Big Threat Spotted In Heavy Metal Contamination To Oceans And Human Health
From mining industries to domestic waste, daily, various human activities release heavy metals into nature. Locations free of this contamination are rare and the oceans end up absorbing a large portion of these pollutants. Its toxicity poses a danger not only to marine life, but also to humans.
Professor Rubens Figueira, specialist in Chemical Oceanography at the Oceanographic Institute (IO) of USP, explains that the term “heavy metals” does not necessarily refer to metals, but to “potentially toxic chemical elements, among which arsenic, cadmium, chromium, copper, mercury, nickel, lead and zinc”. Although they are naturally found in the environment, in large quantities these elements make water and food unfit for consumption, which can cause nervous system dysfunction and increase the incidence of cancer.
When ingested, heavy metals tend to accumulate in tissues such as the liver, kidneys and muscles. Thus, when a living being at the base of the food chain serves as food for another animal, this predator is also contaminated. As predators need to feed on multiple prey, they end up developing higher levels of contamination. “Mercury, for example, stands out among these elements as a metal that can increase its concentration along the food chain, impacting predators at the top of the chain, such as fish, birds and mammals, including us, who also feed on these organisms. ”, explains Figueira.
Environmental accidents and disasters
Paint, chlorine, PVC plastics, metallurgy, garbage incinerators and mining industries can dump large amounts of heavy metals into nature, if there is not an adequate system for treating these residues. Accidents and environmental disasters involving these industries can also have a significant impact. The case of the rupture of the Brumadinho dam, for example, severely affected the local population. According to Fiocruz , more than half of children aged 0 to 6 years had at least one metal above the reference value. In addition, household waste can include heavy metals when paint, batteries, fertilizers, pesticides, water pipes, thermometers and light bulbs are improperly disposed of.
Ocean currents act as dispersers of these pollutants throughout the oceans, making their removal virtually impossible. Thus, Figueira points out that “the installation of sanitary and industrial landfills, air filtration systems and sewage treatment plants, among other strategies, have the potential to significantly reduce contamination of the marine environment”. The professor explains that, associated with public policies, environmental education and recycling, it is possible to reduce or even eliminate the spread of heavy metals in nature.