2021年10月 / 马哥(Marlin)整理

13. Through a Narrow Window / 通过一扇窄窗

(部分节选 - 可能不完整)

If we narrow our focus, we can see the effects of pesticides on the workings of individual cells. Recent medical research shows that energy production via cellular oxidation happens on a cellular level to fuel the body. A prizewinning roster of scientists have over the last quarter century been gradually uncovering the secrets of this beautiful mechanism, which Carson refers to as “one of the wonders of the living world.”

From the macro scale of entire ecosystems, Carson has narrowed her focus first to the human body and now to the functioning of individual cells. This is part of her project of education, as she gives a popular voice to the work of scientists around the world. That pesticides could affect our bodies on even this cellular level is another reason for treating them with extreme caution.

ATP and ADP, the body’s units of energy, are produced in minute structures called mitochondria within each cell. After ATP is used as energy, it loses a group of atoms called a phosphate and becomes ADP. This ADP is then recharged in turn by a process called “coupled phosphorylation,” in a carefully coordinated string of enzyme reactions. Radiation and synthetic chemicals both have the frightening power to uncouple this fundamental process, causing the body to burn itself out. This uncoupling power, which Carson calls “the crowbar to wreck the wheels of oxidation,” is present in many pesticides.

Again comparing the well-known effects of radiation to those of pesticides, Carson explains that even the process that is perhaps most fundamental to life, the production of energy in cells, is in fact another instance of the ‘complex system’ carefully calibrated by nature. Here, too, pesticides have the power to disrupt a careful balance, and the body is not designed to combat them, since their development has been so rapid compared to the pace of evolution.

The disruption of the oxidation process has an effect on fertility that is visible in eggs and other germ cells in animals – this might explain the sterility that has been observed in birds after exposure to DDT. If pesticides prevent ADP from coupling with a new phosphate group, respiration continues but no energy is created, so that the body uses power without creating any. Because ATP is “the universal currency of energy,” the driving energy force in life everywhere, its disruption in other species is a sign that humans can also be affected. We are not immune.

By linking this examination of the process by which cells produce energy to sterility in birds, Carson is driving home her point that humans are vulnerable to the same harm that we see affecting the natural world. ATP, the energy unit at the core of this process, is universal, and so its effects in other species will be mirrored in humans.