Chlordane awareness

Ever wonder what kind of chemicals are lurking around in the water and soil of your local streams and bays? Did you ever wonder how the the streams become so contiminated? The answer can most likely be found right outside on your lawns and gardens. Pesticide use is one of many contributors to soil contamination in many water streams. More specifically, chlordane is among the many chemicals that can be found at high concentrations in different parts of Tecolote Canyon. Tecolote Canyon is a nature park in San Diego, CA that is surrounded by houses, a golf-course and the University of San Diego. Chlordane is a pesticide that is highly toxic. It was prevalent throughout the 1980’s to kill off pests, ants and insects until it was banned from commercial use in 1988. Although, it has been banned for almost twenty years concentrations of chlordane can still be found in some places near home lawns and gardens. Chlordane sticks strongly to soil particles at the surface thus; it can stay in the soil for over 20 years and breaks down very slowly. Chlordane concentrations are highly variable in soil and sediments. In an effort to find more information about what parts of the soil sediments contain Chlordane, samples from varies locations were taken from Tecolote Canyon. The soil samples were then tested for chlordane using the ELISA method. The ELISA method of measuring chlordane samples provides a technique for using a uv-vis spectrophotometer to measure the absence of the chlordane in each sample. From this method, we were able to construct a calibration curve that provided values to use in an equation that ultimately provided a final concentration value in ppb for each solution. We found that chlordane was present in every sample taken from Tecolote Canyon. The samples had concentration values ranging from 5-1900 ppb. This is higher than expected considering that the half life of chlordane varies between 37 to 3500 days and the commercial use of chlordane as a pesticide has been illegal since 1988. The highest of these samples was from the northern region of the canyon below the community center and below the golf course. From the data, we found a correlation between chlordane and soil moisture. Thus, we can conclude that chlordane is present in higher conentrations in moist soil vs. dry soil. The correlation between soil moisture and chlordane also suggests that there is still chlordane coming into the canyon from runoff areas like the golf course and residential areas above the canyon. In conclusion, this should bring some awareness that we should always be aware of the chemicals we use so that we can save our environment and utimately save our selves.