LC50 AND LD50
LETHAL CONCENTRATION AND LETHAL DOSE
What is LC50?
LC50 is a measure of toxicity of a substance found in the environment. LC50 is commonly used to measure, monitor and quantify levels of contaminants in our water supplies or environmental toxins. The value of LC50 is usually experimentally determined by exposing a non-human sample population to the toxin. LC50 is defined as the concentration of the toxin that will kill 50% of the test population exposed to that concentration of the toxin after only a single exposure.
The LD50 is a similar type of measurement typically used for pharmaceuticals or consumer products not naturally found in our environment. LD50 values are typically determined experimentally by exposing a test group of animals to the substance in question. LD50 is defined as the dose that will kill 50% of the animals exposed after a single dose.
The Clean Water Act
The Clean Water Act was originally established in 1948 under the name Federal Water Pollution Control Act. In 1972 its name was officially changed to The Clean Water Act, along with some noted structural and policy changes. These acts were put into place in to establish water pollution regulation and oversight.
Biomagnification
The task of constantly monitoring and testing or air land and water is vital not only to us, but for generations to come. Seemingly small amounts of toxin chemicals that find their way into the environment get quickly amplified. This effect is called biomagnification. In biomagnification, the effects of these environmental contaminants is magnified as the toxin is passed on from organism to organism through the food chain over time!
Many organisms such as plants, fish, and worms, are the foundation of the food chain in nearly every ecosystem on earth. These vital organisms can absorb small amounts of environmental toxins. These, now toxic, organisms are then consumed by another organism higher up on the food chain. These organisms will thereby also become toxic due to their toxic meal. Then these toxic organisms can be consumed by another organism even higher up in the food chain and so on!
In biomagnification the concentration of the persistent toxins (crosses) increases higher up the food chain.
Copper sulfate is a contaminant that is commonly found in our water supply. This compound is used in pesticides and acts to kill bacteria, algae, roots, plants, snails, and fungi. Ingesting large amounts of this environmental contaminant can cause nausea vomiting, kidney failure and even death!
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