One's definition of environmental health depends on how elastic your definition of health is. This month that definition was stretched a little further with the publication of the Clean Neighbourhoods and Environment Act. In it, light pollution, for the first time, is included as a nuisance under the Environmental Protection Act 1990. This makes light pollution, in the legislator's view, prejudicial to health.

Some EHPs are asking whether this is a legitimate environmental health role. But then, what about other aspects of the clean neighbourhoods act? Should EHPs be concerned about litter, especially inert litter, chewing gum and fag ends? What about graffiti? Does this impact on health? Some argue that this is an issue of aesthetics. Others argue that the presence of graffiti and litter does impact on health. It's the broken window syndrome. A smashed window, a little graffiti, some litter, starts the spiral downwards. Before you know it a tipping point is reached and you are facing urban decay, people start feeling alienated. Stress and fear stalk their lives and health is affected.

The contra view is that the evidence base for this theory is slim. There is a direct link between eating contaminated food and falling ill, or working in a dangerous workplace and being injured, but, for some, fag ends on the floor or scrawls on a wall impacting on health is too tenuous a link.

Returning to light pollution, the act is clearly aimed just at security alarms. Unpublished Defra data shows that local authorities receive around 200 complaints a year about this issue. The real problem with light pollution is not security lights but the thousands of miles of street lighting beaming up into the night sky depriving us sight of the Milky Way. Some argue that this is an aesthetic problem, not a nuisance. Others argue that the thousands of mega watts of wasted energy beaming into the night sky contributes to global warming, and there is nothing more prejudicial to health than the potential destruction of the planet.

At the heart of this debate are two polarised views. One is that environmental health is a public function. It is the rigorous definition of what is prejudicial to health which gives public bodies the right to intervene in people's lives, sometimes, to the point of bringing the criminal legal system to bear. The contra view is that in the absence of anyone else doing it someone has to take a holistic view of our relationship between our environment and health. An often used example is that of the fish and chip shop. What is the point of checking that the shop is scrupulously clean and ignoring the chips being fried in lard. Just because EHPs don't have the tools to tackle nutrition should they ignore its relationship to health. Also, if EHPs don't do it, who will?

This debate is set to rage for years to come.