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important. The cooperation of the patient’s relatives ismore likely to be secured when they realise the patient willretain some independence and will not be a total burdenon the household. By placing the emphasis on all thesefactors, we believe the need for geriatric care of thesepatients can be reduced to a minimum and the quality oftheir survival can be thereby improved.

K. P. ROBINSON.

Queen Mary’s Hospital,Roehampton,

London SW15 5PN.

IS SELENIUM A TERATOGEN ?

RAYMOND J. SHAMBERGER.

Division of Laboratory Medicine,Department of Biochemistry,Cleveland Clinic Foundation,Cleveland, Ohio 44106, U.S.A.

SIR,-Robertson 1 has suggested that selenium mighthave been teratogenic in two groups of female workers whoweighed out selenite-containing powder-an ingredientin a medium for salmonella culture. Robertson’s observa-tion is consistent with that of Moxon and Rhian 2 whoreported that affected chickens in high seleniferous regionshave eggs which are either sterile or produce a high per-centage of monstrosities. Hadjimarkos 3 observed thatchildren who were lifelong residents of the high-seleniumareas of Oregon, Wyoming, Montana, and South Dakotahave a greater than average susceptibility to dental caries.On the other hand, Holmberg and Ferm 4 reported thatsodium selenite, under certain conditions, actually protectshamsters against the teratogenic effects of cadmium andarsenic. Because of the possibility that selenium mightalso be a teratogen at physiological levels, a study wasundertaken to see whether there is a relationship betweenselenium concentration in the environment and neonataldeaths.

High, medium, and low selenium States and their respec-tive neonatal death-rates are listed in the figure. TheDistrict of Columbia was included in the low-seleniumgroup. Allaway et al. have shown higher blood-seleniumin normal people in high-selenium areas and lower blood-selenium in people from low-selenium areas. Populationsof these States were found in the 1960 census and neonataldeaths were found in Vital Statistics.1 Neonatal deathswere chosen, since this statistic is most likely to reflect anyteratogenic effect.

Selenium levels in different States, in relation to neonatal death-rate, 1960.

1. Robertson, D. S. F. Lancet, 1970, i, 518.2. Moxon, A. L., Rhian, M. Physiol. Rev. 1943, 23, 305.3. Hadjimarkos, D. M. Lancet, 1970, i, 721.4. Holmberg, R. E., Ferm, V. H. Archs envir. Hlth, 1969, 18, 6.5. Kubota, J., Allaway, W. H., Carter, D. L., Cary, E. E., Lazar, V. A.

J. agr. Fd Chem. 1967, 15, 448.6. Allaway, W. H., Kubota, J., Losee, F., Roth, M. Archs envir. Hlth,

1968, 16, 342.7. Vital Statistics of the United States; Vol. II, part B. United States

Department of H.E.W., Public Health Service, National VitalStatistics Division, Washington, 1960.

The high, medium, and low selenium States had averageneonatal death-rates and standard errors of 720 &plusmn;34-6,760&plusmn;24, and 927 28. The differences between the highand medium selenium States and the low-selenium Statesare highly significant using Student’s t test (P< 0-001).Selenium is an essential trace element necessary for thegrowth and development of quail, rats, and chickens. a

Selenium is probably an essential trace element for humanbeings as well.9 At physiological levels such as those foundin the United States environment, selenium may also benecessary for the proper growth and development of thehuman embryo. No enhancement of teratogenicity was seen.The inverse relationship found here between neonatal

deaths and selenium at physiological levels, and the knownteratogenicity of selenium at toxic levels in animals,2 drawsan interesting parallel to the inverse relationship reportedbetween selenium occurrence and human cancer mortality. 8At nutritional levels, dietary selenium prevented tumourformation in animals,lO but at dosages approaching chronicpoisoning for three years selenium may increase the spon-taneous tumours that occur in old rats.9

ENTEROCOLITIS FOLLOWING EXCHANGETRANSFUSION

A. E. MCCANDLESS.

Alder Hey Children’s Hospital,Eaton Road,

Liverpool L12 2AP.

SIR,-In reply to Dr. Super’s letter (Nov. 27, p. 1203), Iagree that it is likely that several factors are involved in thecomplication ileocolitis following exchange transfusion. In2 of the cases that have occurred in this region sodiumbicarbonate 8-5% was not injected into the umbilical vein.The Department of Health is investigating any possible

hazards associated with the use of the heating coil, and untilit has been passed by them I have discontinued its use.

IS MAN JUST A MACHINE ?

SIR,-Dr. Habershon (Dec. 4, p. 1257) asks this

question and states that " it is one of the most importantquestions for discussion today ". We are not just machines,since the most sophisticated machines that we havedeveloped are simple and crude by comparison with ourbodies. The fact that we have learnt so much about our-selves and the universe in the last few moments of ourevolution is due to the emergence of disciplined thoughtthat requires that the words and concepts that we use be

agreeably defined. When we applythis disciplined thought to the hy-pothesis that we can be other thanwe are-i.e., that we have free-will-we find that the evidence, whichis very extensive, is entirely againstit.Many of us, in the present and

previous centuries, who have cometo the conclusion that free-will isan illusion have been afraid to

accept and broadcast the fact forfear that it might rob life of someof its most precious things and

8. Shamberger, R. J., Willis, C. E. Crit.Rev. clin. Chem. 1971, 2, 211.

9. Schroeder, H. A., Frost, D. V.,Balassa, J. J.J. chron. Dis. 1970 23, 227.

10. Shamberger, R. J. J. natn. CancerInst. 1970, 44, 931.