There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.
You can buy this lab book for $23 at amazon.com or lulu.com. It will take 1-2 weeks to get to you -- Order Now. It’s a great resource!
*Some of you have already purchased my lab book – be sure to check out Page 141 !
“Mercury is considered one of the top 10 chemicals of public health concern by the World Health Organisation. A mercury compound called methylmercury is a strong neurotoxin that accumulates in food webs.
And a danger lies in the increase of runoff of natural organic matter – such as leaves, dirt and soil – into coastal waters.“
“A highly toxic form of mercury could jump by 300 to 600 percent in zooplankton -- tiny animals at the base of the marine food chain -- if land runoff increases by 15 to 30 percent, according to a new study.
And such an increase is possible due to climate change, according to the pioneering study by Rutgers University and other scientists published in Science Advances.
The study showed that an increase in natural organic matter entering coastal waters can boost the bioaccumulation of methylmercury -- a highly toxic chemical found at elevated levels in many species of fish -- in zooplankton by 200 to 700 percent. The huge increase in methylmercury shifts the food web from being autotrophic (largely microscopic plants and cyanobacteria that make food from inorganic matter) to heterotrophic (bacteria that eat organic matter produced by plants and cyanobacteria).
Natural organic matter from plants and animals in runoff also increased methylmercury levels in water by up to 200 percent, increasing exposure to the chemical in the food web, the study says.”
“Shifting rainfall patterns may send 10 to 40 percent more water filled with dissolved bits of organic debris into many coastal areas by 2100. The material can cloud the water, disrupting marine ecosystems by shifting the balance of microbes at the base of the food web, new laboratory experiments suggest. That disruption can at least double methylmercury concentrations in microscopic grazers called zooplankton, researchers report January 27,  in Science Advances.”
“Mercury in the fish we like to eat is a big problem in the United States and increasingly around the world. Mercury itself is a naturally occurring element that is present throughout the environment and in plants and animals. But human industrial activity…ratchets up the amount of airborne mercury which eventually finds its way into lakes, rivers and the ocean, where it is gobbled up by unsuspecting fish and other marine life.
Once this mercury gets into the marine food chain, it ‘bioaccumulates’ in the larger predators. That’s why larger fish are generally riskier to eat than smaller ones. Those of us who eat too much mercury-laden fish can suffer from a range of health maladies including reproductive troubles and nervous system disorders. The U.S. Environmental Protection Agency (EPA) reports that human fetuses exposed to mercury before birth ‘may be at an increased risk of poor performance on neurobehavioral tasks, such as those measuring attention, fine motor function, language skills, visual-spatial abilities and verbal memory.’ Up to 10 percent of American women of childbearing age carry enough mercury in their bloodstreams to put their developing children at increased risk for developmental problems.”
“Mercury is accumulating in the surface layers of the seas faster than in the deep ocean, as we pour the element into the atmosphere and seas from a variety of sources, including mines, coal-fired power plants and sewage. Mercury is toxic to humans and marine life, and accumulates in our bodies over time as we are exposed to sources of it. …
For several years, scientists have warned that pregnant women and small children should limit their consumption of certain fish, including swordfish and king mackerel, because toxic metals including mercury and lead have been accumulating in these species to a degree that made their over-consumption dangerous to human health. Pregnant women are particularly at risk because the metals can accumulate in the growing foetus, and in sufficient quantities can cause serious developmental disorders.”
“The toxic effects of mercury depend on its chemical form and the route of exposure. Methylmercury [CH3Hg] is the most toxic form. It affects the immune system, alters genetic and enzyme systems, and damages the nervous system, including coordination and the senses of touch, taste, and sight. Methylmercury is particularly damaging to developing embryos, which are five to ten times more sensitive than adults. Exposure to methylmercury is usually by ingestion, and it is absorbed more readily and excreted more slowly than other forms of mercury. Elemental mercury, Hg(0), the form released from broken thermometers, causes tremors, gingivitis, and excitability when vapors are inhaled over a long period of time. Although it is less toxic than methylmercury, elemental mercury may be found in higher concentrations in environments such as gold mine sites, where it has been used to extract gold. If elemental mercury is ingested, it is absorbed relatively slowly and may pass through the digestive system without causing damage. Ingestion of other common forms of mercury, such as the salt HgCl2, which damages the gastrointestinal tract and causes kidney failure, is unlikely from environmental sources.”
This research development could be used as an article for students to read, or an Extra Credit topic for student research.
Past Periodic Table related posts include:
02/23/2014 The Periodic Table
09/24/2015 Facts about the element Mercury
12/03/2015 Periodic Table Trend Activities
12/09/2016 Cool Periodic Table
*This Blog contains several entries that would be helpful to your chemistry classroom. Check out the Topic List to help you to find past Blog entries.
Also, Write To Me about your successes, challenges, or questions in the Chemistry Classroom.
Remember, buying a copy of the lab book Chemistry on a Budget can be very useful to your Chemistry classroom with labs and class article ideas.
Have a great weekend!