Light pollution may not warrant the same degree of attention as noise or air pollution, but complaints received by environmental health departments are slowly increasing. The greater reliance on artificial light and the knock-on effect on other environmental health areas is becoming problematic. Nick Warburton argues the EHOs need to remain vigilant.

The former Department of the Environment, Transport and the Regions, in conjunction with the Countryside Commission, acknowledged in its document Lighting in the countryside: Towards good practice, that England's "conglomeration of brightly-lit areas is more extensive than anywhere in Europe other than the Netherlands". The motivating force behind this growth has undoubtedly been the dependence on lighting in providing security and safety, and in the important role it plays in extending entertainment and working opportunities outside daylight hours.

Needless to say, this increased use of artificial light has come at a price. On the one hand there has been the growing prevalence of "skyglow" - the orange haze seen over many urban areas at night caused by upward lighting - a cause of great concern to astronomers. More relevant to environmental health officers however, is the haphazard growth of security, sports, advertising and architectural lighting schemes, which can impact on people's wellbeing in the form of light pollution.

According to Alastair Brown, environmental health officer at Glasgow CC, light pollution can be defined as "the projection of light onto a surface or space to which it is not intended, causing an unwanted effect to persons and/or environments exposed."1 At present, the scale of the problem does not warrant much attention, and occurs "where lighting systems are badly installed or poorly designed." However, even though the number of complaints over the last ten years have been relatively small (EHJ, October 1998, page 276), indications are that inappropriate and intrusive lighting could pose a more serious problem in the future, particularly when it impinges on other areas of environmental health.

Currently, EHOs are under no duty to investigate nor resolve light pollution issues. There is no specific legislation to deal with complaints, particularly those relating to the most common source of nuisance; home security. Up to now, the Government has argued that planning legislation is the most appropriate means to resolving this issue, but has stopped short of applying this to the domestic sector, possibly because it acknowledges the widely-held belief that more lighting equals more security.

Lighting in the countryside did highlight a number of ways in which light pollution could be minimised, but, rather tellingly, also revealed that the impact of light pollution had not really been taken into consideration. The document concluded that there was little data to confirm the impact of lighting because there had been little monitoring or even recognition of its effects. Indeed, unlike noise, which has been closely linked to stress, anxiety and loss of sleep, no research has been produced to convince policy makers that excessive light is damaging to health. Furthermore, the impact of light tends to be more localised than noise, so its effect tends to be downplayed.

To residents living adjacent to sports training grounds however, intrusive light can be a very tangible problem. Ultra bright floodlighting can often penetrate through even the thickest curtains, so residents are left feeling that it is day rather than night outside. Late night road works can also be a localised problem. The noise of the drilling may be the main culprit in disturbing sleep patterns, but how does one measure the impact of the accompanying flashing lights?

Proving that light pollution has a detrimental effect on people's health is incredibly difficult. So too is its impact on people's safety. Unshielded high intensity roadside lighting for instance can produce potentially hazardous glare, which arguably could have serious implications for motorists, pedestrians, and cyclists at night. As security lighting rarely requires any planning permission, the potential for unrestricted growth in this sector is a matter of concern, yet at present the potential for light to compromise safety is still downplayed. Unfortunately as Emma Pearson pointed out three years ago (EHJ, October 1998, page 276) the Government has so far refused to tighten planning controls over lighting.

An alternative approach to tackling the issue could be to challenge the importance of lighting for security purposes. Research carried out by Russell Leslie at the Lighting Research Centre (LRC)2 in the United States appears to dispel the belief that domestic lighting improves security, suggesting that the type of lighting people use and its related brightness may in fact be counterproductive. He claims that, generally, the illuminance (the amount of light transmitted onto a specific area for security purposes) is greatly exceeded. In addition, he argues that the uniformity of light, the coverage (whether there are any gaps with no light) and the colour of light are equally important when lighting is utilised. Light coverage, for instance, influences whether there will be dark shadows and this can reduce the perception of safety rather than enhance it. Tom Lewis, senior EHO at North Lincolnshire Council also believes that security lighting may give homeowners a false sense of security: "If lights are triggered too often, for example by passing animals, owners may become complacent and the purpose of installing them in the first place may be undermined."

The explosion of lighting in the domestic sector is not confined merely to security, however. Particularly in affluent areas, there are signs of an increasing trend towards "24-hour daylight" (the extensive use of artificial light throughout the night) as residents extend lighting into the garden, especially during the summer months. Mr Lewis believes that this trend can partially be attributed to the trend for "outdoor living space". If people are spending more time outdoors entertaining (barbecues, parties etc), there could be a knock on effect on noise levels, and other environmental concerns, such as food safety.

Mr Lewis predicts that "it's going to be virtually impossible to stop this momentum of people moving in to the garden", but adds a cautionary note, stressing that light pollution is not serious enough a problem at present to warrant a great investment in resources and time. He also appreciates that tackling the problem is far from straightforward, not least due to the subjectivity of the issue. "There are people who are quite content to put up with intruding lights on a regular basis, while others will complain even if the problem is not that acute."

Despite the fact that there is no legal framework for EHOs to adhere to, many authorities are still attempting to tackle the problem. Generally speaking, this has tended to be through issuing letters to businesses or residents to try and persuade them to alter the position and angle of the light source. (The best position to direct lights is downwards with the beam angled below 70o). As Mr Lewis points out: "Often the person being complained about is unaware of the problems they are causing and when the situation is explained to them, they are happy to rectify the problem". In fact one of the key roles EHOs can play is a preventative one, through raising awareness of the intrusion of unnecessary lighting before it has been installed. Some of the issues that could be raised include: is lighting necessary, could safety and security be achieved by alternative means, do lights need to be on all the time and are you using the right amount of light?

As Nick Martin from the pressure group Campaign for Dark Skies concludes: "Unnecessary light pollution deprives people of their rightful enjoyment of the natural environment without any compensating benefit. It could be dramatically reduced by better design of lighting installations without reduction of safety, security or convenience. Energy saving would of course be another benefit".

Light pollution may not pose a serious problem at the moment, but EHOs need to remain vigilant of its growing impact on other areas. A preventive strategy is clearly the best means of ensuring that scarce resources are allocated to the most pressing issues rather than wasted on a low priority area. As Mr Lewis notes: "The way we tackle light pollution in the future will require a more holistic approach". That means recognising that light may be a nuisance and can exacerbate other environmental health concerns.

1 Light Relief, Surveyor magazine, May 24, 2001, p16.
2 Russell Leslie has co-authored The Outdoor Lighting Pattern Book. For more information visit: http://www.lrc.rpi.edu/projects/olpb.html