JAMA (Journal of the American Medical Association), April 2, 2008

PESTICIDES: A TOXIC TIME BOMB IN OUR MIDST

[Rachel's introduction: Levine has written a pragmatic book for physicians, health workers, and the general public.... His own perspective as a health professional with a concern for the public health and a fondness for the "precautionary principle," which assumes that a chemical is harmful unless there is good evidence to the contrary, is not hidden.]

By Arnold Schecter

Review of "Pesticides: A Toxic Time Bomb in Our Midst," By Marvin J. Levine (264 pp, $49.95; Wesport, CT, Praeger Press, 2007; ISBN-13: 978-0-2759-9127-2)

This is a well-written and informative book about a relatively little known area of expertise for most physicians -- chemicals in the environment and their impact on health.

The book is devoted to pesticides, which includes herbicides, insecticides, weed killers, rodenticides, bacteriocides, fungicides, and other chemicals frequently called "pesticides." It is reasonably well-referenced text. However, some statements regarding health damage could benefit from more textual references to justify the statements presented.

Levine has written a pragmatic book for physicians, health workers, and the general public. It is relatively easy reading for physicians but demands a bit more attention than a vacation book intended for beach reading. His own perspective as a health professional with a concern for the public health and a fondness for the "precautionary principle," which assumes that a chemical is harmful unless there is good evidence to the contrary, is not hidden. Frequently and throughout this volume, the author attempts to balance industry and environmental points of view and actions. And he notes the eternal conflict between the need for economic productivity and reasonably priced food, with the possible short- and long-term damage to human health from the use or misuse of various chemicals. He favors "integrated pest management," a balanced method of control using far less pesticides than is common at this time.

The book emphasizes farm workers, children, pregnant women, individuals with asthma, and elderly individuals as being more sensitive than the general population to the effects of pesticides. The book also discusses policy issues and political actions sometimes based on lobbying, as well as specific scientific and biological aspects of pesticides. Chapters include those on the presence of pesticides in foods, schools, homes, air, water, and soil; the international trade in pesticides; and suggested remedies. A number of case studies relate to health damage from pesticides or, in one case, to fear of potential but not actual chemical exposure and damage.

The past 60 years are characterized as those when use of synthetic pesticides became common in agriculture, providing a means of producing more crops on a given plot of land than had previously been possible. The author notes that there are more than 17 000 pesticides currently registered in the United States, with more than 800 active ingredients that have contributed to acute and chronic health problems. However, as resistance to pesticides and damage to wildlife and humans was noted, the public and Congress, stimulated by Rachel Carson's book, Silent Spring, began to see the need for laws and regulations to protect the public and wildlife. Many of these laws are described in some detail and illustrated with respect to a variety of chemicals and a number of US government agencies, such as the Environmental Protection Agency.

While cancer was once the major focus of government regulatory agencies, endocrine disruption -- especially from fetal and nursing exposure -- as well as reproductive and developmental alterations have recently become areas of concern. Brain damage has also been described from in utero exposure to some pesticides, especially the "persistent organic pollutants" (POPs). These include dichloro-diphenyl- trichloroethane (DDT), polychlorinated biphenyls (PCBs), dioxins, and other chemicals. Although the author does not make note of them, some brominated flame retardants are considered POPs with persistence, bioconcentration, and deleterious health effects similar to those of other POPs, especially PCBs, at least in laboratory animals.

Levine states that annual pesticide use in the United States is approximately 8.8 pounds per capita, or 2.2 billion pounds of active ingredients (if wood preservatives and disinfectants are also considered). He notes that some of the chlorinated hydrocarbons or organochlorines such as diledrin, chlordane, aldrin, and heptachlor break down very slowly and can remain in the environment for years or decades. Organophosphates, now common in agriculture, on the other hand, break down much more rapidly but also are more toxic to humans.

Levine also notes that because agricultural workers, including children, are heavily exposed to pesticides and usually have little knowledge of their dangers as well as of how to protect themselves, they are at particularly high risk. Lack of good sanitary conditions and health care likewise contributes to this public health problem. Schoolchildren are also a special group at risk because of the lack of knowledge on the part of those applying pesticides, frequently untrained school employees rather than certified pesticide workers.

State laws and regulations are sometimes more stringent than federal laws, although state laws must set standards at least at the level set by the federal government. With constant lobbying on both sides of the issue, the "how safe is safe" frequently changes over time.

The author notes the high industry costs of bringing a product to market and the myriad regulations that must be followed. But he also points out that just because a product is being produced and sold, it does not necessarily follow that it has been tested sufficiently for possible serious health effects. Also, while the term "inert ingredients" was once commonly used, it simply identified ingredients not meant to do what the product was sold to do, and did not indicate that they were not toxic. This term is no longer considered appropriate, and "other ingredients" is now the preferred term.

This book is an interesting and well-written volume that should be useful in providing an up-to-date introduction to pesticides from a variety of aspects, ranging from objective scientific principles to subjective policy directives. Despite some repetition and the occasional need for more extensive scientific citations, it was enjoyable and informative.

Arnold Schecter, MD, MPH, Reviewer University of Texas School of Public Health Dallas arnold.schecter@utsouthwestern.edu

Copyright 2008 American Medical Association