The link between environmental quality and human health has long been recognised. Indeed, this connection has been one of the main driving forces for the introduction of legislation over the last three decades or more to improve air and water quality through control of emissions (e.g. Clean Air Act (1952), Control of Pollution Act (1974), The Environment Act (1995), Pollution Prevention and Control Regulations (2000)). These controls are primarily aimed at maintaining a safe and healthy immediate physical, chemical and biotic environment for people, the latter mostly in the sense of limiting pathogens rather than improving ecosystems. The focus of effort has been, and continues to be, on reducing the concentrations of pollutants and pathogens within environmental media (air, water, soil) as these are the exposure pathways to humans.

The impact on biodiversity was a secondary, but nonetheless important, reason for the improvement of air and water quality – for instance controls on the emission of oxides of nitrogen and sulphur were, in part, prompted by the loss of Scandinavian forests from acidification.

Despite the major reductions in emissions to the environment over the last twenty years there is continuing concern over the impact of poor environmental quality on human health and there are still major scientific uncertainties on what safe levels of certain pollutants might be. This has led to a number of initiatives within the UK and EU for exploring the linkages between environment and health, such as the NERC thematic programme on the environment and human health and the EU 2004-2010 action plan.

More recently researchers have begun to explore the link between biodiversity and human health and there is now an increasing amount of evidence that indicates a link between maintaining biodiversity and protecting human health. The emerging research demonstrates both the direct influence of biodiversity on human health, through the immediate contact of people with ecosystems, and the indirect influence, which arises because of the way that ecosystems interact with, and modify, the environmental media that form the exposure pathways for people. Given the way in which ecosystems interact with environmental media, the influence of biodiversity on human health is inextricably linked with that of environmental quality, forming a troika of biodiversity, human health and environmental quality, with complex feedbacks and linkages between the three. Although much of the research in this field links the issue of biodiversity and health, in reality ‘biodiversity’ serves as an indicator of healthy and functioning ecosystems and it is not simply the biota that influences human health but also the physical processes and biogeochemical cycles mediated by the biota. Despite these strong connections, the issue of biodiversity plays a relatively minor role in much of the ongoing research into environment and human health linkages.

The principal ways in which biodiversity influences human health can be summarised as follows:

• ecosystems as a buffer, or filter, for pollutants and pathogens

• biota as a vector or reservoir of emerging diseases (e.g. bird ‘flu, ebola virus)

• ecosystems as a source of food and clean water for maintaining health

• the influence of biodiversity on agriculture (e.g. natural pest control and pollination)

• ecosystems as a source of medicines and models (i.e. biomimicry)

• psychological and health benefits of green spaces and areas of high biodiversity

• ability of ecosystems to modify the physical environment and reduce hazards (e.g. reduce flooding, moderate temperature, prevent soil erosion increase rainfall)

 The Sibthorp Trust seminar

One of the principal aims of the Sibthorp Trust is to promote the discussion of key environmental issues through the commissioning of workshops, seminars and study groups and to publish the results of these activities in the Sibthorp Papers. Previous seminars have focussed on the issues of ecosystem management and conservation targets. The Trust is now embarking on an exploration of the topic of the link between biodiversity and human health to complement the ongoing initiatives into environment and health.  As much of the research in this area is global in scope and the importance of particular issues varies from country to country and, more significantly, between developed and developing countries, the specific area the Trust will be addressing is the relevance of this work to UK environment and health policy.

The first stage of the Trust’s activities will be a scoping seminar to explore the issue from a UK perspective and identify the priority issues to be discussed in more detail at a later more extensive seminar in Spring 2007. At the scoping seminar the discussion will centre on a series of questions to identify the most important issues and the priorities for action that will be incorporated into a position paper for discussion at the later seminar. The discussions and papers at the main seminar in Spring 2007 will feed into a report summarising the conclusions of the participants and making recommendations for policy makers on how to integrate the consideration of the linkage between biodiversity and human health into UK policy.

For the scoping seminar a number of preliminary discussion questions have been identified:

Which of the issues identified are important in the UK and why? It is easy to see how biodiversity contributes to food sources in developing countries, but how and where is it important in the UK (e.g. marine biodiversity for maintaining fish catches). Is the issue of biodiversity acting as a reservoir for diseases relevant to the UK? While, most of the examples that come to mind are developing country examples (e.g. the expansion of the bushmeat trade is thought to be partly responsible for the increased incidence of some viral diseases), there are developed country examples such as bird ‘flu and Lyme’s disease.

What are the priorities for action in the UK in order to maintain or improve human health though biodiversity protection and restoration? There is evidence that urban green spaces are beneficial for health and well-being, but to what degree is there an important connection to biodiversity? Urban green spaces may contribute to health but do they make a significant contribution to the UK's biodiversity?