Science: Air-conditioned nightmare

How sick are our offices? And what can we do about it? Norman Miller reports on the latest research into a phenomenon linked with up to 5,000 cases of cancer in the US each year

MEET MONIKA, a paranoid office worker's nightmare. All she does is sit around, spying and reporting back to her boss. But don't worry, she's on your side. Monika is a thermal dummy, conceived by Berkeley's Center for Environmental Design Research, built in Copenhagen by the Technical University of Denmark, and crammed full of sensors to measure what her designer Ed Arens calls the "comfort and ventilation effects of heating and cooling systems on people in typical office setups". Though Monika does all her work in a lab, the information she gathers could contribute to studies of that fiercely debated scourge of modern working life: Sick Building Syndrome, or SBS.

Cynics may lump SBS in with conditions like ME, identifying it, in other words, as a form of malingering. But both SBS and the related condition Building Related Illness (BRI) have been implicated by the US government's Environmental Protection Agency in up to 5,000 cancers a year in America, while contributing to a $60bn annual bill for sick leave, medical costs and lost production.

SBS and BRI were initially distinguished by the fact that the former had no easily identifiable specific cause, while the latter could be pinned down to particular airborne contaminants causing specific problems. The symptoms associated with SBS - headache, dizziness, nausea, fatigue, irritation to eyes, nose and throat, difficulty in concentrating - also tended to improve soon after the sufferer left the building, while those of BRI (the short terms ones, at least) - such as chest tightness, fever, muscle aches -often took longer to disappear, if they faded at all. However, this distinction between SBS and BRI has been blurring as scientists have begun to identify a growing list of possible chemical and biological culprits, whose impacts range from the milder symptoms previously classified with SBS through to more serious conditions grouped under the BRI banner such as heart problems, liver damage and cancer. Rather than being separate conditions, SBS and BRI may be part of the same continuum of modern-day office nastiness.

If you're looking for scapegoats, you can partly blame the Arabs. The sharp rise in energy costs during the 1970s due to oil embargoes and price rises prompted energy conservation measures in developed countries, which saw previous standards for ventilation cut by two-thirds. Reduced ventilation, often in tandem with ineffective heating, ventilating and air-conditioning (HVAC) systems, led to a sharp drop in the indoor air quality of office buildings. This is now widely considered to be one of the foundations of sick building syndrome, since poor ventilation allows concentrations of dangerous compounds to rise, and experts are finding plenty of those lurking in the stationery cupboard or round the photocopier.

The list of contaminants splits into chemical and biological sources, though these can act in combination, as well as supplementing problems caused by temperature, humidity and lighting. Studies in America by the EPA over the last two decades have found measurable levels of more than 100 known carcinogens in modern offices, with the main bad guys being volatile organic compounds (VOCs), of which over 250 have been identified in office air. These include benzene, styrene and carbon tetrachloride.

Not spotted those in your in-tray? Well, they may be coming from the in-tray itself and just about everything else around you. Modern furniture, paint, carpets, adhesives, toner, felt tips and correction fluid all emit a complex - and highly reactive - mix of VOCs. Adding to this brew, your photocopier may churn out other reactive compounds such as ozone. Even your colleagues can give off VOCs. Dry-cleaned clothes, for example, emit trichloroethane, the solvent used in cleaning, while the pleasant smelling chemicals in deodorants, perfumes and soaps may contribute a further 100 different chemical ingredients to the atmosphere, with compounds like limonene and camphene lurking in that body mist or eau de toilette. Micro-organisms add their dose, too, from their homes within HVAC systems or as indoor surface pollution on desks. Some fungi from "sick" buildings were found to emit VOCs including hexane and the carcinogen benzene, for example. Stir all this up, sprinkle in toxic compounds pumped into the building from outside, such as carbon monoxide from car exhausts, reduce the ventilation and simmer until sick.

Some of this is the chemistry of the smogs that blight cities such as Los Angeles and London, but until recently scientists thought this was a problem of the unhealthy outdoors rather than the cool and efficient office interior. Recent research, however, has painted a different picture, with levels of some pollutants in the worst buildings found to be up to 20 times higher than the safety standards for outdoor air quality. Meanwhile, indoor VOCs have been found reacting with ozone and nitrogen oxides to create other compounds that literally get up your nose, where the body's own filtration mechanisms are likely to concentrate unpleasant compounds and increase their impact.

It is not just people that suffer from SBS - machines do too. Telecom equipment is particularly vulnerable, and experts such as Charles Weschler of Bell Communications Research in New Jersey have estimated that the cost to American companies over the past decade could be as high as $100m.

The problem for machines are the highly destructive compounds called hydroxyl radicals. Composed of hydrogen and oxygen atoms, they also have a lone electron desperate to find something to get reactive with, like the office lecher after a few drinks too many. Weschler and his colleague Helen Shields were startled to find vast numbers of hydroxyl radicals (produced by reactions between ozone and VOCs) present inside office buildings, even though they had previously been considered to be only an outdoor problem.

The reactiveness of hydroxyl radicals makes them like chemical mines drifting through the air currents of your office. When they encounter the VOCs also drifting there, they blow them apart. Products of this chemical mayhem include compounds such as nitric acid, and these spell trouble for electronic equipment. Reactions involving nitric acid produce water- absorbing nitrate salts which, when they land on circuit boards, form a water-absorbing (hydroscopic) layer which starts to conduct electricity if rising humidity in a poorly ventilated building provides water to absorb. The next step to meltdown is when electrical signals on the circuit board start to pass into the nitrate layer, causing errors in the information being transmitted - a particular problem with telephone exchanges, where early symptoms of sick circuit boards include line noise and crosstalk. Left unchecked, the circuits eventually short out and down goes the exchange. But as Weschler points out, it is often easier and cheaper for companies to replace the occasional crashed computer or dodgy phone rather than tackle the root cause of the problem, VOCs. "It is not cost effective to look at air pollution unless you [have] huge amounts of electronic equipment," he says.

The impact of VOCs on machines is clear. How they might knock out people is much harder to puzzle out given the variables involved, from the particular layout of individual buildings to the individual susceptibility to VOCs and other toxic compounds of each person in a building.

One of the most contentious issues is that of Multiple Chemical Sensitivity (MCS), which has also been linked to conditions such as Gulf War Syndrome. Likewise, some cynics scoff at the whole idea, speaking witheringly of certain people simply being allergic to the 20th century, but a growing number of scientists are now trying to ascertain whether exposure to a range of toxic compounds at very low concentrations can lay some people low, even when the level of any individual substance is below that which is considered dangerous. Is it the accumulated interactions with toxic compounds that lead to the often severe allergic reactions associated with MCS?

Claudia Miller of the University of Texas is an expert on chemical sensitivity. She has suggested a dual process underlying MCS - what she has called "two steps to sensitivity". The first occurs when repeated exposure to toxins causes loss of tolerance, which in turn leaves the way open for step two - triggering -when further exposure to toxins, even at a low level, causes a severe reaction. Such a process is, according to Miller, "a yet-to-be proven mechanism [of disease], which could be underlying a lot of medical conditions". Clinical studies have offered some support to this two-step road to illness, and Miller has come up with a new term to describe it: toxicant-induced loss of tolerance, or TILT.

TILT shares with SBS the idea that exposure even to very low levels of toxins can have a disproportionate impact, depending on some mysterious factor involved in the interaction of the various toxins and their cumulative effect on people. Experiments in Denmark's University of Aarhus have backed the theory, with people becoming sick after breathing in a cocktail of 22 VOCs, despite each individual compound being at concentrations of between one-tenth and one-hundredth of the level defined as safe by environmental health laws.

"The problem," says Maurizio de Bortoli of the EU's Environment Institute at Ispra in Italy, "is that we know practically nothing about mixtures." De Bortoli and his team are now studying the 60 VOCs believed to be most dangerous to humans, the first step to working out how they interact with each other and with people. Another team, led by Peder Wolkoff at the Danish National Institute of Occupational Health, is meanwhile taking the tack that it is not VOCs that are the problem but the compounds and hydroxyl radicals produced by reactions between VOCs and ozone. These, say Wolkoff, have never been tested for irritancy so they remain players in the game of hunt the culprit.

Despite VOCs being many experts' prime suspect, there are others who think they are a red herring. Rather than blaming chemistry, they believe the major culprit is something far more prosaic - simply the dust and micro-organisms that lie around any office. Gary Raw of the Healthy Building Centre in Watford is one of the main proponents of this view of things, pointing the finger of blame at dust and fibres from office equipment and carpets, organic material from office colleagues, debris from shoes and clothing, and the fungi and dust mites that can thrive on such matter. Rather than calling in the scientists, Raw suggests that you should insist on higher standards from the cleaners.

The picture is further confused by contrasting findings from different studies. While one French study recently found around 40 per cent of buildings in their survey displaying signs of sickness, a British study of around 50 buildings made by London's University College suggested that the happiness of employees was more important than physical environment. The more someone hated their job, the more likely they were to complain of sickness.

However simple or complex the causes of Sick Building Syndrome may be, one suggested solution is very simple indeed: get a plant. Former NASA scientist Bill Wolverton, who has studied ways to clean up the air in American spacecraft, claims to have found over 50 different plants that remove VOCs. For example, azaleas, rubber plants and poinsettia seemed to tackle formaldehyde; lady palm sucked up ammonia; and lilies couldn't get enough of acetone, benzene, trichloroethane, methanol and toluene. All provide nutrients for micro-organisms around the plants' roots, where they are broken down into sugars and oxygen. Wolverton's plant research has been backed up by work at the University of Cologne. So next time you think the atmosphere in your office is bad, clear the decks, get out the Hoover, and get yourself a nice potted plant. Then go see Monika.