Dr. Tiina Reponen, PhD has been interested in IAQ since writing her master’s thesis in Finland in 1985. She is a Professor in the Dept. of Environmental Health, College of Medicine at the University of Cincinnati. As an expert in indoor allergens and mold, she served as the principal investigator in several major laboratory and field experiments on airborne allergens, bacteria and fungi and has directed exposure assessment teams in population based studies.
Nuggets mined from today’s episode:
She has studied contamination in metalworking fluids, agricultural worker exposure to bioaerosols, fire fighter exposure to ultrafine particles and home healthcare worker’s occupational safety and health.
We shouldn’t focus only on mold, bacteria such as actinomycetes need to be included.
We still don’t know what in water damaged buildings causes health effects.
When approaching the study of health effects in water damaged buildings mold and bacteria are the best currently available surrogates.
Has seen studies in which visible mold is an indicator of more adverse health effects. In a longitudinal study, children under 1 year old who were exposed to physical mold demonstrated a health association up to age three. PCR based assessment showed an association between early exposure and development of asthma later on life. 36 Species of fungi were studied and strongest association was found with 2 aspergillus and 1 penicillium species. Children who were studied who developed asthma did so by age 7.
In the same study, there was an inverse association of wheezing to Beta glucans.
For exposure assessments she uses a combination of quantitative measurements with visual and olfactory assessment. She uses epidemiological studies and comparisons of microscopy and PCR, Beta glucans and endotoxin sampling. Quantitative assessment doesn’t always correlate well with visible fungal contamination.
The field of microbiome sampling is developing quickly, more data is needed before it enters mainstream.
Several different sampling devices utilize biofluorescence. The more wavelengths the device uses the more identification possible. Use of biofluorescence devices may be useful for better selection of respiratory protection.
A U-shaped bell curve is typical for filtration efficiency HEPA filters have their minimum efficiency at 0.3 micrometers.
Fungal fragments is one of her favorite topics. Using particle counters, her research was among the first to show how fungal particles are released into the air. Upon further analysis, airborne fungal particles often contain fragments of building materials upon which the fungi fed; an exposure that is overlooked by other sampling methods.
Fungal fragments are small so they stay in air longer and are more likely to be transported by air currents. Fragment and spore counts don’t correlate. In cold climates, higher fragment counts are commonly seen in winter when dry.
The inverse protective effect of Beta glucans on wheezing in young children was a surprising discovery.
Opines there is some truth to the hygiene hypothesis.
In a study of homes in New Orleans following Hurricanes Katrina and Rita in which workers were doing remediation airborne concentrations of particulate were shown to have increased 1,000 times from background. Disposable N95 dust masks were found to have a protection factor of <10. Elastomeric N95 devices provided protection factor of 40. For mold remediation OSHA and EPA base their respiratory PPE recommendations on the size of the affected areas and likelihood of aerosolization. The bigger the affected area the higher level of protection is recommended. Respiratory PPE should be fit tested. Act quickly while materials remain wet to minimize aerosolizing of particulate.
She recommends going one step further by providing workers with the next level of respiratory PPE.
Bat guano and the bird feces contain protein and prevent a fungal infection risk to workers. PAPR with tight fitting facepiece is recommended.
Firefighters suffer from higher levels of cancer and heart disease from ultrafine particles and incomplete combustion byproducts. Combustion particles more readily penetrate air filters. The N, R and P which appear before the protection factor number refers to resistance to oil- N= not oil resistant, R= oil resistant and P= oil proof. Oil resistant R or oil proof filters P are recommended for fire damage restoration work. When combustion residues are off-gassing a gas/vapor phase cartridge in conjunction with particle filter is recommended.
She has studied vacuum cleaners for use in lead abatement. Studied 3 different types of vacuums: filter, cyclonic and water. Holes were strategically drilled into the vacuums for instrument probes. An ASTM method was used to imbed dust on test surfaces. Filter bags were weighed before and after use. The filter type vacuum was shown to perform best; particularly when filter was positioned after the motor. The cyclonic and water vacuums re-entrained particulate after loading. In two passes vacuums removed virtually all test dust from hard surfaces. Vacuuming removed fibers from new carpet prior to soiling. After soiling and 10 vacuum passes, 20% of test dust remained in carpet.
Outside air influences inside air and the indoor microbiome. Pets that go outside can bring contaminates indoors. Indoor sources include humans (for bacteria), moisture-damages materials, handling of organic material, such as firewood, moldy food items.
Green Renovation and IAQ
A study of child asthma in renovated low income homes in Cincinnati, OH was part of a larger study. Houses were studied before renovation, and 6 months/12 months after. Energy efficiency retrofit included: roofs, windows, doors, improved insulation, bathroom exhaust fans, kitchen exhausts, more energy efficient furnaces and appliances, low VOC emitters. Found people effect IAQ more than green renovation; occupants and their lifestyle choices are the primary sources of indoor contaminates. Found less traffic related particles after renovation.
- Fungal fragments
- Availability and increased use of sensors.
Z-Man signing off
Name the US Government Agency that is promoting productive workplaces through safety and health research.
The National Institute for Occupational Safety and Health (NIOSH)