Scientists have found that human activity has triggered a sevenfold boost in climatic mercury since 1500 C.E. Using sulfur dioxide as a proxy for volcanic emissions, they established that human sources, such as coal burning and industrial activities, are the main contributors to the existing high levels of mercury in the environment.
Research develops a natural standard for mercury in the environment by estimating emissions from volcanic eruptions.
New research from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) reveals that given that around 1500 C.E., the start of the contemporary period, people have actually increased the concentration of potentially poisonous mercury in the environment sevenfold.
New Methodology for Estimating Mercury Emissions
The research team, led by Elsie M. Sunderland, the Fred Kavli Professor of Environmental Chemistry and Professor of Earth and Planetary Sciences, developed a new approach to accurately estimate just how much mercury is produced every year from volcanos, the biggest single natural emitter of mercury. The team used that price quote– together with a computer system design — to reconstruct pre-anthropogenic atmospheric mercury levels.
Assessment of Pre-Industrial Mercury Levels
The scientists approximated that before human beings started pumping mercury into the environment, it contained on average about 580 megagrams of mercury. Nevertheless, in 2015, independent research that took a look at all available climatic measurements approximated the climatic mercury reservoir was about 4,000 Mg– almost 7 times bigger than the natural condition estimated in this research study.
Human emissions of mercury from coal-fired power plants, waste incineration, mining, and market comprise the difference.
Comprehending the Mercury Cycle
” Methylmercury is a powerful neurotoxicant that bioaccumulates in fish and other organisms– including us,” stated Sunderland, senior author of the paper. “Understanding the natural mercury cycle driven by volcanic emissions sets a standard objective for policies aimed at lowering mercury emissions and permits us to comprehend the complete impact of human activities on the environment.”
The research is released in Geophysical Research Letters..
Obstacles in Mercury Detection.
The obstacle with determining mercury in the atmosphere is that theres not very much of it, despite its outsized effect on human health. In a cubic meter of air, there may be just a nanogram of mercury, making it essentially impossible to identify by means of satellite.
Instead, the researchers required to use another chemical released in tandem with mercury as a proxy. In this case, the group utilized sulfur dioxide, a major part of volcanic emissions.
Utilizing Sulfur Dioxide as a Proxy.
” The nice feature of sulfur dioxide is that its truly simple to see utilizing satellites,” said Benjamin Geyman, a PhD student in Environmental Science & & Engineering at SEAS and first author of the paper. “Using sulfur dioxide as a proxy for mercury enables us to understand where and when volcanic mercury emissions are occurring.”.
Using a collection of mercury to sulfur dioxide ratios measured in volcanic gas plumes, the researchers reverse-engineered how much mercury might be credited to volcanic eruptions. Then, using the GEOS-Chem atmospheric model, they designed how mercury from volcanic eruptions moved throughout the globe.
Effect of Volcanic Emissions.
The team discovered that while mercury blends into the environment and can travel long ranges from its injection website, volcanic emissions are directly responsible for just a couple of percent of ground-level concentrations in most areas on earth. There are areas– such as in South America, the Mediterranean, and the Ring of Fire in the Pacific– where levels of volcanic emissions of mercury make it more difficult to track human emissions..
“But in a place like Hawaii, youve got a huge source of natural mercury that is highly variable over time. This map assists us understand where volcanos are crucial and where they arent, which is truly helpful for comprehending the effect of human beings on long-lasting mercury patterns in fish, in the air, and in the ocean.
Reference: “Impacts of Volcanic Emissions on the Global Biogeochemical Mercury Cycle: Insights From Satellite Observations and Chemical Transport Modeling” by Benjamin M. Geyman, Colin P. Thackray, Daniel J. Jacob and Elsie M. Sunderland, 01 November 2023, Geophysical Research Letters.DOI: 10.1029/ 2023GL104667.
The research study was co-authored by Colin Thackray and, Daniel J. Jacob, the Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering..
The research study was funded by the National Science Foundation.
By Harvard John A. Paulson School of Engineering and Applied Sciences
November 5, 2023