Toxicity Data Obtained From Human Studies

Abstract

The purpose of this chapter is to look at the ethical, scientific and practical issues concerning human data which may be helpful in chemical risk assessment. Such data can come from a variety of sources; case reports, case series and toxicosurveillance data often contain a high level of detail and may allow an estimate of the likelihood of adverse effects occurring. However, they are dependent on relatively few data collection systems, for example those of poison control centres. Exposure studies, in particular those involving biomonitoring, provide insight into individual exposure to chemicals in the workplace or environment. However, it is generally difficult to link the often very low levels of chemicals or their metabolites to health outcomes. Conversely, health surveillance may pick up an increased burden of disease but the degree of underlying chemical exposure is often unknown. Human volunteer studies with nonpharmaceutical chemicals have the advantage of well‐characterized exposure combined with information on the pharmacokinetic behaviour and/or effects of the compound. Nevertheless, outside the area of consumer products their usefulness is limited by ethical concerns and scientific challenges such as study design and small study populations. It is hoped that the present controversy surrounding some aspects of volunteer studies can be resolved through rational, scientific debate involving all stakeholders.