Cesium-137 is a radioactive isotope that is commonly formed from the process of fission. During the 1940s-50s the United States of America began nuclear weapon tests in Alamogordo, New Mexico. These bombs released Cesium-137 into the stratosphere thus having to be transferred from the west coast to the east coast through rainfall and wind. Cesium-137 mimics potassium due to its similar chemical properties. Due to this fact, we see the Cesium-137 in honey is greater in the southeastern U.S. than in the northeastern U.S. The southeastern United States has lower levels of potassium in its soil which explains why the vegetation cycles more Cesium-137 and thus appears more in the honey.
1.1 Why is this important
The purpose of this experiment was to test honey samples and see what levels of radioactive material are in honey across the United States. My hypothesis is if radioactive fallout has spread out throughout the United States due to wind and rainfall, then, there will be radioactive material in honey. Radioactive material is prominent in modern times and people should care about it being in honey. Internal exposure to cesium-137, through ingestion or inhalation, allows the radioactive material to be distributed in the soft tissues, especially muscle tissue, exposing these tissues to the beta particles and gamma radiation and increasing cancer risk (CDC Radiation Emergencies | Radioisotope Brief: Cesium-137 (Cs-137), n.d.). Exposure to high levels of Cesium-137 by ingesting it, can lead to an increase in a person’s chance of getting cancer. Also, In 2020, an estimated 1,806,590 new cases of cancer will be diagnosed in the United States and 606,520 people will die from the disease(Cancer Statistics, 2020). The most recent Annual Report to the Nation, released in March 2020, shows that overall cancer death rates decreased by,1.8% per year among men from 2001 to 2017,1.4% per year among women from 2001 to 2017, and 1.4% per year among children ages 0–14 from 2013 to 2017. Luckily cancer rates are going down but it is still very important to recognize that radioactive isotopes are still around and are important to research.
1.2 Nuclear Bomb Testing
To understand why radioactive materials are in the honey we consume on a day-to-day basis, we have to go back to when the United States government started bomb testing in the 1940s and 1950s in areas like New Mexico and Nevada. Now, due to these bomb tests, there was a fallout of a radioactive isotope called Cesium-137. Cesium-137 is a radioactive isotope with a half-life of about 30 years. Usually, bombs have uranium. Instead, scientists found Cesium-137 instead of uranium. Well, cesium is just a fragment of uranium that flies off when fission occurs. Nuclear fission is when an atom splits into two or smaller nuclei. When the nuclear bombs exploded, Cesium-137 isotopes were released into the stratosphere.
1.3 Cesium-137 hot zones
When it rains those Cesium-137 isotopes are removed from the stratosphere and can cause hot zones in places like the East Coast of the United States. With the Cesium-137 now landing in soils across the East Coast, they create something that is called a hot zone. A hot zone is an area with a harmful amount of radioactive material. Luckily the plants on the East Coast–due to a process of phytoremediation, have absorbed a lot of the Cesium-137 material. The plants absorb Cesium-137 because its chemical properties are so similar to those of potassium. (J.McClain, 2020). The plants get the two confused very easily due to similarities in charge and ion size. Especially in areas that are lacking in potassium in their soil, there will be an increase in Cesium-137 uptake in plants. This shows that plants are absorbing the radioactive material into their roots which ends up in the pollen of the plant. Currently, there is no apparent correlation between the hot honey spots and the levels of cesium in the environment.
1.4 Honey creation
Honey bees (Apis mellifera L.) are one of the many insects that make honey (Saunders, 2018). First older worker bees start by foraging which is when the bees leave their hive and begin the search for nectar-rich flowers. Then they use their proboscis, the worker bees drink the nectar and store it in their special stomach called the honey stomach. The worker bees continue to forage for the nectar until their honey stomach is full. While the nectar is in the honey stomach enzymes break down the complex nectar sugar into simple sugars. When the worker bees are finally full of nectar they return to the hive and deliver the modified nectar to the younger worker bees. When the younger worker bees receive the nectar they ingest it and break it down further. Then they place it into a cell of the honeycomb. Once the even further modified nectar is in the honeycombs, hive bees begin to flap their wings at an exponential rate to help evaporate the water contents in the nectar. This is what thickens the nectar sugar into honey. As soon as that process is over the hive bees seal off the honey with beeswax caps for later consumption like in the winter when there is little nectar available. When thousands of worker bees work together they can produce over 200 pounds of honey for their colony in a year. (Barkman Honey, LLC, 2019)?
1.5 Informal Methods and materials list
In order to do my experiment I needed to obtain certain materials and follow specific steps to ensure I have the most accurate results from my experiment. First, I am going to need to obtain all my materials. One of the materials I used is honey from states that have experienced nuclear bomb testing and states that are on the East Coast. I had to obtain honey from a local beekeeper in certain states and I also made sure to interview the beekeepers to make sure they could verify the hive location and that the samples were pure, raw, and unfiltered. Secondly, once I obtained all the honey I categorized them by state and set up a spreadsheet to record the data of how much radioactive material is in the honey and how much Potassium-40 is in it. I used Becquerel’s(Bq) as my unit of measurement since it is the metric unit. To test the honey, I shipped the honey to Professor Kaste from William & Mary University to do further testing with the honey samples in a gamma spectrometer. Finally, I recorded all my data to compare the radioactive honey to a map to see where the Cesium-137 fallout is. I also compared it to Professor Kaste’s original findings. The independent variable for my experiment is local honey. The dependent variable is the level of radioactive material in the honey. I will not have a control variable.
2. Materials and Methods
4. oz honey jars from Connecticut, Delaware, Florida, Georgia, Maine, Maryland, Massachusetts, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, Vermont, Virginia
SpreadSheet to record data
First I emailed local beekeepers in the states listed in the “Materials and Methods Section” to make sure their honey is raw, natural, and unfiltered.
Next, I recorded all of my data about if the honey is raw, natural, and unfiltered on the spreadsheet with each corresponding state
I mailed all of the honey samples to Professor Kaste from William & Mary to conduct further testing on the honey using a gamma spectrometer
Finally, I recorded all of the data that Professor Kaste obtained from his testing and see if there are any correlations between honey and their location
Table 1: Cesium-137, Potassium-40, and % of Potassium-40 levels in honey, with corresponding states
Figure 1: Bar graph showing Cesium-137 Bq/kg in honey per its corresponding state
Figure 2: United States map with Cesium-137 Bq/kg levels in honey in certain states
Figure 3: Bar graph depicting Potassium-40 Bq/kg levels in honey per its corresponding state
Figure 4: United States map showing levels of Potassium-40 Bq/kg in honey in its corresponding state
Figure 5: Bar graph showing the % of Potassium-40 in honey per its corresponding state
Figure 6: United States map showing the % of Potassium-40 in its corresponding state
4.1 Results and explanation of data tests
The testing of the various honey samples resulted in various amounts of data and allows us to better understand where the fallout of nuclear bombs is present day. Data Table 1 shows all of the data collected from the gamma spectrometer. Figure 1 which is a bar graph and Figure 2 which is a map of the United States, both showing the levels of Cesium-137 Bq/kg in the honey samples throughout the East Coast and Nevada. Figure 3 which is also a bar graph and Figure 4 which is also a map of the United States, both show the level of Potassium-40 Bq/kg in the honey throughout the East Coast and Nevada. Finally, Figure 5 is another bar graph, and Figure 6 is also another map of the United States, both depicting the percentage of Potassium-40 in the honey throughout the East Coast and Nevada. The fiding of Potassium-40 is fine because it is a naturally occurring isotope that both plants and humans need. This also correlates with the earlier statement that areas with low Potassium-40 levels will have higher Cesium-137 levels. This is true because South Carolina has one of the highest detected levels of Cesium-137 at 0.421 Bq/kg. The level of Potassium-40 is 0.03%. The highest level of Cesium-137 found from these tests is in Georgia at 0.591Bq/kg. The percentage of Potassium-40 is 0.06%. The lowest amounts of Cesium-137 were found in Massachusetts, Nevada, New Hampshire, New York, North Carolina, Pennsylvania, and Rhode Island at <0.15 Bq/kg. The Potassium-40 levels varied depending on the state. The most surprising thing about this data is that Nevada had the least amount of Cesium-137 that it was almost undetectable. Nevada was one of the states where the original nuclear bomb tests took place, yet there's barely a trace of the original material. It also does make sense due to rainfall and wind carrying away the debris from the stratosphere in the West to the East Coast.
5.1 Safety and future plans
Although traces of Cesium-137 were found in almost all of the honey samples, it is still safe to consume. I did not have any major problems completing this project except for some minor timing issues. As you can see from the Data Table 1 there is some data missing. This is because this project is still continuously being worked on. In the future, I would like to see how I can use this project and apply it to other radioactive fields. I would like to see how Cesium-137 affects honey bees or how it is affecting different types of foods. In conclusion, my hypothesis, “if radioactive fallout has spread out throughout the United States due to wind and rainfall, then, there will be radioactive material in honey,” is correct because based on all of the tests, data, and information above it proves that honey contains radioactive material.
Barkman Honey LLC. (2022). How Honey Bees Make Honey. Beeresponsible. Retrieved October 19, 2022, from https://www.beesponsible.com/learn/wonder-of-the-bee/?gclid=CjwKCAjw-rOaBhA9EiwAUkLV4tVKt_ShrTbW6wjjgPa3S8AyLnN8PP6jqWNlnCDrmsW0TlLTThQA4hoCvQsQAvD_BwE#!/how-honeybees-make-honey
Kaste, J. M., Volante, P., & Elmore, A. J. (2021, March 29). Bomb 137Cs in modern honey reveals a regional soil control on pollutant cycling by plants. Nature. Retrieved April 16, 2023, from https://www.nature.com/articles/s41467-021-22081-8
McClain, J. (2020, January 31). A radioactive isotope is showing up in honey. William&Mary. Retrieved October 17, 2022, from https://www.wm.edu/news/stories/2020/a-radioactive-isotope-is-showing-up-in-honey.php
National Cancer Institute. (2020, September 25). Cancer Statistics. National Cancer Institue. Retrieved October 30, 2022, from https://www.cancer.gov/about-cancer/understanding/statistics
National Center of Environmental Health. (2018, April 4). Radioisotope Brief: Cesium-137 (Cs-137). Centers for Disease Control and Prevention. Retrieved October 17, 2022, from https://www.cdc.gov/nceh/radiation/emergencies/isotopes/cesium.htm#:~:text=External%20exposure%20to%20large%20amounts,to%20high%2Denergy%20gamma%20radiation.
National Honey Board. (n.d.). How Honey is Made. National Honey Board. Retrieved October 17, 2022, from https://honey.com/about-honey/how-honey-is-made#:~:text=Honey%20starts%20as%20flower%20nectar,nectar%20collected%20by%20the%20bees.
Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). (n.d.). End Nuclear Test Day. United Nations. Retrieved April 16, 2023, from https://www.un.org/en/observances/end-nuclear-tests-day/history#:~:text=The%20history%20of%20nuclear%20testing,exploded%20its%20first%20atomic%20bomb.
Saunders, M. (2018, September 17). Actually, Honey Bees Aren't the Only Insect to Produce Nectar. Inverse. Retrieved April 30, 2023, from https://www.inverse.com/article/48924-wasps-aphids-and-ants-are-all-honey-makers#:~:text=Apis%20mellifera%2C%20the%20western%20honey,indigenous%20cultures%20around%20the%20world.