For my money, one of the most treacherous of them all is dioxin, the name given to a group of persistent, very toxic chemicals.
“Dioxins” collectively refers to hundreds of
chemical compounds that share certain structures and biological
characteristics. Dioxins mainly enter the food chain as byproducts of
industrial processes. To a lesser extent, they also come from natural
processes such as volcanoes and forest fires. They contaminate land and
sea, are consumed in feed, move up the food chain, and end up in the
fatty parts of meat, dairy products and seafood.
Over the past century humans have introduced a
large number of chemical substances into the environment. Some are the
waste from industrial and agricultural processes. Some have been
designed as structural materials and others have been designed to
perform various functions such as healing the sick or killing pests and
weeds. Obviously some chemicals are useful, but many are toxic and their
harm to the environment and our health far outweighs their benefit to
society.
Cancer is caused by changes in a cell’s DNA, its
genetic blueprint. Some of these changes may be inherited from our
parents, while others may be caused by outside exposures, which are
often referred to as environmental factors.
Substances and exposures that can lead to cancer
are called carcinogens. Some carcinogens do not affect DNA directly, but
lead to cancer in other ways. For example, they may cause cells to
divide at a faster than normal rate, which could increase the chances
that DNA changes will occur.
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