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Air, Noise, and Radiation
Published in Gary S. Moore, Kathleen A. Bell, Living with the Earth, 2018
Gary S. Moore, Kathleen A. Bell
Formaldehyde is found in pressed wood products such as cabinets and furniture made from plywood, particleboard, wall paneling, and fiberboard. It is also found in urea formaldehyde foam insulation (UFFI), some textiles and environmental tobacco smoke. However, formaldehyde-emitting products are now being manufactured with much less HCHO emission potential, and emissions from pressed wood products are presently 10 percent of those used 20 years.87 Since older products, and structures, have off-gassed most of the volatile HCHO, and new products have very little HCHO, the significance of formaldehyde as a public health issue has been markedly reduced. Exposures still can occur, which is aggravated in the presence of a confined or poorly ventilated space, combined with high heat and humidity. Adverse health effects include irritation to the mucous membranes, severe allergic reactions, fatigue, wheezing, and coughing.
Evaluation of Changes in Indoor Air Quality Occurring Over the Past Several Decades
Published in Richard B. Gammage, Stephen V. Kaye, Vivian A. Jacobs, Indoor Air and Human Health, 2018
David T. Mage, Richard B. Gammage
In the period following World War II, gradual and sometimes abrupt changes have taken place in people’s life styles and in their homes and workplaces. The demand for improved housing for an increasing population with increased living standards soon outstripped the ability to meet it with traditional building materials such as natural woods. Increasing labor costs led builders to seek alternative materials that were cheaper and could be mass produced and processed. Pressed-wood products and fiberboard were routinely incorporated into new home construction. Household furnishings also changed in composition as plastics and artificial fibers gained acceptance. Household products such as cleansers, insecticides, and personal health care and grooming aid products introduced a host of new synthetic chemicals into the home environment with unknown effects on IAQ and the health of the occupants.
Preparation, Properties, and Bonding Utilization of Pyrolysis Bio-oil
Published in Zhongqi He, Bio-based Wood Adhesives, 2017
An Mao, Zhongqi He, Hui Wan, Qi Li
Phenolic resins are synthesized by reacting formaldehyde with phenols in the presence of alkaline catalyst. As the first commercial synthetic resins, they have been widely used for bonding hot-pressed wood panels, such as plywood, OSB, and laminated veneer lumber (LVL) for their good bonding performance and high exterior durability (Gardziella et al., 2000). Phenol is a petroleum-derived chemical, which means it cannot be obtained directly from biomass in a commercial scale now and its price and availability are closely related to those of fossil fuels. This contradicts with current trends of reducing dependence on nonrenewable resources and promoting the utilization of sustainable bio-based products. Therefore, developing technologies for using alternative raw materials, such as biomass-derived phenols is necessary.
Passive phosphorus capture in biofiltration context: nitrate impact on the performance
Published in Environmental Technology, 2020
Soureyatou Hamidou, Rino Dubé, Paul Lessard, Gerardo Buelna, Caetano C. Dorea, Yann LeBihan
Nitrate reduction occurs in columns C2, C3 and C4 according to Figure 6. This reduction is carried out periodically. Denitrification was practically complete in column C2 at a percentage of 92.2%, compared to 67.5 and 24.9% for columns C3 and C4. The shape of column C2’s curve is substantially similar to the control’s without nitrate. With an initial concentration of 5 mg N-NO3 L−1 in the influent, the average concentration in the effluent was 0.4 mg N-NO3 L−1. For C3 and C4 fed with initial concentrations of 10 and 25 mg N-NO3 L−1, the averages values in the effluent were 3 and 18 mg N-NO3 L−1. It can be noticed (Figure 6) that denitrification was at it highest during the thirty-two days following the addition of nitrate. After that, the performance of denitrification was relatively low for the remaining days. This decrease may have been caused by the depletion of organic matter that comes from the degradation of certain compounds (adhesive, cardboard, pressed wood) present within the filter medium as corroborated by decreased columns effluent COD (Figure 5). The measured values of COD on the 60th day were 37, 30 and 20 mg L−1 for C2, C3 and C4, respectively, whereas it drops to 12 mg L−1 on the 115th day of operation.
Passive environmental design of an eco-house in the hot-humid climate of the Middle East: A qualitative approach
Published in Cogent Engineering, 2020
Maatouk Khoukhi, Awni K. Shaaban, Omar Al Khatib
Formaldehyde is a toxic chemical compound and water-soluble VOC, which is widely used, both by itself and as a constituent, in other construction materials or products. Formaldehyde continues to release dangerous gases for years after it has been initially used; furthermore, exposure to this hazardous material is associated with numerous health effects such as “eye and upper respiratory tract irritation, headaches, drowsiness, and gastrointestinal disturbances” (Committee on Toxicology, Board on Toxicology and Environmental Health Hazards National Research Council, 1980). Formaldehyde is used in many construction materials, products, and industrial processes, including pressed-wood layers (MDF), thermal insulation foams, plastic products, chipboard and plywood, adhesives, glues, wall paneling, and furniture. Typical guidelines of green building design should place emphasis on the use of possible formaldehyde alternatives such as cellulose insulation in lieu of foam insulation; in addition, natural timber would be an expensive replacement of MDF and chipboard as compared with the health risks associated with this indoor pollutant (Halliday, 2008).