vulnerable communities. The New South Wales Government was forced to suspend construction works for several months. During this period, construction workers were urged to get vaccinated, and those from LGAs with especially high infection rates were required to provide evidence of vaccination in order to return to work in other parts of the city.
In Melbourne, the appearance of the Delta Variant was traced back to an international quarantine hotel in the city’s Central Business District (“CBD”) [
6] Like Sydney, the virus quickly spread to Melbourne’s working-class suburbs despite a swift return to lockdown. Construction work was also suspended following findings of widespread non-compliance with COVID-19 Safety measures, and a deadline by which all workers were required to provide evidence of their first and second vaccination as a condition for being able to return to work was imposed, which triggered protests by some workers over several days [
9].In both cities, safety measures set by health authorities included [
10,
11]:
requirements to register a COVID Safety Plan with the relevant state health authority for each site;
providing every employee with a digital copy of the COVID Safety Plan;
installing and maintaining posters with official health information on site;
digital check-ins using the state government’s QR Code system as a condition of entry on site;
provision and mandatory use of PPE;
maintaining one person per square meter;
provision of hand sanitizer and exclusive washing facilities for workers; and
appointment of a dedicated COVID Safety Marshall to monitor compliance.
These were substantively similar to the safety measures imposed on all businesses allowed to operate during lockdown. Nevertheless, when these measures failed to deliver the desired changes in behavior on construction sites and it became necessary to stop construction so as to slow the spread of disease, the decision was consistently framed by political commentators in terms of costs to “
the economy” rather than lives saved in an emergency [
12,
13].
Striking a balance between health and economic policy has been a source of political tension throughout the pandemic. Pressure to skew regulations in favor of commercial interests has yielded dramatic reversals of policy [
14], which has drawn criticism from experts concerned with not losing the hard-fought ground in controlling the spread of COVID-19 [
15]. Overcoming the rhetoric of corporate predation is made all-the-more difficult by the way in which the powerful actively represent ordinary workers as expendable. For example, “
dying for the sake of the economy” was an idea espoused by politicians and commentators in the United States [
16]. The British Prime Minister infamously said, “
let the bodies pile high!” [
17]. No wonder peak industry bodies in this country have been forced to raise concerns about the toll COVID-19 is taking on a sector plagued by mental distress and ill-health [
18].
With that in mind, our aim is to refocus the discourse on workers and their communities in order to show how the epidemiology relates to industry in social terms. Our objective is to quantitatively analyze the vast amounts of COVID-19 surveillance data published by health authorities in this country in light of existing data on the construction industry.
5. Results
5.1. Sydney
Our analysis of the data showed that, in Sydney, infections were only weakly correlated with Construction Workers in general (ρ = 0.4). However, further analysis showed the relationship to be variable based on SES factors. Of the various types of construction workers, Machinery Operators, Drivers and Laborers (ρ = 0.6) were most at risk. Technicians and Clerical and Administrative Staff were moderately at risk (ρ = 0.5). Professionals and Managers, as expected, were very weakly correlated with infections (ρ = 0.07 and ρ = 0.2, respectively). In
Figure 5, the relationship between the most exposed construction workers, Machinery Operators and Drivers, and infections across Sydney is illustrated using bivariate mapping. As can be seen, the incidence of the Delta Variant of COVID-19 is strikingly similar to the distribution of workers known to be exempt from public health orders who travel from site to site in the conduct of their trade.
The results from our investigations also showed how the correlation between construction workers and infections changed over time. In the first month of the outbreak, all workers’ exposure to risk dropped sharply, particularly among Machinery Operators, Drivers and Laborers. This is probably because the Delta Variant first entered the local population via a negligent quarantine worker living in the affluent eastern suburbs of Sydney. However, as the outbreak continued, we observed a steep rise in all workers, except for Professionals and Managers, over four months from June to October. By October, 6 months into the outbreak, the risk profile for vulnerable construction workers peaked and started to fall as the total vaccination rate approached 90% for the population. Throughout the outbreak, it was also observed that the risk profile of Professionals remained below its original levels. In
Figure 6, the change in correlation between infections and construction workers’ SES is plotted over time. As can be seen, low-status workers were exposed to a mounting risk as the outbreak persisted.
Surprisingly, the data also revealed a weak relationship between infections and construction activity based on the number of construction certificates issued per LGA (ρ = 0.09) and the total value of Development Approvals per LGA (ρ = 0.04), which was contrary to expectations. However, the data revealed a strong relationship between infections and business counts per LGA (ρ = 0.8). Similar to construction workers, the relationship is variable based on SES factors such that Sole Traders bore the highest risk of infection (ρ = 0.8), while businesses with 1–19 employees (ρ = 0.7) and 20–199 employees (ρ = 0.6) were moderately at risk. Businesses with over 200 employees bore the least risk (ρ = 0.4).
These findings were echoed in an analysis of business size in terms of income. The data revealed a strong relationship between turnover and exposure to risk. Small companies with an annual turnover of less than AUD $200,000 had the highest exposure (ρ = 0.8), medium-sized companies with incomes ranging from AUD $200,000 to AUD $5,000,000 were also at a high risk (ρ = 0.7), medium-sized companies with a turnover between AUD $5,000,000 and AUD $10,000,000 sustained a moderate risk and companies with incomes over AUD $10,000,000 were at a low risk (ρ = 0.4).
In
Figure 7, these relationships are illustrated spatially such that, similar to construction workers, the footprint of infections closely resembles the distribution of construction businesses.
The data for Sydney construction businesses also returned a similar pattern to that of construction workers’ correlation with infections over time. According to the data, at the start of the outbreak, construction businesses of all sizes experienced a sharp drop in risk, followed by a steep rise in risk over six months, peaking in October as full vaccination of the eligible population approached 90%. In the case of businesses, the only outlier was large companies with annual turnovers of AUD
$10 million or more, whose risk profile remained relatively low and stable over the outbreak (see
Figure 8).
To better understanding the geographic distribution of workers and businesses, their relationship and the pattern of disease across the city, the data again returned useful results. While the data show that where construction workers live is weakly correlated with the number of construction projects (i.e., construction certificates issued) in LGAs (ρ = 0.4), their population is strongly correlated with the total value of Development Applications in LGAs (ρ = 0.9). This relationship is consistently high across SES groupings. Similarly, where construction businesses of all sizes (i.e., income brackets) are located is also strongly correlated with the value of construction work in LGAs (on average, ρ = 0.7).
Based on the above, we estimate that, in Sydney, around 19,000 Machinery Operators, Drivers and Laborers are at a high risk (i.e., 12% of the labor force). Between 15,000 and 18,000 sole traders and small businesses are in LGAs most likely to be affected by future outbreaks (i.e., up to 20% of construction businesses).
5.2. Melbourne
The Melbourne Data also showed a weak correlation between infections and construction workers as a whole (ρ = 0.4). However, further investigation also revealed variable relationships in the data based on SES factors. Unlike Sydney, the data revealed that, in particular, the distribution of Machinery Operators and Drivers was even more strongly correlated with the spread of the Delta Variant in that city (ρ = 0.8). Laborers were also moderately at risk (ρ = 0.6). All other categories of workers were exposed to relatively low levels of risk. As expected, professionals (ρ = 0.01) and managers (ρ = 0.2) were very weakly connected to the spread of the Delta Variant, as were clerical staff and administrative workers (ρ = 0.3). Similarly, technicians and trades workers were also weakly correlated with infections (ρ = 0.4). In
Figure 9, the relationship between infections, Machinery Operators, Drivers and Laborers is illustrated spatially. As can be seen, the footprint of the disease tends towards the Northwest and Southeast of the city in a similar pattern to that of construction workers.
Changes in the correlation between construction workers and the spread of COVID-19 were also distinctly different in Melbourne compared to Sydney. In the first two months, the risk profile of almost all classes of construction workers spiked, with Professionals and Managers most exposed.
Only Machinery Operators and Drivers experienced a sharp drop in exposure to risk. Again, these results probably account for how the Delta Variant gained a foothold in that city—that is, through failures in an international quarantine hotel in Melbourne’s CBD. Nevertheless, over the following four months, that position changed such that their exposure increased steeply above all other workers, peaking in October as the population approached 90% full vaccination. Laborers also suffered a mounting risk over the course of the outbreak, while all other construction workers experienced relatively low levels of exposure, as illustrated in
Figure 10 below.
As was the case in Sydney, the spread of the Delta Variant in Melbourne appears to be moderately correlated with the distribution of construction businesses as a whole (ρ = 0.6). This can be differentiated by SES factors such that sole traders were the most at risk according to the data (ρ = 0.7). Businesses with 1–19 employees (ρ = 0.5) and 20–199 employees (ρ = 0.5) were moderately exposed in equal measure, while large companies with over 200 employees exhibited a very weak negative correlation with the spread of the Delta Variant in Melbourne (ρ = −0.1).
Moreover, the correlation between business and the Delta Variant also varied according to income. Surprisingly however, very small construction businesses with incomes between AUD 0 and AUD 50,000 were only moderately at risk (ρ = 0.5), while small business with incomes between AUD $50,000 and AUD $200,000 (ρ = 0.7) and AUD $200,000 and AUD $2,000,000 (ρ = 0.6) bore the highest risk of infection. Medium-sized companies earning AUD $2,000,000 to AUD $5,000,000 (ρ = 0.4) and AUD $5,000,000 to AUD $10,000,000 (ρ = 0.4) were weakly correlated with disease, and, as expected, large companies earning over AUD $10,000,000 (ρ = 0.1) were very weakly related to the spread of infections in LGAs.
Remarkably, we observed a similar pattern when we analyzed changes in the relationship between business size and infections over time to that of construction workers. In the first two months, the risk profile of most construction businesses spiked and then saw steady increases over the duration of the pandemic. Companies with an income of AUD
$10,000,000 or more saw the most dramatic increase; however, by the third month, their exposure remained at very low levels. Small companies with incomes between AUD
$50,000 and AUD
$200,000 and between AUD
$200,000 and AUD
$2,000,000, on the other hand, experienced a sudden drop in their exposure within the first month followed by a steady increase over the duration of the pandemic, plateauing as the rate of vaccination for the eligible population approached 90% in Melbourne (see
Figure 11 and
Figure 12).
Interestingly, unlike the Sydney data, the Melbourne data revealed that infections were strongly correlated with the number of Building Permits (the equivalent of Construction Certificates in Victoria) in LGAs (ρ = 0.7) and not with the value of work underway (ρ = −0.1).
Figure 13 and
Figure 14 below outline the distribution of construction projects underway in Melbourne and Sydney at the time compared to the footprint of the Delta Variant, which aligns with observations on the ground.
Anecdotally speaking, both cities had major infrastructure works underway during the outbreak of the Delta Variant. In Sydney, transport infrastructure projects worth AUD
$29.5 billion were underway at the time [
34]. In Melbourne, the city had undertaken the removal of dozens of at-grade railway crossings citywide to improve public safety, which was estimated to cost AUD
$8.5 billion [
35]. In addition to the construction of AUD
$1.8 billion in new prisons and correctional facilities [
36]. In both cities, major public works were troublingly close to, or within, LGAs most burdened by the disease. As mentioned earlier, we know that both governments took steps to address concerns about the spread of COVID-19 on construction sites, with the NSW government going as far as to dedicate an entire day to vaccinating as many construction workers as possible at its mass vaccination hub at Sydney’s Olympic site, dubbed “
Super Sunday” [
37]. This shortly preceded a peak in the risk of infection faced by construction workers on site. Victoria took the radical step of imposing a state-wide mandate for all construction workers to address the issue.
6. Discussion
This article presents findings from our study of the outbreak of the Delta Variant of COVID-19 in Australia’s two largest cities and addresses our proposed spatiotemporal analysis and relationships between the location of infections and construction.
Publicly available health, demographic and planning data were analyzed and mapped using GIS. The strength of the relationship between the various factors (construction workers, businesses, the value of construction work and construction certificates) was tested using Pearson’s Correlation Coefficient. We also studied how the strength of that relationship changed over time in each city and differentiated construction workers based on SES factors according to the rule of Fundamental Cause. Analogous tests were also carried out in relation to construction businesses based on their size (i.e., the number of employees) and annual turnover (reported income). The period of study covers the identification of the first case of community transmission and the attainment of 90% full vaccination of the eligible population.
To date, few studies have empirically considered the evolving relationship between the footprint of COVID-19 across major cities and their population of construction workers and businesses according to SES. Moreover, we are not aware of any studies that examine these events under a strict policy of border closures and quarantines similar to that pursued by the Australian government. In that regard, our research takes advantage of a large-scale natural experiment without modern precedent.
We found that, during the outbreak of the Delta Variant, machinery operators and drivers were the construction workers most at risk for infection in both Sydney and Melbourne, followed closely by laborers. While it is tempting to assume that their exposure can be attributed the nature of their work, we have no empirical data to support that finding at this time. The better view is that these workers are lower on the SES ladder and tend to live in LGAs that are more vulnerable to outbreaks of infectious disease. Exempting machinery operators, drivers and laborers from lockdowns without mandatory vaccination may create vectors by which the disease can enter those LGAs despite lockdowns, unduly burdening their communities.
When outbreaks occur, the first eight weeks are critical to the health of the construction industry. During that period, all construction industry workers may experience dramatic changes in their risk profile depending on the circumstances of the outbreak. After this, workers on the lower end of the SES spectrum are likely to experience a steep rise in their exposure to risk over several months until the outbreak is brought under control. Workers higher on the SES scale will experience relatively low levels of exposure over the duration of an outbreak, notwithstanding any spikes which may occur initially due to when and where the virus first appears.
Remarkably, the correlation between construction businesses and infections mirrors the risk profile of workers such that, in the initial eight weeks of an outbreak, most businesses may see dramatic changes to their risk environment depending on the circumstances under which the virus is first detected in the community, after which time sole traders and small businesses are likely to see mounting risk as the outbreak continues. Large construction businesses are likely to enjoy relatively low exposure to the risk of infection, as they tend to be located in LGAs higher on the SES scale.
Based on our research, we estimate that, in Sydney, around 5.6% of the total construction workforce (over 8600 machinery operators and drivers) were at a very high risk, in addition to a further 13.8% of the workforce (21,373 laborers) at a high risk during the Delta Variant outbreak. Similarly, only 1.5% of construction businesses (1449 out of 95,040) experienced very low exposure.
These figures were echoed in Melbourne, where we estimate that around 5.6% of the building industry (7789 machinery operators and drivers) were at a very high risk, on top of an additional 13.2% of high-risk individuals (18,330 laborers). Similar to Sydney, only 1.5% of construction businesses in Melbourne (1328 out of 88,980) experienced low levels of exposure to the risk of infection based on their environment.
This research is based on the outbreak of the Delta Variant, which is no longer the dominant strain of COVID-19. The period of study also covers a public policy environment of border closures strict quarantines, which has given way to lax public health measures and “learning to live with the virus”, despite the appearance of new sub-variants such as Omicron BQ1 and XBB, which once again threaten healthcare systems worldwide. Research must keep pace with the pandemic as it unfolds. Moreover, outbreaks of other diseases such as Monkeypox, Polio and Marburg Virus must be accounted for as the risk environment intensifies.
The demographic data used for this study are based on the 2016 census, which is due to be updated by the publication of the 2021 census later this year. Additionally, the reporting regime for COVID-19 has changed to include both Polymerase Chain Reaction (PCR) tests and Rapid Antigen Tests (RAT), which may impact the reliability of the results given that it is up to individuals to self-report positive RAT test results.
Based on our findings, we recommend short, sharp pauses of all construction works on site to control the spread of future pandemic outbreaks as soon as cases of community transmission are detected. Fiscal policy must support workers and small business owners so they are not forced to choose between their health and earning a living during these periods. Governments and trade unions must commit to mandatory vaccination for construction workers in order to safeguard their communities. Additionally, health authorities must continuously engage with particularly vulnerable workers as general immunity wanes and vaccine boosters become necessary. Digital disinformation must be tirelessly countered by consistent expert medical advice at all levels of the industry.
This study is useful for public health authorities and industry advocates and can be applied to a range of diseases. Future studies could consider other periods of the pandemic, as defined by the dominant strain, the availability of vaccines and changes in public policy settings.
7. Conclusions
This study has taken advantage of a natural experiment without modern precedent. Over seven months in 2021, while international borders were closed and cases of COVID-19 were virtually nil, an outbreak of the Delta Variant occurred in Sydney and Melbourne, which triggered closures of Australia’s internal borders in state-led efforts to contain the spread of the disease. Despite this, construction workers were called upon to keep working, without the benefit of mandatory vaccination. This study analyzed publicly available COVID-19 surveillance data, census data and planning data to better understand how the spread of the Delta Variant related to construction in both cities. We found that machinery operators and drivers were at a very high risk of infection owing to their socio-economic status and where they tend to live in both cities. We also observed a similar pattern of disease disadvantage among construction businesses based on size and income. In both cities, the first eight weeks of an outbreak are critical. After that period, the disease is likely to make its way into vulnerable communities, steeply increasing the risk profile of construction workers, sole traders and most construction businesses. Based on our findings, we recommend:
Snap lockdowns when new pandemic outbreaks occur;
Fiscal policies that support workers, sole traders and small businesses in the event that it becomes necessary to stop works on site;
A serious commitment to mandatory vaccination for all construction workers;
Ongoing engagement with particularly vulnerable workers to prevent disinformation and issue-fatigue.
This research is useful for industry academics and advocates advising policymakers tasked with anticipating new waves of COVID-19 and future outbreaks of other communicable diseases. Despite wishful thinking, the pandemic is not behind us. In fact, we have seen more infections and deaths in the last six months than in the last two years in this country alone.