Bioassay Procedures — Day 1 Step 1 Prepare your salt solutions, then label 10 Petri Dishes with your name and the pre-selected salt concentrations. Nine will be test solutions and one will be a control with distilled water. Step 2 Soak a paper towel with in your first salt solution Just enough to moisten the paper towel- not dripping wet and place in the appropriately labeled Petri Dish. Step 3 complete step 2 for the remainder of the test solutions.
But many polluting substances do not originate from a single source. Rainwater, for example, may become contaminated as it moves over and through the ground, picking up pollutants from many different sources.
This kind of pollution is known as nonpoint source pollution, and now accounts for most of the water pollution in the United States. Pollutants from nonpoint sources include: In fact, nonpoint source pollution comes from such a wide variety of human activities that almost everyone contributes to the problem in some way, often without realizing it.
Because nonpoint source pollution is a serious and pervasive problem that costs millions of dollars in lost and damaged resources, degrades environmental quality, and threatens human health, it has been the focus of numerous state, local, and national efforts.
The diversity of sources and substances that result in nonpoint source pollution often make it difficult to know exactly what actions are needed to reduce or eliminate the problem.
In many cases, the first priorities are to recognize when pollution is taking place, identify the polluting substances, and determine the sources of pollutants.
Through the National Status and Trends Program, CCMA conducts long-term monitoring of toxic chemicals and environmental conditions at more than sites along the the U. Monitoring typically includes measurements of: Often these three types of information are combined to obtain an overall indicator of environmental quality.
This method is known as the sediment quality triad approach. This activity is designed to acquaint students with bioassays tests that use biological organisms to study the action of chemicals or physical changes in the environmentand to provide hands-on experience with a simple bioassay that students can use to study nonpoint source pollution and many other aspects of environmental quality.
This will vary depending upon the size and composition of the paper towel. The towel should be uniformly damp, but there should not be a pool of water in the bag. Students should collect sample volumes approximately four times the volume needed to saturate a single paper towel. Discuss the concept of nonpoint source pollution, or have students review the Nonpoint Source Pollution Tutorial at: Briefly discuss the concept of a pollutant.
Ask students what makes something toxic or poisonous?
How an organism responds to a potentially toxic substance also depends upon the sensitivity of the organism to the substance all substances are not equally toxic to all organisms and the route of exposure whether the substance is inhaled, absorbed through the skin, eaten, injected, etc.
Introduce the concept of bioassays as a way to measure toxicity. Tell students that they will be using radish seeds as a bioassay to investigate nonpoint source pollution in their community. Two responses will be investigated: Have each student group identify three potential sources of nonpoint source pollution that they can sample for their investigation, and submit these for your approval.
Emphasize that because these samples may contain substances that are harmful to human health, it is imperative that students wear protective gloves and safety glasses while handling their samples.
Students should also identify an appropriate control for each of their samples. If samples are from freshwater sources, distilled water would be an appropriate control.
If the samples are from brackish water, it will be necessary to prepare control solutions that have approximately the same salinity as the sample. The easiest way to do this is to measure the specific gravity of the sample with a hydrometer available from aquarium supply stores.INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY ENVIRONMENTAL HEALTH CRITERIA THALLIUM This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of the United Nations Environment Programme, the International Labour Organisation, or the World Health Organization.
lettuce seed bioassay the usual independent variable is the concentration of the solution to which the seeds are exposed. The dependent variable is the factor that you predict will change as a result of variation in your independent variable. The number of seeds that germinate and the lengths of their.
Bioassay of Radish Seeds Essay Bioassay of Radish Seeds Bioassay is a type of scientific experiment used in the development of new drugs and monitoring pollutants.
It estimates the potency of a substance, by testing its effect on living matter. APES LD/Bioassay Salinization Experiment Purpose: The purpose of this lab is to study how a bioassay is used to determine the toxicity of a chemical.
Students will determine the LD50 of salt on the growth of radish seeds.
Objectives: 1. Conduct a controlled experiment to test the toxicity of salt on the growth of radish seeds. 2.
|First draft prepared by Professor G.|
|Thallium (EHC , )||A study of biology includes the study of the chemical basis of living organisms, DNA.|
The purpose of this paper is to evaluate the environmental state of the territory of the famous Russian landscape-architectural museum Kolomenskoye. This park reserve is located on the left bank of the Moscow River in very close proximity to a heavy industrial area of Moscow and a major highway.
The. The Seeds Tell the Story Radish Seed Bioassay Student Worksheet (adapted from Rathbun, ) Wear protective gloves and safety glasses when handling sample solutions!
Soak radish seeds for 20 minutes in about 20 ml of a 10% solution of household bleach in distilled water, then rinse 5 times with distilled water.