June 16, 2008
What is the best way to dispose of the "not so green" detergents I still have in the house?
Dear Besenok:
Although it was not done in a "green" way, a lot of energy and materials went into the "not so green" cleaning products you have. If they are not immediately hazardous (like chlorine bleach or spray cleaners with 2-butoxyethanol) the most environmental thing to do with them is to use them and buy more environmental products when the ones you have are gone.
June 13, 2008
How does one reconcile being kind to the environment--drinking tap water with estrogens, pharma, and other contaminants in our water--with the lack of regulation for bottled water?
Dear MamaBird:
Kindness to the environment (and to ourselves) clearly begins well before the faucet on our kitchen sinks! If we were more considerate of the impacts on our environment we wouldn't be contaminating our surface and ground water with hundreds, perhaps thousands, of industrial and pharmaceutical chemicals. Buying bottled water is not the answer; doing so only exacerbates the problem.
June 2, 2008
What are dioxins and why should I care about them?
Worried Swimmer
Worried Swimmer
Dioxins are one of the most toxic chemicals known. Dioxin is a general term that describes a group of hundreds of chlorine-containing chemicals that are highly persistent in the environment. The most toxic dioxin is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The major sources of dioxins in the environment are waste-burning incinerators. Dioxins are generated when chlorine-containing materials in the waste stream (such as polyvinylchloride (PVC) plastics) are burned in medical and municipal incinerators.
May 16, 2008
I know there are plastics that shouldn't be exposed to chlorine bleach. Is it safe to put these plastics in the dishwasher with Seventh Generation powdered dishwashing detergent? Thank you!
Dear Susan:
First, my apologies for taking so long to answer your question. We had some logistical and technical issues getting me connected to the Scienceman column, and I've been in and out of the office attending some exciting conferences since the end of March.
May 12, 2008
Is chlorine in tap water harmful? What if you drink straight from the hose?
From Tree-Hugger
From Tree-Hugger
Water from public water supplies has been disinfected with chlorine for over 100 years. There is no doubt that that such disinfection has reduced the occurrence of water-borne disease and helped save thousands of lives. However, over the past 30 years there has developed a body of evidence that chlorination of drinking water results in the formation of a family of toxic substances known as chlorinated hydrocarbons. Members of this family include chloroform, chloroacetic acid, and chlorinated phenols.
April 9, 2008
Is it true duct tape will remove warts?
Proponents of duct tape have long held that it has a special and unique ability to remove warts!
Researchers at the University of Minnesota set out to prove, or disprove, the veracity of this thesis. Working with 90 be-warted adults, researchers covered half the warts with moleskin (a heavy cotton fabric used for bandages) and half with duct tape. At the end of the experiment 21% of the warts covered with duct tape were completely resolved, compared to 22% for the moleskin. Statistically, those are identical outcomes.
Researchers at the University of Minnesota set out to prove, or disprove, the veracity of this thesis. Working with 90 be-warted adults, researchers covered half the warts with moleskin (a heavy cotton fabric used for bandages) and half with duct tape. At the end of the experiment 21% of the warts covered with duct tape were completely resolved, compared to 22% for the moleskin. Statistically, those are identical outcomes.
March 12, 2008
Any idea which way would kill more germs – hanging clothes out in the sun, or drying them at high heat?
--Germ A. Titus
--Germ A. Titus
I don’t know which will kill more germs, and it will probably depend on the level of sunshine, actual dryer temperature, and the pathogens present.
From the standpoint of the clothing, drying in the sun is far superior (less damage to fibers). From the standpoint of the environment, drying in the sunshine is better (less energy and associated greenhouse gases).
To my thinking, there is no reason to use the dryer if drying in the sun is an option.
From the standpoint of the clothing, drying in the sun is far superior (less damage to fibers). From the standpoint of the environment, drying in the sunshine is better (less energy and associated greenhouse gases).
To my thinking, there is no reason to use the dryer if drying in the sun is an option.
April 8, 2008
Where do bubbles come from?
--Cheryl Longway/Foam, MT
--Cheryl Longway/Foam, MT
To make a bubble you need a material that, when spread in a thin film, won't pull itself into a tiny drop (like water pulling itself into a bead on a waxed surface). This tendency to pull into a drop is called surface tension, and water has a high surface tension.
Adding a surfactant (SURFace ACTive AgeNT) to water reduces the surface tension so a bubble can form without collapsing itself into a drop.
Reducing the surface tension of water also allows the water to mix with oil and grease, which is why surfactants are used for cleaning!
Adding a surfactant (SURFace ACTive AgeNT) to water reduces the surface tension so a bubble can form without collapsing itself into a drop.
Reducing the surface tension of water also allows the water to mix with oil and grease, which is why surfactants are used for cleaning!
February 19, 2008
I live in Chicago and I've noticed that the city is building more green roofs. I just assumed that their purpose was to make the building and city look nicer, but then I heard about the 'urban heat island effect' and how green roofs can help reduce it. What is the 'urban heat island effect?'
Thank you!
Curious Chicagoan
Thank you!
Curious Chicagoan
The 'Urban Heat Island Effect' describes the difference in temperature between a city and its surrounding countryside. Cities typically have less vegetation and more impervious surfaces, such as roofs and cement roads, which absorb solar radiation and re-radiate it as heat. Urban and suburban areas can by anywhere from 2 to 10°F (1 to 6°C) hotter than nearby rural areas. The presence of tall buildings and narrow streets can trap air and decrease air circulation, which also contributes to the formation of heat islands.
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