October News on Air Polution
For The IAQ Industry
Oct, 2007 Vol.1
Candle Problems
300 million candles are sold in the US each year. It is estimated that at least 3 million of those have wicks that contain lead. Depending upon the amount of candle burning activity, the number burning simultaneously, and indoor room conditions, lead concentrations in excess of both environmental and occupational standards could occur. While the primary danger is from inhalation, the deposition of lead-bearing fine particulate in household dust provides a secondary exposure route for babies and toddlers due to their ubiquitous hand-to-mouth behavior. It was found that individual candles emitted lead to the air at average rates that ranged from 100 to 1700 µg/hr. deposition. This can easily ra ise the source room concentration above the ambient air lead concentration limit of 1.5 µg/m3 set by EPA. Burning multiple candles can elevate it above OSHA permissible exposure limits of 50 µg/m3.
Furnishings Coating
Practically all furnishings sold in the U.S. have a coating on the surface to provide water and stain protection and to enhance appearance. One type of coating used extensively in the furniture industry is the alkyd/urea-formaldehyde topcoat. These are thermo setting resins and are frequently called conversion varnishes or catalyzed finishes. Fr om an indoor air perspective, these varnishes are of interest because VOCs, including formaldehyde, may be emitted during use. It has been proven that these long-lasting formaldehyde emiss ions can cause elevated concentrations in indoor environments. Tests have indicated that a set of kitchen cabinets installed in a typical house will produce formaldehyde of16µg/m3 (12 ppb).
Sick Building Occupants
The relationship between personal and environmental characteristics, occupational factors and psychosocial correlates of sick building syndrome was investigated among 348 employees occupying two buildings. One building was characterized as ‘sick’, while the other was not a known sick building.
Occupants in the ‘sick’ building had a propensity to remain absent from work for significantly more days, and experienced greater productivity decrements.