Effect of relative humidity on the airborne survival of rhinovirus-14

Rhinovirus-14, suspended in tryptose phosphate broth supplemented with uranine (physical tracer) and an antifoam, was aerosolized by use of a Collison nebulizer. The aerosols were held in a rotating drum with the relative humidity at either the low (30 ± 5%), medium (50 ± 5%), or high (80 ± 5%) level at 20 ± 1 °C. An all-glass impinger was used to recover the virus from the air in the drum, with the first air sample being collected after a 15-min period of aerosol stabilization. Subsequent air samples were withdrawn at 2, 4, 8, and 14 h after stabilization of the aerosol. At the low and medium relative humidity levels, the infectivity of the airborne virus was rapidly lost and less than 0.25% could be detected in the first air sample. At the high RH level, however, the airborne virus had a half-life of 13.7 ± 1.91 h and nearly 30% of the input infectious virus could be detected in the drum air even after 24 h of aerosolization. These findings suggest that under certain environmental conditions, notably high relative humidity, air may act as a vehicle for the spread of rhinovirus infections.

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Effect of relative humidity, atmospheric temperature, and suspending medium on the airborne survival of human rotavirus

Canadian Journal of Microbiology ◽

10.1139/m85-129 ◽

1985 ◽

Vol 31 (8) ◽

pp. 681-685 ◽

Cited By ~ 31

Author(s):

M. Khalid Ijaz ◽

Syed A. Sattar ◽

C. Margaret Johnson-Lussenburg ◽

V. Susan Springthorpe ◽

Rama C. Nair

Keyword(s):

Relative Humidity ◽

Half Life ◽

Atmospheric Temperature ◽

High Relative Humidity ◽

Rotating Drum ◽

Virus Particles ◽

Human Rotavirus ◽

Tryptose Phosphate Broth

The Wa strain of human rotavirus, grown in MA-104 cells, was suspended either in tryptose phosphate broth or feces from a case of rotaviral diarrhea. It was then aerosolized into a rotating drum using a Collison nebulizer. The drum air was sampled using an all-glass impinger containing tryptose phosphate broth as collecting fluid. At 20 ± 1 °C, the virus aerosolized from tryptose phosphate broth was found to survive best at 50 ± 5% relative humidity, where its half-life was 44.2 ± 6.3 h. At 30 ± 5% and 80 ± 5% relative humidity, the half-life of the virus was 24.5 ± 3.5 and 3.8 ± 1.0 h, respectively. At 6 ± 1 °C, the airborne survival of the virus at the mid and low relative humidity levels was further enhanced, but at the high relative humidity it remained very similar to that seen at 20 ± 1 °C. When aerosols of fecally suspended human rotavirus were held at 20 ± 1 °C with 50 ± 5% relative humidity, nearly 80% of the airborne virus particles remained infectious even at the aerosol age of 24 h. These findings may help in our understanding of the epidemiology of rotaviral infections.

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Thermodynamic stability of gilded copper and pigments at high relative humidity and at environmental conditions of Lima, Perú

Journal of Physics Conference Series ◽

10.1088/1742-6596/1938/1/012003 ◽

2021 ◽

Vol 1938 (1) ◽

pp. 012003

Author(s):

A Alviz-Meza ◽

J C F Rodríguez-Reyes ◽

J A Chacaliaza

Keyword(s):

Relative Humidity ◽

Thermodynamic Stability ◽

Environmental Conditions ◽

High Relative Humidity

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Conservació i condicionament de la vitrina de les sals del Museu Martorell (Museu de Ciències Naturals de Barcelona): 1921-2018

Treballs del Museu de Geologia de Barcelona ◽

10.32800/tmgb.2018.24.0025 ◽

2019 ◽

pp. 25-37

Author(s):

M. Campeny ◽

M. Pérez-Azcárate ◽

S. Duque-Valero ◽

D. Fernández-Lluch ◽

E. Garcia-Franquesa ◽

...

Keyword(s):

Relative Humidity ◽

19Th Century ◽

Environmental Conditions ◽

High Relative Humidity ◽

Optimal Conditions ◽

Original Design ◽

Salt Rocks ◽

Sustainable System ◽

Set Up ◽

Over Time

Conservation and conditioning of the salts showcase of the Museu Martorell (Museu de Ciències Naturals de Barcelona): 1921-2018 The Cardona salts showcase was built and designed in 1921 by Francesc Pardillo. Located at the Museu Martorell building (Museu de Ciències Naturals de Barcelona) it exposes and preserves a collection of salt rocks from the Cardona Salt Mountain. These specimens were donated at the end of 19th century by Ms. Casilda de Salabert i Arteaga (Medinaceli Duchess) and Mr. Miguel De Elías Marchal and represent a collection with a significant heritage and historic value. Due to the trace of time and the lack of conditioning interventions, this showcase did not preserve the samples in optimal conditions. The specimens began an alteration process interacting with high relative humidity, also generating the general degradation of the showcase furniture. In order to stop this degradation, it has been carried out an integral conditioning of this showcase but also of the salt specimens. This process has been executed respecting the original design of the showcase and carrying out the minimum intervention into the rock samples. In addition, a new passive and sustainable system to control environmental conditions has been set up to maintain optimal humidity conditions. This action stopped the degradation of the showcase as well as the specimens and guarantees their preservation over time.

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