This is an archive story, published in the July 1984 edition of Geographical magazine. All facts, figures and statistics were accurate at the time of original publication.
Sunny Southern California, land of the ‘American dream’, should be an ideal location for the 23rd Olympiad in July and August of this year. But these months are at the height of the smog season. The notorious Los Angeles smog is formed by the action of sunlight on reactive hydrocarbons and oxides of nitrogen, primarily emitted from vehicle exhausts.
July and August are consistently the worst months for smog because of increased exhaust emissions, and meteorological conditions favouring the build-up of levels of photochemical oxidants or smog. Air descends from the North Pacific subtropical anti-cyclone over Southern California, causing compressional heating of the lower atmosphere. Since the air does not descend all the way to the ground a temperature inversion occurs at 500 metres or less, trapping the pollutants beneath it. In addition, such events are associated with low wind speeds, preventing horizontal dispersion of the pollutants, and abundant sunshine which sustains the photochemical reactions.
In the hour or two needed for photochemical reactions to produce ozone from emissions of hydrocarbons and oxides of nitrogen, the polluted airmass has often been carried inland some distance by sea breezes. Consequently, source areas for the pollutants may experience lower ozone or smog concentrations than those further inland which generate few pollutants.
Other pollutants are also usually present in the urban atmosphere such as carbon monoxide and sulphur dioxide. The photochemical pollutants which form include mostly ozone and some peroxyacetyl nitrate (PAN). Ozone is colourless but the typically brownish or yellowish brown colour of the smog, and the associated poor visibility, is due to the light scattering effects of nitrogen dioxide and sulphate aerosols.
At its worst, Los Angeles smog can cause extensive disruption to the community and cause widespread illness. In September 1979, the Los Angeles basin experienced its worst smog episode for many years with hourly ozone concentrations exceeding 0.40ppm in some parts of the basin. Such high levels of ozone represent what is termed a stage two ozone episode or alert which is declared in the basin when hourly concentrations exceed 0.35ppm. During this ten-day smog siege, a survey of residents revealed 83 per cent reporting discomfort or concern for their health, 57 per cent complaining of burning or irritation of the eyes, and 25 per cent reporting headaches, breathing irritation, sore throats, or stuffy noses. Hospitals reported increases of up to 50 per cent in the number of patients admitted for chronic lung diseases such as emphysema and asthma. During the smog, competitive athletic events were postponed to protect athletes even in those areas of the basin which experienced lower ozone concentrations. This situation arises because exercise enhances the toxic effects of ozone by increasing the ‘effective dose’ received.
Recent research has demonstrated that athletes exposed to 0.20ppm for an hour (a stage one episode) suffered breathing difficulties and experienced symptoms including shortness of breath, coughing, excess sputum, throat tickle, raspy throat, and nausea. These effects disappear after exercise but they do prevent athletes from achieving their best performance. Even at 0.10ppm (specified as the state air quality standard for health protection of the most susceptible portion of the population and including a margin of safety) some adverse effects such as coughing have been observed in healthy subjects engaged in vigorous exercise. At levels of 0.30ppm ozone the adverse effects on exercising athletes increase so much so that in laboratory tests some of the subjects were unable to complete set exercise tasks. This research suggests that if a severe smog occurs during the Olympic Games then, despite the months of careful training, competitors – especially in endurance events – may be unable to perform at their best.
What action can be taken to minimise the effects of a potential smog on Olympic competitors? Avoiding it seems to be the only feasible solution but the Olympic villages (university campuses), the Memorial Coliseum (stadium for the field and track events) and many of the sites for Olympic events lie within the area of a potential smog. Even so, it is possible to avoid the smog. Los Angeles residents already recognise this and ensure that they schedule physical activities early in the morning, when ozone levels are usually low because time is needed for the photochemical reactions to operate on hydrocarbons and oxides of nitrogen generated in the morning rush hour. Ozone levels also drop in the evening as solar intensity decreases.
This diurnal cycle in ozone allows competitions to be scheduled even during the worst smog, so as to avoid poor air quality. However, the pressures of scheduling so many events in only two weeks make it inevitable that athletes will be competing at times of potentially high ozone concentrations. Further, commercial pressures on the Los Angeles Games may strongly influence the timing of the more popular events. ABC Television is paying $225million for the television rights and advertisers paying $260,000 for 30 seconds of prime television time.
If competitors have little choice but to compete during times of poor air quality, some individual action can be taken. It is important to minimise exposure to smog until the last possible minute prior to competition. Remaining indoors, warming-up gently, and breathing through the nose rather than the mouth decreases ozone exposure. It has even been suggested by American researchers that vitamin E acts as an anti-oxidant and lessens the adverse effects of ozone.
In the event of a stage two ozone episode (0.35ppm or more) community life in general is affected. All industries which produce hydrocarbons and oxides of nitrogen are required to reduce their output by 20 per cent, oil-burning power stations are forced to switch to natural gas or imported electricity, and householders are requested to switch off electrical appliances, including air-conditioning systems. Residents are advised to avoid strenuous outdoor exercises, school children are kept indoors, and commuters are asked to share car transport to work.
Should hourly ozone concentrations reach 0.50ppm, a stage three alert or emergency situation would be declared which requires the shutting down of industrial and commercial operations, the prohibition of vehicle use, and the cessation of public activities.
Fortunately, an emergency situation has not had to be declared for ten years but nobody can be sure what the effect will be of a huge influx of visitors to the Games. Any increase in traffic (especially traffic jams, because an idling engine releases proportionately greater exhaust emissions), shortages of unleaded gasoline or increased numbers of breakdowns of emission controlling catalytic converters due to the lack of repair facilities during this ‘holiday’ period increase the likelihood of a smog forming.
Unlike other recent Olympic cities, Los Angeles has no metro system so that because of the dispersion of the Olympic events throughout the basin, traffic will be increased. Vehicles are responsible for 80 per cent of emissions. Inability to control the growth in use of vehicles means that the smog problem is unlikely to be solved this decade.
Catalytic converters fitted to exhaust systems are of limited effectiveness faced with the enormous volume of traffic in the area. Local and state authorities have found it easier, and politically less dangerous, to rely on ‘technological fixes’, especially vehicle emission controls. This in spite of the fact that it has been clear for many years that such measures alone could not bring clean air to vehicle-dependent cities like Los Angeles by the original federal deadline of 1977 – currently 1987. Instead of developing a mass transit system Los Angeles has undertaken a huge freeway construction programme.
Any short-term solution to the smog problem would have to be draconian and probably unacceptable to the public. In 1972 a proposal to reduce drastically the average vehicle miles travelled during the smog season by reducing gasoline consumption by 86 per cent through rationing so outraged the public that it was soon dropped! People obviously prefer the adoption of an ‘instant technofix’.
Since the 1950s ‘technofix’ suggestions have ranged from removing the air inversions using ground-based fans, helicopters or thermal means: eliminating the sunlight which initiates the photochemical reactions using aircraft to lay a gigantic parasol of white smoke high over the city: removing the smog through tunnels in the surrounding mountains using huge fans: and seeding the air with an agent that could deplete or neutralise the smog. Currently, the latter ‘solution’ is being investigated. The suggestion is that the smog be neutralised by diethylhydroxylamine claimed to be a relatively inexpensive and ‘safe’ chemical inhibitor of smog. But it is very unlikely that chemical spraying of the urban atmosphere would be popular.
Lasting solutions seem far away. For the immediate future Los Angeles will retain its summer reputation as one of the most polluted cities in the world. Indeed, should a smog, such as happened in September 1979, occur during the forthcoming Olympic Games with a potential television audience of 2,500 million people the smog image of the city will be reinforced.
This is an archive story, published in the July 1984 edition of Geographical magazine.
For access to the entire Geographical archive dating back to 1935, check out our digital subscription options. Every issue of Geographical right at your fingertips!