scholarly journals Observing ozone chemistry in an occupied residence

2021 ◽  
Vol 118 (6) ◽  
pp. e2018140118
Author(s):  
Yingjun Liu ◽  
Pawel K. Misztal ◽  
Caleb Arata ◽  
Charles J. Weschler ◽  
William W Nazaroff ◽  
...  

Outdoor ozone transported indoors initiates oxidative chemistry, forming volatile organic products. The influence of ozone chemistry on indoor air composition has not been directly quantified in normally occupied residences. Here, we explore indoor ozone chemistry in a house in California with two adult inhabitants. We utilize space- and time-resolved measurements of ozone and volatile organic compounds (VOCs) acquired over an 8-wk summer campaign. Despite overall low indoor ozone concentrations (mean value of 4.3 ppb) and a relatively low indoor ozone decay constant (1.3 h−1), we identified multiple VOCs exhibiting clear contributions from ozone-initiated chemistry indoors. These chemicals include 6-methyl-5-hepten-2-one (6-MHO), 4-oxopentanal (4-OPA), nonenal, and C8-C12 saturated aldehydes, which are among the commonly reported products from laboratory studies of ozone interactions with indoor surfaces and with human skin lipids. These VOCs together accounted for ≥12% molecular yield with respect to house-wide consumed ozone, with the highest net product yield for nonanal (≥3.5%), followed by 6-MHO (2.7%) and 4-OPA (2.6%). Although 6-MHO and 4-OPA are prominent ozonolysis products of skin lipids (specifically squalene), ozone reaction with the body envelopes of the two occupants in this house are insufficient to explain the observed yields. Relatedly, we observed that ozone-driven chemistry continued to produce 6-MHO and 4-OPA even after the occupants had been away from the house for 5 d. These observations provide evidence that skin lipids transferred to indoor surfaces made substantial contributions to ozone reactivity in the studied house.

2019 ◽  
Vol 21 (8) ◽  
pp. 1255-1267 ◽  
Author(s):  
Kyle Chin ◽  
Aurelie Laguerre ◽  
Pradeep Ramasubramanian ◽  
David Pleshakov ◽  
Brent Stephens ◽  
...  

Insulation materials affect indoor air by (i) releasing primary volatile organic compounds (VOCs) from enclosure cavities to the interior space, (ii) mitigating exposure to outdoor pollutants through reactive deposition (of oxidants, e.g., ozone) or filtration in infiltration air, and (iii) generating secondary VOCs and gas-phase byproducts from chemical reactions.


Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 250
Author(s):  
Chuloh Jung ◽  
Jihad Awad

Due to unprecedented urbanization, UAE had built many new residential projects with poor choices of material and ventilation. This social phenomenon is leading UAE to Sick Building Syndrome (SBS) faster than any other countries. The Dubai Municipality regulates the indoor air quality with strict stipulation, but the detailed regulations are still insufficient. The objective of this paper is to measure the indoor air quality of new residential projects in Dubai to suggest the improvement of the regulations for indoor air quality. As a methodology, a field survey was conducted to investigate the status of indoor air pollution in residential buildings. Based on the field survey data, lab experiments for building materials were conducted and a computer simulation on radon gas was conducted. The result had shown that radon gas was mainly detected in new townhouses and labor camp houses, and its concentration was found to exceed the standard. Volatile organic solvents (VOCs) and formaldehyde (CH2O) were mainly detected in showhouses and new townhouses, and the concentration distribution was about 10 times higher than that of outdoors. It was proven that emission concentration of radon gas from various building materials were detected, and the order was red clay, gypsum board, and concrete. Volatile organic solvents (VOCs) are mainly detected in oil paints and PVC floor and the radiation amount of all pollutants increased with temperature increase. In computer simulation, it was found that a new townhouse needs a grace period from 20 days to 6 months to lower the radon gas concentration by 2 pCi/L. This study will serve as a basic data to establish more detailed regulation for the building materials and improve the IAQ standards in Dubai.


Author(s):  
Mario Vincenzo Russo ◽  
Ivan Notardonato ◽  
Alberto Rosada ◽  
Giuseppe Ianiri ◽  
Pasquale Avino

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.


Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 806
Author(s):  
Ozge Cemiloglu Ulker ◽  
Onur Ulker ◽  
Salim Hiziroglu

Volatile organic compounds (VOCs) are the main source influencing the overall air quality of an environment. It is a well-known fact that coated furniture units, in the form of paints and varnishes, emit VOCs, reducing the air quality and resulting in significant health problems. Exposure time to such compounds is also an important parameter regarding their possible health effects. Such issues also have a greater influence when the exposure period is extended. The main objective of this study was to review some of the important factors for the emission of VOCs from coated furniture, from the perspective of material characteristics, as well as health concerns. Some methods for controlling VOC emissions to improve indoor air quality, from the point of view recent regulations and suggestions, are also presented in this work.


Indoor Air ◽  
1994 ◽  
Vol 4 (2) ◽  
pp. 123-134 ◽  
Author(s):  
S. K. Brown ◽  
M. R. Sim ◽  
M. J. Abramson ◽  
C. N. Gray

1984 ◽  
Vol 98 (12) ◽  
pp. 1213-1216 ◽  
Author(s):  
Harbans Lal ◽  
O. P. Sachdeva ◽  
H. R. Mehta

AbstractSerum immunoglobulin (IgG, IgA and IgM) levels were determined in patients with chronic tonsillitis before and one month after tonsillectomy. The preoperative levels of serum IgG, IgA and IgM were significantly higher when compared with the controls. The increase may be due to repeated antigenic stimulation. The post-operative levels for the three immunoglobulins were decreased; however, a significant reduction was observed for IgG only where the mean value was comparable with the control group. The data confirm that tonsillectomy does not disturb the humoral immune system of the body.


2021 ◽  
Vol 8 (3) ◽  
pp. 147-152
Author(s):  
Mosmi Lomi ◽  
Jonathan Daniel M

Determining gender is one of the most important procedure in forensics. Teeth are made of the most enduring mineralized tissues in the body, as such, they have an extraordinary resistance to putrefaction and the effects of external agents (physical, thermal, mechanical, chemical or biological) which makes them invaluable material for anthropological, genetic, odontologic and forensic examinations.i)To assess the degree of sexual dimorphism in maxillary canine using maxillary canine index, maxillary first molar and central incisor using mesiodistal (MD) and buccolingual/buccopalatal (BL) dimensions of the crown. ii) To determine the accuracy of maxillary canine index, first molar and central incisor dimensions (mesiodistal and buccolingual/buccopalatal) in determining sex.This study consisted of total 30 participants (males=15, females=15) of age group ranging from 20 to 35 yrs. Measurement of dimensions of selected teeth were performed on maxillary cast using digital Vernier caliper, resolution 0.01mm. Data thus obtained were analyzed statistically.The mean values of all the measurements in males were greater than females. There was statistical significant difference in mean value of bucco-lingual width of molar, mesiodistal width of canine (on left side, right side and average) and the inter-canine distance between males and females. The buccolingual width of molar showed the highest % of sexual dimorphism (5.33%) and the mesiodistal width of molar showed the least % of dimorphism (0.7%). Bucco-lingual width of molar posed the highest prediction accuracy for gender determination. We conclude that buccolingual width of maxillary first molar can be used to predict the gender when only teeth of maxillary arch are available for forensic examination.


Author(s):  
L. L. Zakharova ◽  
◽  
G. A. Zhorov ◽  
V. N. Obryvin ◽  
◽  
...  

The article presents the results of laboratory studies of the effect of sorption-detoxifying means on the accumulation of 90Sr in the body of white rats. The efficiency of a number of selective and polyfunctional sorbents, detoxicants and other biologically active substances and the developed on their basis sorption-detoxifying complexes as means of efferent therapy and detoxification of the animal body at the combined intake of xenobiotics of radiation and chemical nature was evaluated. It was found that 90Sr cumulation in bones (at the level of 53,3–60,8%) was reduced to the greatest extent with the combined use of substances of different mechanisms of action and origin. The effectiveness of separate use of detoxifying drugs did not exceed 29,1%.


Sign in / Sign up

Export Citation Format

Share Document