A Cost Efficient Method, in Conjunction with EPA Method 7474, of Detecting Mercury Contamination in Fish Tissues

Mercury is a highly toxic metallic substance, and a persistent, bio-accumulative, biomagnified environmental contaminant, and is known to cause multiple adverse medical side effects in humans such as damage to the brain, kidney, lungs, and even increases in chances of cardiovascular disease. The biggest source of human mercury poisoning is through the consumption of fish that inhabit contaminated aquatic ecosystems. Current mercury testing methods are time-consuming, insensitive enough to detect the maximum allowable mercury levels in biological tissues established by governmental agencies, and expensive due to required specialized equipment such as an atomic fluorescence spectrometer. By developing a cost efficient and accurate method of mercury testing, universities, research labs, hospitals, and many other organizations that do not possess an atomic fluorescence spectrometer would have an opportunity for increased research and monitoring of mercury contamination levels. Boris’ Mercury CheckTM (BCM) test strips can detect mercury levels in water, are inexpensive, and are sensitive to a concentration of 2 parts per billion, the Maximum Concentration Level established by the United States Environmental Protection Agency (EPA). During a preliminary study, where fish tissues were emulsified in an aqueous solution and spiked with predetermined mercury concentrations, we found that the biological tissue either interfered with the test strips ability to detect mercury or absorbed any mercury that was present, and that further method development and research was required. We expanded our previous study by thermally digesting fish tissues with an acid solution in conjunction with EPA Method 7473 (4), and tested fish tissues from several species that have low, medium, and high ranges of expected mercury bioaccumulation, a laboratory control sample, and spiked samples with predetermined mercury concentrations with the BCM test strips, and verified the results with a replicate of each sample by atomic fluorescence spectrometry