Environmental Contaminants: Heavy Metals, Synthetic Organic Contaminants, Volatile Organic Compounds

What is an Environmental Contaminant?

Environmental contaminants are substances that, when accidentally or deliberately introduced into the environment, may have the potential to harm people, wildlife and plants.
Some of these contaminants may have been manufactured for industrial use and because they are very stable, they do not break down easily. If released to the environment, these contaminants may enter the food chain. Other environmental contaminants are naturally-occurring chemicals, but industrial activity may increase their mobility or increase the amount available to circulate in the environment, allowing them to enter the food chain at higher levels than would otherwise occur.

Contaminant List

Heavy Metals

Heavy Metals refer to a list of naturally occurring metal in soil, rocks, and bodies of water.
The most common are Mercury (Hg) Lead (Pb) Selenium (Se) and Cadmium (Cd)
These metals are highly migratory in water and soil environments and accumulate in living tissue (bioaccumulation)
These metals enter into the environment via mining activities, as waste products of coal fire plants, through burning garbage and in the leachate of landfills

Health Effects of Heavy Metals

Exposure to Hg causes tremors, gingivitis, minor psychological changes, spontaneous abortions and physical deformations of the body and organs
Over exposure to or absorption of Pb causes kidney, gastrointestinal and reproductive dysfunction, as well as damage to the nervous system
Over exposure to or absorption of Cd can cause kidney dysfunction, lung disease and has been linked to lung cancer. It can cause bone defects
Over exposure to or absorption of Se causes damage to the kidney, liver and circulatory system (blood and heart and vessels) and severe damage to the nervous system

Synthetic Organic Contaminants

This is a large group of chemicals that can include pesticides (Chlordane), herbicides (Atrazine), fungicides (Furans), Dioxins, and PCBs
These chemicals are man made.
All of the “cides” and furans are sprayed on crops as a way of controlling pests.
Dioxins and PCBs are banned from being manufactured in developed countries but they form as a waste product during combustion processes such as waste incineration, power generation, metal production, and fuel burning
Health Effects of Synthetic Organic Contaminants
Short term expose to Chlordane causes tremors, convulsions, blood illnesses such as anemia and leukemia
Long term exposure to Chlordane causes damage to liver, kidneys, heat, lungs and cancer
Short term exposure to Atrazine causes congestion of heart, lungs and kidneys, muscle spasms and weight loss
Long term exposure to Atrazine causes cardiovascular damage, breakdown of eye and muscle function and cancer

Health Effects of Synthetic Organic Contaminants

Short term exposure to Furans causes severe headaches, dizziness and muscle weakness
Long term exposure to Furans causes damage to the nervous and reproductive systems
Exposure to dioxins causes damage to the immune system and liver, reproductive damage, infertility and birth defects as well as cancer
Exposure to PCBs causes spasms, vision problems, liver damage as well as cancer

Volatile Organic Compounds (VOCs)

These are man made chemicals and include compounds such as Benzene, Toluene and Vinyl Chlorides
Benzene is the building block for most plastics
Toluene is a main ingredient in industrial cleaners
Vinyl Chlorides is a key ingredient in make rubber, paper and glass. It is found in most automobiles, medical instruments, cables and pipes

Health Effects of Volatile Organic Compounds

Short term high exposure to VOCs can cause a depression of the immune system and temporary nervous system disorders
Long term high exposure to VOCs can cause chromosome deformations and cancer, damage to the nervous system including tremors and spasms, vision problems, coordination and speech problems and damage to the kidney, liver

Microbes

E-coli is a common bacteria usually found in the intestinal tracts of organisms.
There are over 100 strains of E-coli but one of them is emerging a toxic environmental contaminant.
Fecal Coliform are bacteria associated with human or animal waste
Cryptosporidium is a parasite found in animal waste
Giardia lamblia is also a parasite found in animal waste

Health Effects of Microbes

All of these microbes enter into the environment by the improper disposal or treatment of human or animal waste
All cause disorders of the gastrointestinal tract and can include: Cramps, diarrhea, vomiting
Severe exposure can cause bloody diarrhea is common as is anemia, kidney failure and death