Moreover , it could be argued that by not ascribing a sufficient commercial value to human products this leads to an inefficient use of such a resource .sx It is noteworthy that the Nazi concept of lebensunwertes leben ( 'life unworthy of life' ) led to a pragmatic cost-benefit approach seen in such Nazi mathematical texts as 'Mathematics in the Service of National Political Education' .sx While moral aversion to pricing the human body may argue against biotechnology as a whole , so long as commercial exploitation of the body continues , the argument should not deny profit participation to the patient alone .sx It would be anomalous not to treat body parts as involving property interests by considering them as , for example , res nullius .sx In a sophisticated legal system where personal property rights are highly developed so as to include such commodities as electricity and gas the list of items consisting res nullius is short .sx Furthermore , recognition on res nullius of material like limbs severed by assault or accident may be inconsistent with the person's interest in its preparation for prompt surgical rejoining to his body .sx Moreover , the law already recognises a property interest in body waste as in R v Welsh where an accused man who poured his urine sample down the sink was found guilty of stealing it from the police department .sx The recognition of proprietary rights would provide economic incentives for patients to consent and , in principle , where a donor's non-vital and naturally replaceable body material can save the life of a recipient in desperate need , any ethical fastidiousness demanding that donation be only gratuitous could condemn the sick .sx One major objection to this is based on the work of Titmuss in his book The Gift Relationship ( 1970 ) where he pointed out that blood donors in the U.S.A. who sell their blood , more often than not are poor and often unhealthy .sx Subsequent work has challenged this assumption and , in any case , quality control can be solved with adequate screening and independent checks on quality .sx Moreover the problem of economic coercion as a motivating factor for donation can apply in very many areas of human activity so that Dukeminier has pointed out :sx " Yet if a charitable motive is so important in judging conduct in situations involving a risking of one's life , how can we permit men to risk their lives in driving racing cars , in entering boxing contests , and in pursuing all kinds of paid risky occupations and still object to the paid kidney donor ?sx " .sx Clearly , a decision to sell nonregenerative human body parts which will have lifelong implications is not to be taken lightly and the law could insist upon elaborate procedures to be satisfied as seen currently with the marriage contract or the 'cooling off' period seen in consumer credit transactions .sx Such safeguards are necessary in any case even where there is donation as anticipated under the Human Organ Transplants Act 1989 since great psychological and emotional pressure may be brought to bear where there is a needy relative .sx Notwithstanding that the pressure is different from financial inducement , it is nonetheless pressure which is hardly less likely to lead to exploitation of those vulnerable to it .sx The need to protect the proprietary interest in human material will increase as genetic engineering techniques improve .sx This phenomenon can be illustrated by the facts in U.S. v Garber .sx Here the defendant learned that her blood contained an extremely rare antibody .sx A manufacturer of diagnostic supplies induced Garber to undergo frequent withdrawals of her blood to isolate the antibody which the company then marketed .sx Soon afterwards other companies approached Garber with offers of even more money and eventually Garber profited handsomely , giving rise to a federal tax dispute .sx The point is that once the commercial value of Garber's unique antibody became apparent , she was still able to bargain for the highest bid .sx However , when genetic engineering improves it may have permitted the original company to withdraw enough material in the first place so , in the absence of a proprietary right , prejudicing the donor .sx More recently the Court of Appeal of California in John Moore v The Regents of the University of California et al concluded that the plaintiff did enjoy a property right in his own " blood and bodily substances " .sx It is interesting how the influence of contract has permeated this area .sx Before the commercial potential of genetic engineering became evident , scientists freely transferred cell lines and cell products .sx As the commercial value of the cell lines developed , originators of cell lines found written agreements increasingly necessary to protect economic rights in their creations .sx This is reflected in the words of Leon Rosenberg , Dean of the Yale School of Medicine , when he said :sx " The biotechnology revolution has moved us , literally or figuratively , from the class room to the board room and from the New England Journal to the Wall Street Journal .sx " .sx Given the scope of biotechnology , the question is not whether or not to recognise the human body as property but rather what the proper scope of the rights and liabilities in the body should be .sx The Application of Property Law Doctrine to Property Rights in the Human Body .sx ( a ) Product Liability .sx ( i ) Tort .sx The Consumer Protection Act 1987 envisages strict liability for any loss caused by using a defective product within the chain of distribution .sx Since the Act deals with liability for a 'product' , the question is whether an organ or body tissue can constitute this ?sx In the U.S.A. blood has been considered a 'product' and in principle this should be the case where there is commerce in body parts .sx However , the state of the art defence is product liability will be relevant here as long as the defect was not detectable by a test .sx Thus , s.4(1)(e ) of the Act provides .sx " .sx .. that the state of scientific and technical knowledge at the relevant time was not such that a producer of products of the same description as the product in question might be expected to have discovered the defect if it had existed in his products while they were under his control .sx " .sx ( ii ) Contractual liability .sx The question of whether the commercial supply of body material involves a supply of goods or services is highly relevant .sx In Perlmutter v Beth David Hospital there is U.S. authority that although units of blood constitute personal property , in therapy , when service predominates , what we have is a supply of services rather than goods .sx The Supply of Goods and Services Act 1982 places upon the supplier the requirement that he will carry out the service with " reasonable care and skill " .sx On the other hand the Sale of Goods Act 1979 has implied warranties of fitness for purpose which is a more extensive liability .sx In principle , blood or body products should be 'goods' within the meaning of the 1979 Act whenever they are dealt with commercially .sx However it may be possible to draw a distinction between blood transfusions and skin and bone grafting and fitting cardiac pacemakers .sx In the later cases the transfer of the material may be minor compared to the service of installation which will be important for the purposes of product liability .sx ( b ) Property as defining the limits of medicobiology .sx An adequate legal order should define the limits of medicobiology and in this respect , it may be appropriate to distinguish between donated and discarded materials .sx If the doctor has a professional interest in the discarded material which affords the patient no therapeutic or diagnostic benefit , the patient's express consent should be sought beforehand lest abandonment of his property may appear to have been effected by the exercise of undue influence .sx This was the view of the Warnock Committee which required the " informed consent " of the couple if research was to be carried out on " spare embryos " , an approach which recognises the couple's proprietary interest in their embryos .sx It was argued in John Moore v The Regents of the University of California et al that recognition of the donor's property rights would prevent unjust enrichment which was significant because it was held that there was inequality of bargaining power between the doctor and patient .sx In effect a fiduciary obligation was anticipated here which imposed a duty of full disclosure , viz a physician should not commercially profit by being in breach of trust .sx The legal inference from this is that passivity or silence by the source of body material will not , where this is commercially exploited , lead to the conclusion that the separated body material is yielded to the hospital or researcher .sx Here we have echoes of the Peel Report which noted :sx " Where the separation of the fetus from the mother leads to the termination of its life there is no statutory requirement to obtain the parent's consent for research , but equally there is no statutory power to ignore the parent's wishes .sx ... We believe the patient must be offered the opportunity to declare any special directions about the disposal of the fetus .sx " .sx If human body material is treated as the personal property of the patient , then it is possible to argue that the researcher converts the body material when he exploits its commercial value without the express consent of the patient .sx There is a conceptual problem here in the sense that the remedy for conversion sounds in damages based upon market value .sx Since the Human Organ Transplants Act 1989 criminalises the active promotion of a sale as being contrary to public policy then this type of legislation prima facie would seem to prejudice this remedy .sx However , conversion does recognise a special damages heading which the law does not consider too remote such as the lost opportunity for receiving satisfaction from giving benefit to a specified recipient or cause .sx On the other hand , if full commerciality in body parts were recognised this could lead to complex tracing issues as in the Moore case , where the physicians researchers sic !sx produced from the patient's bodily substances without his consent a 'cell line' which was predicted to be worth $3 billion by 1990 .sx The essence of the tracing doctrine is that it involves an in specie claims to property to which the claimant has no property interest other than that which the right provides and the property claimed is identifiably linked to the misappropriated property .sx The concept is restitutionary in the sense that it is premised on the principle of unjust enrichment , the 'unjust' element often being satisfied by the defendant's violation of his fiduciary duties .sx Attempts have been made to restrict the reaches of the tracing doctrine as in the case of 'innocent' converters through the Torts ( Interference with Goods ) Act 1977 and by reference to considerations of 'fairness' as is obvious in the dissenting judgments in Boardman v Phipps .sx The arguments are often predicated upon the thesis that the defrauded person's recovery of the increased value of the trust res is a windfall .sx Interestingly , tracing analysis is still applied but this is restricted to the loss incurred .sx Particular difficulties arise in measuring the loss and the courts , in applying tracing rules , do not generally effect a sophisticated analysis concerning the question of 'benefit' to the wrongdoer .sx By concentrating on physical events , tracing conclusively presumes that the wrongdoer would not have acquired the 'product' but for the conversion .sx If an inquiry were made into the causal events then this could illuminate the problem of quantifying the wrongdoer's benefit which under tracing rules has to be disgorged :sx for example , why should it be assumed that the wrongdoer could only have obtained the 'product' by conversion ?sx The donor may very well have been prepared to sell the material and if this is the case , calculation of benefit should instead consist of the value of the misappropriation of the material at the time of its occurrence plus the interest on that value .sx If the wrongdoer augments the value of the bodily substance by , for example , developing a cell line then there are two aspects to the causal approach ; firstly , the wrongdoer would not have had the asset 'but for' the misappropriation ; secondly , the traceable product that the owner claims may not have been so valuable , 'but for' the wrongdoer's efforts .sx