scholarly journals Seasonal variations in the level of mutagenicity: an assessment of respirable particulate matter in Rio de Janeiro, Brazil

2014 ◽  
Author(s):  
C. R. Rainho ◽  
S. M. Corrêa ◽  
J. L. Mazzei ◽  
C. A. F. Aiub ◽  
I. Felzenszwalb
Keyword(s):  
Particulate Matter ◽  
Seasonal Variations ◽  
Rio De Janeiro ◽  
Respirable Particulate

scholarly journals Airborne Particulate Matter Density in Traditional Bakeries of Saveh, Central of Iran, in 2020

2020 ◽  
Author(s):  
Edris Hoseinzadeh ◽  
Mehrzad Ghorbani ◽  
Mahdi Safari ◽  
Najmeh Ebrahimi
Keyword(s):  
Particulate Matter ◽  
Particle Concentration ◽  
Gravimetric Method ◽  
Airborne Particulate Matter ◽  
High Concentration ◽  
Cross Sectional ◽  
Flour Dust ◽  
Average Size ◽  
High Level ◽  
Respirable Particulate

Introduction: High concentration of inhalable airborne particles can increase the risk of lung disease in exposed people. This study aimed to determine the respirable particulate matter (PM5) concentration in traditional bakeries of Saveh in 2020. Materials and Methods: This cross-sectional descriptive study was conducted among 25 bakeries where the samples were collected by cyclone and teflon filter equipped by air sampling pump. Later, the respirable particulate matter concentration was measured using gravimetric method. The collected PM5 was scanned using a FTIR (Fourier-transform infrared spectroscopy) with regard to flour dust. In addition, size and shape of the collected PM5 were analyzed using a scanning electron microscope (SEM). Results: Findings showed that the Lavash bakery had the highest PM5 concentration (9.15 mg/m3) in comparison with two other bakeries (Sangak and Barbari). However, an inverse relationship was observed between RH and particle concentration. In addition, the results demonstrated that increasing RH decreased the particle concentration, but the relationship was not significant (P = 0.052, Spearman's rho = -0.393). Furthermore, Lavash bakery had the lowest average size of PM5 (0.63 ± 0.32 μm). However, the FTIR scans confirmed that the flour dust had the predominant amount of PM5. Conclusion: Based on the findings, the density of respirable PM5 has a high level in Saveh bakeries and workers  are exposed to high levels of PM.

scholarly journals Spatial and Seasonal Variations of PM Concentration and Size Distribution in Manure-Belt Poultry Layer Houses

2019 ◽  
Vol 62 (2) ◽  
pp. 415-427 ◽  
Author(s):  
Reyna M. Knight ◽  
Xinjie Tong ◽  
Zhenyu Liu ◽  
Sewoon Hong ◽  
Lingying Zhao
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Size Distribution ◽  
Seasonal Variations ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Potential Health ◽  
Significant Difference ◽  
Autumn And Winter ◽  
Mass Concentrations

Abstract. Poultry layer houses are a significant source of particulate matter (PM) emissions, which potentially affect worker and animal health. Particulate matter characteristics, such as concentration and size distribution inside layer houses, are critical information for assessment of the potential health risks and development of effective PM mitigation technologies. However, this information and its spatial and seasonal variations are lacking for typical layer facilities. In this study, two TSI DustTrak monitors (DRX 8533) and an Aerodynamic Particle Sizer (APS 3321) were used to measure PM mass concentrations and number-weighted particle size distributions in two typical manure-belt poultry layer houses in Ohio in three seasons: summer, autumn, and winter. Bimodal particle size distributions were consistently observed. The average count median diameters (mean ±SD) were 1.68 ±0.25, 2.16 ±0.31, and 1.87 ±0.07 µm in summer, autumn, and winter, respectively. The average geometric standard deviations of particle size were 2.16 ±0.23, 2.16 ±0.18, and 1.74 ±0.17 in the three seasons, respectively. The average mass concentrations were 67.4 ±54.9, 289.9 ±216.2, and 428.1 ±269.9 µg m-3 for PM2.5; 73.6 ±59.5, 314.6 ±228.9, and 480.8 ±306.5 µg m-3 for PM4; and 118.8 ±99.6, 532.5 ±353.0, and 686.2 ±417.7 µg m-3 for PM10 in the three seasons, respectively. Both statistically significant (p < 0.05) and practically significant (difference of means >20% of smaller value) seasonal variations were observed. Spatial variations were only practically significant for autumn mass concentrations, likely due to external dust infiltration from nearby agricultural activities. The OSHA-mandated permissible exposure limit for respirable PM was not exceeded in any season. Keywords: Air quality, Particulate matter, Poultry housing, Seasonal variation, Spatial variation.

scholarly journals Summertime and wintertime atmospheric processes of secondary aerosol in Beijing

2019 ◽  
Author(s):  
Jing Duan ◽  
Ru-Jin Huang ◽  
Yongjie Li ◽  
Qi Chen ◽  
Yan Zheng ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Seasonal Variations ◽  
Chemical Speciation ◽  
Fine Particles ◽  
Large Fraction ◽  
Formation Mechanisms ◽  
Urban Air ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
Atmospheric Processes

Abstract. Secondary aerosol constitutes a large fraction of fine particles in urban air of China. However, its formation mechanisms and atmospheric processes remain largely uncertain despite considerable studies in recent years. To elucidate the seasonal variations of fine particles composition and secondary aerosol formation, an Aerodyne quadrupole aerosol chemical speciation monitor (Q-ACSM) combined with other online instruments were used to characterize the submicron particulate matter (diameter 

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