Time lies heavy in an Illinois wintertime. Treasured moments, walking frozen fields swathed in parka and scarves, do little to lift the spirit. Nor do captured memories: the rose-tinted silhouette of a sharp-shinned hawk against a January sky, the track of a determined fox dragging its tail across a frozen pond. As I tramp through frost and mud, the remains of corn stalks rustle in a bitter wind. All the while, the same dreary questions nag at the back of the mind. Am I really safe here? What am I breathing, tracking home on my boots?

The question, I readily admit, is not altogether a rational one. Nor is my behavior at those ill-improved moments I spend lying before the almighty television, yelling in vain at the screen. New pesticides, new fertilizers, new additives; the litany seems endless. Guaranteed to kill plants/worms/bugs more effectively, produce more corn, more soybeans. Have these products been tested? I demand to know. I mean really tested, over long periods of time, to equally guarantee that they kill only a narrow and selected range of nature, rather than indiscriminately endangering everything, including ourselves? Of course not, comes the answer from the rational side of my brain. This is America. This is Progress. We cannot wait 30 years to test something, to see what its effects will be. We must fight the insect enemy right now.

The rational brain also admits the scientific evaluation of the agricultural chemical track record is at best ambiguous. All the old killers -arsenic (in general use in Illinois through World War II), DDT, Chlordane - are admitted threats to life generally; they are now outlawed for use in the United States. Scientific studies of the newer ones are generally unsatisfactory. There is some indication they may be agents in the greater incidence of cancers; yet so many remain unconvinced. Most cancers are the result of smoking tobacco or dietary imbalances, they argue cogently. So, rationally, I am not sure. But irrationally - let us call it intuitively - I am certain that our restless pollution of the environment is endangering our health and well-being. Call it a hunch.

When not slogging through snow-encrusted fields or yelling at the television, I have spent the dark days of winter reading Living Downstream, a "personal investigation of cancer and the environment" written by Sandra Steingraber. This is not exactly light pleasure reading. Steingraber; a native of Pekin, Ill., is a scientist, a plant ecologist trained at the University of Michigan. She is also a cancer victim, diagnosed with bladder cancer in her early 20s. Since Steingraber eats healthy and does not smoke, her cancer is not easily explained away by chemical apologists. Her book, a lengthy and exacting inquiry into the environmental causes of cancer; is punctuated by tales of her experiences and those of friends now dead. Cancer is a living horror in these pages, not merely a statistical presence in some population study.

I suppose Steingraber's own battle with cancer will make her appear biased on the issue in the eyes of many. Clearly she senses this, harkening back to the experiences of her role model, Rachel Carson. Like Steingraber; Carson wrote a scientifically impeccable indictment of the misuse and overuse of chemicals in the environment while suffering from cancer. Unlike Steingraber; Rachel Carson died not long after Silent Spring appeared, a victim of breast cancer. Spokesmen from the chemical industries labeled her a hysterical woman