In the May 27 issue of the Almaden Resident, Broderick Perkins raises some concerns about "pesticides" applied to residential landscaping and gardens ("Study raises new concerns about pregnancy, pesticides"). I share his prudent approach to gardening and do not apply chemicals to my yard.

My wife and I are delighted by the birds and squirrels who use our lawn and patio for morning and evening meals of bugs and seeds.

However, his article had the expression, "deadly toxic danger" in reference to DDT. No reputable document I am aware of characterizes this chemical in such harsh terms. In fact, it is considered to be one of the most benign and effective controls for mosquitoes that carry malaria. It has low acute human toxicity, and reference to the most recent update on the International Agency for Research on Cancer [a part of the World Health Organization] website states that: "There is inadequate evidence in humans for the carcinogenicity of DDT"—after many scientific studies and a massive epidemiological data set. The issue of damage to the reproduction of raptors is certainly of concern but is much too complex to air in this short letter.

We are fortunate to live in one of the most affluent and technically sophisticated areas of the world. Yet, we are exposed almost daily to conclusions based on half-truths or even junk science.

For example, Mr. Perkins will learn that his compost pile is likely generating minute quantities of dioxins—naturally.

Mr. Perkins should take advantage of local scientific learning, and, as a minimum, read the excellent book Naturally Dangerous by James P. Collman.

Collman is a professor of chemistry at Stanford University and a member of the National Academy of Sciences, among other honors to his scholarship.

Mr. Perkins can borrow my copy of the book if he will read it and he doesn't underline. It is a fascinating discussion of our chemically based existence—both natural and manmade. Nearly every page is a revelation, even for those who think they are well-read about environmental matters.

Ed Johnson

Sunnyvale