Rachel Carson had a history of interest with the chemical called DDT. She had tried to get DDT some attention unsuccessfully until her book came out in 1962. She had a friend who wrote her about the large bird kills on Cape Cod from the use of DDT. DDT around the late 40’s and 50’s was thought of a miracle pesticide and its use became very popular. Carson tried over a long period to get a magazine to support her in showing the negative side of DDT usage. But after a long time she had a lot of her own research and decided to go on with her own book. Her book “Silent Spring” showed how ddt entered the food chain and then we stored in the fatty tissues of animals and even humans which was the cause of cancer and genetic damages. Carson discovered that a single application of DDT to a crop would kill insects for months, and it would kill more than just the target insects. Even after being diluted by rain it would still remain toxic to the environment for a long period of time. Carsons book concluded that DDT, along with other pesticides had irrevocably harmed birds and other animals which had contaminated the worlds food supply.
Provide a brief explanation of biomonitoring and the steps involved in risk assessment. Relate these to the case study.
Biomonitoring is a method for determining which chemicals get into members of the populations and what those concentrations are. It can be used to monitor if some groups have a higher or lower exposure than other groups. It can be used to track temporal trends in the levels of exposure. Biomonitoring is used to establish reference ranges. The risk assessment is done on a chemical by chemical basis based on the chemicals exposure and response assessments. The risk assessment sometimes is focused on observable effects. A risk assessment looks similar to a food chain diagram, only you are following a chemical from the point of departure. In “Silent Spring” the chemical DDT was being monitored and the populations in the areas where the chemical was used were compared to populations where the chemical was not being used, along with historical data of what the populations where like prior to the application of DDT. It starts with the bugs, that get eaten by other animals such as birds and rodents, and bigger prey eats those animals and the DDT chemical works its way up to other animals.
How did risk assessment play a part in the disaster that your case describes?
Risk assessment played a vital role in the “Silent Spring”. With all the data Carson collected and used, she was able to give an accurate analysis of the probability of the negative impacts that DDT was having, and would have if it was to be continuously used.
Provide two examples of how biomonitoring could be used in the affected environment.
Biomonitoring allows for the measuring of uptake by animals of the chemicals being used. By doing this in a controlled environment or on a smaller scale like in a specific environment or community, they can pass the information to other communities when a specific hazard is identified, like certain percentages or levels of a toxin.
Biomonitoring allows for testing to be conducted in a specific area, and then compare the results with national averages. So in the case of “Silent Spring” the results of the study and data was collected and compared to the national average, which found that in the area of study that DDT was to blame for the large bird kills and large birds of prey having soft egg shells that would break when the mother bird would sit on them.
What is a biomarker? What biomarker would you use for this case?
A biomarker is a measurable substance in a plant, animal, or human, in which…