This book brings together an eclectic group of topics that originated as papers presented to the thirteenth annual Gordon Cain Conference, Chemical Weather and Chemical Climate: Body, Place, Planet in Historical Perspective, held in March 2011 at the Chemical Heritage Foundation in Philadelphia. The twelve chapters provide historical perspectives on aspects of the atmosphere in different periods that link science, engineering and medicine with regulation, public policy and political decision making.

The topics covered are wide-ranging: the toxic breath of witches in medieval times (Brenda Gardenour Walter); lessons from malarial theory in nineteenth-century India (Christopher Hamlin); the paradox over the use of tear gas for civil control while it is prohibited in international warfare (Roger Eardley-Prior); a medical anthropological study of Gulf War syndrome (Susie Kilshaw); the complexities of Los Angeles smog (Peter Brimblecombe); the interaction of chemistry and technology in automotive emissions controls (Richard Chase Dunn and Ann Johnson); challenges facing the Environmental Protection Agency in collecting, collating and analysing data on air pollution (Jongmin Lee); concerns over the effect of nuclear weapons testing on the stratosphere (E. Jerry Jessee); the role of long-range transboundary regulation in controlling acid rain (Rachel Rothschild); the changing perception of the ozone layer because of supersonic transport and chlorofluorocarbons (Matthias Dörries); the role of contemporary art in addressing climate change (Andrea Polli); and the personal and planetary roles of carbon dioxide (James Rodger Fleming).

Each chapter addresses a serious episode in its own time that often brought fear and uncertainty over its impact on the air being breathed. Many provide an insight into the challenge inherent in achieving a clear and accepted understanding of the science and technology underlying the episode and of the medical consequences. But more important for the continuation of healthy life on the planet is how this knowledge is then used to promote public understanding and implement public policy, at least when it is not hidden from public knowledge.

The interface between the underlying science and technology of these episodes and the likely medical impact remains a challenging domain. Determining the epidemiology and toxicology, and attributing a direct causal link, can remain elusive for policy makers and regulatory authorities (as with our current understanding of car exhaust emissions and air pollution). Even with this causal link, it often proves difficult to persuade governments to take action and put in place the necessary controls to protect the public when concurrently they are being lobbied by powerful industrial and commercial interests. Many of the case studies in the book address these ongoing debates in the context of a specific episode and period of time, but the underlying difficulties with defining regulatory controls and putting effective measures in place to enforce them remain. A key question is, at what point does the government through a regulatory authority take action? Does government action have to wait for a catastrophic event involving the loss of many lives?

Although the conference from which this book draws was held in 2010, the issues raised in many of the chapters remain unresolved and therefore publication of the book at this time serves a very useful purpose. Each chapter is written in clear language using the minimum of scientific and medical terminology, and the extensive references will aid further reading and research. The book will interest not only historians of science, technology and medicine, but also those engaged in determining public policy and regulation of the atmosphere and air quality. In fact, everyone would benefit from reading this book and understanding what we have learnt (and also not learnt) from these episodes while also appreciating the regulatory challenges that lie ahead.

Hopefully the Chemical Heritage Foundation can be persuaded to organize another conference within the next few years that will review the extant position with some of the episodes discussed in this book, while also highlighting some more recent episodes, including those affecting the indoor environment which are often neglected. With the constant revelation of ‘toxic-air’ episodes, a conference every five years or so would seem a sensible approach so these important issues are not neglected or even forgotten.