Weekly Blog for Class 13: The Importance of Human Health Stemming from the Environment

So far on this blog I’ve generally only talked about how certain man-made products and actions affect the environment and its health. However, in this entry I would like to shift my focus towards some of these products and other environmental issues that affect human health. There is actually a number of overlapping human activities that pose some pretty serious threats to both humans and the environment. Before I breakdown some of these issues, I wanted to state that in my personal opinion spreading awareness about the causes and effects of these threats to human health can be a more effective way of targeting and preventing the coinciding environmental issues. A main reason people are against changing their practices to protect the environment is their selfish nature and what better way to change this by then addressing that some of these problems can have some very serious ramifications on them as individuals.

A specific case study mentioned in Chapter seventeen of the textbook is the threat of mercury. There is an abundance of ways that mercury can enter the atmosphere, both natural and anthropogenic. Volcanic eruptions and forest fires are some natural examples, while burning coal and oil are some human activities that allow mercury to enter the environment. Once entering the atmosphere, mercury combines with acids found in atmospheric processes, and is eventually returned to the Earth’s surface during precipitation as a methylmercury. Through runoff, mercury-contaminated water is able to flow into bodies of water. Now this isn’t where it begins to affect humans as the filtration technology we have is able to filter out methylmercury from our drinking water supply. However, once reaching bodies of water it has a different way of threatening humans. Once entering a body of water, methylmercury is consumed by plankton, which are the lowest trophic level on aquatic food webs. This is key as this allows for the phenomenon of bioaccumulation to occur. Bioaccumulation is the gradual accumulation or build up of substances as it goes up through the food web, level by level. Not only does this mean that a majority if not all of the different organisms and species within the web are being exposed to methylmercury but it also leaves humans prone to being exposed. When people go fishing, they typically go for the bigger species which also are usually at the top of the food chain and based on the property of bioaccumulation when methylmercury is present, are the same species that will carry a very high amount of the substance in their tissues. To put into context how dangerous bioaccumulation can be, the State of Vermont Fish Contaminant Monitoring Program has been observing mercury levels in fish tissues since 1987 and have found that measurable concentrations can be seen in 95% of the samples collected from bodies of water across the state (State of Vermont 2). In another study, the EPA found that almost half of the fish tested in 500 lakes and reservoirs across the United States had levels of mercury that exceeded safe levels. I’ve included a diagram below that displays the bioaccumulation of mercury in its entirety.

To further explain how dangerous this can be, let me introduce methylmercury and what it can do to your body. Methylmercury is considered to be an extremely dangerous neurotoxin, a neurotoxin is a chemical that can seriously harm the human nervous system. What does that mean? Neurotoxins can cause attention-deficit disorder, paralysis, and even death, which are all some very serious side effects. As we continue to burn oil and coal as an energy source, it is important to remind yourself that we are not only harming the environment and Earth’s wildlife while doing so, but also our own selves.

Works Cited

State of Vermont. “Mercury in Fish.” Mercury in Fish | Department of Environmental Conservation. Accessed April 28, 2021. https://dec.vermont.gov/waste-management/solid/product-stewardship/mercury/fish.

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Question: Is there a certain threshold that can be reached where the amount of atmospheric mercury becomes so high that it will affect everyone around the world?