Book Review: Child Pollution

Silent Scourge: Children, Pollution, and Why Scientists Disagree
Colleen F. Moore ’72
Oxford University Press, 2003 • 328 pages • $35.00

When it comes to environmental health hazards, Americans have a strong preoccupation with cancer risk and acute toxicity. Indeed, most of the allowable exposure standards that have been established by the U.S. Environmental Protection Agency and other agencies use one of these two factors as their explicit basis. This focus, though understandable, has deflected attention and research effort from at least two categories of even more widespread, albeit more subtle, effects: the effects of contaminants on nervous system development and thereby learning and cognition in children, and the effects of hormone-like contaminants (in many cases the same ones as in the previous category) that disrupt the endocrine system and the development and function of reproductive systems in children and non-human animals. In both of these cases the documented effects occur at doses far smaller than those needed to increase risk of cancer or to acutely poison the victim.

Cognition, nervous system development and environmental contaminants are the subject of this welcome new book by Colleen F. Moore ’72. Endocrine disruptors have received more attention recently, and so it is particularly useful that in this book Moore brings much information to bear on an equally troubling phenomenon, which is that commonly occurring substances in our environment are capable of significantly inhibiting the ability of children to learn and to think. The critical implication here is that the learning and cognitive deficits are often permanent, and will influence the lives of the affected individuals throughout their lifespan. This book contains a great deal of often-frightening information, and is important reading for anyone wishing to raise a child to her or his full potential.

The book very effectively describes the cognitive effects of exposure to lead, mercury, polychlorinated biphenyls (PCBs) and, interestingly, ambient noise. Less effective are chapters on the effects of radiation, and organophosphate (OP) and carbamate pesticides. In the latter case, this is because there is simply no published information available on cognitive effects of pesticides, and Moore highlights the urgent necessity of studies on the subject, pointing out that it will be 15-20 years before the full outcome of such research can be known. Given that these pesticides are ubiquitous in our environment—there is literally no place on earth where pesticide residues cannot be detected in soils, plants and animals (and humans)—the lack of research and understanding of cognitive effects on humans is appalling. These same pesticides are known endocrine disruptors, and their effects on development and reproduction in animals are well documented, yet we know little of their effects on our own children. By comparison, Moore is able to document, from several published sources, the cognitive effects of PCBs, which are also globally ubiquitous pollutants and known endocrine disruptors.

Moore also takes on the difficult and important task of describing the nature of scientific uncertainty, and how statistics are used in assessing what differences among study groups should be considered significant. This is a tall order in a book intended for the educated general public, and indeed, one that I (and many other scientists) struggle with in teaching science classes. Statistics and uncertainty are among the least-understood aspects of the scientific endeavor, and among the most difficult to explain to the public, which expects science to produce certainty. Moore uses a long-running controversy over the effects of lead exposure as her first case in point. Lead has been known to be toxic since Roman times, yet scientific arguments about the effects of sub-acute exposure began in the 1920s and continue to this day, with a changing cast of characters. Moore gives a particularly clear description of the nature of false positive and false negative results, and how statistics are used to assess the risk of each. She also clearly and carefully distinguishes between the results of scientific inquiry, and how those results are used in formulating policy and regulations. Her discussion of the scientific process is among the most effective that I have seen.

Social justice is also a sub-theme throughout the book, and Moore does an effective job of describing how the pollutants themselves are not equitably distributed, nor are the responses to exposure. Low-income and ethnic-minority status are far too well correlated with level of exposure to many of the contaminants discussed. In addition to documenting the effects of the various kinds of contaminant, each of the chapters of this book ends on a practical note with a section titled “Protect Your Family, Protect Our Planet.” These sections are particularly useful for those wishing to avoid exposure for themselves and their families.

Finally, Moore ends with a useful discussion of what has become known as “The Precautionary Principle.” In essence, this holds that when potential harm is suspected but cannot be proven, it is wisest to proceed as though the harm were real. The opposite approach, which is unfortunately more commonly the case, is to not consider any harmful effect until it can be definitively demonstrated. As we have learned repeatedly, it may then be too late.

—Gene S. Fowler is an associate professor of biology and
environmental analysis at Pomona College.