Mercury has always held fascination for humans. Its red sulfide ore is known by the romantic name of cinnabar. Mercury metal, which we played with as kids in the 1950s, is quicksilver. It is clearly not very toxic, or I wouldn’t be writing to you. Some salts of mercury, such as mercuric chloride, are good bacterial poisons and were once used to preserve leather. The Mad Hatter in Alice in Wonderland clearly suffered from an overdose of mercury.
July 27, 2015- I have a confession to make. I have always spent a lot of time outdoors, doing field work and bird watching. But, I don’t like to be a meal for insects.
So I love DEET. What’s more, I believe that a lot of Americans spend a lot more time outdoors because of DEET, and that is ultimately good for the environment (see my 20 July posting here). Undoubtedly DEET has prevented cases of Lyme disease and West Nile Virus in this country, and countless cases of malaria and dengue fever in more tropical regions. Without DEET, I doubt I would have survived the field work for my Ph.D. thesis in Okefenokee Swamp.
It does worry me a bit that a strong bottle of DEET can dissolve a plastic table cloth, take the printing off a ball-point pen, and turn a plastic wine glass cloudy. But in its 60-year existence, DEET has not been found to be carcinogenic. Someday that may change, but for now, I am willing to accept the track record. My friends who alternatively slather on healthy, organic repellants and eat copious quantities of garlic are usually covered with mosquito bites.
July 23- For fear of neighborhood child-molesters, drug pushers, tick-borne disease, and melanoma, parents across the nation are more comfortable knowing their children are playing computer games and surfing the internet than spending time outdoors. Even programs of environmental education, often offered by not-for-profit partners of local school systems, have forsaken the concept of a field trip—driven indoors by fear of liability for accidents in the field and by competing budget and curriculum activities, including athletics.
Felicia Keesing of Bard and Richard Ostfeld of the Cary Institute of Ecosystem Studies write in the current issue of Science that indeed biodiversity seems to reduce the incidence of infectious diseases by reducing the hosts needed by pathogens. Ostfeld has been studying Lyme disease and found that a healthy biodiversity reduces the host carriers of the disease. Their article also cites studies performed by Dr. Barbara Han, mentioned elsewhere in TMI. The article is here: http://www.sciencemag.org/content/349/6245/235.short
July 15- Ever wonder what happens to all the stuff that we put in the atmosphere—gases like ammonia, particles of soot, and other materials, some natural and some as pollutants? These are deposited from the atmosphere, usually downwind of the source, by either wet-deposition—a fancy word for rainfall—or dry deposition. Dry deposition includes the gravitational settling of large particles as well as the reaction of some gases, like ammonia, with plant leaves and other materials on the Earth’s surface.