251. Exposures to Ambient Volatile Organic Air Contaminants in A Lightly Industrialized City

2001 ◽  
Author(s):  
T. Hall ◽  
M. Phillips ◽  
A. Gibson ◽  
N. Esmen ◽  
D. Johnson ◽  
...  
Keyword(s):  
Air Contaminants ◽  
Volatile Organic

scholarly journals Contaminant Emissions As Indicators of Chemical Elements in The Snow Along a Latitudinal Gradient in Southern Andes

2020 ◽  
Author(s):  
Jaime Pizarro ◽  
Pablo Vergara ◽  
Sergio Cerda ◽  
Raul Cordero ◽  
Ximena Castillo ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Atmospheric Transport ◽  
Chemical Elements ◽  
Spatial Scales ◽  
Anthropogenic Pollution ◽  
Air Contaminants ◽  
Latitudinal Transect ◽  
Volatile Organic ◽  
Particulate Contaminants

Abstract The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 mm and 10 mm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.

scholarly journals Assessment of Changes in Microbial Community Structure during Operation of an Ammonia Biofilter with Molecular Tools

1998 ◽  
Vol 64 (12) ◽  
pp. 4877-4882 ◽  
Author(s):  
Y. Sakano ◽  
L. Kerkhof
Keyword(s):  
Community Structure ◽  
Inorganic Compounds ◽  
Molecular Techniques ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Monooxygenase ◽  
Air Contaminants ◽  
Gas Streams ◽  
Monooxygenase Gene ◽  
Volatile Organic ◽  
New Gene

ABSTRACT Biofiltration has been used for two decades to remove odors and various volatile organic and inorganic compounds in contaminated off-gas streams. Although biofiltration is widely practiced, there have been few studies of the bacteria responsible for the removal of air contaminants in biofilters. In this study, molecular techniques were used to identify bacteria in a laboratory-scale ammonia biofilter. Both 16S rRNA and ammonia monooxygenase (amoA) genes were used to characterize the heterotrophic and ammonia-oxidizing bacteria collected from the biofilter during a 102-day experiment. The overall diversity of the heterotrophic microbial population appeared to decrease by 38% at the end of the experiment. The community structure of the heterotrophic population also shifted from predominantly members of two subdivisions of theProteobacteria (the beta and gamma subdivisions) to members of one subdivision (the gamma subdivision). An overall decrease in the diversity of ammonia monooxygenase genes was not observed. However, a shift from groups dominated by organisms containingNitrosomonas-like and Nitrosospira-likeamoA genes to groups dominated by organisms containing onlyNitrosospira-like amoA genes was observed. In addition, a new amoA gene was discovered. This new gene is the first freshwater amoA gene that is closely affiliated with Nitrosococcus oceanus and the particulate methane monooxygenase gene from the methane oxidizers belonging to the gamma subdivision of the Proteobacteria.

Volatile organic air contaminants in plants

1997 ◽  
Vol 4 (3) ◽  
pp. 125-129 ◽  
Author(s):  
Anna Górna-Binkul ◽  
Bogusław Buszewski
Keyword(s):  
Air Contaminants ◽  
Volatile Organic

scholarly journals Air Contaminants in an Underwater Vehicle Cabin During Navigation

2021 ◽  
Author(s):  
Jingjing Fang ◽  
Kexian Li ◽  
Xinhong Xu ◽  
Xiaomeng Ren ◽  
Lu Jiang
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Fine Particles ◽  
Underwater Vehicle ◽  
Air Contaminants ◽  
Vehicle Cabin ◽  
Accommodation Space ◽  
Volatile Organic

The purpose of this study is to study the air contaminants in the cabins of underwater vehicle. The basic data help for the better research of the underwater vehicle cabin environment standard and the control strategy. Pretreatment and analysis method of volatile organic compounds was preconcentration combined with gas chromatography under the condition of liquid nitrogen and detected by chromatography-mass spectrometry. The pollution of particles, carbon monoxide and carbon dioxide during the underwater vehicle voyage were monitored by online monitoring instrument. Altogether 34 kinds of pollution components were detected, most of which were low in concentration. Some are low olfactory threshold or high toxic components, such as dimethyldisulfide, benzene, carbon disulfide, trichloromethane, and several reached to ppm level. The contamination of the particles was mainly fine particles and part cabins exceeded the national standard of indoor air quality. The highest concentration of carbon dioxide in accommodation space exceeded the permissible concentration of atmosphere composition aboard diesel underwater vehicle compartments. The increase submerged time made the environment in the cabins deteriorate. The concentration of trace contaminants may close to or beyond the relevant standards with the prolonged time. The volatile organic compounds, particles, carbon monoxide and carbon dioxide aggravated the air circumstance in the cabins. It should be determined the permissible concentration of air contaminants in underwater vehicle as soon as possible.

scholarly journals Contaminant emissions as indicators of chemical elements in the snow along a latitudinal gradient in southern Andes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jaime Pizarro ◽  
Pablo M. Vergara ◽  
Sergio Cerda ◽  
Raúl R. Cordero ◽  
Ximena Castillo ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Atmospheric Transport ◽  
Chemical Elements ◽  
Spatial Scales ◽  
Anthropogenic Pollution ◽  
Air Contaminants ◽  
Latitudinal Transect ◽  
Volatile Organic ◽  
Particulate Contaminants

AbstractThe chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 μm and 10 μm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.

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