Gold Mining and Its Effects on the Amazon and Its Inhabitants

Right before Thanksgiving I took a trip down to UNCW to attend the State of North Carolina Undergraduate Research and Creativity Symposium (SNCURCS, pronounced as Snickers) where I presented a poster on Gold Mining and its Effects on the Amazon and its Inhabitants. This is the second SNCURCS conference I have attended and I highly recommend it to any science or business majors. It is a great way to network with people throughout the state, and you have multiple people complementing your work, which is always a plus!

Below is the basic outline of the poster that I presented, but without the pictures.


Around the 1970’s there was a global increase for the price of gold, which is believed to be the start of the most recent gold rush in the Amazon area. Since gold was worth more, many from the Indigenous Tribes surrounding the Amazon River took a hand at gold mining, desperate to support their families. Unfortunately, they had no way of knowing that their desire to survive would lead to the destruction of their homeland.

Large scale mine’s are owned by companies who will stay at the mining site until all of the mineral deposits in that area have been acquired. These companies may employee thousands of workers from the community. Large machinery is used to dig gold from the soil and mercury is used to amalgamate the gold deposits.

Small-scale mining consists of 4 to 5 men who travel around looking for gold.  Land and River dredging are the two most popular methods used by small-scale miners.

Land dredging is done by digging a hole into the soil and then using a high-pressure water source to expose the gold. This water runs off into different locations usually making the perfect breeding grounds for mosquito’s carrying malaria.

River dredging consists of sucking up the ground beneath the river into pipes, which then filter out the gold particles. The displaced ground is then released into different areas of the river.

Deforestation of the Amazon

Mining areas all over the Amazon are cutting down trees to make way for large machinery and roads to help accumulate the most gold as possible. In an already fragile ecosystem this method is detrimental to the vast variety of flora and fauna that reside in and around the Amazon River.

Deforestation not only puts endangered and unique plants at risk, it also decreases the vegetative buffer zone around the Amazon River. With the removal of trees there is a removal of stability of the riverbank. This land is now more susceptible to erosion; which leads to a higher concentration of sediment in to the river. This sediment then reduces the amount of dissolved oxygen in the water leading to a decline in the survival of the plants and animals that reside in the river. The decline in fish then affects the Indigenous people that depend on the River for food.

Mercury Contamination

Mercury is used in mining to amalgamate gold and other precious metals. The mercury clumps all of the gold together causing it to fall to the bottom of the water. When the water is drained out then the gold is left behind, this is when the mercury turns into runoff. Even though very little mercury will become runoff, all the small amounts turn into 100 to 200 tonnes per year (Malam 1998).

Mercury that is inhaled will make its way into the kidneys, which is why urine sampling is the best way to test for mercury in humans. Studies have shown that the highest level of mercury can be found in poorly ventilated gold shops. Storeowners heat up the gold and the attached mercury turns into gas and enters atmosphere, and the lungs of the shop owners (Malam 1998).

Methylmercury is the most common form found in humans, because it comes from mercury-contaminated fish. Hair samples are the best way to test for methylmercury according to the WHO. Hair samples that were taken from local fishing villages ranged from 10.2-35.9 ppm of mercury levels. 100 km downstream from one of the largest mining areas, a concentration of 151.2 ppm of mercury was found (Akagi, & Naganuma 2000). The safest levels of mercury in a human should be below 5ppm according to the WHO.


Clearly gold mining is causing massive devastation throughout the Amazon area, but what can be done?

The education of miners is what groups like the Global Mercury Project (GMP) are trying to do. On there website GMP states that there biggest goals are to reduce mercury contamination by introducing cleaner mining technologies and educating workers how to use them.

Tighter laws on the sale of mercury in these countries would greatly reduce the amount of pollution from mining.  In the Guiana’s there are now laws in place in order to obtain mining titles, laws focused on environmental protection, and tighter laws on the exportation of gold (Hilson, & Vieira 2007).

On a small scale just being aware of the gold you buy can make a big difference on the gold that is being mined. On a larger scale the governments of these countries are going to have to step in and put heavier gold mining laws into affect. If they do not then their people may soon no longer have a place to call home.


Akagi, Hirokatsu, & Naganuma, Akira. (2000). Human exposure to mercury and   the accumulation of methylmercury that is associated with gold   mining in the amazon basin, brazil. Journal of Health Science, 46(5), 323-328.

Hilson, Gavin, & Vieira, Rickford. (2007). Challenges with minimizing mercury pollution in the small-scale gold mining sector: experiences from the Guiana’s. International Journal of Environmental Health Research, 17(6), 429-441

Malam, Olaf. (1998). Gold mining as a source of mercury exposure in the Brazilian Amazon. Environmental Research, 77, 73-78.

This entry was posted in Uncategorized. Bookmark the permalink.

2 Responses to Gold Mining and Its Effects on the Amazon and Its Inhabitants

  1. samparton says:

    Emily you are my hero in the scientific world and I strive to be more like you everyday of my life. That being said it is crazy how many consequences there are for mining. The one that stuck out the most was the mercury containation and how harmful this could be to both animals and humans alike. This should be more carefully monitored.

  2. wwhite2221 says:

    What a shame. Money always seems to win out over nature, even though we later find out that it will cost more to fix our inevitable problems. The Amazon is one of the greatest biological diverse places on the Earth that may still hold many cures to our cancers.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s