How We Get Mercury
We humans may get small amounts of direct exposure to elemental mercury—for instance, from a broken mercury thermometer, by breathing polluted air from a nearby coal-fired power plant, or from the mercury-based preservative found in many vaccines.
The majority of our mercury exposure, however, is from eating certain species of fish. But mercury is not a natural toxin in fish, comed with enviromental pollution.
Effects of Mercury
According to Physicians for Social Responsibility (PSR), research has shown that:
- short-term exposure to high concentrations of mercury vapor has harmful effects on the nervous system, digestive system, respiratory system, and kidneys;
- long-term exposure to mercury can permanently damage the brain and kidneys at any age;
- long-term animal studies have also found that exposure to organic mercury (such as methylmercury) at high levels can cause nervous system damage; damage to the kidneys, stomach, and large intestine; changes in blood pressure and heart rate; adverse effects on male reproductive organs, sperm, and developing fetuses; and an increase in the number of spontaneous abortions and stillbirths.
Because mercury is particularly troublesome for developing nervous systems, fetuses, infants, and young children are most at risk. According to PSR, epidemiologic studies have found that children exposed to even low levels of mercury before birth experience subtle symptoms of neurological damage. Specific effects include poor performance on neurobehavioral tests (particularly on tests of attention), fine motor function, language, and memory.
The National Academy of Sciences states that mercury in pregnant women disrupts the development of brain cells in their babies. A report by Centers for Disease Control concluded that one in six women of childbearing age have mercury in their blood above the level that would pose a risk to a developing fetus. Clearly, pregnant women and children should exercise extra caution when it comes to fish consumption.
