The results from a publication: “the public health benefits of insulation retrofits in existing housing in the United States” from theDepartment of Environmental Health, Harvard School of Public Health, Boston, MA, USA, authors Jonathan I Levy, Yurika Nishioka and John D Spengler shows:
If 46 million existing single-family homes in the United States that have inadequate insulation were retrofitted with additional insulation to meet the 2000 IECC* the benefits are:
The health benefits correspond to $1.3 billion per year in externalities averted such health care, and $5.9 billion per year in additional savings associated with reduced energy consumption In total, the insulation retrofits would save 800 TBTU (8 × 1014 British Thermal Units) per year across 46 million homes which would result in lower emissions of:
PM2.5 are particulate smaller than 2.5 microns that have adverse health effects such as premature death, increased respiratory symptoms and disease, chronic bronchitis and decreased lung function.
Nitrous Oxide (NOx): When NOx and volatile organic compounds (VOCs) react in the presence of sunlight; they form photochemical smog, a significant form of air pollution.
Sulfur dioxide (SO2): is also a precursor to tiny sulfate particulates, these particulates can accumulate in the lungs and cause or worsen respiratory disease.
* The 2000 IECC is a public/private sector consensus standard which outlines a minimum energy code for new homes. The US Department of Energy (DOE) and others recommend even higher R-values for insulation in Florida.
The International Agency for Cancer Research (IACR) recently removed glass, rock and slag wool fibers from the list of possible carcinogens, research conducted over the past 70 years shows when the exposure levels are low, even if inhaled into the lung, most fibers disappear quickly with no adverse sides effects.
The IARC change is consistent with the conclusion reached by the U.S. National Academy of Sciences, which in 2000 found no significant association between fiber exposure and lung cancer or nonmalignant respiratory disease in the MVF [man-made vitreous fiber] manufacturing environment.
From NAIMA publication: Facts #62: Health and Safety Facts for Fiber Glass (N040)
Fiberglass insulation will not sustain mold growth. However, mold can grow on almost any material when it becomes wet and contaminated. Carefully inspect any insulation that has been exposed to water and if it shows any sign of mold, it must be discarded. If the material is wet, but shows no evidence of mold, it should be dried rapidly and thoroughly. If it shows signs of facing degradation from wetting, it should be replaced.
Cellulose fiber is a relatively safe and very satisfactory insulating material; it still contains borates, sulfates and other chemicals that could be potentially irritating, in general people may not be bothered at all but little insulation dust in the house.
The rule of thumb to protect the residents of the house is to keep any insulation material out of the living spaces. Proper air and duct leak sealing should take place before insulation, especially for people more sensitive than the general population. We use mandatory safety equipment, follow all safety guidelines and thoroughly clean up after the installation of insulation.
According to the Environmental Protection Agency (EPA), indoor levels of pollutants may be 2 to 5 times and occasionally more than 100 times higher than outdoor pollutant levels. Indoor air pollutants have been ranked among the top five environmental risks to public health.
There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated cabinets, asbestos-containing insulation, wet or damp carpet, furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution.
EPA states “Deficient ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some pollutants”.
Home air sealing, A/C system, adequate ventilation, building materials and furnishings are key factors to analyze when you expect to improve your interior air quality.