Ultrasonic humidifiers said to threaten health
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WftâWfôïWÎÎ?ffî G M Ε Μ I C A L S NEWSCRIPTS by K. M. Reese The formula for success. Today and tomorrow. RASCHIG Chemicals - backed by know-how, tradition, futureoriented innovation, tailormade products, and distinct sense of quality. A constant challenge to our staff of more than 800 qualified collaborators. RASCHIG RASCHIG CORP 5000 Osborne Tpke Richmond, Va. 23231, USA Phone (804) 222-9516 Telefax (804) 2261569 in other countries: RASCHIG AG Mundenheimer StraBe 100 D-6700 Ludwigshafen Phone (621) 561 81 Telefax (6 21) 58 28 85 Telex 464877 ralud Ultrasonic humidifiers said to threaten health Ultrasonic humidifiers, like practi- cally everything else, it seems, may be hazardous to your health, accord- ing to V. Ross Highsmith and Charles E. Rodes of the Environ- mental Protection Agency, Research Triangle Park, N.C., and Richard J. Hardy of Morrison-Knudsen Engi- neers, Boise, Idaho [(Environ. Set. Technol., 22, 1109 (1988)]. The prob- lem is respirable particles. Homeowners have long used por- table humidifiers to relieve symp- toms such as dry nose, throat, and lips caused by dry air. Convention- al humidifiers, which use steam or impellers to disperse moisture, are rapidly being replaced by ultrason- ic devices. Ultrasonic humidifiers are extremely quiet, can humidify larger volumes than earlier equip- ment, and may ease problems with mold and bacteria. Highsmith, Rodes, and Hardy got on to the particle problem while evaluating the impact of wood- burning appliances on air quality in homes in Boise. In one home, with no wood-burning equipment, they found unexpectedly high lev- els of particles in the respirable size range (less than 2.5 μπι aerodynam- ic diameter). They traced the prob- lem to an ultrasonic humidifier "in a sick child's bedroom"—a nice Dickensian note. Confirmatory studies by the au- thors indicated that about 90% of the total dissolved solids in water fed to an ultrasonic humidifier is emitted in the form of respirable particles. In the bedroom of one residence, they say, respirable par- ticle concentrations exceeded 590 μζ per cubic meter when an ultrasonic humidifier was operating in the kitchen on tap water containing 303 mg per L total dissolved solids. When the humidifier was operat- ing in a closed room, respirable par- ticle concentrations exceeded 6300 Mg per eu m. The impeller units tested generated less than a third of the fine particle mass produced by the ultrasonic units. A steam hu- midifier produced no measurable in- crease above background level. Earlier tests of ultrasonic humidi- fiers had shown that particles— termed "dread white dust"—settle on horizontal surfaces near the units. These particles were believed, how- ever, to be too far above the respi- rable size range to pose a signifi- cant health problem. Still, manu- facturers recommend that ultrasonic humidifiers be fed with distilled or deionized water bought for the pur- pose, or with tap water passed through demineralization cartridges. Some manufacturers warn owners that the white dust may be hazard- ous to their health. However, most homeowners seem to ignore these warnings because it's easier and cheaper to use plain tap water, ac- cording to Highsmith, Rodes, and Hardy. Long-term exposure to the con- centrations of fine particles found in their experiments, the authors say, could result in acute or chronic health problems. The discomfort for people with respiratory problems, such as asthma, may completely off- set the benefits of higher humidity. Ultrasonic humidifiers and, to a less- er degree, impeller units could dis- perse waterborne impurities such as lead, aluminum, asbestos, or dis- solved organic gases. Comparison of total dissolved solids in Boise wa- ter with that in other municipally supplied water indicates that the fine-particle problem can be expect- ed to occur across the nation. Too many meetings Too many meetings are being held in Beijing, according to China Daily for July 4. Another newspaper, Guangming Daily, has called for a law that would minimize the num- ber of meetings. The proliferation of meetings, says China Daily, "has not only caused great economic losses to the State but [has] left a bad impression on society." Beijing officials say that 40,000 to 50,000 people attend meet- ings every day. Each month the city must supply them with 160,000 kg of pork, 80,000 kg of eggs, and 30,000 kg of sugar "in addition to high quality cigarettes and wine." 60 August 29, 1988 C&EN TENSIDE SULFOPROPYL- BETAINE ANTIOXIDANTS PYRIDIN- DERIVATE
Transcript of Ultrasonic humidifiers said to threaten health
WftâWfôïWÎÎ?ffî G M Ε Μ I C A L S
NEWSCRIPTS by K. M. Reese
The formula for success. Today and tomorrow. RASCHIG Chemicals -backed by know-how, tradition, futureoriented innovation, tailormade products, and distinct sense of quality. A constant challenge to our staff of more than 800 qualified collaborators.
RASCHIG
RASCHIG CORP 5000 Osborne Tpke Richmond, Va. 23231, USA Phone (804) 222-9516 Telefax (804) 2261569 in other countries: RASCHIG AG Mundenheimer StraBe 100 D-6700 Ludwigshafen Phone (621) 561 81 Telefax (6 21) 58 28 85 Telex 464877 ralud
Ultrasonic humidifiers said to threaten health Ultrasonic humidifiers, like practically everything else, it seems, may be hazardous to your health, according to V. Ross Highsmith and Charles E. Rodes of the Environmental Protection Agency, Research Triangle Park, N.C., and Richard J. Hardy of Morrison-Knudsen Engineers, Boise, Idaho [(Environ. Set. Technol., 22, 1109 (1988)]. The problem is respirable particles.
Homeowners have long used portable humidifiers to relieve symptoms such as dry nose, throat, and lips caused by dry air. Conventional humidifiers, which use steam or impellers to disperse moisture, are rapidly being replaced by ultrasonic devices. Ultrasonic humidifiers are extremely quiet, can humidify larger volumes than earlier equipment, and may ease problems with mold and bacteria.
Highsmith, Rodes, and Hardy got on to the particle problem while evaluating the impact of wood-burning appliances on air quality in homes in Boise. In one home, with no wood-burning equipment, they found unexpectedly high levels of particles in the respirable size range (less than 2.5 μπι aerodynamic diameter). They traced the problem to an ultrasonic humidifier "in a sick child's bedroom"—a nice Dickensian note.
Confirmatory studies by the authors indicated that about 90% of the total dissolved solids in water fed to an ultrasonic humidifier is emitted in the form of respirable particles. In the bedroom of one residence, they say, respirable particle concentrations exceeded 590 μζ per cubic meter when an ultrasonic humidifier was operating in the kitchen on tap water containing 303 mg per L total dissolved solids. When the humidifier was operating in a closed room, respirable particle concentrations exceeded 6300 Mg per eu m. The impeller units tested generated less than a third of the fine particle mass produced by the ultrasonic units. A steam humidifier produced no measurable increase above background level.
Earlier tests of ultrasonic humidifiers had shown that particles— termed "dread white dust"—settle on horizontal surfaces near the units. These particles were believed, however, to be too far above the respirable size range to pose a significant health problem. Still, manufacturers recommend that ultrasonic humidifiers be fed with distilled or deionized water bought for the purpose, or with tap water passed through demineralization cartridges. Some manufacturers warn owners that the white dust may be hazardous to their health. However, most homeowners seem to ignore these warnings because it's easier and cheaper to use plain tap water, according to Highsmith, Rodes, and Hardy.
Long-term exposure to the concentrations of fine particles found in their experiments, the authors say, could result in acute or chronic health problems. The discomfort for people with respiratory problems, such as asthma, may completely offset the benefits of higher humidity. Ultrasonic humidifiers and, to a lesser degree, impeller units could disperse waterborne impurities such as lead, aluminum, asbestos, or dissolved organic gases. Comparison of total dissolved solids in Boise water with that in other municipally supplied water indicates that the fine-particle problem can be expected to occur across the nation.
Too many meetings Too many meetings are being held in Beijing, according to China Daily for July 4. Another newspaper, Guangming Daily, has called for a law that would minimize the number of meetings.
The proliferation of meetings, says China Daily, "has not only caused great economic losses to the State but [has] left a bad impression on society." Beijing officials say that 40,000 to 50,000 people attend meetings every day. Each month the city must supply them with 160,000 kg of pork, 80,000 kg of eggs, and 30,000 kg of sugar "in addition to high quality cigarettes and wine."
60 August 29, 1988 C&EN
TENSIDE SULFOPROPYL-BETAINE ANTIOXIDANTS PYRIDIN-DERIVATE
