Note: Material in this section may repeat that in earlier sections and chapters. (Where data seem to differ it is because different sources are used and the data change over time and with the source.) However, this information is necessary at this place in the book chapter in order to relate to the reader the full story of environmental problems and their inter-relationships as they affect children.

Toxic Chemicals

It is estimated that there are approximately 82,000 chemicals which are used in our society today. Fewer than 200 chemicals are required to be tested under current law. Reports from the National Pollutant Release Inventory and the Toxics Release Inventory indicate that 0.5 million tons of cancer-causing chemicals, 0.5 million tons of developmental and reproductive damage- inducing chemicals and 2 million tons of suspected reproductive and/or neurological toxicants were released into the environment and transferred to other locations in the United States and Canada over a 1-year period. The most recent report on North American pollution for 2005, issued by the Commission for Environmental Cooperation in 2009, reaffirms that there are massive amounts of potential hazardous chemical releases. The recorded list of toxic substances released is less than the actual amount because only a small group of chemicals are actually monitored.

The risk of a toxic chemical, during human exposure, causing an unwanted reaction, may vary with the individual based on route of entry, genetic differences, age, gender, pregnancy status, dietary or nutritional status, existing disease or health status. It also varies with the action of the toxicants within the body and may be increased or decreased by the route of entry, type of absorption and excretion, the time it takes for the toxic action to start, the level of bioaccumulation, the biotransformation of the substance within the body, the metabolites produced, and the duration of the effect of the chemical and metabolites.

Gastrointestinal, respiratory, cardiac, renal, liver, and thyroid disorders can increase the toxicity of environmental chemicals, since the body does not efficiently remove the toxicants from tissues and organs.

Typically, the fetus or child is exposed to more than one chemical at a time. There is poor understanding of the synergistic effect of a mixture of chemicals on the human body.

The fetus as well as the child are especially vulnerable to the various synthetic chemicals that enter the body through ingestion, inhalation, or the skin. Many of the chemicals are easily absorbed. There are a substantial number of chemicals available, as well as their waste and byproducts, to contaminate the air, water, or soil. Just one type of chemical which is released, pesticides, has a profound effect on the brain and nervous system. Over 1 million pounds of pesticides are used in the United States each year.

The chemicals may add another complication if they have immunosuppressive properties. In addition, the concentration of the chemical, the length of exposure, the temperature during the exposure, the amount of moisture, the existence of other chemical contaminants as well as other environmental pressures, contribute to the ultimate effect on the organs and tissues. Bioaccumulation of the chemical may occur if it is in the food chain, so that small amounts of the chemical which may be non-toxic or less toxic increase to substantial amounts which may now be more toxic or hazardous. In the 1990s, it was found that exceedingly low levels of environmental toxicants could be associated with lower intelligence, diminish school performance, increase rates of behavioral problems and asthma, etc. Some of these chemicals have low-level toxicity for adults, but apparently in combination with ambient air pollutants such as nitrogen dioxide, acid vapor, and fine particulate matter, can produce profound effects in children.

There is an ever-evolving concern about children being exposed to very low levels of pesticides. These pesticides, which are commonly used in or around homes or on pets, or may be found as residues on fruits and vegetables consumed by the children, may interfere with immune, thyroid, or neurological and respiratory processes in children. The pesticides include organophosphates, organochlorines, carbamates, and pyrethroids.

An example of a pesticide that works extremely well on bedbugs is the organophosphate Proxor. This is a nerve agent and has now been banned for indoor use because little kids crawl along floors and touch cracks and crevices where this chemical has been applied for residual control of bedbugs and now these areas have become a source of contamination for the child.

Best Practices for Toxic Chemicals (See Chapter 2, “Air Quality (Outdoor [Ambient] and Indoor)”)

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