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CAMP HYGIENE
535
Both these recent papers point to the need for detailed work if the picture is to be further clarified. One valuable contribution is that of Williams,12 who has found in patients with farmer’s lung, firstly, that the aspergillin skin test was negative and, secondly, that whereas an extract of fibre from mouldy hay (but not fresh hay) produced a distinct reaction, the inhalation of an extract of mixed aspergillus, penicillium, and monilia spores did not. This suggests that the noxious agent is not the fungi themselves but the hay or straw, altered by the fungi or the heat the fungi generate. CAMP HYGIENE
No sooner had our ancestors shut themselves within walled cities for safety and commercial advantage than they began to build pleasaunces in the country outside where they might escape the crowds, the noise, and the smell of their fellows. The habit spread; but now paid holidays, the five-day week, the motor-car, and a selfindulgent prosperity have thrown the countryside open to the common man, and what began as " the English weekend " is the rule throughout Western Europe. The elderly, the infirm, or the merely rich may stay at hotels; but almost as many choose an al-fresco holiday in a tent or caravan. To many a farmer whose land lies by the sea, caravans are the most remunerative crop of all, and the effect of the cult of the body brown (or lobster coloured) on the economy of the Mediterranean countries must be considerable. There was a time when the camper came and went as he listed with (perhaps) verbal permission from the landowner. One camper made no difference, and three were a source of income; but thirty-three are liable to be a social and sanitary nuisance. Oddly enough, many campers genuinely prefer the company of other campers. The caravan, being more conspicuous and less mobile than the tent, called attention to the need for some control of the simple life, and now in most countries there are regulations intended to preserve the health and enjoyment of the refugees from the cities. The Council of Europe has published a report on the hygiene of camping sites which compares the regulations in force in the member countries and makes some suggestions for greater uniformity. 13 It recognises that the young man with a tent on the carrier of his bicycle does not ask for the same luxuries as the family in a caravan who intend to outspan for a week or two. Camp sites should be classified by their amenities (cf. Le Guide Michelin), but 2000 inmates are enough anywhere. 30 litres (say 5 gallons) of water per head per day is recommended as a minimum supply for all purposes, and a separate nonpotable supply for washing is very properly discouraged. The drinking-water should be tested for purity twice a year (this to our way of thinking is quite insufficient). The suggested proportion of washbasins (10%), shower-baths (3%), and closets (3°o) seem to us to be, like the water-supply, a bit on the low side. There are some sensible ideas on concentrating toilet and washing facilities (for persons and pans) for better conservancy. In the long run the disposal of waste is the biggest hygienic problem in every camp, and it cannot be neglected because the campers are on holiday. Medical attention (including tetanus antitoxin and anti12. 13.
Williams, J. V. Personal communication. Camping Hygiene. Council of Europe: Committee of Experts on Public Health. Strasbourg. 1961. Pp. 74.
venin) should be available in
emergency. In all but the smallest camps there should be a full-time warden. Before any camp site is inaugurated the plans must be approved by the local health authority, which will supervise the hygiene of the camp as long as it is
open.
Existing local regulations differ from these suggestions only in detail. In the Netherlands and Scandinavia alcoholic drink may not be sold in camps. In some camps there are letter-boxes, telephones, and places where cars may be washed. Some camps hire out airmattresses (and offer facilities for their speedy inflation) and provide sockets for electric razors. Some provide football fields. It all seems a long way from " Scouting for Boys ". In this country it is not usually the temporary camp used for holidays-though some of these are fairly sordid-which worries the medical officer of health, but the permanent caravan colony initiated with or without permission from the planning authority. 14 The usual excuse for their existence is that the inmates cannot get houses, but we suspect that cheapness and the relative absence of domestic responsibility are attractive to many. The standards suggested in this report are below those desirable in a permanent colony, but if every site conformed to them the health authorities would have less cause for worry. ROLE OF RETINAL PIGMENT
IT is well known that in fish, amphibia, and birds, as well as in some invertebrates with compound eyes, the pigment of the retinal pigment epithelium moves to cover at least some of the receptors in response to illumination of the eye. It has been generally assumed 15 16 that this movement of pigment, which in teleost fish and some amphibia is accompanied by appropriate movements of the rods and cones, is a device whereby the sensitive rods are protected from undue stimulation by bright light in the absence of a pronounced pupil response. The idea that pigment migration is associated with adaptation has been strengthened by the work of two Swedish physiologistsBernhard and Ottoson.17 18 They constructed darkadaptation curves for diurnal and nocturnal lepidoptera, using the size of the electroretinogram as their criterion of sensitivity. In the nocturnal species they found that the dark-adaptation curve was in two parts and that the second increase of sensitivity, which was not present in diurnal species, was associated with retraction of retinal pigment uncovering the rhabdomeres of the retinula cells. In many vertebrate eyes in which there is no evidence of pigment migration in response to light and dark, the
epithelial pigment is, nevertheless, extremely prominent. This is particularly true of pure-cone eyes. In the only completely diurnal mammalian family known to have pure-cone retinx-the squirrels-the processes of the pigment-epithelium cells are long and filled with pigment, and these processes envelop the outer segments of the visual cells. 11 20 Tansley has found that this is also true of the geckos, both diurnal 21 and nocturnal 22; but the noc14. See Lancet, July 8, 1961, p. 110. 15. Garten, S. in Graefe-Saemisch Handbuch der gesamten Augenheilkunde; vol. 3, ch. 12, p. 13. Leipzig, 1908. 16. Walls, G. L. Cranbrook Inst. Sci. Bull. 1942, 19, 146. 17. Bernhard, C. G., Ottoson, D. J. gen. Physiol. 1960, 44, 195, 205. 18. Bernhard, C. G., Ottoson, D. Acta physiol. scand. 1961, 52, 99. 19. Arden, G. B., Tansley, K. J. Physiol. 1955, 127, 592. 20. Arden, G. B., Tansley, K. ibid. 1955, 130, 225. 21. Tansley, K. Pfluger’s Arch. ges. Physiol. 1960, 272, 262. 22. Tansley, K. ibid. 1959, 268, 213.
Both these recent papers point to the need for detailed work if the picture is to be further clarified. One valuable contribution is that of Williams,12 who has found in patients with farmer’s lung, firstly, that the aspergillin skin test was negative and, secondly, that whereas an extract of fibre from mouldy hay (but not fresh hay) produced a distinct reaction, the inhalation of an extract of mixed aspergillus, penicillium, and monilia spores did not. This suggests that the noxious agent is not the fungi themselves but the hay or straw, altered by the fungi or the heat the fungi generate. CAMP HYGIENE
No sooner had our ancestors shut themselves within walled cities for safety and commercial advantage than they began to build pleasaunces in the country outside where they might escape the crowds, the noise, and the smell of their fellows. The habit spread; but now paid holidays, the five-day week, the motor-car, and a selfindulgent prosperity have thrown the countryside open to the common man, and what began as " the English weekend " is the rule throughout Western Europe. The elderly, the infirm, or the merely rich may stay at hotels; but almost as many choose an al-fresco holiday in a tent or caravan. To many a farmer whose land lies by the sea, caravans are the most remunerative crop of all, and the effect of the cult of the body brown (or lobster coloured) on the economy of the Mediterranean countries must be considerable. There was a time when the camper came and went as he listed with (perhaps) verbal permission from the landowner. One camper made no difference, and three were a source of income; but thirty-three are liable to be a social and sanitary nuisance. Oddly enough, many campers genuinely prefer the company of other campers. The caravan, being more conspicuous and less mobile than the tent, called attention to the need for some control of the simple life, and now in most countries there are regulations intended to preserve the health and enjoyment of the refugees from the cities. The Council of Europe has published a report on the hygiene of camping sites which compares the regulations in force in the member countries and makes some suggestions for greater uniformity. 13 It recognises that the young man with a tent on the carrier of his bicycle does not ask for the same luxuries as the family in a caravan who intend to outspan for a week or two. Camp sites should be classified by their amenities (cf. Le Guide Michelin), but 2000 inmates are enough anywhere. 30 litres (say 5 gallons) of water per head per day is recommended as a minimum supply for all purposes, and a separate nonpotable supply for washing is very properly discouraged. The drinking-water should be tested for purity twice a year (this to our way of thinking is quite insufficient). The suggested proportion of washbasins (10%), shower-baths (3%), and closets (3°o) seem to us to be, like the water-supply, a bit on the low side. There are some sensible ideas on concentrating toilet and washing facilities (for persons and pans) for better conservancy. In the long run the disposal of waste is the biggest hygienic problem in every camp, and it cannot be neglected because the campers are on holiday. Medical attention (including tetanus antitoxin and anti12. 13.
Williams, J. V. Personal communication. Camping Hygiene. Council of Europe: Committee of Experts on Public Health. Strasbourg. 1961. Pp. 74.
venin) should be available in
emergency. In all but the smallest camps there should be a full-time warden. Before any camp site is inaugurated the plans must be approved by the local health authority, which will supervise the hygiene of the camp as long as it is
open.
Existing local regulations differ from these suggestions only in detail. In the Netherlands and Scandinavia alcoholic drink may not be sold in camps. In some camps there are letter-boxes, telephones, and places where cars may be washed. Some camps hire out airmattresses (and offer facilities for their speedy inflation) and provide sockets for electric razors. Some provide football fields. It all seems a long way from " Scouting for Boys ". In this country it is not usually the temporary camp used for holidays-though some of these are fairly sordid-which worries the medical officer of health, but the permanent caravan colony initiated with or without permission from the planning authority. 14 The usual excuse for their existence is that the inmates cannot get houses, but we suspect that cheapness and the relative absence of domestic responsibility are attractive to many. The standards suggested in this report are below those desirable in a permanent colony, but if every site conformed to them the health authorities would have less cause for worry. ROLE OF RETINAL PIGMENT
IT is well known that in fish, amphibia, and birds, as well as in some invertebrates with compound eyes, the pigment of the retinal pigment epithelium moves to cover at least some of the receptors in response to illumination of the eye. It has been generally assumed 15 16 that this movement of pigment, which in teleost fish and some amphibia is accompanied by appropriate movements of the rods and cones, is a device whereby the sensitive rods are protected from undue stimulation by bright light in the absence of a pronounced pupil response. The idea that pigment migration is associated with adaptation has been strengthened by the work of two Swedish physiologistsBernhard and Ottoson.17 18 They constructed darkadaptation curves for diurnal and nocturnal lepidoptera, using the size of the electroretinogram as their criterion of sensitivity. In the nocturnal species they found that the dark-adaptation curve was in two parts and that the second increase of sensitivity, which was not present in diurnal species, was associated with retraction of retinal pigment uncovering the rhabdomeres of the retinula cells. In many vertebrate eyes in which there is no evidence of pigment migration in response to light and dark, the
epithelial pigment is, nevertheless, extremely prominent. This is particularly true of pure-cone eyes. In the only completely diurnal mammalian family known to have pure-cone retinx-the squirrels-the processes of the pigment-epithelium cells are long and filled with pigment, and these processes envelop the outer segments of the visual cells. 11 20 Tansley has found that this is also true of the geckos, both diurnal 21 and nocturnal 22; but the noc14. See Lancet, July 8, 1961, p. 110. 15. Garten, S. in Graefe-Saemisch Handbuch der gesamten Augenheilkunde; vol. 3, ch. 12, p. 13. Leipzig, 1908. 16. Walls, G. L. Cranbrook Inst. Sci. Bull. 1942, 19, 146. 17. Bernhard, C. G., Ottoson, D. J. gen. Physiol. 1960, 44, 195, 205. 18. Bernhard, C. G., Ottoson, D. Acta physiol. scand. 1961, 52, 99. 19. Arden, G. B., Tansley, K. J. Physiol. 1955, 127, 592. 20. Arden, G. B., Tansley, K. ibid. 1955, 130, 225. 21. Tansley, K. Pfluger’s Arch. ges. Physiol. 1960, 272, 262. 22. Tansley, K. ibid. 1959, 268, 213.