: 5. Organic Chemicals

5. Organic chemicals: Over 700 organic compounds can be found in drinking waters throughout the US.

A quick look at the chart below gives some indication of the extent of water pollution due to chemicals both from industry and residences entering coastal waters. This map does not include data on chemicals found in well drinking water due to pesticides and other industrial wastes entering the ground water supplies. Recent reports which have studied deaths of mammals in the oceans indicate traces of high blood pressure medication among others, which eventually all wash into the ocean and are taken in by the animals.

Check this page if you are interested for a list of chemicals required by law to be tested for in municipal water supplies. A quick look shows that no where near 700 chemicals are being analyzed. It is quite expensive, especially for small town water suppliers to run water samples for all the potential chemicals that may be found in local water supplies. Thus it is quite difficult to assess what actually exists in water supplies.

Recent studies of impacts of pesticides in human toxicology show that it is the interaction of multiple chemicals at low levels ( even those levels considered relatively safe) that may cause permanent damage especially in young, developing children. It is rapidly growing tissue, especially that of the nervous system, and immune system which is most likely to be affected by these organics.

Here, the best solution is not cleanup after release, but prevention of the chemicals from entering the water system in the first place.

Oils, gasoline:

Tanker accidents & blowouts contribute to this problem in acute ways but some say as much as 90% comes from runoff/dumping by cities, their roadways and industries in a low chronic fashion.


1. Volatiles : After a spill, low-boiling aromatic compounds like benzene & toluene are the primary cause of immediate deaths. In warm water they evaporate 1-2 days;in cold waters it may take up to 1 week

2. Floating tar-like globs adhere to birds, otters, seals, rocks etc. Destroys natural insulation, buoyancy, Animal drown or die due to loss of body heat. Bacteria break down globs in weeks, months or in cold waters years.

3. Heavy oil sinks to bottom of waters or wash into estuaries. These masses kill bottom dwelling organisms like crabs, oysters, etc.

Biological effects


Toxicity of Oil Spills:


Routes of Exposure



1. Contact

decrease in water repellency and body insulation leading to hypothermia

decrease in buoyancy

2. Ingestion

anemia, pneumonia, kidney and liver damage

decreased growth, egg production and egg viability

altered blood chemistry

3. PAHs passing through egg shell

decrease in hatching

abnormal and stunted growth

Marine Mammals

1. Inhalation

damage to respiratory surfaces and mucous membranes

2. Surficial exposure

temporary decrease in feeding by baleen whales

eye mucous membrane affected

fur insulated animals experience hypothermia

3. Ingestion

kidney failure, intestinal lining destruction, neural disorder and bioaccumulation

Pelagic Species- swimming species

1. Contact

in fish: increased breathing rates

2. Ingestion

liver effects

3. Egg exposure

decrease in swimming performance

slow initial development after hatching

increased morphological abnormalities

Another Example of oil contamination


Canada's coast guard and other federal agencies are escalating their fight against clandestine, deliberate oil spills that are killing tens of thousands of seabirds annually in busy shipping lanes off Newfoundland. Aerial surveillance is being increased, and authorities want to step up the pace of prosecutions and fines for the owners and operators of the ships.

The coast guard estimates that oil spills annually kill 60,000 to 100,000 of the roughly 10 million seabirds that congregate off the Newfoundland coast each winter. Although the individual spills usually are small, the toll they inflict every three to four years equals the number of birds killed in the massive Exxon Valdez oil spill in Alaska.

Terry Harvey, manager of the coast guard's oiled wildlife project, said many of the spills are ordered by the captains of commercial ships to minimize the cost of pumping oily waste from their bilges when they reach port. "This is usually a willful act of deliberate polluting," Harvey said Tuesday. "The birds die horribly -- they can no longer feed themselves. They come ashore, starving to death and freezing to death, and hope for rehabilitation is lost."

b. Plastics: Studies indicate each year- 2 million sea birds & 100,000 marine animals (whales, seals, dolphins) die when they ingest/entangled in plastic mesh. Merchant ships dump 450,000 plastic containers overboard every DAY ----US ships are responsible for 1/3 of trash thrown into ocean.


Return to introduction 1. Go to sediments 2. Go to inorganics: 3. Go to disease vectors 4. Go to plant nutrients:5. Got to organics 6. Go to Oxygen-demanding wastes 7. Go to radioactive & thermal wastes