A shark’s open mouth is a terrifying sight – especially if you are in the water nearby. You can see the frightening danger. By contrast, an equally deadly threat is present in everyone’s environment: toxic chemicals. The difference is that these chemicals are invisible and the damage occurs slowly over many years. As a result it is all too easy to ignore their threat to our health.
These environmental toxics hit us with a triple whammy: they can inflict cancers, they can disrupt our hormone system, and they can weaken our immune system. Actually it is worse – toxics can damage the development of a fetus in a pregnant woman.
Cancers are so well known that they require no elaboration: cancers of the breast, prostate, lungs, colon, etc., and the blood (e.g., leukemia). Every day a famous person dies of cancer. The endocrine system consists of nine glands: the adrenal, pituitary, thyroid, parathyroid, thymus, hypothalamus, pancreas, pineal, testes and ovaries that secrete more than 50 hormones. Insulin, adrenalin, estrogen and testosterone are familiar examples. Hormones regulate metabolism, reproduction, and the balance of water and salts; maintain levels of calcium and glucose in the blood; regulate biological rhythms; stimulate cells of the immune system and the production of milk; and many aspects of development before birth. In short, hormones are the master controllers of the intricate machinery of our bodies.
As the hormones affect the balanced activity of the whole body, any alteration of their activity has serious effects on health. Many toxic substances can disrupt the normal functioning of endocrine glands
The immune system consists of dendritic cells, macrophages, neutrophils, and B and T lymphocytes that circulate in the blood and lymph. This array of specialized cells protects against foreign microbes that get into the body. Any weakening of the immune system increases the probability of infectious disease and may increase the severity or duration of the disease.
Very low levels of toxic contaminants that have no observable impact on adults can have a devastating impact on the unborn. Because hormones orchestrate many critical aspects of development, from sexual differentiation to brain organization, hormone-disrupting chemicals pose a particular hazard before birth and early in life. The maturing immune system of the embryo represents a vulnerable target for toxicants as it passes through a series of novel growth events that are crucial to later-life host defense against a wide array of diseases. These critical maturation windows display a particular sensitivity to chemical disruption with the outcome usually taking the form of persistent immune dysfunction.
Comparing the effects of toxic chemicals to a shark bite is not crazy. If you want to stay healthy, you will avoid both dangers. Pregnant women will avoid swimming in shark-infested waters, and they will rigorously avoid toxic chemicals.