Kathryn's Blog

First Blog

This is my first year at the Stanford Earth Sciences Internship and I am really enjoying it so far! I am doing research with Kristin Boye in the Green building lab where are analyzing soil from Cambodia and Vietnam for arsenic content. I had come into this internship knowing almost nothing about arsenic or how it is effecting the lives of people whose diets consist mostly of rice that is contaminated with the element. Shikha is another intern who worked with Kristin last year, and she has helped me a lot in understanding what exactly we are doing, and we also watched a Powerpoint Kristin had made, which explained what the research is about. To give some background, arsenic is found naturally in the soil around Southeast Asia, originating from the Himalayas. Arsenic that is in dry, solid soil is not harmful, because the plants cannot absorb arsenic in this state. However, when arsenic-contaminated soil is saturated with water, the arsenic become harmful, enabling plants to uptake the arsenic, which eventually ends up in the grain. Rice is best grown in flooded areas, which is why this crop is the most contaminated. Rice is also a staple in the diet of most Asian countries, leading to large portions of the population being exposed to unsafe levels of Arsenic.

Kristin has brought a lot of samples of rice grains, stems, roots, and soil back from Vietnam and Cambodia, which we we are using. For most of the first two weeks I have been grinding soil, separating rice from husks and weighing samples of roots; all in preparation to see not only the arsenic content, but also what other elements are in the samples that might play a role in the absorption of arsenic into the plants. He have also prepared standard samples for the XRF machine at S.S.R.L., which picks up the diffraction pattern of different elements in the soil, which was really cool to see. The ultimate goal of our research is to find something (such as charred straw or other organic substances) that reduces the amount of arsenic that makes it all the way to the grain of rice. Kristin has found that charred straw, which is found all over the place in Vietnam, did have a positive effect on the amount of arsenic in the rice, but now we want to figure out why.

So far I have gotten some really great experience in the labs here at Stanford, as well a greater understanding of the work that goes on here. The research I am taking part in is really interesting to me and on top of it is an important topic, aiming to help make food more safe to eat for thousands of people. I have also had the chance to see just how we are able to look at the elements in a sample at the S.S.R.L. center in SLAC, and I will probably write about how that works in the future (once I am really able to understand because it’s quite complicated). It’s been a great first two week and I can’t wait to continue working in the lab!

Second Blog

The past weeks at the internship have been great! In the lab we started a batch experiment to analyze the content of different elements, such as arsenic, that are released in the different soils we have. We had about ninety vials of soil, and we added different substances to them such as charred straw, husks, manure and glucose in order to see if any of these soils would reduce the arsenic output below the control. I just got the data back, and it showed that out of all of the non-controlled soils, charred straw had the lowest arsenic output, but still not as low as the control. The experiment was really cool to do, and it gave us a lot of data that hints as to what sort of systems are happening in the soils.

With the general program, I went on a field trip around the Santa Cruz Mountains and to the ocean. It was a really fun and educational experience. We went to the top of Windy Hill Open Space Preserve where we had a view of the bay area. Using a map and compass, they taught us how to orient ourselves, using triangulation. We found our exact position on the map just by using land marks around us, which is a great skill to have when going out to unfamiliar places to collect field samples. We also went to San Gregorio beach where we investigated rock formations in a cliff side. The cliff we looked at resembled a lava lamp, with a flowing wavy structure, unlike the flat lines you would see in normal sedimentary rock. The wavy structure was formed by a more dense mud layer positioned on top of a less dense layer, causing the two layers to mix together, and harden over time, leaving these interesting patterns. For the rest of the day we drove down the coast, stopping and looking at all kinds of rock formations and cliffs. It was a really great trip, and I would love to do more trips like that in the future.

Back at the lab I received a lot of data from the samples Kristin took from Vietnam and Cambodia. Shikha and I decided that we would submit abstracts for the AGU program. Shikha is going to focus her poster on the batch experiment, and I am going to do mine on the samples. Kristin had soil, water, and plant samples, which have been analyzed for arsenic. I am going to use this data to make graphs and draw conclusions as to how much arsenic goes from the soil, to the water, to the plant. Under Kristin’s leadership I’ve learned so much this summer. This internship has flown by fast, but I’m so happy that I got the chance to do it!

Third Blog

This program has been so great that I honestly didn’t want it to end! The final presentations that took place were really interesting, and I got a great chance to look into what sort of work all the other interns did over the summer. The most interesting to me was to see what the other intern working in my lab was doing with regards to soil science, and it was good to know that I could really understand what he was talking about. There was a lot of variety in the work done by interns too, so it was very interesting to see all the science happening! Seeing the posters made by the History of Life interns was also a good chance to get some ideas for my own poster which I will make for the AGU.

On Tuesday of last week I got to do a tour of the farm to get an idea of what the farm interns were working on. We did some fun activities like painting golf balls, feeding chickens and we got a tour of the farm, which was beautiful, with a lot of diversity in the plants they had there. We got to use an outdoor wood oven to make lunch too! Meanwhile I received more data from my own work in the soil sciences lab in regards to the arsenic levels in all of our samples. I began going through the data and created a few graphs to begin to process it, just to see how arsenic levels compare in each plant part, water, and the soil. It has been a very educational experience learning how to take this giant mass of numbers and use it to make clear graphs; graphs I can hopefully use for the AGU poster.

It’s really cool to think that the results we have from our data have made a small contribution to the study of arsenic uptake into crops. Though we never found anything that reduces the arsenic levels so far, our data gave us some interesting looks into what sort of microbial processes that may be happening with in the soil, affecting the arsenic uptake. It’s a really great feeling to be doing science that has a real purpose in the world, and I have learned so much about the scientific process from how Kristin conducted her research. I would like to thank her for giving me this opportunity, and for everything she has taught me in the lab and about her research, and I would like to thank Jenny and everyone else who made this program happen! This summer has been a blast!