Term
|
Definition
| The younger wood of a tree. It is found just inside the bark where most of the tree's nutrients are transported. |
|
|
Term
|
Definition
| substances that get into the air, water, soil or food. These substances happen at a concentration that threatens the health and/or life of an organism |
|
|
Term
Acid Precipitation Acid Rain [image] |
|
Definition
| Pollutants in the air, usually sulfur dioxide and nitrogen monoxide, react with the water in the atmosphere to make an acidic compound. It comes back down to Earth in rain, sleet, hail, snow and even fog. The acid can kill organisms on the land an in the water. |
|
|
Term
|
Definition
represents the concentration of hydrogen ions in a solution. a pH of 7 (water) is said to be neutral, lower than 7 is said to be acidic and higher than 7 is said to be basic |
|
|
Term
|
Definition
| the build up of a substance (usually a pollutant) in an organism over time. As the concentration becomes greater the organism usually gets sick and may die. |
|
|
Term
|
Definition
| Related to bioaccumulation. As the pollutants goes through the food chain it becomes more highly concentrated in the tissues of the organisms. It becomes more concentrated because as you go up the food chain the consumers at each higher level eat more organisms. |
|
|
Term
|
Definition
| chemical substances used to control organisms that humans think of as pests. It usually kills them. |
|
|
Term
|
Definition
| a group of pesticides that are used to kill insect pests |
|
|
Term
|
Definition
| a group of pesticides that are used to kill unwanted plants (weeds) |
|
|
Term
|
Definition
| a group of pesticides that are used to kill fungus pests |
|
|
Term
DDT (dichloro-diphenyl-trichloroethane) [image] |
|
Definition
| A synthetic (man made) pesticide that was used to control insects. It was found to be very harmful to organisms further up the food chain so it was banned. |
|
|
Term
Parts per Million (ppm) [image] |
|
Definition
| a measurement of how many particles of a chemical are found out of every million looked at. |
|
|
Term
Heavy metals [image][image] |
|
Definition
It is not a type of music group. They are a group of metal elements found in the middle of the periodic table. They occur naturally in the Earth's crust and are often used in industry. They are very toxic to organisms in very low concentrations. |
|
|
Term
Endocrine-disrupting compounds (EDC) [image] |
|
Definition
| Chemicals that bioaccumulate. EDC's affect developing embryos and young individuals by mimicking (acting like) natural hormones. In some animals it can change the sex that the animal should have been genetically. these chemicals include PCBs, DT, chlordane and PBDE's (polybrominated diphenyl ethers) |
|
|
Term
|
Definition
| when good fertile topsoil is lost to erosion and/or when soil nutrients are lost or depleted (become less) |
|
|
Term
|
Definition
| the cutting down of large areas of trees without replanting new ones or in not replanting the same number as was cut down. |
|
|
