Sopite syndrome as high-rise buildings sway
For health evaluator Michele Grigg, turning up to work in her high-rise office on gusty days filled her with dread. “My office was on the 10th floor and the building movement on windy days made me feel unwell,” she recalls.
Grigg describes her symptoms as “a woozy head, nausea some days and a feeling similar to what I feel on large boats”.
“The symptoms didn’t get worse in the 18 months I worked there but they were always recognisable as soon as the wind started blowing.”
It is estimated 95 per cent of the population can be affected by motion sickness to varying degrees, and it is commonly caused by motion in cars, boats and planes. But it is only recently that Australian and New Zealand researchers confirmed what significant numbers of people such as Grigg suspected – that exposure to the gentle sway of tall buildings can cause low levels of motion sickness.
Known as sopite syndrome, and identified by two NASA scientists in 1976, it is considered the precursor to full-blown motion sickness.
Sopite syndrome can be described as drowsiness caused by prolonged periods of motion and is characterised by symptoms that include yawning, lack of concentration, apathy and low mood.
A survey in 2012 by wind engineer Professor Kenny Kwok of Western Sydney University involving 1014 high-rise office workers in Wellington, New Zealand, found 41.7 per cent of respondents felt wind-induced building motion. Nearly 42 per cent of that figure reported suffering at least loss of concentration.
“I describe people with this condition as ‘silent sufferers’ because they often pull back from making formal complaints or dismiss the symptoms as general fatigue,” says Kwok.
A year later his team followed up with a longitudinal study involving 108 Wellington workers that focused on the impact wind-induced tall-building motion had on occupant wellbeing and performance over lengthy exposure.
Kwok’s latest research, in collaboration with physiologist Professor Vaughan Macefield, aims to determine the amount of building motion (acceleration) that will induce sopite syndrome, as well as produce a better understanding of the physiological changes it causes.
They are studying changes in the sympathetic nervous system and its interaction with the vestibular system. The vestibular system, which includes part of the inner ear and brain, is so sensitive it can detect subtle differences in gravity and acceleration with no visual cues of motion.
“Even if the person doesn’t feel the movement, the inner ear detects motion and people react to the acceleration differently, and that’s where the problem starts,” says Kwok.
Kwok, 66, who was born in Hong Kong, says his academic interest in tall-building movement began as a PhD student at Monash University in the mid-1970s.
In recent years he has enlisted the help of disciplines outside his own to deal with occupant comfort and the variables of human complexities in terms of physical attributes, personality, behaviour and physiology.
“I got to the point where as an engineer I’d exhausted areas to explore, so I said let’s bring these guys on board,” he says.
Psychologists Dr Steve Lamb and Dr Darren Walton worked with Kwok on both the one-off survey as well as the longitudinal study in New Zealand in which Michele Grigg participated.
Wellington was ideal for the longitudinal study because it is one of the world’s windiest cities, with geographical features that produce consistently high winds. Participants over eight months reported sopite syndrome symptoms including tiredness, low motivation, distraction from work activities and low mood. Research literature likens the effect of the wind movement to “rocking an infant to sleep”.
“If you imagine feeling wide awake, alert and ready for action, then sopite syndrome pushes you towards the other end of the spectrum,” says Lamb.
“During building motion, affected participants reported symptoms two to three times the baseline rate.
“We found self-reported work performance decreased by 30 per cent in those participants affected by sopite syndrome compared with their performance on a normal day,” says Lamb.
Sufferers attempted to manage their own discomfort and indicated a preference to work at a different location during motion. This self-management also extended to some workers increasing breaks by 30 to 40 per cent and self-medicating using analgesics.
Grigg, 49, says she had never heard of sopite syndrome until after taking part in the study, but knew she was suffering some sort of motion sickness.
She shared the space with seven other women, but only her and one colleague felt the sway of the building and suffered the consequences.
“No one else in the office, including our bosses, was affected like we were,” says Grigg. “My colleague and I spoke about it on windy days but we didn’t complain.”
Grigg says she dealt with it by just persevering.
“I didn’t take any medication but I probably drank quite a bit of water, and thankfully the job involved time offsite that got me out of the office,” she says.
Grigg eventually moved out of Wellington for less windy Hawke’s Bay and now works on the first floor of an office block with no ill effects.
Kenny Kwok is hoping his body of work on sopite syndrome, which has been supported by the Australian Research Council’s Discovery Projects scheme, will eventually lead to tighter design guidelines to improve occupant comfort in both residential and office high-rise blocks.
“While building occupants tolerate or adapt to motion, some wind-excited buildings do not provide a healthy or productive work environment,” he says.
“The problem will only get worse because the rate of tall building construction is increasing to cope with growing populations, and these buildings are inherently wind-sensitive due to their increasing height, slender designs and use of lightweight materials.”
Melbourne architect Craig Baudin of Fender Katsalidis Architects, the firm that designed the 297.3-metre Eureka Tower in Melbourne’s Southbank, says occupant comfort in wind-affected high-rises has been an important issue for building designers for some time. While there is no mandatory legislation in Australia that addresses wind-induced human comfort in tall buildings, and the National Construction Code is silent on the issue, designers are not left in the dark.
“Structural engineers and architects in Australia have to look to international best practices to guide them,” says Baudin.
The best practice internationally is governed by an International Organisation for Standardisation level that was updated in 2007 with more stringent criteria.
“Lightweight materials certainly make it harder to deal with these issues, especially in countries like the United States where steel-framed tall buildings are quite common, but tall towers in Australia are almost always concrete framed,” says Baudin.
“However, even with lightweight buildings there are established design strategies that can be taken to counteract the effect of wind-induced motion.”
Baudin says mitigating wind effects can have significant impact on the structural cost of a project “but in our experience projects of this size have very professional clients and development teams, and they are unwilling to take the risk of cutting corners on this significant issue.”
Meanwhile, Kwok’s research team is keen to hear from more people who find windy days and tall buildings an utterly upsetting combination.
This article was first published in the print edition of The Saturday Paper on May 7, 2016 as "Taking it queasy". Subscribe here.