Some User Objections to Fluorescent Lighting*

TT is about 10 years since 5-foot tubular fluorescent lamps were first used in this country for factory lighting. At first, and throughout the years of war, only one type of lamp, designated as " white," was made available, and the use of this was controlled and limited to vital factories and other war establishments where there was special need, not only of good artificial lighting, but also of light similar in colour quality to daylight. I had some association with what I believe was the first factory installation, this being arranged in consequence of my recommendation to a Government committee—then concerned as to the probable effect of the daylight black-out upon industrial morale—that it would be expedient to " naturalise," as far as practicable, the artificial lighting of the most important war factories. This " beat the black-out" installation was made in the foundry of a Midlands factory, and it took the form of artificial windows inside the real but blackened windows of the saw-tooth roof. Each of these artificial windows contained six of the new fluorescent tubular lamps. The effect produced was almost startlingly realistic. The original natural lighting appeared to have been restored and no longer was there any sense of deprivation of an habitual amenity, nor any dissatisfaction in working continuously under artificial lighting. Moreover, there was an incidental advantage which was not foreseen; owing to the diffusion and spectral quality of the light, the atmosphere in the foundry appeared to be clearer than when tungsten lighting was used. In fact, the workers remarked that the ventilation had been improved, so similar was the appearance of the foundry haze to that familiar to them when there had been natural lighting and open windows. The acceptability of fluorescent lighting as a substitute for daylight was so successfully demonstrated by this installation that it was thought that, even without the device of artificial windows, it would prevent the dissatisfaction which might otherwise be expected to develop with the protraction of work under more unnatural conditions of lighting. From then onwards during the period of hostilities fluorescent lighting was installed in parts of many vital factories, and that it was a significant factor in preventing the deterioration of morale, and in raising it where it had already deteriorated, is not, I think, doubted by most of those who were in a position to observe its effects. It may be mentioned that within the past two years a large windowless factory has been equipped with fluorescent artificial-window lighting, giving complete satisfaction to the workers. A great extension of the use of fluorescent lighting in factories has occurred since the termination of the war, besides its application in many offices, shops, and buildings of other kinds. Probably something like a million fluorescent tubes are now in use in this country and at least a similar number of persons have actual experience of fluorescent lighting. It is well at the outset to appreciate this fact so that complaints shall be set in correct perspective. It is true that there are no means of enumerating complaints with any precision, but all the available indications suggest that the number is exceedingly small by comparison with the number of apparently contented users. Apart from enquiries for information concerning rumoured ill-effects of fluorescent lighting which have been addressed to the Medical Research Council and to me personally, and from communications referring to illdefined effects reported by an unspecified number of persons, not more than 30 definite cases of ill-effects alleged to be due to fluorescent lighting have been brought to our notice since the advent of lighting of this kind. These cases have been considered carefully and, as the effects complained of include all those with which one is familiar by hearsay, an analysis of them will I believe be instructive and useful. From some of these enquiries and complaints one gets the impression that the fluorescent lamp is suspected of magic second only to the fabulous Aladdin's lamp—only it is "black magic! " For instance, an M.O.H. wished to know if there was any truth in the statement that it causes sterility ; and a popular illustrated weekly journal sought confirmation or denial of the claim that it causes baldness ! It has been accused of producing vitamin deficiency; of making vision more distinct outside than inside the foveal area—contrary to the normal conditions; of having an injurious hammering effect on the retina by bombarding it with unperceived pulses of light; and of giving light that is too hot ! As to the last of these, one of the undeniable characteristics of fluorescent lamps is that they produce considerably less heat per unit of luminous flux than do ordinary filament electric lamps. Leaving aside bizarre accusations let us consider some of the more usual objections raised against fluorescent lighting. It is, however, impossible to judge what substance there may be in these without knowing the properties of the fluorescent lamp; it is to ignorance of these that