This is the first survey which explores the general view of toilet use in China and a preference for a squatting or seated arrangement, and whether there was any apprehension of contamination via splashing of toilet water. This report addresses an important public health concern, particularly during the COVID-19 pandemic. SARS-CoV-2, a virus responsible for COVID-19 and is transmitted via infected respiratory droplets [2] but also may be transmitted via faecal-oral route [5]. The majority of public toilets in China are of the uncovered squatting type.
Toilet flushing is potentially an ‘aerosol generating procedure’. Johnson and colleagues reported about 145,000 droplets per flush in high-energy flushometer toilets, and 95% of droplets were <2 m in diameter and [10]. SARS-CoV-2 aerosol droplets found in hospitals in Wuhan were reported as 0.25-1 m in diameter [12]. The toilets used in Johnson et al’s study were seated and quite possibly the water flow was higher than that in squatting toilets in China. However, over 63% of the participants in our survey encountered an incidence of splashing during toilet flushing. Clearly, flushing an uncovered toilet poses a risk of viral spread to the user. This survey showed while a third of the participants considered the hygienic condition of public toilets satisfactory, many would prefer the flushing conditions to be improved. While only about half of the participants considered they were worried public toilet hygiene during the COVID-19 pandemic, 72% of them admitted they were worried about personal contamination and all participants were willing to spend extra waiting time for any necessary sanitization procedure. If an improved sanitizing procedure were in place which required extra time for the cleaning process, the majority of our survey participants expressed a willingness to spend an extra 30 seconds, and some even more than 5 minutes waiting for the sanitizing process.
Upgrading public toilets in China is a considerable task because almost all public hospitals, schools, universities and the majority of commercial buildings have squatting public toilets without covers. In 2019, there are 147,466 independent and movable public toilets [13], these figures do not include public toilets in hospitals, schools, universities, or commercial malls. In 2019, the Chinese government allocated 7 billion RMB in upgrading rural toilet facilities [14]. The Chinese government actively supported the concept of a ‘Toilet Revolution’ originally proposed by UNICEF in 1997 [15]. China is a major industrialised country and most probably has the largest squatting toilet market in the world [15]. Squatting toilets with covers are available in some commercial malls in major cities, however most of these covers are hand controlled (Figure A1) and cleaning and disinfection procedures need further refining. Figure A2 shows an integrated toilet with a foot-controlled lid, but currently only available for domestic use. Designing covers for a large number of public toilets must obviously take into consideration production costs. Rather than a sophisticated device, simple step-to-open and step-to-close mechanisms might be considered. Factors that affect the ease of cleaning and disinfection are also essential considerations and must be carefully contemplated in a pandemic. Investment in effective public health disease prevention strategies in a pandemic is easily offset by a reduced healthcare spending treating people infected by COVID-19. The risk of splashing must be eliminated, and the manoeuvrer for operation of the cover should be foot-controlled, to avoid direct physical contact of the toilet.
This survey reveals that 91% of the participants prefer a squatting toilet compared to a sitting one. Although a sitting toilet may be more convenient, a squatting toilet has some advantages over a seated toilet. Firstly, no physical contact with a squatting toilet is necessary. Secondly, the squatting position facilitates relaxation of the muscles around the anal canal and widens the anorectal angle to allow a straighter passage for defaecation [9]. This theory led to the use of a ‘Defecation Posture Modification Device’ (DPMD) with the seating type of toilet. The DPMD brings the hips and knees in a pseudo-squatting position thus facilitates relaxation of the pelvic floor muscles during defecation [16]. It was also reported that the squatting action during use of squatting toilets improved blood flow velocity in the lower extremities [17], and the user is subjected to squatting, as a form of exercise for strengthening of the quadriceps muscles. Quadriceps strength is associated with a lower cardiovascular mortality in patients with coronary artery disease [18]. However, not everyone can squat [19, 20], especially those with restricted lower limb joint mobility and older people with poor balance and muscle weakness.
Irrespective of the type of toilet, limiting toilet flush water splash may reduce oral-faecal contamination and save on sanitation costs. The current COVID-19 pandemic provides opportunities for strengthening public health systems globally, and it is time to consider long term optimal environmental plans beyond disaster response [21].
There are several limitations in this survey. Our questionnaire did not explore why our participants favored squatting toilets. It is therefore not clear whether squatting toilets were preferred on a cultural or a zero physical contact hygienic basis. Further, while we inquired about an improved sanitizing process, we did not explore whether our participants were willing to pay for a higher level of sanitization. Understanding the level of commitment of the general public help with the planning and future design of public toilets. Lastly, our sample size was relatively small and not randomised, nonetheless the results provide useful information for improvement of public toilets in China.