The Book Review: Chasing The Sun, by Linda Geddes

Linda Geddes’ new book explores the vital relationship between the sun and the human race suggests directions for improving our health and well-being. Designers of biodynamic lighting need to read this.

Over a period of two hundred years, from the beginning of the 17^th century, successive parliaments at Westminster passed over 5000 Acts of Enclosure, affecting just over a fifth of the total area of England and millions of country people. These Acts drove families out of the countryside and into the new industrial towns, out of the natural environment of the fields and woodlands and into the new factories of the developing Industrial Revolution. Its a lifestyle that we still recognise today; our lives are spent mainly indoors and access to the natural environment is limited to ‘leisure time’. But what hasn’t been appreciated are the ways that the shift from country to town also brought with it a chronic health crisis, because urban living ain’t all that it’s cracked up to be.

Linda Geddes’ study into the effects of sunlight on our lives, ‘Chasing the Sun’ doesn’t touch on the political backdrop to our urban existence – I suspect its only folk singers who really care about the Enclosures these days (and don’t get me started on The War of the Spanish Succession), but she is absolutely clear that our health and well-being is influenced by our access to natural light and provides plenty of examples of the effect of urbanisation on people all around the planet. Even today, rural populations are gravitating to new urban centres and sacrificing their health in the process.

I’ve been looking for a ‘third voice’ to help me understand where the lighting industry might head in its pursuit of Human Centric Lighting (a term that doesn’t make a single appearance on the book, by the way). I sense that the scientific community feels backed into a corner by our continuous clamour for how this stuff can be exploited for (our) commercial gain, to the extent that the most common thing we’re hearing from scientists is that ‘we need more information; the research is on-going; conclusions cannot be drawn.’

Meanwhile, the lighting community fixes onto whatever science we think we know – and tries to build biodynamic lighting systems around it. But I don’t see anyone putting up their hands and offering to deliver a sound RoI for a human centric solution to 130 million days lost to sickness and working age ill health costing over £100 billion a year.

Which is probably just as well. Linda Geddes is robustly positive when it comes to boosting Circadian entrainment in the workplace. She also ‘gets’ tunable white systems from the point of view of reducing blue-end exposure, but that’s it when it comes to artificial lighting. The chief problem for those who want to offer a cure-all via biodynamic lighting is that the circadian clock isn’t the only timepiece in town. One of my favourite phrases in the book is ‘susceptible to perturbation by external factors’ – which describes my life perfectly. What Geddes is talking about is the effect on the cells of the body by things like; when we exercise; drug intake (legal and illegal); timing of meals, influencing the activity of the microbes in the gut. Think of the body as an orchestra but with half a dozen conductors trying to call the tune. We can only feel the real health benefits of the music when the conductors are all in synch, and biodynamic light stimulus is only one of those conductors.

The final section of the book can be read as a call-to-action. There are things that we can do as individuals and there are certainly things that can be done to create and support health initiatives in our daily lives; for office workers; teachers and pupils in schools; nursing staff and patients in hospitals. The starting point is to recognise that we are all ‘chronotypes’ somewhere on the ‘wakeful spectrum. We all react to daylight in a particular way – whether we’re early morning ‘larks’ or dirty-stop-out ‘owls’, for example. The evidence is strong that there is no one-size-fits-all at the level of our daily lives. Personal fine-tuning is the answer to better health – it just needs the management classes to get behind the programme.

I’d like to thank Linda Geddes for providing a very accessible ‘third voice’ in my own confused search for a route into the impacts of biodynamic lighting. The book comes at a time when there is really solid research taking place in many quarters, not least here in the UK at the BRE where the Biophilic Office project is underway. And The Light Review will be reporting on progress on the project in the coming months.