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An international symposium on the impact of environmental hazards, chemicals and drugs on the developing immune system of children was held in Berlin (Germany) organized by the BgVV. Epidemiological evidence indicates that an immature immune system challenged early in life by bacterial antigens may prevent, to some extent, allergic reactions including asthma bronchiale triggered by environmental pollutants. However, the prevalence for infectious disease is increased in childhood, especially when exposure to contaminants takes place in the period of pregnancy and breast-feeding. The effects of chlorinated biphenyls, dioxin, endotoxins, hexachlorobenzene, and direct and indirect in utero tobacco smoke exposure are examples. All participants recommend comparative and follow-up epidemiological studies and clinical examination of infants and children at risk during upbringing. There is ample evidence from experimental studies that indicates adverse effects on the developing immune system after in utero and postnatal exposure to chemicals and drugs. The adverse reactions of aciclovir, benzodiazepines, hexachlorobenzene, organotins (di-n-octyltin dichloride, tributyltin oxide), pesticides (methoxychlor, heptachlor) and polyhalogenated aromatic hydrocarbons (2,3,7,8-tetrachlorodibenzo-p-dioxin) are presented and reviewed. To determine the predictive value of test data in risk assessment for neonates and children, development, differentiation and maturation of the immune system in humans and laboratory rodents is compared in their pre- and postnatal stages. Considering some differences in immunocompetence at birth and after lactation, and differences in the time frame for maturation of the immune system, reaction types are thought to be common, comparable and similar in human childhood and early adolescence and the postnatal lifetime of laboratory rodents. The participants of the symposium felt strongly that regulatory steps urgently need to be initiated to incorporate some relevant aspects into existing test guidelines for testing developmental immunotoxicity. In this context, it is recommended that animals culled otherwise in one- and two-generation studies be examined for developmental immunotoxicity according to the valid methods and parameters discussed. The majority of participants agreed that a safety factor of 10 is too low in risk assessment and management to protect a sensitive subpopulation of children against man-made environmental pollutants.

There is limited availability of reliable and valid information on alternative methods to the use of experimental animals from open access data banks. In 1989, the Centre for Documentation and Evaluation of Alternative Methods to Animal Experiments (ZEBET) at the German Federal Health Office started a data bank to meet requirements of the German Animal Protection Act. In comparison with other data banks in this field, ZEBET's data bank comprises two types of evaluation: firstly, whether a specific method contributes to the Three Rs concept of Russell & Burch, i.e. replacement, reduction and refinement, and secondly, whether the method meets the criteria of validation as outlined in the report of the Amden workshop on validation of toxicity test procedures. This information is primarily available to the scientific and ethical commissions which have been introduced by the Animal Protection Act in order to reduce the numbers of animals used in experiments in Germany. However, other users of the ZEBET data bank are also welcome, e.g. local animal protection officers, interested scientists and the public. Although the language of ZEBET's data bank is German, the documentation also contains English summaries, key words, and updated lists of references. Here, the concept of ZEBET's data bank and its scientific background are described and compared with other alternatives data banks.